Medicine › Surgery

Orthopaedic implants and arthroplasty

Works Count: 109535

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Description

This cluster of papers focuses on advancements in hip arthroplasty techniques and materials, including the use of metal-on-metal bearings, the impact of wear particles and osteolysis, implant failure and revision surgery, as well as the potential health effects of cobalt toxicity. It also explores minimally invasive approaches and the management of femoral fractures associated with hip replacements.

Keywords

Hip Arthroplasty; Total Hip Replacement; Wear Particles; Metal-on-Metal Bearings; Osteolysis; Implant Failure; Revision Surgery; Cobalt Toxicity; Femoral Fractures; Minimally Invasive Approaches

Ectopic Ossification Following Total Hip Replacement: Incidence and a Method of Classification

2013-12-07

Paul A. Banaszkiewicz

Acetabular defect classification and surgical reconstruction in revision arthroplasty

1994-02-01

Wayne G. Paprosky , Paul G. Perona , Jeffrey M. Lawrence

Traumatic Arthritis of the Hip After Dislocation and Acetabular Fractures: Treatment by Mold Arthroplasty: An End-Result Study Using a New Method of Result Evaluation

2013-12-07

Paul A. Banaszkiewicz

Dislocations after total hip arthroplasty.

1982-12-01

Raymund Woo , B.F. Morrey

During the ten-year period ending in 1978, 10,500 conventional total hip arthroplasties were performed at the Mayo Clinic; dislocation developed after 331 (3.2 per cent) of these procedures. Cross correlations … During the ten-year period ending in 1978, 10,500 conventional total hip arthroplasties were performed at the Mayo Clinic; dislocation developed after 331 (3.2 per cent) of these procedures. Cross correlations of the data were performed using multivariate analysis. This analysis showed that previous surgery on the hip was the most significant of the factors predisposing to dislocation, the incidence doubling from 2.4 per cent (in hips without previous surgery) to 4.8 per cent (in hips with previous surgery) (p less than 0.001). The dislocation rate was 2.3 per cent after an anterolateral approach and 5.8 per cent after a posterior approach (p less than 0.01). The size of the head of the femoral component was not a strongly influential factor. The incidence of dislocation was 17.6 per cent in the hips that had osteotomy and avulsion of the greater trochanter, compared with 2.8 per cent in those in which the trochanteric osteotomy united (p less than 0.001). Reoperation for instability of the hip was performed in a third of the patients, but in 31 per cent of the patients whose hip was reoperated on the instability persisted after the revision.

BONE-GRAFTING AND BONE-GRAFT SUBSTITUTES

2002-03-01

Christopher G. Finkemeier

Christopher G. Finkemeier, MD; Department of Orthopaedic Surgery, University of California Davis Medical Center, 4860 Y Street, Suite 3800, Sacramento, CA 95817 Christopher G. Finkemeier, MD; Department of Orthopaedic Surgery, University of California Davis Medical Center, 4860 Y Street, Suite 3800, Sacramento, CA 95817

The compressive behavior of bone as a two-phase porous structure

1977-10-01

D.R Carter , WC Hayes

Compression tests of human and bovine trabecular bone specimens with and without marrow in situ were conducted at strain rates of from 0.001 to 10.0 per second. A porous platen … Compression tests of human and bovine trabecular bone specimens with and without marrow in situ were conducted at strain rates of from 0.001 to 10.0 per second. A porous platen above the specimens allowed the escape of marrow during testing. The presence of marrow increased the strength, modulus, and energy absorption of specimens only at the highest strain rate of 10.0 per second. This enhancement of material properties at the highest strain rate was due primarily to the restricted viscous flow of marrow through the platen rather than the flow through the pores of the trabecular bone. In specimens without marrow, the strength was proportional to the square of the apparent density and the modulus was proportional to the cube of the apparent density. Both strength and modulus were approximately proportional to the strain rate raised to the 0.06 power. These power relationships, which were shown to hold for all bone in the skeleton, allow meaningful predictions of bone tissue strength and stiffness based on in vivo density measurements.

The Biology of Bone Graft Repair

1983-04-01

Hans Burchardt

Cancellous and cortical autografts histologically have three differences: (1) cancellous grafts are revascularized more rapidly and completely than cortical grafts; (2) creeping substitution of cancellous bone initially involves an appositional … Cancellous and cortical autografts histologically have three differences: (1) cancellous grafts are revascularized more rapidly and completely than cortical grafts; (2) creeping substitution of cancellous bone initially involves an appositional bone formation phase, followed by a resorptive phase, whereas cortical grafts undergo a reverse creeping substitution process; (3) cancellous grafts tend to repair completely with time, whereas cortical grafts remain as admixtures of necrotic and viable bone. Physiologic skeletal metabolic factors influence the rate, amount, and completeness of bone repair and graft incorporation. The mechanical strengths of cancellous and cortical grafts are correlated with their respective repair processes: cancellous grafts tend to be strengthened first, whereas cortical grafts are weakened. Bone allografts are influenced by the same immunologic factors as other tissue grafts. Fresh bone allografts may be rejected by the host's immune system. The histoincompatibility antigens of bone allografts are presumably the proteins or glycoproteins on cell surfaces. The matrix proteins may or may not elicit graft rejection. The rejection of a bone allograft is considered to be a cellular rather than a humoral response, although the humoral component may play a part. The degree of the host response to an allograft may be related to the antigen concentration and total dose. The rejection of a bone allograft is histologically expressed by the disruption of vessels, an inflammatory process including lymphocytes, fibrous encapsulation, peripheral graft resorption, callus bridging, nonunions, and fatigue fractures.

The estimation of cement film thickness by an in vivo technique

1971-08-01

J W McLean , Fraunhofer von

Elastic modulus and hardness of cortical and trabecular bone lamellae measured by nanoindentation in the human femur

1999-10-01

Philippe K. Zysset , X. Edward Guo , C. Edward Hoffler +2 more

Future Young Patient Demand for Primary and Revision Joint Replacement: National Projections from 2010 to 2030

2009-07-29

Steven M. Kurtz , Edmund Lau , Kevin Ong +3 more

Previous projections of total joint replacement (TJR) volume have not quantified demand for TJR surgery in young patients (< 65 years old). We developed projections for demand of TJR for … Previous projections of total joint replacement (TJR) volume have not quantified demand for TJR surgery in young patients (< 65 years old). We developed projections for demand of TJR for the young patient population in the United States. The Nationwide Inpatient Sample was used to identify primary and revision TJRs between 1993 and 2006, as a function of age, gender, race, and census region. Surgery prevalence was modeled using Poisson regression, allowing for different rates for each population subgroup over time. If the historical growth trajectory of joint replacement surgeries continues, demand for primary THA and TKA among patients less than 65 years old was projected to exceed 50% of THA and TKA patients of all ages by 2011 and 2016, respectively. Patients less than 65 years old were projected to exceed 50% of the revision TKA patient population by 2011. This study underscores the major contribution that young patients may play in the future demand for primary and revision TJR surgery.Level II, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

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Titanium alloys in total joint replacement—a materials science perspective

1998-09-01

Marc Long , H.J. Rack

Sterilization, toxicity, biocompatibility and clinical applications of polylactic acid/ polyglycolic acid copolymers

1996-01-01

Kyriacos A. Athanasiou

Fabrication methods of porous metals for use in orthopaedic applications

2006-01-20

Gerard Ryan , Abhay Pandit , Dimitrios P. Apatsidis

Hip joint loading during walking and running, measured in two patients

1993-08-01

G. Bergmann , F. Graichen , A. Rohlmann

Economic Burden of Periprosthetic Joint Infection in the United States

2012-05-02

Steven M. Kurtz , Edmund Lau , Heather Watson +2 more

PEEK biomaterials in trauma, orthopedic, and spinal implants

2007-08-08

Steven M. Kurtz , John N. Devine

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Comparison of the elastic and yield properties of human femoral trabecular and cortical bone tissue

2003-07-31

Harun Bayraktar , Elise F. Morgan , Glen L. Niebur +3 more

Porous-coated hip replacement. The factors governing bone ingrowth, stress shielding, and clinical results

1987-01-01

CA Engh , JD Bobyn , AH Glassman

Total hip replacement using porous-coated cobalt-chrome femoral implants designed for biological fixation has been evaluated in 307 patients after two years and in 89 patients after five years. Histological study … Total hip replacement using porous-coated cobalt-chrome femoral implants designed for biological fixation has been evaluated in 307 patients after two years and in 89 patients after five years. Histological study of 11 retrieved specimens showed bone ingrowth in nine and fibrous tissue fixation in two. Fixation by bone ingrowth occurred in 93% of the cases in which a press fit of the stem at the isthmus was achieved, but in only 69% of those without a press fit. The clinical results at two years were excellent. The incidence of pain and limp was much lower when there was either a press fit of the stem or radiographic evidence of bone ingrowth. Factors such as age, sex, and the disease process did not influence the clinical results. Most cases showed only slight resorptive remodelling of the upper femur, but in a few cases with a larger, more rigid stem, more extensive bone loss occurred. The results after five years showed no deterioration with time. Fixation by the ingrowth of bone or of fibrous tissue both appeared to be stable, but bone ingrowth gave better clinical results.

Pseudotumours associated with metal-on-metal hip resurfacings

2008-06-30

Hemant Pandit , Sion Glyn‐Jones , P. McLardy-Smith +7 more

We report 17 patients (20 hips) in whom metal-on-metal resurfacing had been performed and who presented with various symptoms and a soft-tissue mass which we termed a pseudotumour. Each patient … We report 17 patients (20 hips) in whom metal-on-metal resurfacing had been performed and who presented with various symptoms and a soft-tissue mass which we termed a pseudotumour. Each patient underwent plain radiography and in some, CT, MRI and ultrasonography were also performed. In addition, histological examination of available samples was undertaken. All the patients were women and their presentation was variable. The most common symptom was discomfort in the region of the hip. Other symptoms included spontaneous dislocation, nerve palsy, a noticeable mass or a rash. The common histological features were extensive necrosis and lymphocytic infiltration. To date, 13 of the 20 hips have required revision to a conventional hip replacement. Two are awaiting revision. We estimate that approximately 1% of patients who have a metal-on-metal resurfacing develop a pseudotumour within five years. The cause is unknown and is probably multifactorial. There may be a toxic reaction to an excess of particulate metal wear debris or a hypersensitivity reaction to a normal amount of metal debris. We are concerned that with time the incidence of these pseudotumours may increase. Further investigation is required to define their cause.

Effect of femoral head size on wear of the polyethylene acetabular component.

