No differences in the efficacy among various core decompression modalities and non-operative treatment: a network meta-analysis

Core decompression combined with bone marrow mononuclear cells in the treatment of femoral head necrosis: a systematic review and meta-analysis

BACKGROUND

The effectiveness of bone marrow mononuclear cells combined with core decompression in the treatment of femoral head necrosis is controversial. The purpose of this study was to conduct a meta-analysis and systematic review of the evaluation of bone marrow mononuclear cells combined with core decompression in the treatment of femoral head necrosis, and to compare the therapeutic effect of this method with that of core decompression alone, so as to provide a basis for subsequent research and clinical treatment.

METHODS

We conducted detailed searches across four databases in Embase, PubMed, Web of Science, and the Cochrane Library (up to October 2023), including eight studies with a total of 370 participants and 491 hip cases. This meta-analysis followed the Preferred Reporting Project (PRISMA) guidelines. Review Manager 5.4 was used to summarize and analyze the outcome indicators and the quality and reliability of the MAs were graded against a Measurement Tool to Assess Systematic Reviews 2 (AMSTAR 2).

RESULTS

Eight studies were included inclusion criteria. The results of meta-analysis showed that the therapeutic effect of CD combined with BMMC on VAS was better than that of CD alone (MD =-5.32, 95%CI: -9.90, -0.74, P=0.02, I²=98%), and there was no statistically significant difference between CD combined with BMMC and CD alone in the treatment of HHS (MD =2.73, 95%CI: -2.63,8.09, P=0.32, I²=82%). We conducted sensitivity analysis, the results showed that CD joint BMMC treatment effect on the HHS is superior to the single CD (MD = 5.57, 95% CI: 1.94, 9.20, P = 0.003, I squared = 0%), both no significant differences in VAS (MD = 0.47, 95% CI: -1.74, 0.79, P=0.46, I²=83%).

CONCLUSION

In this study, we found that core decompression combined with bone marrow monocyte therapy improved femoral head necrosis better than core decompression alone.

Evaluation of the Tensor Fascia Lata Muscle Pedicle Bone Grafting Technique in the Management of Avascular Necrosis of the Femoral Head: An Observational Clinical Study

BACKGROUND

Osteonecrosis of the hip is defined as necrosis of the bone tissue due to some form of vascular insult, subsequently leading to the collapse of the femoral head and secondary osteoarthritis, which leads to pain and impaired joint function. This disease is widely known to affect middle-aged groups; however, in the Indian population, even younger people are more commonly affected. The disease has a debilitating effect on the activities of daily living (ADL) and the productivity of individuals and has financial consequences. With the increased utilization of magnetic resonance imaging (MRI) in society, the disease is diagnosed in its early stages. Hip-preserving surgery like tensor fascia lata (TFL) muscle pedicle iliac bone grafting should be given a chance to preserve the native femoral head.

METHODOLOGY

At a tertiary care teaching hospital in Gorakhpur, India, an observational clinical study was carried out. This study comprised 40 patients, ages 18-50 years, with femoral head osteonecrosis (stages II and III of the Ficat-Arlet staging system), who came to our institute's orthopedic outpatient department. Patients were treated with multiple drillings, curettage, and cheilectomy of the femoral head, in addition to TFL muscle pedicle bone grafting. The Harris hip score (HHS) was utilized to assess the clinical results, and the radiological assessment focused on signs of revascularization.

RESULT

In our study, the most prevalent age group was 20-30 years (67.5%), with a male predominance (85%). Among our cohort of 40 patients, the HHS indicated excellent outcomes (90-100) in 14 cases (35%), good outcomes (80-89) in 19 cases (47.5%), fair outcomes (70-79) in six cases (15%), and poor outcomes (<70) in one case (2.5%), at the time of the final follow-up. The final follow-up period varied from one to 10 years.

CONCLUSION

TFL muscle pedicle bone grafting procedure provides excellent clinical and radiological outcomes, especially in young patients in whom femoral head-preserving surgery is preferred over total hip arthroplasty. This procedure is effective in both early and advanced stages of femoral head osteonecrosis, provided there are no arthritic changes. It reduces symptoms and improves functional outcomes.

