High-Energy Extracorporeal Shock Wave for Early Stage Osteonecrosis of the Femoral Head: A Single-Center Case Series

Steroid-Induced Avascular Necrosis in the Foot and Ankle-Pathophysiology, Surgical, and Nonsurgical Therapies: Case Study and Literature Review

Steroid-induced avascular necrosis (AVN) of the lower extremity is a destructive process of the bone found in patients who have been treated with these medications for a variety of medical conditions. There are several proposed etiologies for development of this condition, however much debate still remains for the exact pathophysiology. The main clinical characteristics include edema, arthralgias, and restricted joint range of motion. Diagnostic imaging is a key aspect in the analysis of this pathologic process. When steroid-induced AVN affects multiple bones, this atypical presentation is difficult to treat due to its diffuse nature, therefore surgical options are limited. In these cases, conservative therapy is targeted toward pain relief and preserving joint range of motion. This review aims to provide an overview on the presentation of steroid-induced AVN in the foot and ankle, outline the pathophysiology of the process, and describe a variety of both conservative and surgical treatment options. A case study is provided to showcase a patient presentation of diffuse steroid-induced AVN of the foot and ankle and their course of treatment.Levels of Evidence: Level V: Expert opinion.

The use of extracorporeal shock wave therapy (ESWT) in treating osteonecrosis of the femoral head (AVNFH): a retrospective study

PURPOSE

As most of the cases of avascular necrosis (AVN) in Saudi Arabia is seen in young population and as literature showed good effect of extracorporeal shock wave therapy (ESWT) in reducing pain and oedema in avascular necrosis and delaying the need of surgical intervention. Our purpose of this study is to assess the effectiveness of ESWT in reducing pain, improving range of motion (ROM) and delaying the surgical intervention in patient with AVN of femoral head and compare our results to published literature.

MATERIAL AND METHODS

We have treated 24 patients, 13 males and 11 females with a mean age of 29 years (range 14-48) with 34 hips affected. There were 14 unilateral and ten bilateral lesions. In our series 11 out of 24 patients (45.8%) were due to sickle cell disease. Other causes included idiopathic in five patients (20.8%), corticosteroids use and systemic lupus erythematous in three patients each (12.5% each) and post-traumatic AVN in two patients (8.3%). Extracorporeal shock wave therapy was implanted in FICAT stage I, II and III. All patients had two sessions of extracorporeal shock wave therapy, four to six weeks apart, each with 4000 impulses divided into four points. Radiological and MRI assessment were performed at regular time intervals with a minimum follow-up of two years. Clinical assessment was based on Visual Analog Scale and Harris Hip Score (HHS). The end point outcome measurement was the need for any operative intervention.

RESULTS

Operative intervention was necessary in eight out of 34 hips (23.5%), within an average of 2.5 years (range 1 to 5 years). A hip salvage was achieved in 76.5%. Function was improved with the Harris Hip Score from a mean of 54.6 to 80.4 (P value using paired t test ≤ 0.05). Pain assessed with Visual Analog Scale improved from 5.73 to 2.75 (P value using paired t test ≤ 0.05).

CONCLUSION

We do recommend the use of ESWT in treating AVN of bone whether of femoral head or other sites prior to the collapse of the articular surface. Further studies are needed to compare using two or more sessions as well as using four or six points for ESWT.

High-energy focused extracorporeal shock wave prevents the occurrence of glucocorticoid-induced osteonecrosis of the femoral head: A prospective randomized controlled trial

Background

Studies have shown that high-energy focused extracorporeal shock wave therapy (HF-ESWT) has a certain therapeutic effect on glucocorticoid-induced osteonecrosis of the femoral head (ONFH). This study aimed to observe the efficacy and safety of HF-ESWT as a precautionary measure to reduce the probability of glucocorticoid-induced ONFH.

