Higher failure rate and stem migration of an uncemented femoral component in patients with femoral head osteonecrosis than in patients with osteoarthrosis

Long-term outcomes of the mayo conservative hip system in patients aged 30 years or less with osteonecrosis of the femoral head: mean follow-up of more than 10 years

INTRODUCTION

Historically, total hip arthroplasty (THA) in very young patients has been associated with lower survivorship. However, the long-term outcomes of THA using short stems for osteonecrosis of the femoral head (ONFH) in very young patients remain unclear. Therefore, this study aimed to investigate the long-term outcomes of the Mayo conservative hip system, a short metaphyseal stabilised stem, in patients with ONFH aged ≦30 years.

MATERIALS AND METHODS

We retrospectively reviewed 104 joints in 76 patients with ONFH who underwent THA using the Mayo conservative hip system with a minimum follow-up of 8 years. The mean follow-up period was 12.5 (range, 8-19) years. Patients were categorised into two age groups (≦30 years, n = 21 and > 30 years, n = 83). Radiographic evaluation was used to assess stem sinking, stress shielding, and spot welds. The clinical evaluations were performed using the Japanese Orthopedic Association (JOA) hip score. Postoperative major complication and revision surgery rates were also assessed.

RESULTS

The patient characteristics were similar between the two groups, except for the age. Revision surgeries were performed in five cases, with similar implant survival rates between the groups. Dislocations occurred in the older age group alone (four joints). One case of intra-operative periprosthetic femoral fracture was found in the younger age group. Stem sinking of > 3 mm occurred in one and seven joints in the younger and older age groups, respectively. Spot welds were observed in most joints (93.2%) in modified Gruen zones 2 and 6 without significant differences between the groups. Stress shielding showed no significant differences in the frequency of occurrence or location between the two groups. Furthermore,the JOA score showed no significant difference between the two groups.

CONCLUSION

The use of short stems in patients aged ≤ 30 years with ONFH showed favourable long-term outcomes.

Anti-sclerostin antibody therapy prevents post-ischemic osteonecrosis bone collapse via interleukin-6 association

Osteonecrosis of the femoral head (ONFH) is a debilitating condition characterized by subchondral bone necrosis, which frequently culminates in joint destruction. Although total hip arthroplasty is conventionally practiced to remediate ONFH, for patients under the age of 60, the outcomes can be suboptimal. Chronic inflammation, particularly that mediated by interleukin-6 (IL-6), has been conjectured to be a potential mechanism underlying the etiology of ONFH. This study aimed at exploring the interplay between IL-6, the canonical Wnt signaling pathway, and ONFH to provide insights for potential therapeutic interventions. Human ONFH specimens depicted an elevation in β-catenin expression in the transitional layer, while IL-6 levels were pronounced in the same region. Subsequently, mouse models of ischemic osteonecrosis were treated with an anti-sclerostin antibody to assess its effects on bone metabolism and cellular processes. Histological analysis revealed that the administration of anti-sclerostin antibodies effectuated early recovery from bone necrosis, reduced empty lacunae, and suppressed IL-6 expression. The treatment evidently initiated the activation of the Wnt/β-catenin signaling pathway, presenting a potential mechanism associated with IL-6-mediated inflammation. Furthermore, the antibody upregulated osteoblast formation, downregulated osteoclast formation, and increased bone volume. Micro-CT imaging demonstrated increased bone volume, prevented epiphyseal deformity, and improved compression strength. Therefore, this study yields significant findings, indicating the potency of anti-sclerostin antibodies in effectively modulating the Wnt/β-catenin pathway, associating with IL-6 expression, and preventing post-ONFH bone collapse. Additionally, this preclinical investigation in mouse models offers an avenue for prospective research on potential therapeutic interventions against human ONFH.

The outcomes of total hip replacement in osteonecrosis versus osteoarthritis: a systematic review and meta-analysis

PURPOSE

This systematic review and meta-analysis aimed to compare the outcomes of THA in patients with osteonecrosis (ON) and those with osteoarthritis (OA).

METHODS

Four databases were searched from inception till December 2022 for original studies that compared the outcomes of THA in ON and OA. The primary outcome was the revision rate; the secondary outcomes were dislocation and Harris hip score. This review was conducted in line with PRISMA guidelines, and the risk of bias was assessed using the Newcastle-Ottawa scale.

RESULTS

A total of 14 observational studies with 2,111,102 hips were included, with a mean age of 50.83 ± 9.32 and 55.51 ± 8.95 for ON and OA groups, respectively. The average follow-up was 7.25 ± 4.6 years. There was a statistically significant difference in revision rate between ON and OA patients in favour of OA (OR: 1.576; 95%CI: 1.24-2.00; p-value: 0.0015). However, dislocation rate (OR: 1.5004; 95%CI: 0.92-2.43; p-value: 0.0916) and Haris hip score (HHS) (SMD: - 0.0486; 95%CI: - 0.35-0.25; p-value: 0.6987) were comparable across both groups. Further sub-analysis adjusting for registry data also showed similar results between both groups.

CONCLUSION

A higher revision rate, periprosthetic fracture and periprosthetic joint infection following total hip arthroplasty were associated with osteonecrosis of the femoral head compared with osteoarthritis. However, both groups had similar dislocation rates and functional outcome measures. This finding should be applied in context due to potential confounding factors, including patient's age and activity level.

Comprehensive analysis of femoral head necrosis based on machine learning and bioinformatics analysis

Osteonecrosis of the femoral head (ONFH) is a kind of disabling disease, given that the molecular mechanism of ONFH has not been elucidated, it is of significance to use bioinformatics analysis to understand the disease mechanism of ONFH and discover biomarkers. Gene set for ONFH GSE74089 was downloaded in the Gene Expression Omnibus, and "limma" package in R software was used to identify differentially expressed genes related to oxidative stress. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyze were performed for functional analysis. We constructed a protein interaction network and identified potential transcription factors and therapeutic drugs for the hub genes, and delineated the TF-hub genes network. Least absolute shrinkage and selection operator regression, support vector machine and cytoHubba were used to screen feature genes and key genes, which were validated by Receiver operating characteristic. CIBERSORT was used to explored the immune microenvironment. Subsequently, we identified the function of key genes using Gene set variation analysis and their relationship with each type of immune cell. Finally, molecular docking validated the binding association between molecules and validated genes. We detected 144 differentially expressed oxidative stress-related genes, and enrichment analysis showed that they were enriched in reactive oxygen species and AGE-RAGE signaling pathway. Protein-protein interaction and TF-hub genes network were conducted. Further exploration suggested that APOD and TMEM161A were feature genes, while TNF, NOS3 and CASP3 were key genes. Receiver operating characteristic analysis showed that APOD, CASP3, NOS3, and TNF have strong diagnostic ability. The key genes were enriched in oxidative phosphorylation. CIBERSORT analysis showed that 17 types immune cells were differentially relocated, and most of which were also closely related to key genes. In addition, genistein maybe potential therapeutic compound. In all, we identified that TNF, NOS3, and CASP3 played key roles on ONFH, and APOD, CASP3, NOS3, and TNF could serve as diagnostic biomarkers.

Prognostic factors in the management of osteonecrosis of the femoral head: A systematic review

BACKGROUND

Several hip preserving techniques have been described for the management of osteonecrosis of the femoral head (ONFH). This systematic review identified prognostic factors in the treatment of ONFH that are associated with treatment failure and conversion to total hip arthroplasty (THA).

MATERIAL AND METHODS

This study followed the PRISMA guidelines. The literature search was conducted in November 2021. All clinical trials comparing two or more treatments for femoral head osteonecrosis were accessed. A multivariate analysis was performed to investigate the association between baseline characteristics and the surgical outcome. A multiple linear model regression analysis through the Pearson Product-Moment Correlation Coefficient (r) was used.

RESULTS

Data from 88 articles (6112 procedures) were retrieved. Female gender was associated with increased time to THA (P = 0.03) and reduced rate of THA (P = 0.03). Longer symptom duration before treatment was associated with shorter time to failure (P = 0.03). Increased pre-treatment VAS was associated with reduced time to failure (P = 0.03) and time to THA (P = 0.04). Reduced pre-treatment hip function was associated with increased rate of THA (P = 0.02) and failure (P = 0.005). Patient age and BMI, aetiology, time from surgery to full weight bearing and the side did not show evidence of a statistically significant association with the surgical outcome.

CONCLUSION

Male gender, longer symptom duration before treatment, higher VAS scores, and lower HHS scores were negative prognostic factors after treatment for osteonecrosis of the femoral head.

Outcomes of total hip arthroplasty after failed free vascularized fibular grafting for osteonecrosis of the femoral head

PURPOSE

Total hip arthroplasty (THA) after vascularized fibular grafting (VFG) is technically demanding with poorer outcomes compared to primary THA in patients with osteonecrosis of the femoral head (ONFH). The purpose of this study was to compare the outcomes of THA after VFG after removal of the graft with that of primary THA.