Regenerative therapies for femoral head necrosis in the past two decades: a systematic review and network meta-analysis

BACKGROUND

Regenerative techniques combined with core decompression (CD) are commonly used to treat osteonecrosis of the femoral head (ONFH). However, no consensus exists on regeneration therapy combined with CD that performs optimally. Therefore, we evaluated six regenerative therapies combined with CD treatment using a Bayesian network meta-analysis (NMA).

METHODS

We searched PubMed, Embase, Cochrane Library, and Web of Science databases. Six common regeneration techniques were categorized into the following groups with CD as the control group: (1) autologous bone graft (ABG), (2) autologous bone graft combined with bone marrow aspirate concentrate (ABG + BMAC), (3) bone marrow aspirate concentrate (BMAC), (4) free vascular autologous bone graft (FVBG), (5) expanded mesenchymal stem cells (MSCs), and (6) platelet-rich plasma (PRP). The conversion rate to total hip arthroplasty (THA) and progression rate to femoral head necrosis were compared among the six treatments.

RESULT

A total of 17 literature were included in this study. In the NMA, two of the six treatment strategies demonstrated higher response in preventing the progression of ONFH than CD: MSCs (odds ratio [OR]: 0.098, 95% confidence interval [CI]: 0.0087-0.87) and BMAC (OR: 0.27, 95% CI: 0.073-0.73). Additionally, two of the six treatment strategies were effective techniques in preventing the conversion of ONFH to THA: MSCs (OR: 0.062, 95% CI: 0.0038-0.40) and BMAC (OR: 0.32, 95% CI: 0.1-0.074). No significant difference was found among FVBG, PRP, ABG + BMAC, ABG, and CD in preventing ONFH progression and conversion to THA (P > 0.05).

CONCLUSIONS

Our NMA found that MSCs and BMAC were effective in preventing ONFH progression and conversion to THA among the six regenerative therapies. According to the surface under the cumulative ranking value, MSCs ranked first, followed by BMAC. Additionally, based on our NMA results, MSCs and BMAC following CD may be necessary to prevent ONFH progression and conversion to THA. Therefore, these findings provide evidence for the use of regenerative therapy for ONFH.

Updating Osteonecrosis of the Femoral Head

Osteonecrosis of the femoral head (ONFH), a condition characterized by the presence of a necrotic bone lesion in the femoral head, is caused by a disruption in the blood supply. Its occurrence is more common in young and middle-aged adults and it is the main reason for performance of total hip arthroplasty in this age group. Its incidence is increasing along with increased use of glucocorticoids for management of adjuvant therapy for treatment of leukemia as well as organ transplantation and other myelogenous diseases. Current information on etiology and pathogenesis, as well as natural history, stage system, and treatments is provided in this review. A description of the Association Research Circulation Osseous (ARCO) criteria for classification of glucocorticoids- and alcohol-associated ONFH, 2019 ARCO staging system, and 2021 ARCO classification using computed tomography for the early stages of ONFH is also provided.

Trends in Surgical Treatment of Femoral Head Osteonecrosis in South Korea: An Analysis Using Nationwide Claims Database

BACKGROUND

Osteonecrosis of the femoral head (ONFH) involves young or middle-aged adults, and its incidence is increasing along with increasing use of steroids in the management of organ transplantation and adjuvant therapy for malignant neoplasms. To date, no pharmacological agent has been proven to prevent or retard the progression of ONFH, and surgical procedures including joint preservation procedures and hip arthroplasties are main treatments for the disease. Although ONFH is the most common or second most common disease for hip arthroplasty in East Asian countries, the trend of surgical procedures in this region remains unknown. Thus, we evaluated trends in surgical treatment of the disease in South Korea.

METHODS

We identified patients with ONFH from the Korean Health Insurance Review and Assessment (HIRA) database, a nationwide medical claims database of South Korea, between January 2007 and December 2018 and calculated the proportions of following surgical procedures at each year: total hip arthroplasty (THA), hemiarthroplasty (HA), core decompression/multiple drilling, femoral osteotomy, and vascularized bone grafting.

RESULTS

The total number of procedures increased from 3,824 in 2007 to 6,929 in 2018. Overall, the rate of THA (86%) was far greater than other procedures. From 2007 to 2018, the percentage of THA among the procedures increased from 80% to 91%, while that of joint preservation procedures decreased from 11% to 5%.