Methods

A prospective randomized controlled trial was designed to evaluate whether HF-ESWT (Group A) can significantly prevent the incidence of glucocorticoid-induced ONFH relative to a control group without shockwave intervention (Group B). MRI was used to assess whether all participants experienced ONFH at 3, 6, and 12 months after the intervention. Continuous scoring was used to evaluate the intervention results: the 10-cm visual analog scale (VAS) was used to evaluate pain, and the hip Harris score (HHS) was used to evaluate the function of the hip joint. Any adverse events were recorded.

Results

153 patients (89 females and 64 males) who had been allocated to group A (75 patients) or Group B (78 patients) were included in the final analysis. The patients were 45.0 ​± ​13.0 years old. There were significant differences between the two groups in MRI diagnosis of ONFH patients (2 cases in Group A, 9 cases in Group B; p ​= ​0.034). Significant differences between groups were found in bilateral hip function measured using the HHS at 6 months (Left p ​= ​0.026; Right p ​= ​0.033) and 12 months (Left p ​= ​0.018; Right p ​= ​0.038). However, there was no difference in the functional results measured at 3 months and the VAS at any points.

Conclusions

This study confirms that HF-ESWT can be successfully used to reduce the probability of glucocorticoid-induced ONFH. Pain and hip dysfunction are common clinical manifestations when ONFH is unavoidable. Therefore, HF-ESWT can be recommended for the prevention and intervention of ONFH high-risk populations receiving high-dose glucocorticoid therapy.

The Translational potential of this article

The effective prevention of HF-ESWT on ONFH after high-dose glucocorticoid application demonstrated its transformation potential as a preventive method in the clinical prevention of glucocorticoid-induced ONFH.

The use of extracorporeal shock wave therapy for the treatment of bone marrow oedema - a systematic review and meta-analysis

BACKGROUND

Extracorporeal shock wave therapy (ESWT) has been used for various pathologies associated with bone marrow oedema (BME). However, it is still not clear whether ESWT may be favourable in the treatment of BME. Therefore, the aim of this systematic review was to assess the efficacy of ESWT for the treatment of BME.

METHODS

MEDLINE was searched for relevant literature with no time constraints. Both randomized and non-randomized trials were included. Case reports and conference abstracts were excluded. Titles and abstracts were screened and full-text articles of included studies were retrieved. Data on the effect of ESWT on pain, function, and the BME area on magnet resonance imaging were extracted.

RESULTS

Pain, function, and magnet resonance imaging results all improved across the studies - regardless of whether it was a randomized or non-randomized study. This effect was consistent across multiple pathologies such as osteonecrosis of the femoral head, BME associated with knee osteoarthritis, Kienböck's disease, and osteitis pubis. The meta-analysis showed that pain (after 1 month: weighted mean difference (WMD) = - 2.23, 95% CI - 2.58 to - 1.88, P < 0.0001; after 3-6 month: WMD = - 1.72, 95% CI - 2.52 to - 0.92, P < 0.00001) and function (after 1 month: WMD = - 1.59, 95% CI - 2.04 to - 1.14, P < 0.0001; after 3-6 month: WMD = - 2.06, 95% CI - 3.16 to - 0.96, P = 0.0002; after ≥ 12 month: WMD = - 1.20, 95% CI - 1.83 to - 0.56, P = 0.0002) was reduced in terms of ESWT treatment compared to a control group.

CONCLUSIONS

Based on the available evidence, ESWT may be an adequate option for conservative therapy in pathologies involving BME.

TRIAL REGISTRATION

PROSPERO, CRD42021201719 . Registered 23 December 2020.

High-energy extracorporeal shock wave therapy for early stage femoral head osteonecrosis: A protocol of systematic review

BACKGROUND

Published trials reported that high-energy extracorporeal shock wave therapy (HEEPSWT) can effectively treat early stage femoral head osteonecrosis (ESFHO). However, their results are still inconsistent. Thus, this study will systematically and comprehensively explore the effectiveness and safety of HEEPSWT for ESFHO.