METHODS

ONFH patients treated by VFG at a single institution were studied retrospectively. THAs after VFG performed by single arthroplasty surgeon with a single type of THA prosthesis were enrolled in the study. A control cohort of patients was created by 1:1 matching with the THA after VFG cohort according to age, gender, and American Society of Anesthesiology (ASA) score from ONFH patients treated by primary THA. Early and long-term outcomes were compared between the two groups.

RESULTS

A total of 24 hips were included in the THA after VFG group and compared with 24 primary THA hips. No significant difference was noted in stem position. The THA after VFG group had increased blood loss and longer duration of operation time. There were two cases of intraoperative femur fractures in the THA after VFG group. The femoral stem of both groups were stable, with no cases of revision, and similar HHS scores at the last follow-up.

CONCLUSION

THA after VFG may have similar short to midterm outcomes with primary THA after removal of the residual abutting bone graft and correct positioning of the femoral stem.

Total Hip Arthroplasty via direct anterior approach for osteonecrosis; comparison with primary hip osteoarthritis in a mid term follow up

Background

To determine the mid-term outcomes of conventional cementless Total Hip Arthroplasty (THA) in patients with avascular necrosis (AVN) of the femoral head and compare to patients with primary hip osteoarthritis (OA).

Method

A total of 330 consecutive primary THA procedures (AVN and OA) performed between 2010 and 2013 by a single surgeon and in a single center using the direct anterior approach (DAA) were included. Assessments including SF-36, WOMAC, and Harris Hip Scores (HHS) were retrieved from patients before the surgery and at the latest follow-up. Clinical and functional outcomes were compared between the AVN and OA groups.

Results

A total of 294 consecutive THA (AVN = 107, OA = 187) with 104.4 ± 6.2 months follow-up were analyzed, which AVN patients were significantly younger (32.0 vs. 59.6 y/o). Corticosteroid 34 (31.8%), idiopathic AVN 31 (29.0%) and use of unapproved weight gain supplements (UWGS) 23 (21.5%) were the main reasons for AVN. Despite that preoperative scores were comparable (P > 0.05), the HHS, SF-36, and WOMAC scores are significantly higher in the AVN group after THA surgery (P < 0.05). Moreover, flexion and abduction ROM were significantly higher in the AVN group (P < 0.05). Regarding each complication, no significant difference was observed between groups. In the whole sample, there were 5 (1.7%) revisions due to loosening of acetabular components, all the OA group (P > 0.05).

Conclusion

Conventional cementless THA with highly cross-linked polyethylene provides satisfactory mid-term results in patients with AVN with a low rate of postoperative complications. Compared to primary OA patients, this group reaches superior postoperative scores.

LINC00473-modified bone marrow mesenchymal stem cells incorporated thermosensitive PLGA hydrogel transplantation for steroid-induced osteonecrosis of femoral head: A detailed mechanistic study and validity evaluation

The pathogenesis of steroid-induced osteonecrosis of the femoral head (SONFH) involves a glucocorticoid-induced imbalance of osteogenic and adipogenic differentiation, and apoptosis of bone marrow mesenchymal stem cells (BMSCs). An increasing number of genes, especially noncoding RNAs, have been implicated in the function of BMSCs. Our previous studies have confirmed the key role of LINC00473 and miR-23a-3p on the osteogenic, adipogenic differentiation, and apoptosis of BMSCs. However, the underlying mechanism of this process is still unclear. Based on bioinformatics analysis, here we investigated the effects of LINC00473 on the LRP5/Wnt/β-catenin signaling pathway in the osteogenesis and adipogenesis of BMSCs, as well as the PEBP1/Akt/Bad/Bcl-2 signaling pathway in dexamethasone- (Dex-) induced apoptosis of BMSCs. Our data showed that LINC00473 could promote osteogenesis and suppress the adipogenesis of BMSCs through the activation of the miR-23a-3p/LRP5/Wnt/β-catenin signaling pathway axis, while rescuing BMSCs from Dex-induced apoptosis by activating the miR-23a-3p/PEBP1/Akt/Bad/Bcl-2 signaling pathway axis. Notably, we observed that LINC00473 interacted with miR-23a-3p in an Argonaute 2 (AGO2)-dependent manner based on dual-luciferase reporter assay, AGO2-related RNA immunoprecipitation, and RNA antisense purification assay. Furthermore, injectable thermosensitive polylactic-co-glycolic acid (PLGA) hydrogel loaded with rat-derived BMSCs (rBMSCs) modified by LINC00473 were used for the treatment of SONFH in a rat model. Our results demonstrated that PLGA hydrogels provided a suitable environment for harboring rBMSCs. Besides, transplantation of PLGA hydrogels loaded with rBMSCs modified by LINC00473 could significantly promote the bone repair and reconstruction of the necrotic area at the femoral head in our SONFH rat model. Surprisingly, compared with the transplantation of BMSCs alone, the transplanted rBMSCs encapsulated within the PLGA hydrogel could migrate from the medullary cavity to the femoral head. In summary, LINC00473 promoted osteogenesis, inhibited adipogenesis, and antagonized Dex-induced apoptosis of BMSCs. Therefore, LINC00473 could provide a new strategy for the treatment of SONFH.

Comparison Between Concentrated Autologous Bone Marrow Aspirate Transplantation as a Hip Preserving Surgery and Natural Course in Idiopathic Osteonecrosis of the Femoral Head

Purpose The purpose is to compare the therapeutic efficacy of concentrated autologous bone marrow aspirate transplantation (CABMAT) with that of observation alone for osteonecrosis of the femoral head (ONFH). Methods This single-center study included patients with idiopathic ONFH that were either treated with CABMAT (CABMAT group) or managed through observation alone (observation group) over a >2-year follow-up period. The Japanese Investigation Committee classification was used to diagnose and classify ONFH. The collapse rates for stages 1 and 2 ONFH (i.e., pre-collapse stages) and the THA conversion rates were compared between the CABMAT and observation groups. Results The CABMAT and observation groups comprised 232 (mean follow-up: 8.2 years) and 106 (mean follow-up: 6.0 years) patients, respectively. No significant intergroup differences were noted in the stages, types, and associated factors of ONFH. The collapse rates for pre-collapse stages in the CABMAT and observation groups were 67.1% and 65.3%, respectively. For stage 1, the collapse rates were significantly lower in the observation group than in the CABMAT group (p<0.05). The overall THA conversion rates in the CABMAT and observation groups were 24.3% and 41.5%, respectively (p<0.0001). For ONFH of stages 3A and 3B (collapse stages), the THA conversion rates were significantly lower in the CABMAT group (p<0.05). Conclusion Collapse rates were significantly higher for stage 1 ONFH; for collapse stages, the THA conversion rates were significantly lower in the CABMAT group than in the observation group. Therefore, observation and CABMAT are recommended for ONFH of stage 1 and for ONFH of higher stages, respectively.

Alumina ceramic-on-ceramic hybrid total hip arthroplasty. A median of 15 years follow-up

INTRODUCTION

The optimum choice of bearing surfaces in total hip replacement (THR) in the younger and active patient remains controversial. The aim of this study was to report the 10 year clinical outcomes, and a median of 15 year implant survival and incidence of complications in a series of Alumina ceramic-on-ceramic THRs utilising an uncemented shell and cemented stem.

METHODS

From January 2004 to December 2007, 175 consecutive patients (195 hips) underwent primary THR. The acetabular components was Trident Peripheral Self Locking (Stryker Orthopaedics) with a third-generation ceramic head and liner (Alumina ceramic, Stryker Orthopaedics). The stem utilised was an Exeter V-40 (Stryker Orthopaedics). Data were collated on demographics, surgical factors, clinical outcomes, radiographic outcomes and revision.

RESULTS

23 patients (27 THRs) died during the follow-up period at a median of 7.8 (3.8 to 9.0) years post-operatively due to causes unrelated to the THR. Median age at time of surgery was 55 (interquartile range 48-60) years. Median follow-up for surviving patients was 15.2 years. Survivorship for all-cause revision was 97.2%. Increasing patient age at time of surgery was associated with a higher OHS at 10 years (p = 0.022). 32 mm head diameter had an improved OHS at 3 months (p = 0.014) and 10 years (p = 0.030). Posterior surgical approach had a statistically significant better OHS at 3 months (p = 0.015) and 1 year (p < 0.001), but the effect was not significant at 10 years (p = 0.440).

CONCLUSION

The findings of this study support excellent long-term outcomes and survivorship of Alumina ceramic-on-ceramic bearing in a hybrid THR in a younger population. Surgical factors leading to a more favourable outcome were the use of a 32 mm femoral head and a posterior approach. Increasing age at surgery demonstrated the most sustained improvement in 10 year clinical outcomes.

