Did Osteoblastic Cell Therapy Improve the Prognosis of Pre-fracture Osteonecrosis of the Femoral Head? A Randomized, Controlled Trial

The efficacy of core decompression combined with regenerative therapy in early femoral head necrosis: a systematic review and meta-analysis involving 954 subjects

Background

The debate continues on whether combining core decompression (CD) with regenerative therapy provides a more effective treatment for early femoral head necrosis than CD alone. This systematic review and meta-analysis endeavored to assess its efficacy.

Methods

We systematically searched PubMed, Web of Science, and Cochrane Library through July 2024 for RCTs and cohort studies evaluating the impact of core decompression (CD) with regenerative therapy versus CD alone in early-stage osteonecrosis (ARCO I, II or IIIa or Ficat I or II) of the femoral head (ONFH). Bias was evaluated using the Cochrane ROB 2.0 for RCTs and the Newcastle-Ottawa Scale (NOS) for cohort studies. The primary outcome was disease progression, measured by the incidence of staging advancement and total hip arthroplasty (THA) conversion. Clinical outcomes, including VAS, HHS, WOMAC, and Lequesne index, were secondary measures. Subgroup analyses were performed for variables such as age, BMI, follow-up period, and dosage in the bone marrow aspirate concentrate (BMAC) group, with results depicted in forest plots.

Results

This study represented a total of seven RCTs (mean follow-up time 36.57 months) and eight cohort trials (mean follow-up time 74.18 months) involving 954 hips. CD, when combined with agents, exhibited considerably enhanced efficacy over CD alone (risk ratio (RR) = 0.55 (95% CI 0.39-0.77), p < 0.001, I 2 = 54%) and 0.59 (95% CI 0.43-0.81), p = 0.001, I 2 = 51%), respectively). However, a significant difference was exclusive to the CD combined with BMAC group in terms of stage progression outcomes (stage progression, RR = 0.47 (95% CI 0.28-0.78), p = 0.004, I 2 = 67%); THA conversions, RR = 0.41 (95% CI 0.32-0.52), p < 0.001, I 2 = 43%). Secondary outcomes (VAS, HHS, WOMAC score and Lequesne index) showed improved results when CD was combined with other regenerative agents, such as bone mesenchymal stem cells (BMSCs) and bone morphogenetic proteins (BMPs), etc. In the reported data, the regenerative group demonstrated significantly higher rates of subjective improvement in pain and functional outcomes compared to those in the CD group (71.74% (66/92) vs. 56.38% (53/94). Subgroup analysis revealed superior outcomes in the low-dose (less than 20 mL) BMAC group and patients aged under 40 years old in stage progression rate and THA conversion rate.

Conclusion

CD, when combined with regenerative therapy, can diminish hip pain and enhance functionality, but its ability to slow disease progression remains uncertain. BMAC presents a more substantiated efficacy evidence than other agents, with low-doses of BMAC in patients under 40 years potentially slowing ONFH progression. Nonetheless, the high heterogeneity and relatively short follow-up time of these studies make it difficult to draw accurate conclusions, which necessitates verification through future trials comparing CD versus CD combined with regenerative therapy, with a focus on extended follow-up periods.

Systematic Review Registration

identifier CRD42023467873.

Orthobiologic therapies delay the need for hip arthroplasty in patients with avascular necrosis of the femoral head: A systematic review and survival analysis

PURPOSE

The aim of this systematic review and survival analysis was to quantify the benefits of orthobiologic augmentation therapies for the treatment of avascular necrosis (AVN) of the femoral head and identify the most effective approach to delay the need for total hip arthroplasty (THA).

METHODS

A systematic review of the literature was performed on PubMed, Scopus, and Cochrane on clinical studies on orthobiologic therapies used alone or as an augmentation to core decompression or other procedures to address hip AVN. A qualitative analysis of the different biological therapies applied was performed. Afterward, the results of these procedures were quantitatively analysed to document their survivorship from THA compared to treatment groups without orthobiologics. Kaplan-Meier analysis was performed for all studies and then by categorising orthobiologics into treatment subgroups.