METHODS

We will retrieve the electronic databases of Cochrane Library, EMBASE, PubMed, Web of Science, Cumulative Index to Nursing and Allied Health Literature, VIP database, and China National Knowledge Infrastructure from inception to the present. All randomized controlled trials that focusing on the effectiveness and safety of HEEPSWT for ESFHO will be considered. Two researchers will undertake literature selection, information collection, and risk of bias evaluation separately. If disagreements occur, we will invite a third researcher for consultation and a final decision will be made. Cochrane risk of bias tool, and Grades of Recommendation, Assessment, Development and Evaluation will be utilized to assess the risk of bias and quality of evidence, respectively. We will perform statistical analysis using RevMan 5.3 software.

RESULTS

This study will provide a detailed summary of exist evidence related to the effectiveness and safety of HEEPSWT for ESFHO.

CONCLUSION

The results of this study synthesize the evidence regarding the HEEPSWT for ESFHO, which may help to guide clinical management in the future.

SYSTEMATIC REVIEW REGISTRATION

INPLASY202060055.

The effect of the necrotic area on the biomechanics of the femoral head - a finite element study

Background

Femoral head collapse is the key to the progress of osteonecrosis of the femoral head (ONFH), but the causes of collapse are not completely clear. The better understanding of the progress of femoral head collapse will guide the treatment strategy for ONFH patients. The purpose of this study was to evaluate the biomechanical influence of necrosis area on the collapse of the femoral head by finite element analysis.

Methods

CT and MRI data from the hip joint of a healthy volunteer were collected to establish a finite element (FE) model of a normal hip. Subsequently, five categories of osteonecrosis FE models were established by using the normal model and computer software according to China-Japan Friendship Hospital (CJFH) classification for ONFH. The CJFH system includes five types based on the size and location of necrosis lesions in the femoral head (type M, C, L1, L2, and L3) and the stage of ONFH. The collapse indices of each model were analyzed by FE method, including the displacement, peak von Mises stress and stress index of the simulated necrotic area as well as the lateral pillar contact area of the femoral head to acetabular.

Results

(1) The displacement increments in the simulated necrotic areas of type M, C, L1, L2, and L3 models were 3.75 μm, 8.24 μm, 8.47 μm, 18.42 μm, and 20.44 μm respectively; the peak von Mises stress decrements were 1.50 MPa, 3.74 MPa, 3.73 MPa, 4.91 MPa, and 4.92 MPa respectively; and the stress indices were 0.04, 0.08, 0.08, 0.27, and 0.27 respectively. (2) The displacement increments in the lateral pillar contact areas of five type models were significantly different (P < 0.001) and increased in sequence as follows: 1.93 ± 0.15 μm, 5.74 ± 0.92 μm, 5.84 ± 1.42 μm, 14.50 ± 3.00 μm, and 16.43 ± 3.05 μm. The peak von Mises stress decrements were also significantly different (P < 0.001) and increased in sequence as follows: 0.52 ± 0.30 MPa, 0.55 ± 0.12 MPa, 0.67 ± 0.33 MPa, 4.17 ± 0.59 MPa, and 4.19 ± 0.60 MPa. (3) The collapse indices including the displacement increments and peak von Mises stress decrements of type L2 and L3 models were markedly higher than those of type M, C, and L1 models (P < 0.001).

Conclusions

The collapse indices of the femoral heads of type L2 and L3 FE models were significantly higher than those of type M, C, and L1. Different areas of necrosis result in varied impact on the femoral head collapse.