Stem cell therapy for osteonecrosis of femoral head: Opportunities and challenges

Osteonecrosis of the femoral head (ONFH) is a progressive disease with a complex etiology and unclear pathogenesis, resulting in severe hip pain and dysfunction mainly observed in young patients. Although total hip arthroplasty (THA) is the most effective treatment for patients with ONFH in the terminal stage, the results of THA in young patients or active populations are often not favorable, with some complications related to the prosthesis. With the development of biotechnology, an increasing number of studies pay attention to use of stem cells for the treatment of ONFH. Stem cells are characterized by the ability to self-renew and differentiate into multiple cell types, including differentiation into osteoblasts and endothelial cells to mediate bone repair and angiogenesis. Furthermore, stem cells can offer growth factors to promote blood supply in the necrotic regions by paracrine effects. Therefore, stem cell therapy has become one of the hip-preserving alternatives for ONFH. This review summarized the current trends in stem cell therapy for ONFH, from clinical applications to related basic research, and showed that an increasing number of studies have confirmed the effectiveness of stem cell therapy in ONFH. However, many unsolved problems and challenges in practical applications of stem cell therapy still exist, such as patient selection, standardized procedures, safety assessment, and the fate of transplanted cells in the body. Additional studies are required to find ideal cell sources, appropriate transplantation methods, and the optimal number of cells for transplantation.

•

Diversities in repair processes present a challenge in the targeted treatment of ONFH.

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Osteogenesis and angiogenesis are the primary mechanisms of MSCs treatment in ONFH.

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Systematic safety assessment and cell tracing are necessary for stem cell therapy.

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Optimal numbers and methods of cell transplantation need to be further confirmed.

Hip survival rate in the patients with avascular necrosis of femoral head after transtrochanteric rotational osteotomy: a systematic review and meta-analysis

Supplemental Digital Content is available in the text

Background:

The clinical outcome of transtrochanteric rotational osteotomy (TRO) for osteonecrosis of the femoral head (ONFH) remains controversial, and the promising clinical results of several Japanese studies could not be reproduced in American and European studies. Trying to solve controversies on TRO for ONFH rising from apparently conflicting studies, a meta-analysis was conducted to assess the 5- and 10-year hip survival rates (with conversion to artificial joint replacement and radiographic failure as endpoints) after TRO.

Methods:

All eligible studies were searched in seven comprehensive databases including PubMed, Web of Science, Embase, Cochrane Library, VIP Database, China Knowledge Resource Integrated Database, and Wan Fang Database prior to June 2019. The outcomes evaluated were 5- and 10-year hip survival rates after TRO. The odds ratio and risk difference for the non-comparative binary data with the 95% confidence intervals (CIs) were calculated for each outcome. The included studies were assessed for methodologic bias and potential reasons for heterogeneity were explored.

Results:

Nineteen studies of TRO for ONFH were eligible for this meta-analysis according to inclusion criteria. Based on the previous report, two calculation methods (Methods 1 and 2) were adopted in this meta-analysis. Furthermore, we performed a sub-group analysis of the 5- and 10-year hip survival rates (Method 1) after TRO for ONFH: Asian sub-population and non-Asian sub-population. Taking conversion to artificial joint replacement as the endpoint, 5- and 10-year hip survival rates (Method 1) after TRO for ONFH in the Asian population were 0.86 (95% CI = 0.82–0.89) and 0.72 (95% CI = 0.65–0.78), respectively, and 5- and 10-year hip survival rates after TRO for ONFH in the non-Asian population were 0.55 (95% CI = 0.43–0.67) and 0.42 (95% CI = 0.28–0.55), respectively. The 5- and 10-year hip survival rates (Method 2) after TRO for ONFH were 0.90 (95% CI = 0.79–0.95) and 0.89 (95% CI = 0.81–0.94), respectively. Taking radiographic failure as the endpoint, 5- and 10-year hip survival rates after TRO for ONFH were 0.70 (95% CI = 0.64–0.76) and 0.53 (95% CI = 0.46–0.61), respectively.

Conclusions:

The 5- and 10-year hip survival rates after TRO for ONFH were satisfactory in the Asian population, and were acceptable in the non-Asian population despite high early failure rates.

Curved Intertrochanteric Varus Osteotomy vs Total Hip Arthroplasty for Osteonecrosis of the Femoral Head in Patients Under 50 Years Old

BACKGROUND

Given recent advances in total hip arthroplasty (THA), curved intertrochanteric varus osteotomy (CVO) is not indicated as a treatment for osteonecrosis of the femoral head (ONFH), unless indicated to maintain long-term hip function and achieve patient satisfaction. We aimed to compare the clinical outcomes of CVO with those of THA for treatment of ONFH in young adults <50 years old.

METHODS

This comparative study included 105 ONFH patients: 59 patients (65 hips) who underwent CVO and 46 patients (56 hips) who underwent THA. Assessment tools included the Harris hip score (HHS), patient-reported outcomes of the Short Form-36, Oxford hip score, Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire, and University of California, Los Angeles score, together with complication and survival rates.

RESULTS

Preoperative HHS was significantly higher in the CVO group than in the THA group (P < .01). At the last follow-up, no between-group differences were noted in HHS, all domains of Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire scores, Oxford hip score, and Short Form-36. University of California, Los Angeles scores and complication rates were comparable: 3% for the CVO and 7% for the THA group. The 10-year survival rate with surgery for any reason as the end point was comparable, at 91.8% for the CVO and 97.7% for the THA group.

CONCLUSION

Functional outcomes, survival rate, and sporting activities for patients <50 years old undergoing CVO or THA for ONFH were comparable after a mean follow-up period of 10 years. Strict indications for CVO can help maintain hip function and patient satisfaction equivalent to that for THA, in the long term.

[Total hip replacement in avascular femoral head necrosis]

BACKGROUND

Avascular necrosis of the femoral head is a progressive perfusion disorder of the hip joint. Progress in avascular necrosis causes structural damage to the affected joint, often requiring total hip replacement.

AIM

This article is intended to give the reader an overview of the current literature on total hip replacement of patients with an avascular necrosis of the femoral head.

RESULTS

Before 1990, patients with avascular necrosis of the femoral head had significantly higher revision rates after total hip replacement. Recent studies, however, showed no significant differences in clinical outcomes after total hip replacement in femoral head necrosis and primary osteoarthritis. Despite the young age of the patients, good long-term clinical results can be expected even in patients with an avascular necrosis of the femoral head after total hip replacement.

Outcomes of Conversion Total Hip Arthroplasty From Free Vascularized Fibular Grafting

BACKGROUND

Conversion total hip arthroplasties (THAs) from prior free vascularized fibular grafting (FVFG) are infrequently reported in the literature. We characterized the perioperative outcomes of patients undergoing conversion THA and compared them with those of a matched cohort of patients undergoing primary THA for osteonecrosis of the femoral head and neck (ONFHN).

METHODS

The institutional database was queried for patients with FVFG requiring conversion to THA. This cohort was then matched 1:1 for age, gender, and American Society of Anesthesiologists (ASA) score for patients with ONFHN undergoing primary THA. Medical records were reviewed for intraoperative and postoperative complications, which were then compared between conversion and primary THA patient cohorts.

RESULTS

Two hundred eighty-eight THA patients were included for analysis (144 patients with FVFG matched to 144 patients with ONFHN and no prior FVFG). Patients with prior FVFG who underwent THA had significantly greater operative time and blood loss (P < .001). Although not significant, there were more intraoperative fractures in the FVFG cohort (P = .053). Postoperatively, patients with FVFG had significantly greater blood transfusions (P < .001) and hematoma formation (P = .004) than the matched cohort. There was no difference in length of stay, discharge disposition, or venous thromboembolism; however, patients who underwent conversion THA showed increased deep infection (P = .044) and rate of return to the operating room (P = .010).

CONCLUSION

Although there are numerous treatment strategies for patients with ONFHN, many patients will ultimately require THA. Patients undergoing conversion after FVFG are more likely to have complications including increased blood loss, hematoma formation, and intraoperative fractures. Consequently, surgeons should concentrate on preoperative optimization and prepare for specific technical challenges.

Total hip arthroplasty after failed transtrochanteric rotational osteotomy for osteonecrosis of the femoral head: A systematic review and meta-analysis

BACKGROUND

Several studies have reported regarding total hip arthroplasty (THA) for osteonecrosis of the femoral head after failed transtrochanteric rotational osteotomy (TRO). However, to our knowledge, no formal systematic review and meta-analysis have been published yet summarizing the clinical results of a THA after failed TRO. Therefore, we conducted a systematic review and meta-analysis of the THA outcomes after failed TRO. We focussed on the issue whether a previous TRO affects the results of subsequent THA, including operative time, operative blood loss, radiological parameters, postoperative complications, and clinical outcomes.