1990-04-01

J Livermore , D M Ilstrup , B.F. Morrey

A technique was developed to determine the wear of the acetabular component of a total hip replacement by examination of standardized initial and follow-up radiographs. Three hundred and eighty-five hips … A technique was developed to determine the wear of the acetabular component of a total hip replacement by examination of standardized initial and follow-up radiographs. Three hundred and eighty-five hips were followed for at least 9.5 years after replacement. The least amount and rate of linear wear were associated with use of a femoral head that had a diameter of twenty-eight millimeters (p less than 0.001). The greatest amount and mean rate of linear wear occurred with twenty-two-millimeter components, but these differences were not statistically significant. The greatest volumetric wear and mean rate rate of volumetric wear were seen with thirty-two-millimeter components (p less than 0.001). A wider radiolucent line in acetabular Zone 1 was associated with use of the thirty-two-millimeter head. The amounts of resorption of the proximal part of the femoral neck and of lysis of the proximal part of the femur both correlated positively with the extent of linear and volumetric wear; this suggests an association between the amount of debris from wear and these changes in the femoral neck and proximal part of the femur.

“Modes of Failure” of Cemented Stem-Type Femoral Components: A Radiographic Analysis of Loosening

2013-12-07

Paul A. Banaszkiewicz

Proceedings of the International Consensus on Periprosthetic Joint Infection

2013-10-22

Javad Parvizi , Thorsten Gehrke , A. F. Chen

Louis Pasteur once said that: “Fortune favours the prepared mind.” As one of the great scientists who contributed to the fight against infection, he emphasised the importance of being prepared … Louis Pasteur once said that: “Fortune favours the prepared mind.” As one of the great scientists who contributed to the fight against infection, he emphasised the importance of being prepared at all times to recognise infection and deal with it. Despite the many scientific discoveries and technological advances, such as the advent of antibiotics and the use of sterile techniques, infection continues to be a problem that haunts orthopaedic surgeons and inflicts suffering on patients. The medical community has implemented many practices with the intention of preventing infection and treating it effectively when it occurs. Although high-level evidence may support some of these practices, many are based on little to no scientific foundation. Thus, around the world, there is great variation in practices for the prevention and management of periprosthetic joint infection. This paper summaries the instigation, conduct and findings of a recent International Consensus Meeting on Surgical Site and Periprosthetic Joint Infection. Cite this article: Bone Joint J 2013;95-B:1450–2.

Primary total hip replacement surgery: a systematic review of outcomes and modelling of cost-effectiveness associated with different prostheses.

1998-01-01

Ray Fitzpatrick , E Shortall , Mark Sculpher +7 more

Objectives- T identify the literature on primary total hip replacement(THR) surgery that is relevant to the question of whether prostheses differ in their medium to longer term outcomes, and to … Objectives- T identify the literature on primary total hip replacement(THR) surgery that is relevant to the question of whether prostheses differ in their medium to longer term outcomes, and to synthesise this evidence. To use evidence regarding both costs and outcomes of primary THR to model how much more effective newer prostheses must be to justify higher costs

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Roentgenographic Assessment of the Biologic Fixation of Porous-Surfaced Femoral Components

1990-08-01

Charles A. Engh , P. Massin , Kathleen Suthers

Certain roentgenographic signs have value in predicting the fixation of a cementless femoral component to bone by osseointegration. Other signs have value in predicting the gross stability of a cementless … Certain roentgenographic signs have value in predicting the fixation of a cementless femoral component to bone by osseointegration. Other signs have value in predicting the gross stability of a cementless femoral component. The authors have determined the specificity and sensitivity of the signs for osseointegration in cases in which the histologic fixation has been confirmed after implant removal. The authors have also determined the specificity and sensitivity of the signs for gross implant stability in cases in which the stability has been confirmed at reoperation. Statistical methods were used to determine a numeric value for each of these roentgenographic signs, and these values were combined into a score. The score was divided into fixation by osseointegration and mechanical implant stability. The two scores were then combined into an overall score. When signs of osseointegration were present, the implant was always stable, and the overall scores were the highest. When signs of osseointegration were absent, the mechanical stability varied, and the scores were lower. A neutral or slightly negative score correlated with failed osseointegration but secondary successful implant stabilization. A very low negative score correlated with gross implant instability. To confirm the validity of the scoring system, the two-year postoperative score was determined for 1005 cases in which the clinical outcome was known. A strong correlation between the presence of symptoms and a low score confirmed the value of the scoring system for diagnosing implant loosening as the cause of symptoms. As a second test, the two-year and five-year postoperative results were compared in the same patients. A high two-year score correlated with durable implant stability through five years. A low two-year score correlated with a higher incidence of late symptomatic loosening.

Adaptive bone-remodeling theory applied to prosthetic-design analysis

1987-01-01

R. Huiskes , Harrie Weinans , H.J. Grootenboer +3 more

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The Epidemiology of Revision Total Hip Arthroplasty in the United States

2009-01-21

Kevin J. Bozic , Steven M. Kurtz , Edmund Lau +4 more

The Relationship Between Stress Shielding and Bone Resorption Around Total Hip Stems and the Effects of Flexible Materials

1992-01-01

R. Huiskes , Harrie Weinans , Bert van Rietbergen

Bone resorption around hip stems is a disturbing phenomenon, although its clinical significance and its eventual effects on replacement longevity are as yet uncertain. The relationship between implant flexibility and … Bone resorption around hip stems is a disturbing phenomenon, although its clinical significance and its eventual effects on replacement longevity are as yet uncertain. The relationship between implant flexibility and the extent of bone loss, frequently established in clinical patient series and animal experiments, does suggest that the changes in bone morphology are an effect of stress shielding and a subsequent adaptive remodeling process. This relationship was investigated using strain-adaptive bone-remodeling theory in combination with finite element models to simulate the bone remodeling process. The effects of stem material flexibility, bone flexibility, and bone reactivity on the process and its eventual outcome were studied. Stem flexibility was also related to proximal implant/bone interface stresses. The results sustain the hypothesis that the resorptive processes are an effect of bone adaptation to stress shielding. The effects of stem flexibility are confirmed by the simulation analysis. It was also established that individual differences in bone reactivity and mechanical bone quality (density and stiffness) may account for the individual variations found in patients and animal experiments. Flexible stems reduce stress shielding and bone resorption. However, they increase proximal interface stresses. Hence, the cure against bone resorption they represent may develop into increased loosening rates because of interface debonding and micromotion. The methods presented in this paper can be used to establish optimal stem-design characteristics or check the adequacy of designs in preclinical testing procedures.

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Prevalence of Primary and Revision Total Hip and Knee Arthroplasty in the United States From 1990 Through 2002

2005-07-01

Steven M. Kurtz

The purpose of this study was to quantify the procedural rate and revision burden of total hip and knee arthroplasty in the United States and to determine if the age … The purpose of this study was to quantify the procedural rate and revision burden of total hip and knee arthroplasty in the United States and to determine if the age or gender-based procedural rates and overall revision burden are changing over time.The National Hospital Discharge Survey (NHDS) for 1990 through 2002 was used in conjunction with United States Census data to quantify the rates of primary and revision arthroplasty as a function of age and gender within the United States with use of methodology published by the American Academy of Orthopaedic Surgeons. Poisson regression analysis was used to evaluate the procedural rate and to determine year-to-year trends in primary and revision arthroplasty rates as a function of both age and gender.Both the number and the rate of total hip and knee arthroplasties (particularly knee arthroplasties) increased steadily between 1990 and 2002. Over the thirteen years, the rate of primary total hip arthroplasties per 100,000 persons increased by approximately 50%, whereas the corresponding rate of primary total knee arthroplasties almost tripled. The rate of revision total hip arthroplasties increased by 3.7 procedures per 100,000 persons per decade, and that of revision total knee arthroplasties, by 5.4 procedures per 100,000 persons per decade. However, the mean revision burden of 17.5% for total hip arthroplasty was more than twice that for total knee arthroplasty (8.2%), and this did not change substantially over time.The number and prevalence of primary hip and knee replacements increased substantially in the United States between 1990 and 2002, but the trend was considerably more pronounced for primary total knee arthroplasty.The reported prevalence trends have important ramifications with regard to the number of joint replacements expected to be performed by orthopaedic surgeons in the future. Because the revision burden has been relatively constant over time, we can expect that a greater number of primary replacements will result in a greater number of revisions unless some limiting mechanism can be successfully implemented to reduce the future revision burden.

Zirconia as a ceramic biomaterial

1999-01-01

C. Piconi , Giulio Maccauro

Metal-on-Metal Bearings and Hypersensitivity in Patients with Artificial Hip Joints

2005-01-01

Hans-Georg Willert , Gottfried Buchhorn , Afshin Fayyazi +4 more

Background: Some patients who have a total hip replacement with a second-generation metal-on-metal articulation have persistent or early recurrence of preoperative symptoms. Characteristic histological changes in the periprosthetic tissues suggested … Background: Some patients who have a total hip replacement with a second-generation metal-on-metal articulation have persistent or early recurrence of preoperative symptoms. Characteristic histological changes in the periprosthetic tissues suggested the development of an immunological response. Therefore, in order to determine the relevance of these symptoms, we performed a study of the clinical data and periprosthetic tissues associated with endoprostheses with a metal-on metal articulation that had been retrieved at revision. Methods: Periprosthetic tissues as well as the clinical data on the patients were obtained from the first nineteen consecutive revisions performed at the treating hospitals. At the time of the revision, fourteen patients had the metal-on-metal articulation exchanged for either an alumina-ceramic or a metal-on-polyethylene articulation. Five patients received another second-generation metal-on-metal total joint replacement. Five-micrometer sections were prepared from the tissue samples, were stained with routine and immunohistochemical methods, and were examined histologically. Histological specimens from three groups of patients, two of which were treated with non-metal-on-metal implants, served as controls. Results: The majority of patients had persistence of their preoperative pain or early recurrence of the pain after the original total hip replacement, and often a pronounced hip joint effusion had developed after the original replacement. Radiographic follow-up showed the development of radiolucent lines in five hips and of osteolysis in another seven hips. At the revision surgery, both the cup and the stem were found to be well fixed in nine patients. The characteristic histological features were diffuse and perivascular infiltrates of T and B lymphocytes and plasma cells, high endothelial venules, massive fibrin exudation, accumulation of macrophages with droplike inclusions, and infiltrates of eosinophilic granulocytes and necrosis. Only a few metal particles were detected. Immunohistochemical analysis demonstrated that the cellular reaction was still active. The patients who received another second-generation metal-on-metal articulation at the time of the revision had no decrease in symptoms. In the control group of tissues obtained at revisions of endoprostheses without cobalt, chromium, or nickel articulations, there were no similar signs of immune reactions. Conclusions: These histological findings support the possibility of a lymphocyte-dominated immunological response. Although the prevalence of this reaction is low, the persistence or early reappearance of symptoms, including a marked joint effusion and the development of osteolysis, after primary implantation may suggest the possibility of such a reaction.