CONCLUSIONS

The total number of surgical procedures performed for ONFH increased and the percentage of THA increased, while that of joint preservation procedures decreased from 2007 to 2018 in South Korea.

Prediction of collapse in femoral head osteonecrosis: role of volumetric assessment

PURPOSE

The purpose of this study was to evaluate and compare the accuracy of three different techniques of measuring the extent of osteonecrosis involvement of the femoral head on MRI to determine the best predictor of collapse and to identify the size of the lesion volume which best predicts collapse.

METHODS

We prospectively enrolled 48 hips of osteonecrosis femoral head (ONFH) with stage 1 or 2 osteonecrosis and the enrolled patients were followed up for 1 year. Angular measurements (modified Kerboul Angle and modified index of necrotic extent) were compared with the 3D volumetric measurement of necrotic lesion based on MRI in predicting the collapse of the head. ROC analysis was done to evaluate the diagnostic performance of the 3 indices in predicting collapse. Survival analysis of all the hips in the collapsed and non-collapsed group were interpreted using Kaplan Meir survival analysis.

RESULTS

In lesion sizes larger than 25% of femoral head volume - 90.6% (29/32) of hips collapsed within 1 year as compared to 31.3% (5/16) hips collapsed in lesion volume <25% of femoral head (Log-rank test p = 0.001). There was good inter-observer (ICC, 0.94; 95% CI, 0.89-0.97) and intra-observer reliability (ICC, 0.93; 95% CI, 0.88-0.96).

CONCLUSIONS

The Volumetric method assessed the severity of lesion size with the future collapse better and more predictably than angular measurements. Necrotic lesion volume of 25% is a potential cut off beyond which future collapse of early ONFH can be predicted and aid in the further management. This study can help in solving the mystery behind prediction of collapse in ONFH.

Efficacy and Safety of Stem Cell Combination Therapy for Osteonecrosis of the Femoral Head: A Systematic Review and Meta-Analysis

Background

The treatment results of core decompression (CD) and biomechanical support are not always satisfactory in osteonecrosis of the femoral head (ONFH). Stem cell therapy has been incorporated into traditional treatment in order to promote bone regeneration. The efficacy and safety of stem cell therapy combined with CD or biomechanical support on advanced and long-term patients with ONFH were unknown. The aim of this study was to assess whether stem cell combination therapy is superior to single CD or porous tantalum rod implantation treatment in ONFH.

Methods

A systematic search of the literature was performed to evaluate all included randomized controlled trials (RCTs) on stem cell combination therapy for patients with ONFH in PubMed, Cochrane Library, Web of Science, and Embase sites. We assessed the quality and risk of bias for the included studies. And the outcomes of Harris hip score (HHS), visual analogue scale (VAS), and adverse events were statistically analyzed.

Results

We included 10 randomized controlled trials, containing a total of 498 patients with 719 hips. Stem cell therapy combined with CD versus CD alone for HHS of ONFH was different (MD = 8.87, 95% CI = [5.53, 12.22], P < 0.00001). The combination of stem cell therapy and CD can effectively improve HHS. Similarly, the VAS of the stem cell combination therapy group also differed compared with the control group (MD = -14.07, 95% CI = [-18.32, -9.82], P < 0.00001). The result showed that stem cell combination therapy can relieve the pain of patients with ONFH. There was no significant difference in adverse response outcome events between the combination therapy group and the control group (RR = 1.57, 95% CI = [0.62, 3.97], P = 0.34).

Conclusions

Stem cell therapy combined with core decompression is an effective and feasible method with few complications in the clinical treatment of early-stage ONFH. Even in the combination of porous tantalum rod implantation and peripheral blood stem cells, stem cell combination therapy is superior to single biomechanical support treatment. But high-quality, large-sample, multicenter, and long-term follow-up RCTs are still needed to corroborate the efficacy and safety of stem cell combination therapy in ONFH treatment.

Insufficient blood supply of fovea capitis femoris, a risk factor of femoral head osteonecrosis

Background

A defective nutrient foramen in the fovea capitis femoris was hypothesized to reflect the blood circulation pattern of the femoral head, leading to insufficient blood supply and causing osteonecrosis of the femoral head.