RESULTS

A total of 106 studies were included (4505 patients). Different orthobiologic approaches have been evaluated: cell-based therapies including bone marrow aspirate concentrate (BMAC) and bone marrow mesenchymal stromal cells (BM-MSCs), platelet-rich plasma (PRP), or other bioactive molecules applied in the osteonecrotic area or as intra-arterial injections. The survival analysis at 120 months documented a higher (p < 0.0005) cumulative survivorship with orthobiologics (69.4%) compared to controls (48.5%). The superiority was shown specifically for BMAC (p < 0.0005), BM-MSCs (p < 0.0005), intra-arterial (p < 0.0005) and PRP (p = 0.011) approaches, but the direct comparison of these approaches with their controls confirmed benefits only for BMAC (p < 0.0005).

CONCLUSION

This systematic review and survival analysis demonstrated that orthobiologics have the potential to improve survivorship in patients affected by hip AVN. In particular, the specific analysis of different orthobiologic products supported relevant benefits for BMAC augmentation in terms of survival from the need for THA, while no clear benefits were confirmed for other orthobiologics.

LEVEL OF EVIDENCE

Level III.

Advances in mechanism and management of bone homeostasis in osteonecrosis: a review article from basic to clinical applications

Osteonecrosis, characterized by bone cell death leading to impaired bone recovery, causes challenges in bone homeostasis maintenance. Bone homeostasis relies on the delicate balance between osteoclasts and osteoblasts, encompassing a series of complex and strictly regulated biological functions. Current treatments, including conservative therapies and surgeries, often fall short of expected outcomes, necessitating a reorientation towards more effective therapeutic strategies according to the pathogenesis. In this review, we hierarchically outlined risk factors, emerging mechanisms, and last-decade treatment approaches in osteonecrosis. By connecting mechanisms of bone homeostasis, we proposed future research directions should be focused on elucidating risk factors and key molecules, performing high-quality clinical trial, updating practice, and accelerating translational potential.

Zoledronic Acid and Enriched Autologous Bone Marrow Stem Cell Implantation for Femoral Head Osteonecrosis

Purpose

This study evaluated the clinical results of zoledronic acid in the treatment of early osteonecrosis of the femoral head (ONFH).

Materials and Methods

Study retrospectively analyzed 60 patients with zoledronic acid with bone marrow stem cell (BMSC) implantation (The study group) and 64 patients with BMSC implantation (The control group). The primary evaluation index included VAS, HHS, collapsed rate, and total hip replacement arthroplasty (THA) conversion rate.

Results

The study group had a lower VAS (1.12 ± 0.22 vs 1.44 ± 0.32) and higher HHS (75.07 ± 3.66 vs 68.78 ± 2.24) compared to the control group in 6 months after surgery (P < 0.05). In the study group, 12 hips (20%) collapsed, and 7 of 60 hips (11.67%) required THA surgery at the last follow-up. However, 25 hips (38.8%) collapsed in the control group, and 19 hips (29.69%) required THA surgery. The study group had a lower collapsed rate (P = 0.029) and THA conversion rate (P = 0.016) in survival analysis.

Conclusion

Zoledronic acid and BMSC implantation in the treatment of early ONFH is safe and effective, reduces pain shortens recovery time, and reduces collapsed rate and THA conversion rate in ONFH patients.

Implantation of Culture-Expanded Bone Marrow Derived Mesenchymal Stromal Cells for Treatment of Osteonecrosis of the Femoral Head

BACKGROUND

Although core decompression (CD) with stem cell for the treatment of osteonecrosis of the femoral head (ONFH) showed promising results in many reports, the efficacy remains uncertain. We aimed to evaluate the efficacy of CD with culture-expanded autologous bone marrow-derived mesenchymal stem cell (BM-MSC) implantation in early stage ONFH.

METHODS

A total of 18 patients (22 hips) with ONFH who underwent CD with culture-expanded BM-MSC implantation from September 2013 to July 2020 were retrospectively reviewed. The median age was 35.0 years [interquartile range (IQR), 28.5-42.0], and the median follow-up period was 4.0 years (IQR, 2.0-5.3). The median number of MSCs was 1.06 × 108. To evaluate radiographic and clinical outcomes, Association Research Circulation Osseous (ARCO) classifications, Japanese Investigation Committee classification, combined necrotic angle (CNA) visual analogue scale (VAS) and Harris Hip Score (HHS) were checked at each follow-up.