Hip contact forces and gait patterns from routine activities

2001-07-01

G. Bergmann , Georg Deuretzbacher , Markus O. Heller +4 more

Corrosion of Metal Orthopaedic Implants*

1998-02-01

Joshua J. Jacobs , Jeremy L. Gilbert , Robert M. Urban

JACOBS, JOSHUA J. M.D.†; GILBERT, JEREMY L. PH.D.‡; URBAN, ROBERT M. †, CHICAGO, ILLINOIS Author Information JACOBS, JOSHUA J. M.D.†; GILBERT, JEREMY L. PH.D.‡; URBAN, ROBERT M. †, CHICAGO, ILLINOIS Author Information

The definition and measurement of acetabular orientation

1993-03-01

DW Murray

The orientation of an acetabulum or an acetabular prosthesis may be described by its inclination and anteversion. Orientation can be assessed anatomically, radiographically, and by direct observation at operation. The … The orientation of an acetabulum or an acetabular prosthesis may be described by its inclination and anteversion. Orientation can be assessed anatomically, radiographically, and by direct observation at operation. The angles of inclination and anteversion determined by these three methods differ because they have different spatial arrangements. There are therefore three distinct definitions of inclination and anteversion. This paper analyses the differences between the definitions and provides nomograms to convert from one to another. It is recommended that the operative definitions be used to describe the orientation of prostheses and that the anatomical definitions be used for dysplastic acetabula.

Dislocations After Total Hip-Replacement Arthroplasties

2013-12-07

Paul A. Banaszkiewicz

The operation of the century: total hip replacement

2007-03-31

Ian D. Learmonth , Claire F Young , Cecil H. Rorabeck

Current Concepts Review - Acetabular and Femoral Anteversion

1999-12-01

Dietrich Tönnis , Achim Heinecke

†Departments of Orthopedics and Diagnostic Radiology, Städtische Kliniken, Syburger Strasse 14, D-44265, Dortmund, Germany. ‡Institute of Medical Informatics and Biomathematics, University of Münster, Domack Strasse 9, D-48149 Münster, Germany. †Departments of Orthopedics and Diagnostic Radiology, Städtische Kliniken, Syburger Strasse 14, D-44265, Dortmund, Germany. ‡Institute of Medical Informatics and Biomathematics, University of Münster, Domack Strasse 9, D-48149 Münster, Germany.

The direct lateral approach to the hip

1982-02-01

K Hardinge

Infection after Total Hip Arthroplasty. A Study of the Treatment of One Hundred and Six Infections*

1996-04-01

Dean T. Tsukayama , RUPERTO ESTRADA , Ramon B. Gustilo

We evaluated the results of treatment for ninety-seven patients (106 infections in ninety-eight hips) who had had either an infection after a total hip arthroplasty or positive intraoperative cultures of … We evaluated the results of treatment for ninety-seven patients (106 infections in ninety-eight hips) who had had either an infection after a total hip arthroplasty or positive intraoperative cultures of specimens obtained during revision of a total hip arthroplasty for presumed aseptic loosening. The patients were managed according to various protocols on the basis of the clinical setting (positive intraoperative cultures, early postoperative infection, late chronic infection, or acute hematogenous infection). Aerobic gram-positive cocci accounted for 109 (74 per cent) of the 147 microbial isolates; gram-negative bacilli, for twenty-one (14 per cent); and anaerobes, for twelve (8 per cent). The white blood-cell count and erythrocyte sedimentation rate were elevated in association with seventeen (16 per cent) and sixty-seven (63 per cent) of the 106 infections, respectively.The mean duration of follow-up was 3.8 years (range, 0.3 to eleven years). A good result was noted after the initial treatment of twenty-eight (90 per cent) of the thirty-one infections that had been diagnosed on the basis of positive intraoperative cultures at the time of the revision, twenty-five (71 per cent) of the thirty-five early postoperative infections, twenty-nine (85 per cent) of the thirty-four late chronic infections, and three of the six acute hematogenous infections. Of the twenty-one infections for which the initial therapy failed, twelve eventually were eradicated after additional treatment and the hip had a functional prosthesis at the time of follow-up. Of the ninety-seven infections that were treated successfully (there was a functional retained or exchange prosthesis in place at the time of the most recent follow-up and infection had not recurred at least two years after the discontinuation of antibiotic therapy), nine were associated with subsequent aseptic loosening of the prosthesis. The factors associated with recurrent infection were retained bone cement, the number of previous operations, potential immunocompromise, and early postoperative infection after arthroplasty without cement.

Osseointegration of Ti6Al4V alloy implants coated with titanium nitride by a new method

2000-03-01

S. F. Journeaux , D.A.L. Morgan , William J. Donnelly

We have reviewed 202 consecutive primary hip replacements using a Freeman cemented femoral component after a mean period of follow-up of 64 months (23 to 113). There was only one … We have reviewed 202 consecutive primary hip replacements using a Freeman cemented femoral component after a mean period of follow-up of 64 months (23 to 113). There was only one revision for aseptic loosening. Retention of the femoral neck may act to reduce the torsional and shear forces at the implant-cement interface and may provide a seal against the migration of polyethylene-laden joint fluid in the potential joint space. The cemented Freeman femoral component with retention of the femoral neck was successful for up to nine years.

FUNCTIONAL RESULTS OF HIP ARTHROPLASTY WITH ACRYLIC PROSTHESIS

1954-06-01

R Merle D'aubigne , M Postel

Late results in 243 arthroplasties with an acrylic prosthesis for traumatic or osteoarthritic conditions are reported. Early results (after one year) show the importance of the restoration of the normal … Late results in 243 arthroplasties with an acrylic prosthesis for traumatic or osteoarthritic conditions are reported. Early results (after one year) show the importance of the restoration of the normal mechanics of the hip joint by the preservation or the restoration of normal length of the femoral neck, the exact correction of anteversion, and the precise fit of the prosthetic head to the acetabulum. A good exposure of the joint through the posterolateral approach appears necessary in order to fulfill these conditions. Late results (from two to five years) show deterioration of the functional results in 20 per cent. These deteriorations appear to be caused by bone absorption around the Judet prosthesis and the consequent loosening of the prosthesis. A new type of cervico-capital prosthesis is proposed which makes possible: 1. Restoration of the normal length of the femoral neck when it is congenitally or pathologically short; 2. Correction of anteversion, even when very marked; 3. A weight-bearing surface on a more vascularised part of the femur; 4. The distribution of pressure on bone so as to lessen bone absorption, to prevent its ill effects, and, particularly, to decrease mobility of the prosthesis.

THE LONG-TERM RESULTS OF LOW-FRICTION ARTHROPLASTY OF THE HIP PERFORMED AS A PRIMARY INTERVENTION

1972-02-01

John Charnley

1. The results have been reported of total hip replacement by a low-friction technique using high-density polyethylene for the acetabular component in 379 primary interventions, performed between November 1962 and … 1. The results have been reported of total hip replacement by a low-friction technique using high-density polyethylene for the acetabular component in 379 primary interventions, performed between November 1962 and December 1965 and followed for between four and seven years. 2. Apart from failures due to infection, the rate of which in the era under review was 3·8 per cent, late failures from mechanical causes were unusual after total hip replacement by this technique. When the socket was cemented in position, which is now routine, the late mechanical failure from all causes was only 1·3 per cent in 210 cases. 3. As regards the quality of the results and their maintenance over the years, the results were so good (Table X) that it was unnecessary to distinguish an intermediate class of "improvement" between success and failure. 4. As regards relief of pain and ability to walk, the average final rating, on a scale numbered 1 to 6, was 5·9 for both, indicating 90 per cent of patients in Grade 6 (excellent) and only 10 per cent in Grade 5 (good). 5. The average recovery of movement was not as spectacular and was influenced considerably by the pre-operative range, but in all cases that range was improved on. Even starting with the stiffest of hips about one patient in four regained a right angle of flexion movement. There was no tendency to lose movement with the passage of time. 6. As regards late infection (2·2 per cent out of a total of 3·8 per cent), the various findings tend to exonerate cement as a cause. 7. The mechanical details of the technique became stabilised in the period 1959 to 1962 in the Teflon era, and with the exception of improved methods of reattachment of the greater trochanter, they are identical with our current practice in 1971.

Projections of Primary and Revision Hip and Knee Arthroplasty in the United States from 2005 to 2030

2007-04-01

Steven M. Kurtz , Kevin Ong , Edmund Lau +2 more

Background: Over the past decade, there has been an increase in the number of revision total hip and knee arthroplasties performed in the United States. The purpose of this study … Background: Over the past decade, there has been an increase in the number of revision total hip and knee arthroplasties performed in the United States. The purpose of this study was to formulate projections for the number of primary and revision total hip and knee arthroplasties that will be performed in the United States through 2030. Methods: The Nationwide Inpatient Sample (1990 to 2003) was used in conjunction with United States Census Bureau data to quantify primary and revision arthroplasty rates as a function of age, gender, race and/or ethnicity, and census region. Projections were performed with use of Poisson regression on historical procedure rates in combination with population projections from 2005 to 2030. Results: By 2030, the demand for primary total hip arthroplasties is estimated to grow by 174% to 572,000. The demand for primary total knee arthroplasties is projected to grow by 673% to 3.48 million procedures. The demand for hip revision procedures is projected to double by the year 2026, while the demand for knee revisions is expected to double by 2015. Although hip revisions are currently more frequently performed than knee revisions, the demand for knee revisions is expected to surpass the demand for hip revisions after 2007. Overall, total hip and total knee revisions are projected to grow by 137% and 601%, respectively, between 2005 and 2030. Conclusions: These large projected increases in demand for total hip and knee arthroplasties provide a quantitative basis for future policy decisions related to the numbers of orthopaedic surgeons needed to perform these procedures and the deployment of appropriate resources to serve this need.

Dislocations after total hip-replacement arthroplasties.

1978-03-01

G E Lewinnek , J L Lewis , R Tarr +2 more

In a series of 300 total hip replacements, nine (3 per cent) dislocated. Precise measurements of the orientation of the acetabular cup were made and it was found that anterior … In a series of 300 total hip replacements, nine (3 per cent) dislocated. Precise measurements of the orientation of the acetabular cup were made and it was found that anterior dislocations were associated with increased acetabular-component anteversion. There was no significant correlation between cup-orientation angle and posterior dislocation. The dislocation rate for cup orientation with anteversion of 15 +/- 10 degrees and lateral opening of 40 +/- 10 degrees was 1.5 per cent, while outside this "safe" range the dislocation rate was 6.1 per cent. Other factors that were documented include time after surgery (with the greatest risk in the first thirty days) and surgical history (with a greater risk in hips that have had prior surgery).