Methods

Normal and necrotic femoral head specimens were collected. The necrotic femoral head group was divided into a non-traumatic and traumatic subgroup. 3D scanning was applied to read the number, the diameter, and the total cross-sectional area of the nutrient foramina in the fovea capitis femoris. Chi-squared tests and independent t-tests were used to detect any differences in the categorical and continuous demographic variables. Logistic regression models were used to estimate the odds ratio (OR) for non-traumatic and traumatic osteonecrosis in different characteristic comparisons.

Results

A total of 249 femoral head specimens were collected, including 100 normal femoral heads and 149 necrotic femoral heads. The necrotic femoral head group revealed a significantly higher percentage of no nutrient foramen (p < 0.001), a smaller total area of nutrient foramina (p < 0.001), a smaller mean area of nutrient foramina (p = 0.014), a lower maximum diameter of the nutrient foramen (p < 0.001), and a lower minimum diameter of the nutrient foramen (p < 0.001) than the normal femoral head group. The logistic regression model demonstrated an increasing number of nutrient foramina (crude OR, 0.51; p < 0.001), a larger total area of nutrient foramina (crude OR, 0.58; p < 0.001), a larger mean area of nutrient foramina (crude OR, 0.52; p = 0.023), a greater maximum diameter of the nutrient foramen (crude OR, 0.26; p < 0.001), and greater minimum diameter of the nutrient foramen (crude OR, 0.20; p < 0.001) significantly associated with reduced odds of osteonecrosis of the femoral head (ONFH). The necrotic femoral head group was further divided into 118 non-traumatic and 31 traumatic necrotic subgroups, and no significant difference was observed in any characteristics between them.

Conclusions

Characteristics of the nutrient foramen in the fovea capitis femoris showed a significant defect of necrotic than normal femoral heads, and significantly reduced odds were associated with the higher abundance of the nutrient foramen in ONFH. Therefore, the condition of the nutrient foramen might be the indicator of ONFH.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-021-02564-6.

Osteonecrosis of the Femoral Head: an Updated Review of ARCO on Pathogenesis, Staging and Treatment

Non-traumatic osteonecrosis of the femoral head (ONFH) usually affects adults younger than 50 years and frequently leads to femoral head collapse and subsequent arthritis of the hip. It is becoming more prevalent along with increasing use of corticosteroids for the adjuvant therapy of leukemia and other myelogenous diseases as well as management of organ transplantation. This review updated knowledge on the pathogenesis, classification criteria, staging system, and treatment of ONFH.

Multiple drilling is not effective in reducing the rate of conversion to Total hip Arthroplasty in early-stage nontraumatic osteonecrosis of the femoral head: a case-control comparative study with a natural course

BACKGROUND

To determine whether multiple drilling is effective in postponing the need for total hip arthroplasty (THA) in early-stage nontraumatic osteonecrosis of the femoral head (ONFH).

METHODS

We identified 514 patients who were diagnosed with early-stage ONFH between January 2008 and December 2018. One hundred ninety-six patients underwent multiple drilling, and 318 patients had a natural course of progression. One hundred fifty-nine patients were selected for each group after case-control matching for preoperative demographics and modified Ficat and Arlet stage. The rates of THA conversion were compared. We also performed Cox regression to identify risk factors associated with THA conversion in patients who underwent multiple drilling.

RESULTS

Kaplan-Meier survivorship with an endpoint of THA for nontraumatic reasons were not significantly different between the multiple drilling group (75.6, 95% confidence interval 67.8-83.4%) and the natural course group (72.2, 95% confidence interval 64.8-79.6%) at 5 years (log-rank, P = .191). In the Cox regression model, a larger extent of necrotic lesion, bone marrow edema (BME), and higher postoperative work intensity significantly increased the risk of THA conversion (P < .05). Among patients treated with autogenous bone grafting, there was a lower risk of failure in patients with necrotic lesion less than 15% (P < .05).

CONCLUSIONS

Multiple drilling is not effective in reducing the rate of THA conversion in early-stage nontraumatic ONFH. The risk of conversion to THA after multiple drilling is increased by a larger extent of necrotic lesion, presence of BME, and higher postoperative work intensity in patients with early-stage ONFH.