METHODS

Literatures published up to January 2018 were searched in the PubMed, Web of Science, and Cochrane Library, and the pooling of data was performed using a RevMan software (version 5.3, Cochrane Collaboration, Oxford, UK). A p-value<0.05 was considered statistically significant. We calculated the mean differences (MD) for continuous data and the odds ratio (OR) for dichotomous data with 95% confidence intervals (CI) for each outcome. Statistical heterogeneity was assessed based on I² using the standard Chi². When I²>50%, significant heterogeneity was assumed, and a random-effects model was applied for the meta-analysis. A fixed-effects model was applied in the absence of significant heterogeneity.

RESULTS

Five studies were included in this meta-analysis. The results showed that operative time was significantly longer in the THA after the TRO than that for the THA without previous osteotomy (I²=92%; MD=31.62; 95% CI: 5.95 to 57.28; p=0.02). Operative blood loss was significantly greater in the THA after the TRO than that in the THA without previous osteotomy (I²=71%; MD=123.30; 95% CI: 22.21 to 224.39; p=0.02). The rate of stem malalignment was significantly higher in the THA after the TRO than that in the THA without previous osteotomy (I²=0%; OR=5.23, 95% CI: 1.95 to 14.06; p=0.001). There was no significant difference in the dislocation rate (I²=0%; OR=2.12; 95% CI: 0.64 to 6.99; p=0.22), and the postoperative Harris hip score at the final follow-up (I²=75%, MD=-0.46, 95% CI: -3.92 to 3.01, p=0.80) between the groups.

CONCLUSION

The results demonstrate that, performing the THA after the TRO is technically more demanding than the THA without previous osteotomy. TRO does not affect the clinical results of future THA, and is a sufficient therapeutic alternative in younger patients.

LEVEL OF EVIDENCE

III, systematic and meta-analysis of case control studies.

Cementless total hip arthroplasty for osteonecrosis and osteoarthritis produce similar results at ten years follow-up when matched for age and gender

PURPOSE

The aim of this study was to compare the clinical outcomes of cementless total hip arthroplasty (THA) used for the treatment of osteonecrosis of the femoral head (ONFH) and for osteoarthritis (OA) at a mean ten years follow-up.

METHODS

Case-control study of 78 patients (86 hips) who underwent THA for ONFH treatment (ONFH group). Patients were matched for age and sex to 78 patients (86 hips) who underwent THA for OA (OA group). We compared the clinical and patient-reported outcomes, implant survival rates, and rates of complications between the groups.

RESULTS

There were no between-group differences in the Harris Hip Score and in the following patient-reported outcomes at the last follow-up: Japanese Orthopedic Association Hip-Disease Evaluation Questionnaire (JHEQ) pain and movement scores and the Physical Component Summary and Role/Social Component Summary scores of Short Form-36 (SF-36). However, the mental score of the JHEQ, the Mental Component Summary score of SF-36, and The Visual Analog Scale score for satisfaction were lower for the ONFH group than for OA group. The rate of complication was equivalent between the groups: 5% for the ONFH group and 3% for the OA group. The ten year implant survival rate was equivalent between the groups, at 97.5% for the ONFH group and 98.2% for the OA group.

CONCLUSION

The functional outcomes, implant survival, and rate of complications for cementless THAs are comparable at a mean follow-up of ten years for ONFH and OA.

Bone-preserving total hip arthroplasty in avascular necrosis of the hip-a matched-pairs analysis

PURPOSE

Short-stem hip arthroplasty has the potential advantage of femoral bone stock preservation, especially in view of the expected revisions in the often relatively young patients. Despite short-stem hip prosthesis are increasingly used for total hip arthroplasty, there are no sufficient mid- and long-term results especially for patients with avascular femoral head osteonecrosis. The present study investigates mid-term functional results as well as the revision rate following implantation of a short-stem prosthesis.

METHODS

In the period 06/2005 until 12/2013, a total of 351 short-stem hip prostheses were implanted. The study included 331 complete data sets. A retrospective analysis was performed using the Oxford Hip Score. All revisions were registered.

RESULTS

In a total of 331 prostheses, the Oxford Hip Score was "excellent" in 66.2%, "good" in 12.7%, "fair" in 13.0%, and "poor" in 8.2% with a mean follow-up of 57.4 months (SD ± 29.8; range 24-115). In 26 cases, aseptic osteonecrosis of the hip was the indication (7.9%). The Oxford Hip Score was "excellent" in 66.7%, "good" in 0.0%, "fair" in 20.8%, and "poor" in 12.5%. The cumulated five year survival rate was 96.7%.

CONCLUSION

In mid-term observation, the Metha® short-stem prosthesis shows no disadvantage in functional outcome and in survival time compared to a standard hip stem. Providing a correct indication, the Metha® short stem is a valuable option in total hip arthroplasty for younger patients with avascular osteonecrosis of the femoral head. Evaluation has shown no significant differences between aseptic osteonecrosis and other indications.

The Results of Total Hip Arthroplasty After Sugioka Transtrochanteric Anterior Rotational Osteotomy for Osteonecrosis

BACKGROUND

Since Sugioka transtrochanteric anterior rotational osteotomy (ARO) for osteonecrosis of the femoral head (ONFH) changes the morphology of the proximal femur, total hip arthroplasty (THA) after previous ARO is considered a technically demanding procedure. The purpose of this study was to compare the clinicoradiologic outcomes of THA after ARO with those of THA without any antecedent surgery for ONFH.

METHODS

Twenty-four hips in 20 patients who underwent cementless THA after ARO (postosteotomy group) were retrospectively reviewed and compared with patients who underwent cementless THA without any antecedent surgery for ONFH during the same period (primary group). In the postosteotomy group, the mean duration from ARO to THA was 19.7 years. All patients were followed for at least 5 years (mean, 8.3 years; follow-up rate, 78.5%). A clinical assessment was performed preoperatively and at the latest follow-up using the Harris Hip Score. A radiographic examination was performed at 3 months after THA and at the latest follow-up.

RESULTS

The Harris Hip Score at the latest follow-up in the postosteotomy group was equivalent to that in the primary group, but longer operation time and greater intraoperative blood loss were observed in the postosteotomy group. There were no significant differences in postoperative complications, including dislocation (2 hips in each group). The leg lengthening in the postosteotomy group tended to be longer. No hips showed implant malpositioning, loosening, or required any revision surgery.

CONCLUSION

The clinicoradiologic outcomes of THA after ARO are considered to be comparable with those of THA without any antecedent surgery for ONFH.

Hip resurfacing for osteonecrosis

Aims

Hip resurfacing arthroplasty (HRA) is an alternative to conventional total hip arthroplasty for patients with osteonecrosis (ON) of the femoral head. Our aim was to report the long-term outcome of HRA, which is not currently known.

Patients and Methods

Long-term survivorship, clinical scores and radiographic results for 82 patients (99 hips) treated with HRA for ON over a period of 18 years were reviewed retrospectively. The mean age of the 67 men and 15 women at the time of surgery was 40.8 years (14 to 64). Patients were resurfaced regardless of the size of the osteonecrotic lesion.

Results

The mean clinical follow-up was 10.8 years (2 to 18). The mean University of California, Los Angeles hip scores at the last follow-up were 9.3, 9.4, 9.2 and 6.8 for pain, walking, function and activity, respectively. A total of six hips underwent revision surgery, four for loosening of the femoral component and two for loosening of the acetabular component. Using any revision as an end point, the 15-year Kaplan-Meier survivorship was 90.3%. There were no wear-related failures. There were no femoral failures among the hips reconstructed with a cemented metaphyseal stem. A total of five hips showed narrowing of the femoral neck; all stabilised and remain asymptomatic, 21 showed signs of femoral neck impingement.

Conclusion

To our knowledge, this is the first report of a series of HRA performed for ON with 15-year survivorship. Our data confirm that patients with advanced stages of ON of the femoral head are excellent candidates for HRA. Cite this article: Bone Joint J 2016;98-B:901–9.

Migration pattern of a cobalt-chrome monoblock acetabular component after metal-on-metal hip resurfacing

OBJECTIVES

The purpose of this study was to study the initial fixation and migration pattern of a monoblock acetabular component used for a metal on metal hip resurfacing using Einzel Bild Roentgen Analyse (EBRA).

METHODS

99 patients with a mean age of 49.6 years (range 28.5-66.3 years) of whom 14 were bilateral underwent a hip resurfacing (Conserve Plus®, MicroPort, Memphis, TN) for a total of 113 resurfacings. Acetabular component orientation was noted with 35 of the 113 components (31.0%) having a lucency &gt;2 mm on the immediate postoperative radiograph.