[Extracorporeal shockwave therapy for osteonecrosis of femoral head: traps and challenges]

Extracorporeal shock wave (ESW), as a noninvasive, safe, and effective treatment, was applied to the treatment in osteonecrosis of femoral head (ONFH) since the end of last century. Although this therapy is more and more widely used, there are many traps and challenges. We recommend using the high-energy focus ESW to treat ONFH, rather than using the low energy radial pressure wave. Furthermore, for different types ONFH, scientific personalized treatment planning should be made first. There are demands of multicenter united researches for this unknown field of ONFH treated with ESW, and so to provide high-level evidence-based medicine evidence.

Clinical and Radiological Outcomes of Extracorporeal Shock Wave Therapy in Early-Stage Femoral Head Osteonecrosis

Objective

Femoral head osteonecrosis is a progressive clinical condition with significant morbidity and long-term disability. Several treatment modalities including both surgical and nonsurgical options have been used with variable levels of success. High-energy extracorporeal shock wave therapy is a nonoperative treatment option that has been described for early-stage disease. We aimed to assess the functional and radiological outcomes of extracorporeal shockwave therapy (ESWT) in the treatment of osteonecrosis of the femoral head (ONFH).

Methods

Thirty-three hips of 21 patients were included in this study. Adult patients with ONFH of any etiology and in the precollapse stage were included. Clinical (visual analogue scale [VAS] and Harris hip score [HHS]) and radiological (plain radiographs and magnetic resonance imaging [MRI]) evaluations were performed before and after intervention. We used 3000–4500 pulses in a single session performed under general anesthesia.

Results

At an average of 8 months after ESWT, pain scores and HHS were significantly improved compared with the preintervention scores (p<0.001). The overall clinical outcomes were improved in 21 hips (63.3%), unchanged in 5 hips (15.15%), and worsened in 7 hips (21.2%). A trend toward a decrease in the size of the ONFH was observed although not of clinical significance (p=0.235). MRI revealed significant resolution of bone marrow edema (p<0.003). Regression was observed in 9 lesions (42.9%) and progression in 1 lesion (4.7%); no change was observed in the remaining 23 lesions (52.4%).

Conclusion

ESWT is a viable noninvasive treatment option for early-stage ONFH. It significantly improves clinical outcomes and may halt or delay the radiographic progression of the disease in the precollapse stage.

Bayesian Network Meta-Analysis of the Effectiveness of Various Interventions for Nontraumatic Osteonecrosis of the Femoral Head

Objective

To assess the effectiveness of various therapeutic hip preservation strategies on patients with nontraumatic osteonecrosis of the femoral head (ONFH).

Design

This is a systematic review of previous literature and in-depth Bayesian network meta-analysis of randomized controlled trials (RCTs) to compare the clinical effect of various operation methods and one physical intervention (extracorporeal shockwave).

Data Sources

Electronic literature, for studies published up to December 2017, was collected from PubMed, Medline, and the Cochrane Library.

Study Selection

We selected RCTs on patients with ONFH. Treatment methods included extracorporeal shockwave (ESW), core decompression (CD), multiple drilling decompression (DD), vascularized fibular grafting (VFG), free-vascularized fibular grafting (FVFG), inverted femoral head grafting (IFHG), vascular iliac pedicle bone grafting (VIPBG), osteotomy, and tantalum implantation (TI).

Outcome

The primary outcome was Harris score; the secondary outcome was Harris hip score (HHS), including total hip arthroplasty requirement (THA) and progression to collapse.

Results

A total of 14 randomized controlled trials were investigated. ESW had the highest improvement on Harris score (probability best 52%), followed by VFG (probability was 38%). In the meanwhile, VFG also proved to be superior in reducing the failure rates of treatment (probability lowest 59%), followed by ESW (probability lowest 24%). In femoral necrosis stage-II, VFG achieved the highest probability in preventing treatment failures (52%) and showed better performance in reducing treatment failure rates than CD.

Conclusion

ESW therapy (ESWT) is the most effective intervention to improve HHS, and VFG shows superior effect on reducing treatment failure rates.