Radiological Demarcation of Cemented Sockets in Total Hip Replacement

1976-11-01

JESSE G. DELEE , John Charnley

DELEE, JESSE G.; CHARNLEY, JOHNEditor(s): Urist, Marshall R. M.D., Editor-in-Chief Author Information DELEE, JESSE G.; CHARNLEY, JOHNEditor(s): Urist, Marshall R. M.D., Editor-in-Chief Author Information

Periprosthetic bone loss in total hip arthroplasty. Polyethylene wear debris and the concept of the effective joint space.

1992-07-01

Thomas P. Schmalzried , Murali Jasty , W.H. Harris

Thirty-four hips in which there had been prosthetic replacement were selected for study because of the presence of linear (diffuse) or lytic (localized) areas of periprosthetic bone loss. In all … Thirty-four hips in which there had been prosthetic replacement were selected for study because of the presence of linear (diffuse) or lytic (localized) areas of periprosthetic bone loss. In all hips, there was careful documentation of the anatomical location of the material that had been obtained for histological analysis, and the specific purpose of the removal of the tissue was for examination to determine the cause of the resorption of bone. Specimens from twenty-three hips were retrieved during an operation and from eleven hips, at autopsy. The area of bone loss was linear only in sixteen hips, lytic only in thirteen, and both linear and lytic in five. In all thirty-four hips, intracellular particulate debris was found in the macrophages that were present in the area of bone resorption. All thirty-four had intracellular particles of polyethylene, many of which were less than one micrometer in size. Thirty-one hips had extracellular particles of polyethylene as well. Twenty-two of the thirty-four hips had intracellular metallic debris; in ten, metallic debris was found extracellularly as well. Ten of the sixteen cemented specimens had intracellular and extracellular polymethylmethacrylate debris. In the mechanically stable prostheses--cemented and uncemented--polyethylene wear debris was identified in areas of bone resorption far from the articular surfaces. The number of macrophages in a microscopic field was directly related to the amount of particulate polyethylene debris that was visible by light microscopy. Although the gross radiographic appearances of linear bone loss and lytic bone loss were different, the histological appearance of the regions in which there was active bone resorption was similar. Regardless of the radiographic appearance and anatomical origin of the specimen, bone resorption was found to occur in association with macrophages that were laden with polyethylene debris. In general, the number of macrophages present had a direct relationship to the degree of bone resorption that was seen. We believe that these findings indicate that joint fluid penetrates far more extensively than previously thought, even in a well fixed component, along the interface between the prosthesis and bone and in the periprosthetic tissues; it is often more extensive than is shown by arthrography. We therefore suggest the concept of the effective joint space to include all periprosthetic regions that are accessible to joint fluid and thus accessible to particulate debris.(ABSTRACT TRUNCATED AT 400 WORDS)

QUESTIONNAIRE ON THE PERCEPTIONS OF PATIENTS ABOUT TOTAL HIP REPLACEMENT

1996-03-01

Jill Dawson , Ray Fitzpatrick , Andrew Carr +1 more

We developed a 12-item questionnaire for completion by patients having total hip replacement (THR). A prospective study of 220 patients was undertaken before operation and at follow-up six months later. … We developed a 12-item questionnaire for completion by patients having total hip replacement (THR). A prospective study of 220 patients was undertaken before operation and at follow-up six months later. Each completed the new questionnaire as well as the SF36, and some the Arthritis Impact Measurement Scales (AIMS). An orthopaedic surgeon assessed the Charnley hip score. The single score derived from the questionnaire had a high internal consistency. Reproducibility was examined by test-retest reliability and was found to be satisfactory. The validity of the questionnaire was established by obtaining significant correlation in the expected direction with the Charnley scores and relevant scales of the SF36 and the AIMS. Sensitivity to change was assessed by analysing the differences between the preoperative scores and those at the follow-up. The standardised effect size for the new questionnaire compared favourably with that for the SF36 and the AIMS. The new questionnaire provides a measure of outcome for THR which is short, practical, reliable, valid and sensitive to clinically important changes.

Ectopic Ossification Following Total Hip Replacement

1973-12-01

Andrew F. Brooker , Jack W. Bowerman , Robert A. Robinson +1 more

A method to classify the degree of ectopic-bone formation about the hip following total hip arthroplasty revealed that 21 per cent of 100 consecutive patients treated by total hip arthroplasty … A method to classify the degree of ectopic-bone formation about the hip following total hip arthroplasty revealed that 21 per cent of 100 consecutive patients treated by total hip arthroplasty had ectopic-bone formation about the hip of various degrees when reviewed six months following the operation. Ectopic-bone formation, however, did not seem to affect the functional result as judged by the Harris hip evaluation unless apparent bone ankylosis resulted.

Bone Graft Materials

2000-02-01

Thomas W. Bauer , George F. Muschler

Autograft, allograft, and synthetic bone graft substitute materials play an important role in reconstructive orthopaedic surgery, and understanding the biologic effects of these materials is necessary for optimum use. Although … Autograft, allograft, and synthetic bone graft substitute materials play an important role in reconstructive orthopaedic surgery, and understanding the biologic effects of these materials is necessary for optimum use. Although vascularized and cancellous autograft show optimum skeletal incorporation, host morbidity limits autograft availability. Experimental studies have confirmed an immune response to allograft bone, but the clinical significance of this response in humans still is unclear. Small amounts of cancellous allograft in humans usually are remodeled completely; large allografts become incorporated by limited, surface intramembranous bone formation suggesting that these graft are primarily osteoconductive. Several synthetic skeletal substitute materials also are osteoconductive, and may show remodeling characteristics similar to allograft. Demineralized bone matrix and some isolated or synthetic proteins can induce endochondral bone formation, and therefore are osteoinductive. The extent and distribution of remodeling of bone graft materials are influenced by many factors, including the quality of the host site and the local mechanical environment (strain). Graft materials are likely to become more specialized for use in specific clinical applications, and composite preparations may soon provide bone graft materials with efficacy that equals or exceeds that of autogenous grafts.

Radiological Demarcation of Cemented Sockets in Total Hip Replacement

2013-12-07

Paul A. Banaszkiewicz

Low Friction Arthroplasty of the Hip

1979-01-01

John Charnley

Use of Anatomic Landmarks for Assessment of Intraoperative Restoration of Offset in Total Hip Arthroplasty

2025-06-25

Girish Gadekar , Ravindra H Mahajan , Yasmine Zedan +1 more | Techniques in Orthopaedics

Frequency of safety signals from scientific reports, manufactures, registers, and other sources for a random selection of hip and knee prostheses

2025-06-25

Yijun Ren , Lotje A. Hoogervorst , Enrico G. Caiani +5 more | Acta Orthopaedica

Background and purpose: The safety and performance of hip and knee prostheses can be assessed by analyzing peer-reviewed literature, registry reports, and safety notices published by national competent authorities/regulatory agencies, … Background and purpose: The safety and performance of hip and knee prostheses can be assessed by analyzing peer-reviewed literature, registry reports, and safety notices published by national competent authorities/regulatory agencies, or manufacturers. The percentage of hip and knee prostheses with a safety signal published through any of these data sources is unknown. We aimed to assess the frequency of signals identified for a random sample of 10 hip stems, 10 hip cups, and 10 knee implants.Methods: 3 literature libraries were searched to find safety signals defined as information on patterns/occurrences that may alter the device’s benefit–risk profile, reported in peer-reviewed publications for the randomly selected implants. Annual registry reports from 5 national registries were examined to check whether any of the selected implants had outlier performance. The CORE-MD post-market surveillance (PMS) tool was used to collect all related safety notices from 13 competent authority/regulatory agency websites. Manufacturers’ websites were screened for any reported safety information.Results: Safety signals were identified for 21 of the 30 randomly selected implants: 18 identified by registries, 7 by the CORE-MD PMS tool, and 8 based on literature, with 10 implants identified by multiple sources. There was no systematic pattern in timing of publication with a particular source publishing safety signals earlier than other sources.Conclusion: 70% of the randomly selected hip and knee prostheses had ≥ 1 safety signals published, with registries as the source for the majority. No single source identified all 21 implants with signals, which highlights the need for a comprehensive surveillance strategy to aggregate safety signals from multiple sources.

Structure Optimization of Mandibular Reconstruction Plates: Finite Element Modelling of Biomechanical Risk Factors

2025-06-24

C. Leung , David Koper , P. Keßler | International Journal of Oral and Maxillofacial Surgery

Characterization of Enhanced <scp>UHMWPE</scp>‐Hap Composites Manufactured by Hot Pressing

2025-06-24

G. Çelebi Efe , Tuba Yener , Mehmet Zor +2 more | Polymer Composites

ABSTRACT In the present study, a hip joint cup/liner material has been developed using ultra high molecular weight polyethylene (UHMWPE) matrix material which is reinforced by hydroxyapatite (HAp) particles with … ABSTRACT In the present study, a hip joint cup/liner material has been developed using ultra high molecular weight polyethylene (UHMWPE) matrix material which is reinforced by hydroxyapatite (HAp) particles with the 0.5, 1, 2, and 4 wt.% using mechanical activation followed by hot pressing. The main goal of the present study is to increase the life cycle of UHMWPE joint material, increasing wear resistance with HAp. The homogeneous distribution of HAp particles was confirmed by scanning electron microscopy (SEM) and the presence of characteristic peaks of UHMWPE and HAp was detected by x‐ray diffraction (XRD) analysis. It was concluded that the hardness value of the UHMWPE‐4 wt.% HAp composite increased by 118%, the wear rate decreased by 81%, and the coefficient of friction decreased by 65% compared to pure UHMWPE. The presence of an apatite structure was detected in the in vitro experiments performed after the UHMWPE‐4 wt.% composite was kept in simulated body fluid (SBF) solution at 37°C for 8 days. Differential scanning calorimetry (DSC) analysis revealed an increase of 7.91% in the melting temperature and 159% in the crystallinity value of pure UHMWPE with HAp reinforcement. All results revealed that UHMWPE‐HAp composites demonstrate suitability for application as cup and/or liner components in hip joint prosthetic systems.