RESULTS

The mean follow-up for our cohort of 113 hips is 50 months (2-79 months). When examining the 2-year migration mark, 37 of the 113 hips exceeded the threshold of 0.5 mm/year with a median total migration of 1.40 mm (range 1.02-4.24). 6 resurfacings underwent revision surgery for aseptic loosening of the acetabular component at a mean time of 43.6 months. Presence of initial lucency (OR 2.29, p = 0.05) was the only significant predictor of migration over threshold at 2-years. Those that had migrated over the threshold (1.0 mm) at 2 years were at significantly greater risk of continued migration at 4 years.

CONCLUSIONS

The migration pattern of this component raises concerns about long term performance, with postoperative lucencies representing a significant factor for future migration.

Decreased femoral periprosthetic bone mineral density: a comparative study using DXA in patients after cementless total hip arthroplasty with osteonecrosis of the femoral head versus primary osteoarthritis

INTRODUCTION

Trabecular properties in osteonecrosis of the femoral head (ONFH) are altered for bone volume and structure in the femoral head and proximal femoral canal. We analysed the periprosthetic bone mineral density (BMD) as a correlate to bony ingrowth in patients with ONFH who received a cementless THA.

MATERIALS AND METHODS

We performed a matched-pair analysis of 100 patients with ONFH (n = 50) and primary osteoarthritis (n = 50) who received the same, unilateral cementless THA. We compared the periprosthetic BMD 5 years after surgery by means of dual energy X-ray absorptiometry (DXA) analysing the seven femoral regions of interest (ROIs) according to Gruen.

RESULTS

Within the ONFH group, significantly lower BMD values were found in the ROI 1 and 7 (p < 0.05). No statistically significant difference was found for ROIs 2-6.

CONCLUSIONS

An altered periprosthetic bone stock in the proximal femur in patients with prior ONFH might be a possible risk factor for premature loosening of the femoral stem in THA. Surgeons need to consider coating and fixation philosophy of cementless implants when choosing the right stem for patients with ONFH.

Does osteonecrosis of the femoral head increase surgical and medical complication rates after total hip arthroplasty? A comprehensive analysis in the United States

Total hip arthroplasty (THA) is a definitive option for end-stage osteonecrosis of the femoral head (ONFH). Historically, higher revision rates were observed in this population compared to THA for osteoarthritis (OA). This study provides a comprehensive evaluation of postoperative medical and surgical complications comparing THA in ONFH and OA at 90 days, 1 year, and 2 years after surgery. The PearlDiver database identified 45,002 OA and 8,429 ONFH patients who underwent THA. Mechanical complications (prosthetic loosening and osteolysis, implant failure), dislocation, renal and respiratory complications were significantly increased in the ONFH group within 2 years after THA. Pulmonary embolism rates where increased in younger ONFH patients within 2 years after THA. This data helps clinicians in the postoperative risk assessment of patients with ONFH.

S3-Guideline non-traumatic adult femoral head necrosis

INTRODUCTION

The treatment of adult non-traumatic avascular necrosis of the femoral head (AVN; N-ANFH) within an estimated incidence of 5000-7000 cases per annum in Germany remains a challenge. Risk factors include steroids, alcohol abuse, chemotherapy and immunosuppressive medication, but a genetic predisposition has been suggested. Early diagnosis of this often bilateral disease process is essential for successful conservative or joint preserving surgical management. In this review, we present the update German consensus S3 guideline "diagnosis and management for N-ANFH" as a concise summary.

MATERIALS AND METHODS

This systematic review is based on the published literature from January 1, 1970 to April 31, 2013 (German and English language). Inclusion criteria were systematic reviews, meta-analyses and relevant peer review publications. We identified a total of 3715 related publications, of which 422 were suitable according to the SIGN criteria, but only 159 fulfilled our inclusion criteria.

RESULTS AND CONCLUSIONS

Clinical suspicion of N-ANFH mandates radiographic evaluation. If radiographs are normal MRI scans are recommended, which should be evaluated according to the ARCO-classification. Differential diagnoses include transient osteoporosis, bone bruise, insufficiency fracture and destructive arthropathy. Untreated, subchondral fractures commonly occur within 2 years, during which the risk for contralateral involvement is high-thereafter unlikely. Conservative management with Ilomedin and Alendronat can be tried, but other pharmacological or physical treatments are inappropriate. No specific joint preserving procedure can be recommended, but core decompression should be considered in early stages if necrosis is <30 %. In ARCO stages IIIc or IV total hip arthroplasty (THA) should be contemplated, which offers similar outcome compared to osteoarthritis. Young age is the main risk factor for higher revision rates after THA for N-ANFH.

Difference in periprosthetic acetabular bone mineral density: Prior total hip arthroplasty: Osteonecrosis of the femoral head versus primary osteoarthritis

BACKGROUND

Total hip arthroplasty (THA) could be associated with a higher failure rate in patients after osteonecrosis of the femoral head (ONFH) compared to a patient population with primary osteoarthritis prior THA, especially regarding the acetabular component. One major reason could be the compromised acetabular bone quality. Therefore, we performed a retrospective case matched study to assess: 1) Is there a difference in periprosthetic bone mineral density between patients with an ONFH prior THA and controls? 2) Do patients with an ONFH prior THA have a lower bone mineral density compared to controls? 3) Which region in the periprosthetic bone stock is more likely to present differences in periprosthetic bone mineral density between both groups?

HYPOTHESIS

We hypothesized that there is a poorer bone mineral density (BMD) in the periacetabular bone stock in patients with an ONFH prior THA compared to controls receiving a THA due to primary osteoarthritis.

PATIENTS AND METHODS

We compared the BMD of 50 patients with ONFH to 50 controls with primary osteoarthritis prior THA using the same implant in mean 5 years after surgery by means of dual energy X-ray absorptiometry (DXA). We analysed 3 acetabular ROIs according to DeLee and Charnley in a modified measurement technique.

RESULTS

In ROI 3, representing acetabulum's upper aspect, statistically significant lower BMD values for the ONFH group could be found (P < 0.05). No difference was found for the modified ROIs 1 and 2 (respectively medial and lower acetabulum).

DISCUSSION

The results indicate a poorer periacetabular BMD in patients with ONFH prior THA, which might be responsible for premature loosening of the acetabular cup in THA. Due to a lack of literature, further clinical investigations are required to confirm our results.

LEVEL OF EVIDENCE

III: retrospective case-control study.

Treatment of osteonecrosis of the femoral head with focal anatomic-resurfacing implantation (HemiCAP): preliminary results of an alternative option

Background

The optimal treatment of osteonecrosis of the femoral head has not been established yet. The aim of this study was to report preliminary clinical results of focal anatomic-resurfacing implantation for the treatment of osteonecrosis of the femoral head.

Methods

Five patients (four male, one female) with seven surgical procedures, ages between 37 and 52 with an average age of 45.2 (+/− 7.2), diagnosed as femoral head avascular necrosis and who were unresponsive to conservative management or had failed previous surgical treatments were treated with a focal anatomic femoral head resurfacing between the years 2011–2012 and were retrospectively reviewed. Five patients with at least two years of follow-up, one left hip, two right hips, and two patients with bilateral hip surgery were included in this review. After safe surgical dislocation of the hip, full exposure of the femoral head was established. A focal-resurfacing implant matching patient anatomy and femoral head curvature was performed accordingly. Neither intraoperative or postoperative complications nor revision ensued. Visual analogue scores and Harris Hip Scores were recorded both preoperatively and at postoperative 2 years for all seven surgeries.

Results

The mean follow-up period was 26.6 +/− 3.8 months, with a range between 24–33 months. The mean visual analogue scores were 8.9 +/− 0.9 preoperatively and 2.3 +/− 1.0 postoperatively at year two (p = 0.017). Harris Hip Scores at postoperative follow-up were found to improve significantly from good to excellent scores (86.0 +/− 7.9), compared with preoperative poor scores (26.7 +/− 11.8) (p = 0.018). The clinical improvements in visual analogue scores (VAS) and Harris Hip Scores were also found to correlate with each other (p < 0.05).

Conclusions

In the present study, the alternative technique of focal anatomic hip resurfacing with HemiCAP® yielded preliminary successful results for the treatment of osteonecrosis of the femoral head. To the best of our knowledge, this is the first case series in the literature, reporting functional clinical results with the use of a focal anatomic-resurfacing implant for the treatment of focal femoral head osteonecrosis.