Significance of Lateral Pillar in Osteonecrosis of Femoral Head: A Finite Element Analysis

Background:

The lateral pillar of the femoral head is an important site for disease development such as osteonecrosis of the femoral head. The femoral head consists of medial, central, and lateral pillars. This study aimed to determine the biomechanical effects of early osteonecrosis in pillars of the femoral head via a finite element (FE) analysis.

Methods:

A three-dimensional FE model of the intact hip joint was constructed from the image data of a healthy control. Further, a set of six early osteonecrosis models was developed based on the three-pillar classification. The von Mises stress and surface displacements were calculated for all models.

Results:

The peak values of von Mises stress in the cortical and cancellous bones of normal model were 6.41 MPa and 0.49 MPa, respectively. In models with necrotic lesions in the cortical and cancellous bones, the von Mises stress and displacement of lateral pillar showed significant variability: the stress of cortical bone decreased from 6.41 MPa to 1.51 MPa (76.0% reduction), while cancellous bone showed an increase from 0.49 MPa to 1.28 MPa (159.0% increase); surface displacements of cortical and cancellous bones increased from 52.4 μm and 52.1 μm to 67.9 μm (29.5%) and 61.9 μm (18.8%), respectively. In addition, osteonecrosis affected not only pillars but also adjacent structures in terms of the von Mises stress and surface displacement levels.

Conclusions:

This study suggested that the early-stage necrosis in the femoral head could increase the risk of collapse, especially in lateral pillar. On the other hand, the cortical part of lateral pillar was found to be the main biomechanical support of femoral head.

Corticosteroid-induced Osteonecrosis of the Femoral Head: Detection, Diagnosis, and Treatment in Earlier Stages

Objective:

This review aimed to provide a current recommendation to multidisciplinary physicians for early detection, diagnosis, and treatment of corticosteroid-induced osteonecrosis of the femoral head (ONFH) based on a comprehensive analysis of the clinical literature.

Data Sources:

For the purpose of collecting potentially eligible articles, we searched for articles in the PubMed, Cochrane Library, Embase, and CNKI databases up to February 2017, using the following key words: “corticosteroid”, “osteonecrosis of the femoral head”, “risk factors”, “diagnosis”, “prognosis”, and “treatment”.

Study Selection:

Articles on relationships between corticosteroid and ONFH were selected for this review. Articles on the diagnosis, prognosis, and intervention of earlier-stage ONFH were also reviewed.

Results:

The incidence of corticosteroid-induced ONFH was associated with high doses of corticosteroids, and underlying diseases in certain predisposed individuals mainly occurred in the first 3 months of corticosteroid prescription. The enhanced awareness and minimized exposure to the established risk factors and earlier definitive diagnosis are essential for the success of joint preservation. When following up patients with ONFH, treatment should be started if necessary. Surgical treatment yielded better results than conservative therapy in earlier-stage ONFH. The ideal purpose of earlier intervention and treatment is permanent preservation of the femoral head without physical restrictions in daily living.

Conclusions:

Clinicians should enhance their precaution awareness of corticosteroid-induced ONFH. For high-risk patients, regular follow-up is very important in the 1^st year after high-dose prescription of corticosteroids. Patients with suspected ONFH should be referred to orthopedists for diagnosis and treatment in its earlier stage to preserve the joint.

Nationwide study on the risk of unprovoked venous thromboembolism in non-traumatic osteonecrosis of femoral head

PURPOSE

Endothelial dysfunction is a risk factor for osteonecrosis of femoral head (ONFH) and venous thromboembolism (VTE) [defined as deep venous thrombosis (DVT) or pulmonary embolism (PE)]. However, the risk of unprovoked VTE in non-traumatic ONFH patients remains unclear.