TRIAL REGISTRATION

The trial was registered in the Chinese Clinical Trial Registry ( ChiCTR2000035180 ) dated 2 August 2020.

Difference in Therapeutic Strategies for Joint-Preserving Surgery for Non-Traumatic Osteonecrosis of the Femoral Head between the United States and Japan: A Review of the Literature

For patients with non-traumatic osteonecrosis of the femoral head (ONFH), core decompression (CD) and bone grafts (BG) are mainly performed in the West, while osteotomy is found to be predominant in Japan. It is not well recognized how the surgical procedures for joint preservation in patients with ONFH are completely different between the United States and Japan. This paper identifies the contexts and the differences in treatment strategies for ONFH between the two countries. We compared the surgical trends of the two countries over three periods, 1997-2001, 2002-2006, and 2007-2011 (the US data for the third period was 2007-2008), based on a 2014 US paper and a 2013 national publication in Japan. We compared the details of surgery for non-traumatic ONFH under the same conditions in the two reports. For the period 1997-2001, the rates of surgeries for ONFH in the US were as follows: total hip arthroplasty (THA), 86%; CD, 10%; and osteotomy, 0.4%. In Japan, THA was 61%, osteotomy 38%, and CD 0%. For the recent period, 2007-2011 (US 2007-2008), the rate of THA was 91%, CD 6%, and osteotomy 0.1%, in the US, compared to a THA rate of 73%, CD 0%, and osteotomy 26% in Japan. The results for the interim period (2002-2006) were between the old and new data. The use of joint-preserving surgery for ONFH differs greatly between the US and Japan. The first-line joint-preserving surgery was CD in the US and osteotomy in Japan. Each procedure was rarely done in the other country. From about 2000 to 2010, the percentage of THA increased in both countries. The proportion of joint-preserving surgery (CD in the US and osteotomy in Japan) declined. The decrease in joint-preserving procedures may be largely attributed to improved long-term outcomes of THA due to technological advances. There is also a reluctance for young ONFH patients to undergo joint-preserving procedures, such as osteotomy, that require long-term hospitalization.

Treatment of aseptic osteonecrosis of the femoral head: Historical aspects

The treatment of aseptic osteonecrosis (ON) of the femoral head has been the subject of numerous therapeutic and surgical proposals due to the absence of medical treatment with proven efficacy. For many years, the goal of surgical treatment was to avoid total hip replacement (THR) with uncertain survival in patients considered too young (30-50 years) for this procedure. Numerous conservative treatments were thus proposed: core decompression with numerous variants, non-vascularized and vascularized bone grafts, intertrochanteric and rotational transtrochanteric osteotomies, cementing. The lack of a common classification and a lack of knowledge of natural history complicated the interpretation of the results for a long time. Nevertheless, it appeared that these treatments were effective only in the very early stages and among these in the limited ONs, medial rather than central and especially lateral, with discrepancies according to etiologies apart from sickle cell disease recognized by all as being pejorative. For the same reason, partial arthroplasties have been attempted and abandoned in turn: femoral head total and partial resurfacing and femoral prosthesis. The most recent advances are stem-cell-enhanced core decompression and progress in total arthroplasty, whose reliability has made it possible to extend the indications to increasingly younger patients seeking treatment with guaranteed or near-guaranteed efficacy. Most of the other interventions have disappeared or almost disappeared because of their lack of effectiveness especially in extensive and post-fracture ONs, sometimes because of their complexity and the length of their post-operative management, and also because they complicate and penalize a future total arthroplasty. This argues for early detection of ON at an early stage where the "head can be saved" by stem cell augmented core decompression, a minimally invasive treatment that leaves the chances of success of a THR intact.

ARCO Consensus on the Pathogenesis of Non-traumatic Osteonecrosis of the Femoral Head

Osteonecrosis of the femoral head (ONFH) is a devastating disease frequently leading to femoral head collapse and hip arthritis. Specifically, non-traumatic ONFH primarily affects young and middle-aged adults. Although compromised local circulation of the femoral head seems to be pathognomonic for the disease, the pathogenesis is perplexing and continues to be an area of scrutiny and research. Comprehension of the pathogenesis is of crucial importance for developing and guiding treatments for the disease. Therefore, we provide an up-to-date consensus on the pathogenesis of non-traumatic ONFH.