Early repair of necrotic lesion of the femoral head after high-degree posterior rotational osteotomy in young patients-a study evaluated by volume measurement using magnetic resonance imaging

We investigated the repair of femoral head necrosis with extensive necrotic lesions treated by high-degree posterior rotational osteotomy (HDPRO) in young adults and adolescents (mean age; 30.8 years) using magnetic resonance imaging (MRI). HDPRO was performed on 72 hips from 66 cases, and of those, 60 hips from 60 cases were included in this study for data analysis. All cases had extensive collapsed lesion preoperative anteroposterior radiographs. In total, 34 hips were male and 26 were females. In total, 19 had a history of steroid administration, 11 had a previous femoral neck fracture, 7 had no particular etiologic factor, and 4 had a followed slipped capital femoral epiphysis. Antero-inferior viable areas were transferred to the loaded portion below the acetabular roof by this operation. The mean posterior rotational angle was 118.5°. MRI was taken after 1 month, 6 months and 1-year post-operatively. Post-operative necrotic lesion volume compared with the preoperative necrotic lesion volume was defined as lesion volume ratio (%). The reduction of necrotic volume was observed over time, and at 1 year post-operatively, it was 19.4% for patients in their teens, 35.3% for those in twenties, 42.8% for those in their thirties and 59.5% for those in their forties. From this study, we concluded that the extensive necrotic lesions decreased in size within a short period after HDPRO in young patients.

Total Hip Arthroplasty in Patient with the Sequelae of Legg-Calvé-Perthes Disease

Purpose

Patients who have secondary hip osteoarthritis as sequelae of Legg-Calvé-Perthes disease (LCPD) are severe deformities of femoral head and acetabulum. A few studies have presented that the clinical results and risks associated with total hip arthroplasty (THA) for patients with a history of LCPD were not satisfactory. In this study, we reported the radiographic and clinical outcomes of THA in patients with sequelae of LCPD.

Materials and Methods

Between March 2007 and May 2012, 23 hips (23 patients) underwent cementless THA and were followed up at least 2 years after surgery. There were 11 male patients and 12 female patients with an average age of 49.2 years old (range, 25 to 69 years old), and the average follow up period was 40.8 months (range, 24 to 84 months). The clinical and radiological evaluations were performed.

Results

The Harris hip score improved from 48.3 points preoperatively to 92.4 points at the time of the last follow-up. The shortening of affected limb was improved from -1.6 cm to 0.2 cm. The complications included one case of sciatic nerve palsy that developed after extensive lengthening of lower extremity, three cases of intraoperative femur fractures. There was no component loosening.

Conclusion

Fractures and motor nerve palsies may be more frequent in this population. Careful preoperative planning should be performed to overcome the technical pitfalls. If overcoming this early complication, the clinical and radiological evaluations showed excellent outcomes at average 40-month follow-ups.

Revision hip arthroplasty in patients with a previous total hip replacement for osteonecrosis of the femoral head

Patients with osteonecrosis of the femoral head are typically relatively young and active and often require high rates of revision after primary total hip arthroplasty. However, outcomes of revision hip arthroplasty in this patient population have rarely been reported in the literature. The authors conducted a retrospective review of 72 patients (75 hips) who underwent revision hip arthroplasty with a primary diagnosis of osteonecrosis of the femoral head. Mean age at index revision was 53.3 years (range, 34-76). Components of acetabular revision included a cementless porous-coated cup in 58 hips and an acetabular cage in 3 hips. Components of femoral revision included a fully grit-blasted tapered stem in 30 hips and a proximally porous-coated modular stem in 9 hips. Mean duration of follow-up was 7 years (range, 3-17). Mean Harris Hip Score improved from 49 points preoperatively to 90 points postoperatively. At final follow-up, 11 hips (14.7%) required reoperation because of aseptic loosening (6 hips), infection (2 hips), recurrent dislocation (1 hip), periprosthetic fracture (1 hip), and ceramic fracture (1 hip). Kaplan-Meier survivor-ship with an endpoint of re-revision for any reason was 81% and for mechanical failure was 87.5% for the cup and 100% for the stem at 10 years. Unlike the previous report, the authors' study showed a lower failure rate of the femoral stem after revision hip arthroplasty using modern cementless femoral components in patients with osteonecrosis of the femoral head. Aseptic cup loosening or osteolysis is the most common mechanism of failure at medium-term follow-up.

Prediction of osteonecrosis collapse of the femoral head based on the proportion of the proximal sclerotic rim

PURPOSE

The purpose of this study was to predict ONFH-induced collapse based on the percentage of the proximal sclerotic rim.

METHODS

In total, 101 patients satisfying the inclusion criteria who received treatment at Guang'anmen Hospital were enrolled. Bilateral hip-joint computed tomography (CT) of the necrotic tissue was performed, and the largest layer within the coronal CT images was selected together with its anterior and posterior layers to calculate the proportion of the proximal sclerotic rim. The patients were divided into collapse and non-collapse groups, and the difference in the proportions of their proximal sclerotic rims was analysed. Specifically, a receiver operating characteristic (ROC) curve was created. The proportion of the proximal sclerotic rim represented by the maximal Youden's index was used as the reference value for collapse prediction, and its predictive value was assessed.

RESULTS

The proportion in the collapse group was 13.11 ± 10.65 %, whereas the proportion in the non-collapse group was 51.91 ± 21.29 % (P < 0.01). Additionally, the proportion corresponding to the maximal Youden's index (0.902) was 29.24 %. For clinical convenience, 30 % was selected as the reference value for collapse prediction, with 97.30 % sensitivity, 87.5 % specificity, 94.01 % accuracy, a positive likelihood ratio (LR) of 7.78, and a negative LR of 0.03. Therefore, the proportion of the proximal sclerotic rim is of great significance in predicting ONFH-induced collapse, and 30 % could be used as the critical value in clinical practice.

CONCLUSION

When the proportion is >30 %, the collapse risk is low, whereas at <30 %, the risk is high, and effective mechanical support should be provided.

Custom cementless THA in patients with Legg-Calve-Perthes Disease

Legg-Calve-Perthes disease is characterized by osteonecrosis of the femoral head during childhood. Outcomes of total hip arthroplasty (THA) for these patients are less satisfactory than for those with primary osteoarthritis, often complicated by young patient age, multi-planar deformities and previous childhood surgery. To our knowledge no one has reported the long-term outcomes of cementless custom-made THA in patients with Legg-Calve-Perthes disease. We reviewed 15 THAs with an average follow-up of ten years. Survivorship rates of the femoral and acetabular components were 100% and 79% respectively. Mean Harris Hip Scores improved from 41 preoperatively to 80 at final follow-up. With excellent functional outcome, custom-made cementless prostheses should be considered as a treatment option for osteoarthritis secondary to Legg-Calve-Perthes disease in the presence of abnormal proximal femoral and acetabular anatomy.

Cementless modular total hip arthroplasty in patients younger than fifty with femoral head osteonecrosis: minimum fifteen-year follow-up

This study aimed to report the outcome of total hip arthroplasty (THA) with a modular femoral component in patients younger than fifty years with osteonecrosis of femoral head. Sixty-four osteonecrotic hips in fifty-five patients were available for clinical and radiographic analyses at minimum follow-up of fifteen-years. The mean Harris hip score improved from 36 points preoperatively to 92.7 points at final follow-up. Sixty-two (95.3%) hips demonstrated stable bone ingrowth. No hips showed loosening or required revision for aseptic loosening. Survivorship with an end point of stem revision for any reason was 93.8% and for aseptic loosening was 100% at 16.8years. We believe that cementless THA with a modular stem is a promising procedure for young and active patients with osteonecrosis of the femoral head.

Outcomes of total hip replacement in patients with slipped capital femoral epiphysis

BACKGROUND

Total hip replacement has been advocated for the treatment of degenerative hip diseases secondary to slipped capital femoral epiphysis; nonetheless, outcomes of this procedure have not been well established. We reviewed the outcomes of modern total hip replacements in patients who suffered from slipped capital femoral epiphysis.

METHODS

A retrospective study was carried out on 32 total hip replacements performed on 28 patients who suffered from slipped capital femoral epiphysis from August 1994 to January 2007. The average age at the time of surgery was 45 years. Clinical evaluation was performed using the Harris Hip Score, radiographic assessment measuring cup and stem orientation, the extent of osteolysis around the implant, and leg length discrepancy. The average follow-up was 98 months (range 25-204 months).

RESULTS

Two total hip replacements failed, one for stem aseptic loosening and the other for modular neck failure. The cumulative survival rate at 9 years was 92.8 %. If the end point was revision for implant loosening, the survival rate improved to 96.8 % at 9 years. The only complication recorded was an intraoperative fracture of the lesser trochanter immediately treated with cerclage wire. At the latest follow-up, the Harris Hip Score averaged 86 (range 70-97). Leg length discrepancies greater than 1 cm were present in 18 cases before surgery, and in only 6 cases after surgery.

DISCUSSION

We recommend total hip replacement for patients who suffer from slipped capital femoral epiphysis because of the satisfactory survival, low complication rate, and the possibility of restoring leg length.

Migration analysis of a metaphyseal anchored short-stem hip prosthesis

BACKGROUND AND PURPOSE

Metaphyseal anchored short-stem hip implants were designed to improve load transmission and preserve femoral bone stock. Until now, only few outcome data have been available and migration studies are one of the few ways of obtaining data that are predictive of implant survival. We therefore evaluated a metaphyseal anchored short-stem hip implant by Ein Bild Roentgen Analyse femoral component analysis (EBRA-FCA).