METHODS

We investigated the relationship between ONFH and VTE using Taiwan National Health Insurance Research Database (NHIRD). Between 1997 and 2010, a total of 1514 non-traumatic ONFH patients were identified from 1,000,000 general populations after excluding initially concomitant diagnoses of DVT and PE, and subjects undergoing lower limb surgery within one year since enrollment. The comparison group (n = 15,140) without ONFH was set up by matching study cohort with age, gender, income and urbanization in a 1:10 ratio. Subjects diagnosed with VTE within one year after surgery were also excluded.

RESULTS

The patients with non-traumatic ONFH had significantly higher frequency of unprovoked VTE, including DVT, than general population (1.19 vs. 0.5%, p < 0.0007), whereas the frequency of PE was similar between these two groups (p = 0.4922). The cumulative incidence of VTE and DVT was also remarkably higher in the ONFH than non-ONFH group (all p < 0.001). After adjusting for age, gender, medications and comorbidities with multivariate analysis, the ONFH patients had a 2.3-fold increase in risk of DVT compared with non-ONFH counterparts (95% CI 1.28 to 4.13, p = 0.0053). Apart from ONFH, age > 65 years and hypertension were also identified as risk factors for DVT occurrence.

CONCLUSIONS

The incidence and risk of unprovoked VTE were significantly increased in the non-traumatic ONFH population.

Quantitative Assessments of Mechanical Responses upon Radial Extracorporeal Shock Wave Therapy

Although radial extracorporeal shock wave therapy (rESWT) has been widely used to treat orthopedic disorders with promising clinical results, rESWT largely relies on clinicians' personal experiences and arbitrary judgments, without knowing relationships between administration doses and effective doses at target sites. In fact, practitioners lack a general and reliable way to assess propagation and distribution of pressure waves inside biological tissues quantitatively. This study develops a methodology to combine experimental measurements and computational simulations to obtain pressure fields from rESWT through calibrating and validating computational models with experimental measurements. Wave pressures at the bottom of a petri dish and inside biological tissues are measured, respectively, by attaching and implanting flexible membrane sensors. Detailed wave dynamics are simulated through explicit finite element analyses. The data decipher that waves from rESWT radiate directionally and can be modeled as acoustic waves generated from a vibrating circular piston. Models are thus established to correlate pressure amplitudes at the bottom of petri dishes and in the axial direction of biological tissues. Additionally, a pilot simulation upon rESWT for human lumbar reveals a detailed and realistic pressure field mapping. This study will open a new avenue of personalized treatment planning and mechanism research for rESWT.

The role of Iloprost on bone edema and osteonecrosis: Safety and clinical results

INTRODUCTION

Iloprost is a commercially available prostaglandin I₂ (PGI₂) analogue that is shown to have antithrombotic, vasodilatative and antiproliferative effects. A number of clinical studies have shown that Iloprost can be effective in the management of bone marrow oedema and the treatment of avascular necrosis. The aim of this manuscript is to present our current understanding on the effect of Iloprost on the treatment of these conditions.

AREAS COVERED

The authors offer a comprehensive review of the existing literature on the experimental and clinical studies analysing the effect of Iloprost on bone, bone marrow oedema and avascular necrosis.

EXPERT OPINION

The available data from the clinical studies suggest that Iloprost has limited effect in advanced stages of avascular necrosis. However, literature suggests that Iloprost administration can be a viable option in the management of bone marrow oedema and early stages of osteonecrosis. Despite these promising results its effect on bone homeostasis needs further elucidation. Moreover, further data on its safety, dosage and efficiency through randomized multicenter studies are desirable in order to reach final conclusions.

Efficacy of lateral- versus medial-approach hip joint capsule denervation as surgical treatments of the hip joint pain; a neuronal tract tracing study in the sheep

OBJECTIVE

To evaluate efficacy of denervation of the of the hip joint capsule (HJC), as a treatment of hip joint pain. Specifically, we tested the hypothesis that HJC denervation will significantly reduce the number of sensory neurons innervating the capsule.

STUDY DESIGN

Denervation of the HJC from a medial or lateral approach was followed by retrograde tracing of sensory neurons innervating the capsule.