Combining Platelet-Rich Plasma Instillation With Core Decompression Improves Functional Outcome and Delays Progression in Early-Stage Avascular Necrosis of Femoral Head: a 4.5- to 6-Year Prospective Randomized Comparative Study

BACKGROUND

Avascular necrosis of femoral head is a debilitating disease frequently progressing to femoral head collapse and joint destruction. The efficacy of core decompression (CD) remains controversial.

METHODS

About 40 consecutive age-matched and gender-matched patients (53 hips) were randomized into 2 groups by computer-generated algorithm table in a prospective randomized double-blinded comparative study. Group A (platelet-rich plasma [PRP] with CD) included 19 patients (25 hips), and group B (CD only) included 21 patients (28 hips). Postoperative Harris Hip Score and magnetic resonance imaging to quantify the necrotic area by using modified Kerboul angle were done and evaluated. Mean follow-up was 64.3 months (range, 54-72) and 63.7 months (range, 56-72) in groups A and B, respectively.

RESULTS

There was statistically significant difference between PRP and control groups in pain score (P = .00), functional score (P = .02), and Harris Hip Score (P = .00) at final follow-up. There was no progression in stage 1 disease. Stage 2 disease showed 24% progression in group A and 43% progression in group B. The difference was statistically significant (P = .025). Survivorship from femoral head collapse, any procedure, and total hip arthroplasty was 84%/68% (P = .00), 76%/57% (P = .02), and 92%/78% (P = .01) in 2 groups, which was statistically significant.

CONCLUSION

PRP use after CD provides significant pain relief, better midterm functional outcome, retards the progression, and enhances the survivorship free from reoperation for hip arthroplasty and femoral head collapse in early stages of avascular necrosis of hip than CD alone.

Does augmented core decompression decrease the rate of collapse and improve survival of femoral head avascular necrosis? Case-control study comparing 184 augmented core decompressions to 79 standard core decompressions with a minimum 2 years' follow-up

INTRODUCTION

Avascular necrosis of the femoral head often progresses to femoral head collapse if not treated. Conservative treatment yields highly variable results and is not standardised, mainly because it is typically evaluated in small patient populations. This led us to conduct a large retrospective comparative study with the goals of 1) analysing survival and functional outcomes, 2) looking for differences in survival between core decompression techniques (standard versus augmented), and 3) studying the risk factors for femoral head collapse and revision by arthroplasty.

HYPOTHESIS

Core decompression limits the number of patients who suffer femoral head collapse requiring arthroplasty at 2 years' follow-up.

METHODS

This multicentre, comparative, retrospective study analysed 330 patient records (1975-2016) where at least 2 years' follow-up was available. Sixty-two patients were excluded from the analysis: 5 had a stage III with collapse, 5 were lost to follow-up, 2 died within 24 months of the procedure and 50 had incomplete data. The study included 263 patients with a mean age of 42 years (15.7-70). In the Ficat classification, there were 51 cases of stage I necrosis, 186 cases of stage II and 22 cases of stage II with crescent sign (transition stage). The Kerboull angle on radiographs was between 5° and 20° in 40 patients, between 20° and 40° in 107 patients, between 40° and 60° in 52 patients and more than 60° in 29 patients. A standard core decompression was done in 79 patients and an augmented one in 184 patients. The more severe AVN cases (stage II) were more likely to be treated by augmented CD (160/184 patients, 87%) than by standard CD (48/79 patients, 61%) (p<0.001).

RESULTS

In the 263 patients, the overall survival (no arthroplasty at 2 years) was 73% (196/263). At 2 years, the survival rate (without arthroplasty) was 71% (56/79) in the standard CD group versus 76% (140/184) in the augmented CD group. This difference was significant when adjusted for Ficat stage and Kerboull angle [HR=0.457, 95% CI (0.247-0.844) (p=0.012)]. When the survival data was adjusted to the Ficat stage, augmented CD was better than standard CD with 10-year survival of 58.1% vs. 57.9% (p=0.0082). More than 30% necrosis volume increased the risk of failure [HR=3.291 95%CI (1.494-7.248) (p=0.0031)]. Also, a Kerboull angle above 60° increased the risk of failure [HR=3.148 95%CI (1.346-7.5) (p=0.0083)].