PATIENTS AND METHODS

First, the EBRA-FCA method was validated for the short-stem hip implant. Then 80 of the first 100 consecutive implants were evaluated after at least 2 years. Clinical assessment was performed using the WOMAC and the UCLA score.

RESULTS

After 2.7 (2.0-4.2), years none of the implants had been revised and by that time the stems had subsided by a mean of 0.7 mm (SD 1.8) (95% CI: 0.3-1.1). Of the 80 implants, 78 were stable after 2 years, with 74 being primary stable and 4 showing secondary stabilization after initial subsidence. Continuous migration was seen in only 2 patients. The clinical outcome showed good results with a mean WOMAC of 11 (SD 13) and a mean UCLA score of 7.3 (SD 2.0).

INTERPRETATION

The metaphyseal anchored short-stem hip implant showed good functional results and a high degree of stability after 2 years. The outcome is comparable to that of clinically proven conventional hip implants and if the results are confirmed by long-term studies, short-stem hip arthroplasty might be an alternative for young patients requiring hip replacement.

High incidence of migration with poor initial fixation of the Accolade stem

BACKGROUND

Numerous cementless femoral stem design variations are in clinical use. Because initial implant instability and micromotion are associated with aseptic loosening of the femoral component, migration analysis provides an early assessment of implant survivorship.

QUESTIONS/PURPOSES

We determined the (1) migration pattern of the Accolade cementless femoral stem; (2) clinical factors predisposing to stem migration; (3) self-reported patient outcomes; and (4) our current rate of aseptic stem loosening.

METHODS

We retrospectively analyzed 81 femoral stems for aseptic migration using Ein-Bild-Roentgen-Analyse-femoral component analysis. Postoperatively, patients completed the WOMAC and SF-12 questionnaires. We assessed radiographic factors potentially associated with subsidence: indices of bone shape and quality, canal fill of the implant, and radiographic signs of loosening. Minimum followup was 24 months (mean, 29 months; range, 24-48 months).

RESULTS

The average subsidence at 24 months was 1.3 mm (range, 0-1.5 mm). In the first 2 years, 36% of stems subsided more than 1.5 mm. Large stem size was associated with subsidence. Radiolucent lines (> 1.5 mm in three zones) were present in 10% of stems and associated with lower questionnaire scores. The 5-year survivorship for aseptic loosening of the 367 stems was 97% with revision as end point and 95% for radiographic failure.

CONCLUSIONS

The high incidence of migration and stems with radiographic failure raises concerns about patient clinical function and long-term survivorship of this stem design. This migration pattern may be due to poor initial stability with a subsequent lack of osseointegration. Our results differ from radiographic findings and clinical durability of other similar cementless stem designs.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Long-term results of total hip replacement in patients with Legg-Calvé-Perthes disease

BACKGROUND

Total hip replacement in patients with Legg-Calvé-Perthes disease can be difficult because of the multiplanar deformities of the proximal part of the femur and previous surgery during childhood. The aim of the present study was to assess the long-term outcomes of total hip replacement in patients who had Legg-Calvé-Perthes disease during childhood.

METHODS

A retrospective study was carried out to assess the results of thirty-two total hip replacements that had been performed for twenty-seven patients from January 1989 to November 2004. The average age at the time of surgery was 37.8 years. The average duration of follow-up was 124 months (range, fifty-eight to 248 months). All but one of the implants were cementless.

RESULTS

There was only one failure in the present study; specifically, the one cemented stem in the study failed two years after surgery. The cumulative survival rate at fifteen years was 96.9% (95% confidence interval, 90.8% to 100.0%). The overall rate of complications was 12.5%, with two permanent sciatic nerve palsies. At the time of the latest follow-up, the average Harris hip score was 87.5 (range, 73 to 96), which was a marked improvement in comparison with the preoperative score (average, 50.1; range, 25 to 75).

CONCLUSIONS

Despite the high rate of neurological complications, possibly related to excessive limb lengthening or inadequate soft-tissue release, total hip replacement can be considered a feasible option for patients with Legg-Calvé-Perthes disease. Careful preoperative planning is advisable in order to overcome the technical pitfalls related to the abnormal proximal femoral and acetabular anatomy of these patients.

Hip resurfacing results for osteonecrosis are as good as for other etiologies at 2 to 12 years

A bone-conserving prosthetic solution, such as hip resurfacing arthroplasty, is desirable for patients with osteonecrosis (ON) of the femoral head because of their young age. However, many surgeons are reluctant to perform hip resurfacing for ON because of large femoral head defects. To ascertain whether this reluctance is warranted, we determined the mid- to long-term effects of ON on the survivorship, radiographic implant fixation, and disease-specific and quality-of-life scores of hip resurfacing. We compared the results of metal-on-metal resurfacing performed for ON of the hip (including large lesions) with those of resurfacing performed for other causes. The ON group had 70 patients (85 hips) and the control group 768 patients (915 hips) including all other etiologies operated on during the same period. The ON group was younger and had a greater incidence of femoral defects, a smaller component size, and a lower body mass index, three variables previously shown to reduce survivorship in hip resurfacing. We observed no difference in survivorship between the ON group and the control group even after adjusting for head size, body mass index, and defect size. Pain relief, walking, and function scores were comparable postoperatively. The activity level was lower in the ON group. Our data suggest ON is not a contraindication for resurfacing even with large femoral head defects.

LEVEL OF EVIDENCE

Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Analysis of bone matrix composition and trabecular microarchitecture of the femoral metaphysis in patients with osteonecrosis of the femoral head

Osteonecrosis of the femoral head (ONFH) usually affects young individuals. In advanced stages of ONFH, total hip replacement is the golden standard. However, survivorship after total hip replacement has been reported to be poorer in patients with ONFH compared to patients with primary osteoarthritis (OA). In radiological and histological studies, an impaired bone quality was found not only for the femoral head, but also for the intertrochanteric and metaphyseal region. We hypothesize that alterations of bone quality in the femoral metaphysis might contribute to early stem loosening. The objective of this study was to assess the gene expression levels of factors regulating bone formation and remodeling of the intertrochanteric regions and the proximal femoral canal in patients with ONFH and those with primary OA. The cellular and macromolecular composition of the bone matrix was assessed by osteocalcin immunohistochemistry, and the three-dimensional organization of trabecular bone was characterized by microCT analysis. Gene expression of BMP-2 is twofold higher in the proximal femur in the region of the greater trochanter of patients with ONFH compared to those with OA. The number of osteoblasts in the greater trochanter of patients with ONFH (253/mm(2)) is increased compared to patients with OA (156/mm(2)). Trabecular properties in ONFH bone are altered for bone volume (OA: 32 mm(3), ONFH: 51 mm(3)) and structure model index (OA: 2.2, ONFH: 1.6) in the proximal femoral canal, but not in the trochanteric regions. These alterations in bone metabolism and architecture might contribute to the higher rates of stem loosening after total hip replacement in patients with ONFH, however, further experimental and clinical studies are needed to support our findings.

Evaluation of instability after transtrochanteric anterior rotational osteotomy for nontraumatic osteonecrosis of the femoral head

BACKGROUND

Transtrochanteric anterior rotational osteotomy results in improvement of joint congruity and prevention of progressive collapse and osteoarthritic changes in patients with femoral head osteonecrosis. However, this procedure remains controversial for patients with extensive collapse due to potential osteoarthritis caused by postoperative instability. The purpose of this study was to evaluate hip instability after osteotomy and determine the relation between instability and radiological and clinical outcomes.

METHODS

In all, 27 hips of 24 patients that were followed up for a mean period of 3.8 years were included. Instability was defined as more than 1 mm translation of the femoral head in transverse computed tomography scans obtained at 0 degrees and 45 degrees flexion of the hip joint. Hips were divided into instability and stability groups.

RESULTS

Eleven hips (40%) developed instability after surgery. Osteophytes on the femoral head in 10 hips of the instability group and 2 hips of the stability group had increased in size at follow-up. There was a significant relation between postoperative instability and osteophyte formation. Joint space narrowing was not seen in any of the cases. There was no significant difference between the groups in either the postoperative intact ratio of the femoral head or the Japanese Orthopaedic Association hip score.

CONCLUSIONS

Neither instability nor osteophyte formation on the femoral head after transtrochanteric anterior rotational osteotomy correlated with progressive osteoarthritic changes or clinical outcome in the presence of an adequate femoral head intact ratio facing the weight-bearing area.