ANIMALS

Twenty adult male sheep (30-40 kg of body weight; Polish merino breed) were used in the study.

METHODS

The hip joint was denervated from medial (n = 5) or lateral (n = 5) surgical approaches. Immediately after denervation, the retrograde neural tract tracer Fast Blue (FB) was injected into the HJC. An additional ten animals (n = 5 for medial and n = 5 for lateral approach) received the same treatment without HJC denervation to provide the appropriate controls.

RESULTS

Results of the study revealed that the vast majority of retrogradely labelled sensory neurons innervating the HJC originate from fifth lumbar to second sacral dorsal root ganglia. Both the medial and the lateral denervations significantly reduced the number of sensory neurons innervating the HJC (39.2% and 69.0% reduction respectively).

CONCLUSIONS

These results show that denervation of the HJC is an effective surgical procedure for reduction of the sensory neuronal input to the HJC. Moreover, the lateral approach was found to be significantly more effective for reducing sensory innervation as compared to the medial one.

Extracorporeal shockwave therapy in osteonecrosis of femoral head: A systematic review of now available clinical evidences

BACKGROUND

Osteonecrosis is an incapacitating disorder with high morbidity. Though extracorporeal shockwave therapy (ESWT) provides a noninvasive treatment option, controversial subjects still exist about its effectiveness, indications, and mechanism of action.

METHODS

An electronic databases search was performed using PubMed, Embase, and the Cochrane library to collect clinical trials, case reports, and cases series on this topic and then useful data were extracted and appraised by experienced clinicians. We evaluated the quality of included evidences by using the Oxford Centre for evidence-based medicine (EBM) Levels of Evidence.

RESULTS

A total of 17 articles including 2 case reports, 9 open label trials, 2 cohorts, and 6 randomized controlled trials were considered to be eligible for this systematic review. Visual analog scale (VAS), Harris hip scores, and the imaging results were the frequently-used outcome estimates of included studies.

CONCLUSION

By systematically analyzing these evidences, we could conclude that ESWT could act as a safe and effective method to improve the motor function and relieve the pain of patients with osteonecrosis of femoral hip, especially those at early stage. Imaging revealed that bone marrow edema was significantly relieved, but the necrotic bone could not be reversed after ESWT. This technique could slow or even block the progression of ONFH and therefore reduce the demand for surgery. Collaboration with other conservative modalities would not improve the curative benefits of ESWT. Meanwhile, ONFH with various risk factors showed similar reaction to this noninvasive treatment method. However, these conclusions should be interpreted carefully for the low-quality of included publications and further studies are requisite to validate the effect of ESWT in ONFH.

Porous Tantalum Implant in Treating Osteonecrosis of the Femoral Head: Still a Viable Option?

The purpose of this study is to evaluate the survivorship and risk factors for radiographic progression and conversion to total hip arthroplasty (THA) after porous tantalum implant surgery in the treatment of osteonecrosis of the femoral head (ONFH). The study comprised 90 ONFH patients (104 consecutive hips) who were treated with a porous tantalum implant combined with bone grafting between June 2008 and December 2013. The patients were 19–61 years of age (mean age, 38 years). The mean follow-up was 42 months. The outcome measures included Harris hip score (HHS), radiographic outcome measures, and survivorship analysis with conversion to THA as the endpoint. The mean postoperative HHS was significantly lower than the mean preoperative HHS (P < 0.001). The Cox proportional hazards model showed that age and Association Research Circulation Osseous (ARCO) stage were independent risk factors for conversion to THA, while age, China-Japan Friendship Hospital (CJFH) type, and ARCO stage were independent risk factors for radiological progression. Ultimately, only 52.9% hips survived. Porous tantalum implant surgery combined with bone grafting is not a viable option for treating ONFH, especially in patients >35 years of age with preoperative ARCO stage III and CJFH type L3.