Association of serum metallic ion levels in patients with total joint arthroplasty with their adverse effects: a comparative cross-sectional study

2025-06-24

Harmeet Singh Rehan , J. B. Singh , Tarun Arora +4 more | International Journal of Research in Orthopaedics

Background: Metallic implants used in joint arthroplasty release ions gradually sometimes resulting in their toxicity. Hence, data regarding exact correlation between serum metallic ion levels and toxicity occurrence is still … Background: Metallic implants used in joint arthroplasty release ions gradually sometimes resulting in their toxicity. Hence, data regarding exact correlation between serum metallic ion levels and toxicity occurrence is still lacking. Methods: A total of 90 adult subjects, each with a single total joint arthroplasty (TJA between 1 to 5 years), or without were recruited. The serum levels of Cr, Co, Ni, & Mo in above 2 groups were estimated and correlated with signs and symptoms related to Cr, Co, Ni, & Mo ion toxicity Unpaired Student's t-test, Chi-square test and Pearson correlation coefficient were used to analyses data. A p value<0.05 was considered significant. Results: The mean serum levels of Cr (21.53±7448 µg/l vs. 19.03±0.3372 µg/l; p=0.0026), Ni (9.643±0.2486 µg/l vs. 9.303±0.2729 µg/l; p=0.83), Co (5.482±0.20 µg/l vs. 5.573±0.21 µg/l; p=0.76), and Mo (5.573±0.2159 µg/l vs. 5.290±0.2208 µg/l; p=0.36) in subjects with implants were higher than in subjects without implants. Five subjects reported six adverse effects (AE) specifically numbness in hands (4), fatigue (1), and bone pain (1), which showed no significant association or correlation with the mean serum levels of the metallic ions. Conclusion: Results showed increased mean serum chromium levels post one year of implant surgery, while mean serum levels of Co, Ni, and Mo did not demonstrate any significant elevation. No correlation between serum levels of Cr, Co, Ni, and Mo, duration of implant, and observed AE was seen. Causality assessment between reported AE and metal ions (Cr, Co, Ni, and Mo) levels was “possible."

Biotribological Wear Prediction of Alumina–Polymer Hip Prostheses Using Finite Element Analysis

2025-06-24

Mhd Ayham Darwich , Hasan Mhd Nazha , Hiba Mohsen Ghadir +1 more | Applied Mechanics

This study investigates the biotribological performance of alumina–UHMWPE and alumina–PEEK hip implant couples through finite element simulation (ANSYS v24) and statistical inference (STATA v17). During gait cycle loading simulations, significant … This study investigates the biotribological performance of alumina–UHMWPE and alumina–PEEK hip implant couples through finite element simulation (ANSYS v24) and statistical inference (STATA v17). During gait cycle loading simulations, significant disparity in wear behaviour was observed. Alumina–UHMWPE demonstrated superior mechanical resistance, with a wear volume of 0.18481 mm3 and a wear depth of 6.93 × 10−4 mm compared to alumina–PEEK, which registered higher wear (volume: 8.4006 mm3; depth: 3.15 × 10−2 mm). Wear distribution analysis indicated alumina–UHMWPE showed an even wear pattern in comparison to the poor, uneven alumina-PEEK high-wear patterns. Statistical comparison validated these findings, wherein alumina–UHMWPE achieved a 27.60 hip joint wear index (HCI) value, which is better than that of alumina–PEEK (35.85 HCI), particularly regarding key parameters like wear depth and volume. This computational–statistical model yields a baseline design for biomaterial choice, demonstrating the potential clinical superiority of alumina–UHMWPE in reducing implant failure risk. While this is a simulation study lacking experimental validation, the results pave the way for experimental and clinical studies for further verification and refinement. The approach enables hip arthroplasty design optimization with maximal efficiency and minimal resource-intensive testing.

Biomechanical Comparison of Two Open TMJ Disc Repositioning Techniques: A Finite Element Analysis

2025-06-24

Tianqi Wan , Xiao Dong Chen , S. Zhang | International Journal of Oral and Maxillofacial Surgery

Minimally Invasive Implantology: Using BioMiniature Implants for Full Arch Rehabilitation

2025-06-24

O. Allan | International Journal of Oral and Maxillofacial Surgery

Full Arch Implants Immediate Loading Using Titanium Bar

2025-06-24

Osama E. Amer | International Journal of Oral and Maxillofacial Surgery

Biomechanical impact of enoxaparin sodium-chitosan-PMMA bone cement in hip arthroplasty: a preliminary finite element analysis

2025-06-24

Jianchao Chen , Xinzhe Ma , Zhiyong Li +2 more | Frontiers in Surgery

Objective To determine the material parameters of PMMA and ES-CS-PMMA, and compare the stress distribution differences in hip arthroplasty postoperatively using finite element analysis. Methods The Young's modulus and Poisson's … Objective To determine the material parameters of PMMA and ES-CS-PMMA, and compare the stress distribution differences in hip arthroplasty postoperatively using finite element analysis. Methods The Young's modulus and Poisson's ratio of PMMA and ES-CS-PMMA were calculated by measuring the propagation speed of ultrasound waves through the bone cements. Using CT images of a healthy adult male, a three-dimensional model of the natural femur and two postoperative 3D models (with PMMA and ES-CS-PMMA as adhesives) were established. Simulating slow walking motion, stress distribution differences in the cement sheath and femur were observed between the two postoperative models. Results The Young's modulus of PMMA was 4,127 MPa with a Poisson's ratio of 0.25; ES-CS-PMMA exhibited an Young's modulus of 4,331 MPa and a Poisson's ratio of 0.28. In the two postoperative models, no significant differences were observed in stress distribution within the cement sheath or femur after prosthesis implantation. Compared to the natural femur, both PMMA and ES-CS-PMMA reduced cortical stress postoperatively, transferring stress to the femoral stem. In the distal region of the prosthesis, mean stress was significantly reduced post-implantation. In the midsection of the prosthesis, the implanted prosthesis bore higher peak stress than the natural femur. Conclusions This study measured the material parameters of PMMA and ES-CS-PMMA. Compared to PMMA, using ES-CS-PMMA as an adhesive in hip arthroplasty did not alter the stress distribution of the cement sheath or femur post-implantation.

Femoral Fixation for Primary Total Hip Arthroplasty—An International Registry Perspective

2025-06-23

Tony Gaidici , David G. Deckey , Thorsten M. Seyler +3 more | Arthroplasty Today

CBC Mathys and CLS Spotorno stems: similar in design, different in outcomes. A comparative study of clinical and radiological differences

2025-06-23

Pedro Luis Bazán , Adrián Torres , Jorge Gómez-Álvarez +3 more | Archives of Orthopaedic and Trauma Surgery

Synergistic Enhancement of Wear Resistance in Zirconium Alloys via Combined Laser Texturing and Thermal Oxidation

2025-06-23

Qingchun Zheng , Jiachen Zhang , Zhitao Cao +4 more | Research Square (Research Square)

<title>Abstract</title> Zirconium (Zr)-based alloys have great potential for orthopedic implants due to their excellent mechanical properties, corrosion resistance, and biocompatibility. However, untreated Zr-based alloys exhibit inadequate wear resistance, which limits … <title>Abstract</title> Zirconium (Zr)-based alloys have great potential for orthopedic implants due to their excellent mechanical properties, corrosion resistance, and biocompatibility. However, untreated Zr-based alloys exhibit inadequate wear resistance, which limits their service life as joint prostheses. This study employed a combined surface texturing and thermal oxidation approach to enhance wear resistance. Biomimetic micro-textures were fabricated on the alloy surface via laser processing, followed by high-temperature oxidation to produce a textured ceramic coating. The influence of micro-texture diameter on anti-friction performance was systematically investigated. Results demonstrated significant improvements in hardness and wettability. Rotary friction tests were performed using a pin-on-disc tribometer. Tests revealed that ceramic-textured specimens outperformed smooth surfaces in terms of friction reduction and wear resistance. Specifically, the friction coefficient was reduced by 25.24%, with a maximum wear reduction rate of 27.7%. This study provides a novel strategy for improving the surface properties of Zr-based alloys.

The Femoral Neck-Bite Sign: A Radiographic Indicator of Catastrophic Sandwich Liner Failure in Total Hip Arthroplasty

2025-06-23

Hendrik Pott , Ricarda Stauß , Peter Savov +2 more | Arthroplasty Today

The Role of Osteoporosis in Total Hip Arthroplasty Periprosthetic Fractures and Current Management Strategies: a Review

2025-06-23

Jürgen M. Bauer , Joseph Duero , Adam Lindsay | Current Osteoporosis Reports

Effects of K-wire diameter and insertion angle on femoral bone medial closing-wedge osteotomies: a finite element study

2025-06-20

Ayda Karimi Dastgerdi , Alireza Yahyaiee Bavil , Markus T. Berninger +4 more | Scientific Reports

Abstract Medial closing-wedge surgery for distal femoral osteotomy is employed to correct genu valgum by correcting coronal plane malalignment. This procedure involves pre-surgery planning, creating a wedge incision, performing the … Abstract Medial closing-wedge surgery for distal femoral osteotomy is employed to correct genu valgum by correcting coronal plane malalignment. This procedure involves pre-surgery planning, creating a wedge incision, performing the osteotomy, and stabilizing with plates and screws. However, hinge fractures during wedge closure present significant challenges, often necessitating revisions. Contemporary solutions have explored the use of k-wires, and this study investigates their biomechanical implications. The interplay between k-wire insertion angle and diameter, often overlooked in existing literature, is a critical determinant of their efficacy in achieving successful osteotomies, highlighting gaps in our understanding of these key parameters. We hypothesize that k-wire mechanics vary with insertion angle and diameter. This study examines the introduction of k-wires at different angles (30°, 45°, and 60°) and diameters (1.6, 1.8, and 2 mm) using computed tomography-based finite element models to assess structural integrity during femoral medial closing-wedge osteotomy. Results reveal angle-dependent stress variations, with 60° configurations exhibiting favorable patterns that reduce tensile and compressive loads and plastic deformation—crucial in preventing hinge fractures. Diameter variations show no significant differences in stresses or system stiffness. It was also found that while angle significantly affects stresses, lower diameters appear optimal only in combination with higher angles. Comparative analysis of k-wire systems with a naïve model demonstrates that k-wires at a 60° angle reduce tensile and compressive loadings and plastically deformed volume fractions, thus lowering fracture risk. This study underscores the importance of optimizing k-wire placement and configuration, particularly highlighting the significance of the insertion angle. Future research should expand the range of angles and diameters tested and examine different femoral geometries and osteotomy angles to provide a more comprehensive understanding and enhanced clinical application.