RESULTS

The preoperative stage of ONFH was ARCO 2 in 14 hips and ARCO 3a in 8 hips. The ARCO staging was maintained in 7 hips in ARCO 2 and 4 hips in ARCO 3a. The radiographic failure rate of ARCO 2 and 3a was 14.3 and 50%, respectively. Furthermore, CNA decreased to more than 20° in 6 hips (four were ARCO 2 and two were ARCO 3a).There was no significant difference in the VAS and HHS (P = 0.052 and P = 0.535, respectively). Total hip arthroplasty was performed in 4 hips.

CONCLUSION

CD with culture-expanded autologous BM-MSCs showed promising results for the treatment of early stage ONFH.

Cellular therapies for bone repair: current insights

Mesenchymal stem cells are core to bone homeostasis and repair. They both provide the progenitor cells from which bone cells are formed and regulate the local cytokine environment to create a pro-osteogenic environment. Dysregulation of these cells is often seen in orthopaedic pathology and can be manipulated by the physician treating the patient. This narrative review aims to describe the common applications of cell therapies to bone healing whilst also suggesting the future direction of these techniques.

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.

Comparative analysis of surgical interventions for osteonecrosis of the femoral head: a network meta-analysis of randomized controlled trials

BACKGROUND

Despite several surgical options, there remains no consensus regarding the optimal approach for osteonecrosis of the femoral head (ONFH), a prevalent and refractory disease. To determine the most suitable treatment modality, we compared randomized controlled trials (RCTs) that evaluated multiple surgical treatments for ONFH using a Bayesian network meta-analysis (NMA).

METHODS

The outcomes of 11 different surgical treatments were assessed using NMA comparisons of the rate of progression of femoral head necrosis, the rate of conversion to total hip arthroplasty, and improvement of the Harris hip score (HHS). A random effects model was used to analyze the odds ratio (OR) or mean difference, and risk of bias was assessed using the Cochrane risk of bias assessment tool for randomized trials. The confidence of the results was assessed using the confidence in network meta-analysis tool.

RESULTS

A total of 18 RCTs were included in the meta-analysis. Compared with core decompression (CD), the forest plot showed that autologous bone grafting (ABG), free fibula grafting (FFG), vascularized bone grafting (VBG), autologous bone grafting combined with bone marrow aspirate concentrate (ABG + BMAC), and biomaterial grafting combined with vascularized bone grafting (BMG + VBG) delayed ONFH progression. Among them, ABG + BMAC showed the most promising results (OR 0.019; 95% confidence interval [CI] 0.0012-0.25). However, upon comparing CD with different surgical modalities, no significant differences were found in preventing total hip arthroplasty. Furthermore, we cannot draw conclusions regarding the HHS due to attribution and high heterogeneity across the studies.

CONCLUSION

Overall, ABG, VBG, FFG, ABG + BMAC, and BMG + VBG showed significant results in preventing ONFH progression compared with that shown by CD. Based on the surface under the cumulative ranking, ABG + BMAC was the most effective. Moreover, all treatments involving bone grafting were found to be effective, possibly indicating the necessity of its use in the treatment of ONFH.

Does Adjunction of Autologous Osteoblastic Cells Improve the Results of Core Decompression in Early-stage Femoral Head Osteonecrosis? A Double-blind, Randomized Trial

BACKGROUND

Osteonecrosis of the femoral head (ONFH) is a disabling disease that can ultimately progress to collapse of the femoral head, often resulting in THA. Core decompression of the femoral head combined with cell therapies have shown beneficial effects in previous clinical studies in patients with early-stage (Association Research Circulation Osseous [ARCO] Stage I and II) ONFH. However, high-quality evidence confirming the efficacy of this treatment modality is still lacking.

QUESTIONS/PURPOSES

(1) Is core decompression combined with autologous osteoblastic cell transplantation superior to core decompression with placebo implantation in relieving disease-associated pain and preventing radiologic ONFH progression in patients with nontraumatic early-stage ONFH? (2) What adverse events occurred in the treatment and control groups?