CONCLUSION

After 2 years, CD for non-collapsed femoral head AVN prevents collapse and revision to arthroplasty in 73% of cases (196/268). Augmented CD improves the 2-year survival and the long-term survival after adjusting for preoperative characteristics (Kerboullangle and Ficat stage). The risk of collapse and need for arthroplasty is greater in patients with 30% necrosis volume on MRI and Kerboull angle above 60°.

LEVEL OF EVIDENCE

III; retrospective case-control study.

Does prior core decompression have detrimental effect on subsequent total hip arthroplasty for osteonecrosis of the femoral head: A systematic review and meta-analysis

BACKGROUND

Core decompression (CD) is effective in relieving pain and delaying the progression to total hip arthroplasty (THA) for osteonecrosis of the femoral head (ONFH). However, the influence of CD on subsequent THA has not yet been established. Therefore, we performed this systematic review to answer: does prior CD have detrimental effect on subsequent THA for ONFH, especially with regards to survivorship and functional results, as well as perioperative and postoperative complications.

PATIENTS AND METHODS

After registration on PROSPERO (CRD42019118861), literature published up to and including November 2018 was searched in the PubMed, Embase and Cochrane library databases with predetermined terms. Comparative studies on the clinical outcomes between conversion to THA with prior CD (the Prior CD group) and primary THA (the Control group) for ONFH were included. The outcomes of interest included survivorship free from revision, the postoperative functional performance, perioperative and postoperative complications. Data was extracted systematically and a meta-analysis was performed.

RESULTS

Overall, 5 retrospective cohort studies with 110 hips were identified for the Prior CD group and 237 hips were identified for inclusion in the Control group. All of the studies were of high quality in terms of the Newcastle-Ottawa Scale. No difference in the rate of revision between the two groups (2/42 (4.8%) vs. 4/160 (2.5%); RR=1.92; 95% CI=0.34 to 10.75; p=0.46) was detected after a minimum two-year follow-up. The mean postoperative Harris Hip Score was similar between the two groups in all 5 studies. The two groups experienced similar blood loss (Mean difference=12.17ml; 95% CI= -15.28 to 39.61ml; p=0.38). Moreover, intraoperative fracture was increased in the Prior CD group, though this did not reach statistical significance (3/31 (9.7%) vs. 0/55 (0.0%); RR=7.05; 95% CI=0.82 to 60.78; p=0.08). Similarly, osteolysis or radiolucent lines were more likely to occur in the Prior CD group without statistical significance (9/81 (11.1%) vs. 6/200 (3.0%); RR=3.14, 95% CI=0.98 to 10.06; p=0.05).

DISCUSSION

The present evidence indicated that prior CD does not detrimentally affect the survivorship nor hip scores of subsequent THA. Attention should be paid, however, to the potential for intraoperative fracture, postoperative osteolysis or radiolucent lines.

LEVEL OF EVIDENCE

III; systematic review and meta-analysis of level III retrospective comparative studies.

What are the outcomes of core decompression without augmentation in patients with nontraumatic osteonecrosis of the femoral head?

Purpose

Core decompression (CD) of the femoral head is performed to preserve the hip in avascular necrosis (AVN). The outcome following this procedure differs based on the medical centre and the technique. Also, the time to total hip replacement (THR) and the percentage of patients subsequently undergoing a THR are controversial.

Methods

A systematic review was performed following PRISMA guidelines. The search included CENTRAL, MEDLINE, EMBASE, Scopus, AMED and Web of Science Core Collection databases. Studies reporting the outcome of CD for AVN were assessed. Studies using additional implants, vascularized grafts or any type of augmentation were excluded. Quality assessment was performed using the Joanna Briggs Institute Critical Appraisal Checklist (JBI CAC) tool.

Trial registration

International prospective register of systematic reviews (PROSPERO) - CRD42018100596.