The effect of lower-midsole G-frame integration on ankle stability during power walking

2025-06-20

Young Kyu Jeong , Kong Sejin , Sihyun Ryu +3 more | Footwear Science

Open anterior hip dislocation combined with infection and injury of the common femoral artery and vein: A case report and literature review

2025-06-20

Jiabao Jiang , Zhong Zhou , Yijie Yin +5 more | Medicine

Open anterior hip dislocation resulting in vascular injury is extremely rare and is a severe orthopedic emergency that can potentially lead to limb necrosis and even life-threatening consequences. A 51-year-old … Open anterior hip dislocation resulting in vascular injury is extremely rare and is a severe orthopedic emergency that can potentially lead to limb necrosis and even life-threatening consequences. A 51-year-old woman presented to our hospital with an open anterior dislocation of the left hip secondary to a fall from height. The patient had a severe infection in the left inguinal area; at presentation, there was dislocation of the femoral head lasting for the past 5 days. Doppler ultrasound revealed left common femoral vein thrombosis. The patient was diagnosed with a multiple-injury patient with an acetabular fracture, femoral head fracture, and open anterior dislocation of the hip with vascular injury and infection. After placement of an inferior vena cava filter, the reduction was performed under general anesthesia. The common femoral artery ruptured during the process. After suturing, continuous drainage was maintained. During the subsequent treatment, the infection gradually eroded the common femoral artery and formed a pseudoaneurysm. Lower limb vascularity was restored by autologous saphenous vein grafting, repeated debridement, and sensitive antibiotics. The infection of the patient was gradually controlled, and the lower limb was successfully preserved. During the 1-year follow-up, the patient returned to normal life without disability. From this rare case, we suggest that a therapeutic approach should be evaluated after adequate exclusion of deep vein thrombosis to prevent thromboembolic events. Moreover, gentle reduction operation, thorough debridement, and timely infection control are essential to prevent complications and improve the functional prognosis of patients.

Pericapsular Nerve Group Block at the Hip

2025-06-20

Steven D. Waldman | Elsevier eBooks

Prosthesis

2025-06-19

Anna Fishzon | Routledge eBooks

Increasing reaming depth enhances implant stability while minimizing bone strain

2025-06-19

Monil Karia , Ruben Doyle , A. J. Reynolds +2 more | Bone and Joint Research

Aims Increasing the interference fit of the acetabular component can increase primary stability, but it introduces excessive periacetabular strain during impaction, which can lead to fractures. An optimal outcome following … Aims Increasing the interference fit of the acetabular component can increase primary stability, but it introduces excessive periacetabular strain during impaction, which can lead to fractures. An optimal outcome following cementless acetabular component impaction is maximal primary implant stability with minimal periacetabular bone strain. The aim of this study was to investigate whether a simple modification to a surgeon’s reaming technique can achieve this desirable outcome. Methods A custom drop rig simulated impaction strikes, seating acetabular components of either 1 mm or 2 mm interference fit into synthetic sawbones with cavities reamed to either a true hemisphere or a hemisphere with an enhanced reaming depth of 2 mm or 4 mm. Synthetic bone strain was recorded using strain gauges, and push-out tests were conducted to assess implant stability. Polar gaps were measured using optimal trackers. Results Compared to a true hemispherical cavity, enhancing the reaming depth significantly increased the primary stability of the implant (p < 0.001) while reducing both the periacetabular strain and strain deterioration for both 1 mm and 2 mm interference fit components. A 4 mm reaming depth enhanced the primary stability of 1 mm press-fit components to a level almost equivalent to a 2 mm press-fit, albeit reducing strain to the bone. Enhancing reaming depth did not significantly affect polar gap. Conclusion Enhancing cavity reaming depth is a simple technique to increase the implant primary stability of press-fit uncemented acetabular components, while avoiding any excess in periacetabular strain and the associated fracture risk. Cite this article: Bone Joint Res 2025;14(6):551–559.

Comparison of the Trabecular Titanium Acetabular Shell with Burch–Schneider Cages in Revision Hip Arthroplasty

2025-06-19

Pawel M. Kaminski , Jarosław Ambroży , Rafał Obuchowicz | Journal of Clinical Medicine

Objective: In recent years, a significant increase in the incidence of both total hip arthroplasty and acetabular revision surgery has been observed. A substantial proportion of patients requiring these revision … Objective: In recent years, a significant increase in the incidence of both total hip arthroplasty and acetabular revision surgery has been observed. A substantial proportion of patients requiring these revision procedures present with major bone deficits and extensive osteolysis. In light of these challenges, this study aims to provide a comprehensive comparison between two commonly utilized methods: trabecular titanium shell implants and Burch-Schneider acetabular reinforcement cages. Methods: Participants of both sexes were included through a retrospective review of medical records. The sole inclusion criterion was that the patient had undergone revision hip arthroplasty using either Burch-Schneider acetabular reinforcement cages or Regenerex trabecular titanium shell within the past 18 years. No exclusion criteria were applied concerning patient age, laterality, ethnicity, or post-operative status. Each patient was evaluated based on nine predictive factors, including the Paprosky classification, duration of surgery, perioperative blood loss, number of bone grafts and screws used, as well as pre- and post-operative Harris Hip Score (HHS) and Visual Analogue Scale (VAS). Results: A total of 220 patients were included in the analysis, with 75% (n = 165) comprising the group treated with trabecular titanium implants and 25% (n = 55) treated with Burch-Schneider cages. The use of Regenerex trabecular titanium was associated with a 32.40% (n = 23.13 mL) reduction in bone graft tissue required and a 13.7% (n = 0.59) increase in the number of screws needed. Additionally, the trabecular titanium group experienced a 15.93% (n = 179.64 mL) reduction in perioperative blood loss compared to the Burch-Schneider cage group. The other parameters analyzed in the study did not demonstrate statistical significance. Conclusions: The use of a trabecular titanium acetabular shell may be an effective option, particularly in patients with severe acetabular deficits, as it provides favorable clinical and radiological outcomes. Additionally, it reduces the number of bone grafts required and allows for faster and more immediate partial weight-bearing on the operated limb.

Articular noise after Delta-on-Delta revision hip arthroplasty at a long-term follow-up: incidence and impact on clinical outcomes

2025-06-19

Andrea Minerba , Nicola Valerio Capitaneo , Francesco Castagnini +3 more | International Orthopaedics

Screw Coating as a Solution to Solve Screw Loosening Complications: An In Vitro Study

2025-06-19

Lara Coelho , María Cristina Manzanares‐Céspedes , Joana Mendes +2 more | Materials

Background: This study aimed to evaluate the influence of a screw coating on the screw preload and removal torque value (RTV) with and without the application of a cyclic load … Background: This study aimed to evaluate the influence of a screw coating on the screw preload and removal torque value (RTV) with and without the application of a cyclic load (CL) to make screws with greater untightening resistance to prevent screw loosening. Methods: Ninety complexes composed of implants, abutments, and prosthetic screws were examined and tested under CL oral conditions (n = 45) and non-CL conditions (nCL, n = 45). Each group was divided into three subgroups (n = 15): a control group (CG) without a screw coating, a GapSeal®-coated screw group (GG), and a polytetrafluoroethylene (PTFE) tape-wrapped screw group (PG). All screws were tightened at 30 Ncm, and the preload was recorded. In the nCL group, the screws were untightened to record the RTV. In the CL group, the screws were tightened, subjected to a CL in distillated water at a temperature of 37 °C, and then untightened to record the RTV. Micro-Ct analysis was conducted on two samples from each group before CL. SEM analyses of two samples per subgroup before and after CL were also performed. Results: The preload in the PG was significantly lower under nCL (29.92 Ncm) compared with CG (30.95 Ncm) and GG (31.19 Ncm) and also under a CL (PG: 30.92 Ncm) compared with CG (31.72 Ncm) and GG (31.42 Ncm). The RTVs of the PG were significantly lower under nCL (15.30 Ncm) compared with CG (27.98 Ncm) and GG (28.46 Ncm). Under CL, the RTVs of the PG were significantly higher (31.50 Ncm) compared with CG (26.00 Ncm) and GG (27.44 Ncm). Conclusions: Wrapping the screw with PTFE tape significantly reduced the preload but resulted in a significantly greater RTV under CL conditions in the simulated oral environment, suggesting that this could be a solution to decrease the risk of screw loosening.

Pure high-offset stems can cause an unexpected increase in femoral length in robotic-assisted primary total hip arthroplasty

2025-06-18

Wei-Shao Tung , Aidin Eslam Pour , Johannes Sieberer +3 more | World Journal of Orthopedics

Certain implant combinations change leg length and offset in primary total hip arthroplasty (THA). Poor restoration of leg biomechanics is a frequently cited reason for patient dissatisfaction following primary THA. … Certain implant combinations change leg length and offset in primary total hip arthroplasty (THA). Poor restoration of leg biomechanics is a frequently cited reason for patient dissatisfaction following primary THA. A pure high-offset stem should provide direct lateralization without affecting femoral length when compared to a standard stem. However, clinical experience with preoperative planning software based on computed tomography-based three-dimensional-models reveals that using pure high-offset stems in THA may cause a difference between expected (no change in femoral length) and actual (small increase) in postoperative femoral length. To elucidate the causes of these femoral length discrepancies using preoperative planning software. Preoperative templating for 43 robotic-assisted THAs, optimizing acetabular size and orientation, center of rotation, stem size and offset, and prosthetic head diameter were obtained. The preoperative planning software was used to calculate differences between preoperative and postoperative femoral length for standard and pure high-offset stems, unique to each patient. Whilst the increase in femoral length between standard and high-offset stems was not significant (P = 0.93), 35 femurs (81.4%) experienced a 1-mm increase, and 3 (7.0%) experienced a 2-mm increase in femoral length while using high-offset stem compared to the standard stem. The incidence of femoral length increase was lower for patients with shorter femurs (18/22; 81.8%) compared to patients with longer femurs (20/21; 95.2%). When pure high-offset stems were used in preoperative planning software, we demonstrated an unexpected increase in leg length between 1-2-mm in 88.4% of patients. This unexpected increase in femoral length is due to a function of the preoperative planning software's planned stem alignment with the anatomical axis, and not an inherent fault in the stem design. With expanding accessibility of robotic-assisted THA platforms, all potential sources of postoperative leg length discrepancy should be identified during preoperative templating and necessary alterations to the surgical plan should be made to accommodate this unexpected difference when using a pure high-offset stem.

Prevalence of metal detector activation and its psychological impact in patients with TKA: A case-control study.

2025-06-18

Jérôme Murgier , Étienne Cavaignac , Regis Pailhé | Research Square (Research Square)

<title>Abstract</title> Purpose Metal detectors in airports are designed to identify metallic objects on passengers, which can inadvertently trigger alarms for patients with TKA implants. The main goal of this study … <title>Abstract</title> Purpose Metal detectors in airports are designed to identify metallic objects on passengers, which can inadvertently trigger alarms for patients with TKA implants. The main goal of this study was to compare the prevalence of metal detection at security airport between a cohort of patient who sustained an TKA and another group free of any metallic implants. The hypothesis was that patients with TKA would trigger metal detectors more frequently than those without TKA and this would have a detrimental impact on their whole post-surgical experience. Methods A continuous, non-randomized, case-control, cross-sectional study was carried out. Patients who underwent a TKA between 2020 to 2021 at the same hospital were included in this study. A control group was included to compare the results and improve the level of evidence. This cohort was recruited via patient fellows who accompanied them in clinics. Results 51 Patient in the TKA group set off the metal detector (79.7% - CI 95% : [68.3; 87.7]) versus 5 in the control group (13.5% - CI 95% : [5.9; 28.0]). This difference was statistically significant (p < 0.0001). For those who triggered the alarm (51 patients in the TKA group), this event occurred at all security checkpoints they went through for 42 (82.4%) of them whereas in the control group it occurred 20% of the time. This difference was also statistically significant (p < 0.05). Additionally, 28 out of the 51 TKA patients who triggered alarms (54.9%) reported that the experience was bothersome and had a negative impact on their mood. Conclusion Total Knee Arthroplasty patients more frequently trigger metal detector alarms at airport security checkpoints than patients free of any prosthesis, which cause unnecessary stress and discomfort. As the global number of TKA procedures continues to rise, it is crucial to implement strategies that acknowledge the unique needs of patients with TKA, ensuring both security and comfort during air travel.