Assessment of the initial stability of the Symax femoral stem with EBRA-FCA: a multicentric study of 85 cases

We report a study of 85 Symax femoral stems that were followed at regular intervals with radiographs at 6, 12, 24 and 36 months. The radiological migration of each stem was measured using the computer-assisted EBRA -FCA method. In 30 cases in which the EBRA method did not provide a complete measurement another computer-assisted method (Roman version 1.7) was employed. In all cases the distal migration of the stems was minimal, The threshold migration value used to define the stability of a stem was 1.5 mm at 24 months. The mean migration within the first two years was -0.17 mm (+/- 0.3) at 6 months, -0.31 mm (+/- 0.4) at 12 months and -0.45 mm (+/- 0.5) at 24 months. Only two cases exceeded the threshold limit of 1.5 mm at the two-year follow-up, but both values were lower than 2 mm. In the 25 cases which reached three-year follow-up the mean distal migration was -0.84 (+/-0.7). In four of them the subsidence exceeded 1.5 mm, but only one exceeded 2 mm. These data represent a positive predictive factor for the minimal risk of future aseptic loosening.

The effect of a single infusion of zoledronic acid on early implant migration in total hip arthroplasty. A randomized, double-blind, controlled trial

BACKGROUND

Aseptic loosening is the most frequent cause of implant failure in total hip arthroplasty. While a direct link between aseptic loosening and periprosthetic bone loss remains elusive, there is plentiful evidence for a close association with early implant migration. The present trial was primarily designed to evaluate whether a single infusion of 4 mg of zoledronic acid prevented early implant migration in patients with osteonecrosis of the femoral head.

METHODS

Fifty patients were consecutively enrolled to receive either zoledronic acid or saline solution after cementless total hip arthroplasty. Radiographs, biochemical parameters of bone turnover, and the Harris hip-rating score were determined preoperatively and at each follow-up examination at seven weeks, six months, one year, and yearly thereafter. The median follow-up period was 2.8 years.

RESULTS

We found a significant subsidence of the stem of up to a mean (and standard deviation) of -1.2 +/- 0.6 mm at two years within the control group, and the cups had a mean medialization of 0.6 +/- 1.0 mm and a mean cranialization of 0.6 +/- 0.8 mm (p < 0.001). Treatment with zoledronic acid effectively minimized the migration of the cups in both the transverse and the vertical direction (mean, 0.15 +/- 0.6 mm and 0.06 +/- 0.6 mm, respectively; p < 0.05), while only a trend to decreased subsidence of the stem was detected. Finally, the Harris hip score rapidly increased over time in both treatment groups, although this increase was significantly more pronounced in the zoledronate-treated group than in the control group (analysis of variance, p = 0.008).

CONCLUSIONS

A single infusion of zoledronic acid shows promise in improving initial fixation of a cementless implant, which may improve the clinical outcome of total hip arthroplasty in patients with osteonecrosis of the femoral head.

No increased stem subsidence after arthroplasty in young patients with femoral head osteonecrosis: 41 patients followed for 1-9 years

BACKGROUND

Poor bone stock in patients with osteonecrosis of the femoral head may be a reason for poor outcome after hip replacement. One way of studying bone quality is to measure implant migration. We thus investigated the clinical and radiographic results of cementless THR in younger patients with femoral head osteonecrosis.

PATIENTS AND METHODS

We studied hips in 41 patients (mean age 48 (25-63) years) with a cementless hip arthroplasty after late stage osteonecrosis. Clinical evaluation was by the Harris hip score, the WOMAC score and the SF-36 score. Stem subsidence was measured with the Ein Bild Roentgen Analyse femoral component analysis (EBRA-FCA) at 3, 12, 24, 60, and 72 months after operation. The average duration of follow-up was 7(1-9) years, with less than 2 years for 2 patients.

RESULTS

There was no revision of any hip. No radiographic or clinical stem loosening was seen. After 60 months, the cementless stems showed a median subsidence of -0.7 mm (95% CI: -0.9 to -0.2). No femoral osteolysis occurred. Femoral radiolucent lines, all < 1 mm, were seen in 10 hips. At the latest follow-up the Harris hip score was 83 (23-100) points.

INTERPRETATION

Our findings for porous-coated stems in patients with femoral osteonecrosis indicate no greater risk of stem subsidence and rate of osteolysis after an average of 7 years follow-up. Thus, we continue to use uncemented stems in younger patients with femoral osteonecrosis. However, continued follow-up will be necessary to evaluate the long-term outcome.

Use of an alumina-on-alumina bearing system in total hip arthroplasty for osteonecrosis of the hip

BACKGROUND

The results of total hip arthroplasty in patients with osteonecrosis of the femoral head are not always optimal. The use of alumina-on-alumina interfaces in young and active patients may decrease wear and lower the rate of aseptic loosening of the implant and appears to be an attractive alternative to the use of conventional cobalt-chromium-on-polyethylene bearings. The purpose of this study was to evaluate the safety and efficacy of the alumina-on-alumina bearing in patients with osteonecrosis and to compare this group of patients to a group of similarly treated patients with osteoarthritis and a group of patients who received conventional cobalt-chromium-on-polyethylene bearings.

METHODS

Patients were selected from a United States Investigational Device Exemption multicenter prospective randomized clinical study that was initiated in 1996. Seventy patients with osteonecrosis of the femoral head (seventy-nine hips) received a cementless alumina-on-alumina bearing system and were directly matched to seventy-six patients with osteoarthritis of the hip (seventy-nine hips) who were managed with the same implant. Both groups were compared with twenty-five patients (twenty-six hips) with osteonecrosis and twenty-five patients (twenty-six hips) with osteoarthritis who were managed with a cementless cobalt-chromium-on-polyethylene bearing system. All patients received a cementless hydroxyapatite-coated femoral stem and were followed both clinically and radiographically.

RESULTS

The clinical outcomes for alumina-on-alumina bearings were similar for both osteonecrotic and osteoarthritic hips. The seven-year survival probability was 95.5% for the osteonecrotic hips and 89.4% for the osteoarthritic hips in the alumina-on-alumina bearing group and 92.3% for the osteonecrotic hips and 92.9% for the osteoarthritic hips in the cobalt-chromium-on-polyethylene bearing group. At the time of the most recent follow-up, the mean Harris hip score was 96 points for both the osteonecrotic and the osteoarthritic hips in the alumina-on-alumina group and 96 points for the osteonecrotic hips and 97 points for the osteoarthritic hips in the cobalt-chromium-on-polyethylene bearing group.

CONCLUSIONS

The results of the use of alumina-on-alumina and cobalt-chromium-on-polyethylene bearings in cementless standard total hip implants in patients with osteonecrosis and osteoarthritis were comparable. The low revision rate for the alumina-on-alumina bearing is encouraging and offers a promising option for younger, more active patients who have this challenging disease.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions to Authors on jbjs.org for a complete description of levels of evidence.

Total hip arthroplasty following failure of free vascularized fibular graft

BACKGROUND

Many treatments for osteonecrosis of the femoral head, including the use of a free vascularized fibular graft, have been advocated in an attempt to delay the need for hip arthroplasty. The purpose of this study was to document the clinical and radiographic results of total hip arthroplasty performed following failure of a free vascularized fibular grafting procedure.

METHODS

Twenty total hip arthroplasties in eighteen patients who had previously undergone a free vascularized fibular grafting procedure for the treatment of osteonecrosis were retrospectively reviewed. A straight-stem femoral component was used in twelve hips, a tapered femoral component with removal of residual fibular graft was used in five hips, and a tapered stem without graft removal was used in three hips. The twelve hips with a straight-stem femoral component and previous vascularized fibular grafting were compared with thirty-six osteonecrotic hips in thirty other patients who had undergone total hip arthroplasty but had not had previous free vascularized fibular grafting. The radiographic outcomes with respect to initial femoral component alignment and subsequent migration and the clinical outcomes were compared.

RESULTS

Analysis of the immediate postoperative radiographs demonstrated significantly improved alignment of the femoral component when a high-speed burr had been used to remove residual fibular graft (p = 0.001), although doing so did significantly increase both the intraoperative blood loss (p = 0.017) and the operative time (p = 0.0002). There was no significant difference in the amount of migration of either the acetabular or the femoral component between the control and study groups at the time of the most recent follow-up. When comparing patients with or without a previous free vascularized fibular graft, the mean postoperative scores at three years were significantly worse in patients who had undergone a previous free vascularized fibular graft (p = 0.03). One revision occurred in the study group at seventy-two months due to acetabular wear, and one revision occurred in the control group at 108 months due to aseptic loosening.

CONCLUSIONS

This study raises concern that the outcome of total hip arthroplasty in patients who previously underwent a free vascularized fibular graft for the treatment of osteonecrosis of the femoral head may be worse than that in patients without previous free vascularized fibular grafting. The intraoperative use of a high-speed burr can improve the alignment of the femoral component by removing more of the residual graft. However, this technique does increase intraoperative blood loss and operative time.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions to Authors on jbjs.org for a complete description of levels of evidence.