Results

A total of 49 studies describing 2540 hips were included. The mean weighted follow-up time was 75.1 months and the mean age at surgery was 39 years. Twenty-four of 37 studies reported improvement in all outcome scores, whilst 9/37 studies report only partial improvement post-operatively. Four studies (4/37) described poor clinical outcomes following intervention. Data was pooled from 20 studies, including 1134 hips with a weighted mean follow-up of 56 months. The percentage of hips undergoing THR averaged 38%. The time to THR had a weighted mean of 26 months after CD.

Conclusion

Pooled results from 1134 hips and of these nearly 80% with early stage of osteonecrosis, showed that approximately 38% of patients underwent a total hip replacement at an average of 26 months following core decompression without augmentation.

Electronic supplementary material

The online version of this article (10.1007/s00264-020-04790-9) contains supplementary material, which is available to authorized users.

What are the outcomes of core decompression in patients with avascular necrosis? Protocol for a systematic review

Background: Core decompression is a hip preserving surgical procedure that is used to treat avascular necrosis (AVN) of the femoral head. The eventual clinical and radiological outcome following this procedure is varied in literature. Also, the time to a total hip replacement (THR) from the index procedure and the percentage of patients subsequently undergoing a THR is controversial. Furthermore, there are multiple surgical methods along with multiple augmentation techniques and various classification and staging systems described. The purpose of this systematic review, therefore, is to analyse the outcomes following decompression only, excluding any augmentation techniques for non-traumatic AVN of the femoral head. Methods: This protocol is being developed in line with the PRISMA-P guidelines. The search strategy includes articles from Medline, Embase, Google Scholar, CINHAL and Cochrane library. The review and screening will be done by two independent reviewers. Review articles, editorials and correspondences will be excluded. Articles including patients with sickle cell disease and with core decompression where augmentation is used will be excluded. The risk of bias and quality of articles will be assessed using the Joanna Briggs Institute Critical Appraisal Checklist for the different study designs included. Discussion: This study will be a comprehensive review on all published articles having patients with AVN of the femoral head and undergoing core decompression surgery only. The systematic review will then define the outcomes of the core decompression surgery based on clinical and radiological outcomes. Each outcome will include the different stages within it and finally, the total mean time to THR will be calculated. This will then be followed by assessing the cumulative confidence in evidence from all the data collected using the GRADE tool.   Registration: This systematic review is registered in the International Prospective Register for Systematic Reviews and Meta-analysis (PROSPERO) under the registration number:  CRD42018100596.

Classification of osteonecrosis of the femoral head: Who should have surgery?

Objectives

Using a simple classification method, we aimed to estimate the collapse rate due to osteonecrosis of the femoral head (ONFH) in order to develop treatment guidelines for joint-preserving surgeries.

Methods

We retrospectively analyzed 505 hips from 310 patients (141 men, 169 women; mean age 45.5 years (sd 14.9; 15 to 86)) diagnosed with ONFH and classified them using the Japanese Investigation Committee (JIC) classification. The JIC system includes four visualized types based on the location and size of osteonecrotic lesions on weightbearing surfaces (types A, B, C1, and C2) and the stage of ONFH. The collapse rate due to ONFH was calculated using Kaplan–Meier survival analysis, with radiological collapse/arthroplasty as endpoints.

Results

Bilateral cases accounted for 390 hips, while unilateral cases accounted for 115. According to the JIC types, 21 hips were type A, 34 were type B, 173 were type C1, and 277 were type C2. At initial diagnosis, 238/505 hips (47.0%) had already collapsed. Further, the cumulative survival rate was analyzed in 212 precollapsed hips, and the two-year and five-year collapse rates were found to be 0% and 0%, 7.9% and 7.9%, 23.2% and 36.6%, and 57.8% and 84.8% for types A, B, C1, and C2, respectively.

Conclusion

Type A ONFH needs no further treatment, but precollapse type C2 ONFH warrants immediate treatment with joint-preserving surgery. Considering the high collapse rate, our study results justify the importance of early diagnosis and intervention in asymptomatic patients with type C2 ONFH.

Cite this article: Y. Kuroda, T. Tanaka, T. Miyagawa, T. Kawai, K. Goto, S. Tanaka, S. Matsuda, H. Akiyama. Classification of osteonecrosis of the femoral head: Who should have surgery?. Bone Joint Res 2019;8:451–458. DOI: 10.1302/2046-3758.810.BJR-2019-0022.R1.