Correction to: Implant removal: benefits and drawbacks - Results of a survey with five hundred participants from the Italian Society of Orthopedic Surgery and Traumatology (SIOT) and comparison with other international trends

2025-06-18

Virginia Masoni , Corrado Ciatti , Luca Andriollo +2 more | International Orthopaedics

Biomechanical comparison of cemented versus cementless fixation in intraoperative femoral fractures during total hip arthroplasty

2025-06-18

Ryunosuke Watanabe , Tomofumi Nishino , Tomohiro Yoshizawa +4 more | Research Square (Research Square)

<title>Abstract</title> Introduction: Intraoperative periprosthetic femoral fractures (IPFF) are serious complications of total hip arthroplasty (THA) that occur more frequently with cementless stems than with cemented stems. Although cerclage wiring is … <title>Abstract</title> Introduction: Intraoperative periprosthetic femoral fractures (IPFF) are serious complications of total hip arthroplasty (THA) that occur more frequently with cementless stems than with cemented stems. Although cerclage wiring is commonly used to stabilize IPFFs, the biomechanical effects of subsequent stem fixation methods remain unclear. This study aimed to compare the biomechanical stability of cemented and cementless stems following cerclage wire fixation in an experimental IPFF model. Materials and Methods: Six fourth-generation composite femurs with simulated Vancouver A2-type fractures were stabilized using a single 1.8 mm cerclage wire. Identical stem designs of polished cemented stems and fully hydroxyapatite-coated cementless stems were implanted in three specimens of each group. After applying a vertical axial load of 2000 N, an additional 40° of internal rotation was imposed. The primary outcome was the maximum torque at the time of fracture. Secondary outcomes included the maximum internal rotation angle, construct stiffness (calculated from force-displacement curves above 1500 N), and peak strain at three positions on the cerclage wire, measured using strain gauges. Results: The maximum torque was significantly higher in the cemented group compared to the cementless group (160.8 ± 24.9 vs. 89.1 ± 18.0 N·m, p = 0.016). Although the differences in stiffness and internal rotation angle were not statistically significant, both trended higher in the cemented group. The peak strain was consistently lower in the cemented group, with a significant difference at the medial side of the fracture line (p = 0.011, Cohen’s d = − 3.64). Conclusions: Cemented stems demonstrated superior biomechanical stability following cerclage wire fixation in the IPFF model, likely because of improved stress distribution via the cement mantle. Therefore, cemented fixation may be a favorable option for managing IPFF during THA.

The SMA

2025-06-18

Mario Alejandro Rosato | CRC Press eBooks

Addressing the Inadequacy of BMI: Superior Prediction of Aseptic Loosening Risk in TKA Using Weight-to-Implant Surface Area Ratio

2025-06-18

Morad Karimpour , Arash Sharafatvaziri | Journal of Bone and Joint Surgery

Retrograde nail/plate combination for interprosthetic femoral fractures: technical note and case series

2025-06-17

M. Kareem Shaath , Brendan Page , Brendan Kosko +4 more | European Journal of Orthopaedic Surgery & Traumatology

Robotic Versus Manual Total Hip Arthroplasty: A Marginal Time-driven Activity-based Costing Analysis

2025-06-17

Perry L Lim , Graham S. Goh , Hany S. Bedair +1 more | Journal of the American Academy of Orthopaedic Surgeons

Background: Standard cost analyses of robotic total hip arthroplasty (THA) have been done. However, no studies have used time-driven activity-based costing (TDABC), a novel cost calculation method that more accurately … Background: Standard cost analyses of robotic total hip arthroplasty (THA) have been done. However, no studies have used time-driven activity-based costing (TDABC), a novel cost calculation method that more accurately reflects true resource utilization in health care. This study aimed to compare healthcare facility costs between robotic and manual THA using TDABC. Methods: We conducted a retrospective analysis of 384 consecutive THAs performed between 2019 and 2023. Total healthcare facility costs, comprising personnel and supply costs, were calculated using TDABC. Separate analyses including and excluding implant costs were done. Multiple regression was used to determine the independent effect of robotic assistance on facility costs. Results: A total of 384 THAs (190 manual, 194 robotic) were analyzed. Patients undergoing robotic THA had a significant shorter length of stay (1.9 vs. 2.3 days, P = 0.033), but similar surgical times (1.00x, P = 0.936) and total personnel costs ( P = 0.080). Robotic THAs had higher total supply costs and facility costs when including (1.19x, P < 0.001; 1.08, P = 0.017) and excluding (1.91x, P < 0.001; 1.10x, P = 0.013) implant cost. However, when controlling for demographics and comorbidities known to influence costs in arthroplasty, similar total facility costs between robotic and manual THA, when including ( P = 0.095) and excluding ( P = 0.087) implant cost, were noted. A comparison of perioperative outcomes revealed no significant difference in 90-day emergency department visits, 90-day readmissions, 90-day complications, reoperations, or revision surgeries. Conclusion: Using TDABC, total healthcare facility costs of robotic THA were similar to those of manual THA when controlling for variables known to influence costs in total joint arthroplasty. This study offers patient-level cost insights on the economic feasibility of robotic THA. Additional studies evaluating the long-term outcomes of robotic THA are needed to determine its long-term advantages.

Modular Femoral Stem for Hartofilakidis Type C Hip Dysplasia: Is It Necessary for 1-mm Increment of Distal Stem Diameter?

2025-06-17

Jiafeng Yi , Hongbin Xie , Yubo Liu +3 more | PubMed

S-ROM prosthesis, one well-used femoral prosthesis in the patients with developmental dysplasia of the hip (DDH), has a skipping size of the distal stem diameter. The purpose of this study … S-ROM prosthesis, one well-used femoral prosthesis in the patients with developmental dysplasia of the hip (DDH), has a skipping size of the distal stem diameter. The purpose of this study was to investigate whether its 2-mm incremental diameter could meet clinical needs for high-riding DDH patients. Between July 2018 and December 2022, the Hartofilakidis type C DDH patients with S-ROM stem (9 or 11 mm) were retrospectively enrolled according to the inclusion criteria and exclusion criteria in our institute. The intraoperative femur fractures, the diameter of the femoral medullary cavity, the canal filling ratio of the S-ROM stem, the closure conditions of the stem slot, and the healing rate of subtrochanteric osteotomy were analyzed to evaluate the effect of stem design on clinical outcomes. Statistical analyses were conducted using independent samples t-tests, chi-square test, and logistic regression analysis with a significance threshold of p < 0.05. A total of 95 patients (109 hips) were included in this study, including 60 hips with 9 mm S-ROM and 49 hips with 11 mm S-ROM. Compared with the 9 mm S-ROM group, the 11 mm S-ROM group presented nearly 5 times the intraoperative fracture rate (16.3%, 3.3%, p < 0.05). The mean diameter of the femoral medullary cavity in the 9 mm S-ROM group was 0.84 ± 0.20 mm and in the 11 mm S-ROM group was 1.03 ± 0.18 mm. The canal filling ratio in the 9 mm S-ROM group is significantly lower than that of the 11 mm S-ROM group. In the 11 mm S-ROM group, the filling ratio of the femoral medullary cavity of fracture hips was significantly higher than that in non-fracture hips. The S-ROM design with a distal stem diameter increment of every 2 mm would increase the risk of intraoperative periprosthetic femoral fractures in high-riding DDH patients. It is necessary for a 1-mm increment of distal stem diameter in such patients. Level III, retrospective comparative study.

Ex vivo micro-computed tomography analysis of the fracking technique for a nodular calcification in the common femoral artery

2025-06-17

Norihito Nakamura , Yuki Matsumoto , Manabu Shiozaki +1 more | Cardiovascular Intervention and Therapeutics

Total hip arthroplasty in patient with hip fracture and congenital pubic diastasis

2025-06-17

K Saravanan , Khalid Malik-Tabassum , Asim Rajpura +1 more | Annals of The Royal College of Surgeons of England

Congenital pelvic deformities, such as pubic diastasis, significantly complicate the surgical planning and execution of total hip arthroplasty (THA), the gold standard for treating degenerative hip disease unresponsive to conservative … Congenital pelvic deformities, such as pubic diastasis, significantly complicate the surgical planning and execution of total hip arthroplasty (THA), the gold standard for treating degenerative hip disease unresponsive to conservative measures. These challenges are exacerbated in the context of trauma, because of disrupted anatomical landmarks and soft tissue imbalances. THA becomes particularly demanding in cases involving traumatic femoral neck fractures in patients with congenital anomalies of the pelvis. We present a unique case of a 62-year-old man with an acute, post-traumatic left-sided hip fracture, and a history of congenital bladder exstrophy and pubic diastasis, who successfully underwent THA. Meticulous preoperative planning with three-dimensional reconstruction software was essential in overcoming the anatomical challenges posed by this case, enabling our successful outcome.

SPM Differences in Gait Pattern of Women After Total Hip Replacement: A Longitudinal Study

2025-06-17

Krzysztof Aleksandrowicz , Wojciech Kosowski , Agata Michalska +1 more | Journal of Clinical Medicine

Background: Total Hip Replacement (THR) is a standard treatment for advanced hip osteoarthritis; yet, its effects on gait recovery remain understudied. This study examines gait pattern changes in women undergoing … Background: Total Hip Replacement (THR) is a standard treatment for advanced hip osteoarthritis; yet, its effects on gait recovery remain understudied. This study examines gait pattern changes in women undergoing monitored rehabilitation after unilateral THR, using Statistical Parametric Mapping (SPM) to detect significant motion differences over time. Methods: This longitudinal study included 32 women who underwent primary cementless THR. Gait was assessed preoperatively and postoperatively at 6 weeks, 3 months, 6 months, and 12 months using a motion analysis system. Repeated measures ANOVA and post hoc SPM{t} analyses were conducted to evaluate significant gait changes across time points. Results: Significant improvements (p < 0.05) were observed in spatio-temporal parameters. Velocity increased from 0.42 ± 0.10 m/s (Ex1) to 0.72 ± 0.06 m/s (Ex5), stride length from 0.85 ± 0.12 m to 1.15 ± 0.07 m, and step length (involved leg) from 0.32 ± 0.08 m to 0.48 ± 0.05 m. Cycle time decreased from 1.50 ± 0.20 s to 1.22 ± 0.10 s, indicating improved gait efficiency. Post hoc SPM{t} analysis revealed significant kinematic changes in hip flexion-extension, knee flexion, and pelvic tilt, particularly between Ex2 and Ex3. Statistically significant improvements (p < 0.001) were observed in key spatio-temporal parameters. Conclusions: Gait parameters improved significantly within the first year post-THR, with the most pronounced changes occurring between the early and mid-term recovery phases. These findings support the need for targeted rehabilitation strategies in the first six months post-surgery. SPM analysis provides a robust method for detecting subtle gait adaptations, contributing to the refinement of post-THR rehabilitation strategies.

Monoblock or Modular? Impact of Stem Design and Conicity Angle on Long-Term Implant Survival in Revision Total Hip Arthroplasty: A 20-Year Follow-Up Registry Study On 3647 Implants

2025-06-17

Matteo Brunello , Alberto Di Martino , Manuele Morandi Guaitoli +4 more | Research Square (Research Square)

<title>Abstract</title> Introduction: Revision total hip arthroplasty (rTHA) often requires femoral stem revision due to aseptic loosening, instability, or fractures. Long, tapered conical stems are preferred for stability and bone loss … <title>Abstract</title> Introduction: Revision total hip arthroplasty (rTHA) often requires femoral stem revision due to aseptic loosening, instability, or fractures. Long, tapered conical stems are preferred for stability and bone loss management. Recent design changes, like increased conicity angles, aim to enhance fixation and reduce subsidence. Monoblock and modular stems offer distinct pros and cons, but their long-term outcomes remain debated. This study evaluates the long-term survival of monoblock vs. modular conical stems, with a focus on conicity angles (2° vs. 3°), using 20 years of registry data. Methods: A retrospective review was conducted using the Emilia Romagna Registry of Orthopedic Prosthetic Implants (RIPO) from 2000–2021. A total of 3,647 non-cemented conical stems used in rTHA were analyzed: 32.4% monoblock and 67.6% modular. Kaplan–Meier survival analysis assessed implant longevity, stratified by stem design and conicity angle. Results: Use of modular stems increased from 24% to over 82% during the study period. Overall failure rate was 6.3%—5.1% for monoblock stems (mainly due to aseptic loosening) and 6.9% for modular stems (primarily due to instability). Monoblock stems had superior 20-year survival (93.7%) compared to modular (86.8%, p = 0.009). Among modular stems, those with 2° conicity had significantly better 15-year survival (91.9%) than 3° designs (88.0%, p = 0.001). No significant difference was observed between conicity angles in monoblock stems. Conclusion: Monoblock stems provide better long-term survival in rTHA. Modular designs, while offering intraoperative flexibility, carry higher revision risk, especially with greater conicity. Stem selection should balance design features with patient needs and surgical expertise

Comparison of External Rotation Torque of Short External Rotator Muscles in Hip Flexion Position

2025-06-16

Yoshiaki Ito , Daisuke Suzuki , Fumiya Kizawa +5 more | Journal of Orthopaedic Research®

ABSTRACT Preservation of the short external rotator muscles of the hip is effective in preventing dislocation after total hip arthroplasty. The external rotation torque exerted by the short external rotator … ABSTRACT Preservation of the short external rotator muscles of the hip is effective in preventing dislocation after total hip arthroplasty. The external rotation torque exerted by the short external rotator muscles can resist internal rotation of the hip joint; however, the absence of quantitative data on external rotation torque makes it difficult to determine which short external rotator muscles should be preserved. We compared the external rotation torque of individual short external rotator muscles in hip flexion. The external rotation torque of the piriformis, obturator internus, conjoined tendon, and obturator externus was evaluated in 15 fresh‐frozen cadaveric hips from 0° to 105° of hip flexion, by applying muscle force based on physiological cross‐sectional area to the muscle‐string model constructed along the anatomical course of each muscle on the pelvis. External rotation torque of the piriformis, obturator internus, and conjoined tendon peaked at 15° hip flexion, and then decreased as the hip flexed. External rotation torque of the obturator externus increased as the hip flexed. At 75° of flexion or more in deep flexion, ranges associated with a high risk of dislocation, the obturator externus had the highest external rotation torque. External rotation torque of the obturator externus was, on average, 2.18 times greater than that of the conjoined tendon at 90° of hip flexion, and 3.80 times greater at 105° flexion. These findings, which include the element of muscle force, suggest that preservation of the obturator externus is the most effective in resisting dislocation among the short external rotator muscles. Clinical Relevance No study has evaluated dislocation resistance based on external rotation torque, including both a force component and muscle course. In this study, we estimated the muscle force of the short external rotator muscles from the PCSA, and quantitatively evaluated how that muscle force changes as external rotation torque during hip flexion. While approaches to hip replacement surgery and the preservation of tissues vary, our results suggest criteria for which muscles should be effectively preserved to resist dislocation in selective dissection of the posterior soft tissues of the hip joint. In future, surgeons will be able to advocate surgical approaches that are less invasive and more resistant to dislocation, which will require clinical evaluation.

Practice Makes Perfect: Using Soft Embalmed Cadavers as a Teaching Model for Hip Reduction

2025-06-16

Michael R. Nash , Joshua Altman , Jeremy Taylor +4 more | Western Journal of Emergency Medicine

Acetabular revision with moderate-to-severe bone loss using a trabecular titanium cup-cage construct with impaction grafting

2025-06-16

Ioannis S. Vasios , Konstantinos G. Makiev , Efthymios Iliopoulos +2 more | Orthopedic Reviews

Introduction Total hip arthroplasty (THA) is one of the most commonly performed procedures the last decades in the field of orthopaedics. However, there has been a subsequent increase in revision … Introduction Total hip arthroplasty (THA) is one of the most commonly performed procedures the last decades in the field of orthopaedics. However, there has been a subsequent increase in revision rates for various reasons with instability and aseptic loosening being the predominant ones. Revision surgeries pose many challenges to the treating orthopaedic surgeons as well as significant burdens on patients and on healthcare systems globally. After a revision procedure, in addition to the best possible functional outcomes, longer lifespan of the implants, the least possible bone loss and restoration of as much as possible of bone stock should also be of priority. Materials & Methods A case series of 11 patients with aseptic loosening of the acetabular component having moderate-to-severe acetabular bone loss is presented. All patients were managed with a trabecular titanium cup-cage construct in conjunction with impaction of morselized allograft. Results This study assessed 11 patients (mean age 67.9 years) with Paprosky 2B-3B acetabular defects undergoing revision surgery (mean follow-up: 54.6 months). Functional outcomes improved significantly, including Harris Hip Score (44.8% to 80.7%), HOOS-JR (49.9% to 70.4%), and Forgotten Joint Score (13.6% to 81.8%). VAS and EQ-5D-5L scores also showed marked improvement. Logistic regression found no significant impact of age, sex, or ASA score on outcomes (p = 0.6). These results demonstrate notable functional recovery post-surgery. Conclusions Revision surgery for aseptic loosening of the acetabular component using a trabecular titanium cup-cage construct with morselized allograft demonstrates excellent functional improvement and patient satisfaction. The procedure is effective in managing moderate-to-severe acetabular bone loss (Paprosky 2B-3B), restoring function and quality of life. Despite the challenges associated with such revisions, these findings highlight the efficacy and reliability of this approach in addressing complex cases without being significantly influenced by patient demographics or preoperative risk factors.

Reproducibility of the Barrack and Gruen Grading Systems in Assessing Cement Mantle Quality in Hip Arthroplasty

2025-06-16

Manel Fa-Binefa , Alex Grau-Blanes , Esther Moya-Gómez +2 more | Indian Journal of Orthopaedics

Defibrillate, Cardiovert, Pace! Translating Skills from Simulated to Real Equipment

2025-06-16

Diana Labrada , Steven H. Chapman , Jonathan Bronner +3 more | Western Journal of Emergency Medicine

L4 Radiculopathy Presenting as Postoperative Femoral Nerve Neuropraxia Following Total Hip Arthroplasty (THA) in the Setting of Hip-Spine Syndrome

2025-06-16

Caroline Lindsey , Robert Bilodeau , Christopher Gonzalez +3 more | Cureus

Probing mechanical, wear, and in vivo cytotoxicity properties of PEEK-based polymer composites for orthopedic implant applications

2025-06-16

S. Sathishkumar , Muthusivaramapandian Muthuraj , J. Chandradass +2 more | Macromolecular Research

Effects of Physiological Loading from Patient-Derived Activities of Daily Living on the Wear of Metal-on-Polymer Total Hip Replacements

2025-06-16

Benjamin A. Clegg , Samuel C. Perry , Enrico De Pieri +7 more | Bioengineering

The current pre-clinical testing standards for total hip replacements (THRs), ISO standards, use simplified loading waveforms that do not fully replicate real-world biomechanics. These standards provide a benchmark of data … The current pre-clinical testing standards for total hip replacements (THRs), ISO standards, use simplified loading waveforms that do not fully replicate real-world biomechanics. These standards provide a benchmark of data that may not accurately predict in vivo wear, necessitating the evaluation of physiologically relevant loading conditions. Previous studies have incorporated activities of daily living (ADLs) such as walking, jogging and stair negotiation into wear simulations. However, these studies primarily used simplified adaptations that increased axial forces and applied accelerated sinusoidal waveforms, rather than fully replicating the complex kinematics experienced by THR patients. To address this gap, this study applied patient-derived ADL profiles-jogging and stair negotiation-using a three-station hip simulator, obtained through 3D motion analysis of total hip arthroplasty patients, processed via a musculoskeletal multibody modelling approach to derive realistic hip contact forces (HCFs). The results indicate that jogging significantly increased wear rates compared to the ISO walking gait waveform, with wear increasing from 15.24 ± 0.55 to 28.68 ± 0.87 mm3/Mc. Additionally, wear was highly sensitive to changes in lubricant protein concentration, with an increase from 17 g/L to 30 g/L reducing wear by over 60%. Contrary to predictive models, stair descent resulted in higher volumetric wear (8.62 ± 0.43 mm3/0.5 Mc) compared to stair ascent (4.15 ± 0.31 mm3/0.5 Mc), despite both profiles having similar peak torques. These findings underscore the limitations of current ISO standards in replicating physiologically relevant wear patterns. The application of patient-specific loading profiles highlights the need to integrate ADLs into pre-clinical testing protocols, ensuring a more accurate assessment of implant performance and longevity.