METHODS

This study was a Phase III, multicenter, randomized, double-blind, controlled study conducted from 2011 to 2019 (ClinicalTrails.gov registry number: NCT01529008). Adult patients with ARCO Stage I and II ONFH were randomized (1:1) to receive either core decompression with osteoblastic cell transplantation (5 mL with 20 x 10 6 cells/mL in the study group) or core decompression with placebo (5 mL of solution without cells in the control group) implantation. Thirty percent (68 of 230) of the screened patients were eligible for inclusion in the study; of these, 94% (64 of 68) underwent a bone marrow harvest or sham procedure (extended safety set) and 79% (54 of 68) were treated (study group: 25 patients; control group: 29). Forty-nine patients were included in the efficacy analyses. Similar proportions of patients in each group completed the study at 24 months of follow-up (study group: 44% [11 of 25]; control: 41% [12 of 29]). The study and control groups were comparable in important ways; for example, in the study and control groups, most patients were men (79% [27 of 34] and 87% [26 of 30], respectively) and had ARCO Stage II ONFH (76% [19 of 25] and 83% [24 of 29], respectively); the mean age was 46 and 45 years in the study and control groups, respectively. The follow-up period was 24 months post-treatment. The primary efficacy endpoint was the composite treatment response at 24 months, comprising the clinical response (clinically important improvement in pain from baseline using the WOMAC VA3.1 pain subscale, defined as 10 mm on a 100-mm scale) and radiologic response (the absence of progression to fracture stage [≥ ARCO Stage III], as assessed by conventional radiography and MRI of the hips). Secondary efficacy endpoints included the percentages of patients achieving a composite treatment response, clinical response, and radiologic response at 12 months, and the percentage of patients undergoing THA at 24 months. We maintained a continuous reporting system for adverse events and serious adverse events related to the study treatment, bone marrow aspiration and sham procedure, or other study procedures throughout the study. A planned, unblinded interim analysis of efficacy and adverse events was completed at 12 months. The study was discontinued because our data safety monitoring board recommended terminating the study for futility based on preselected futility stopping rules: conditional power below 0.20 and p = 0.01 to detect an effect size of 10 mm on the 100-mm WOMAC VA3.1 pain subscale (improvement in pain) and the absence of progression to fracture (≥ ARCO Stage III) observed on radiologic assessment, reflecting the unlikelihood that statistically beneficial results would be reached at 24 months after the treatment.

RESULTS

There was no difference between the study and control groups in the proportion of patients who achieved a composite treatment response at 24 months (61% [14 of 23] versus 69% [18 of 26]; p = 0.54). There was no difference in the proportion of patients with a treatment response at 12 months between the study and control groups (14 of 21 versus 15 of 23; p = 0.92), clinical response (17 of 21 versus 16 of 23; p = 0.38), and radiologic response (16 of 21 versus 18 of 23; p = 0.87). With the numbers available, at 24 months, there was no difference in the proportion of patients who underwent THA between the study and control groups (24% [six of 25] versus 14% [four of 29]). There were no serious adverse events related to the study treatment, and only one serious adverse event (procedural pain in the study group) was related to bone marrow aspiration. Nonserious adverse events related to the treatment were rare in the study and control groups (4% [one of 25] versus 14% [four of 29]). Nonserious adverse events related to bone marrow or sham aspiration were reported by 15% (five of 34) of patients in the study group and 7% (two of 30) of patients in the control group.

CONCLUSION

Our study did not show any advantage of autologous osteoblastic cells to improve the results of core decompression in early-stage (precollapse) ONFH. Adverse events related to treatment were rare and generally mild in both groups, although there might have been a potential risk associated with cell expansion. Based on our findings, we do not recommend the combination of osteoblastic cells and core decompression in patients with early-stage ONFH. Further, well-designed studies should be conducted to explore whether other treatment modalities involving a biological approach could improve the overall results of core decompression.

LEVEL OF EVIDENCE

Level II, therapeutic study.

Single-cell transcriptome analysis reveals aberrant stromal cells and heterogeneous endothelial cells in alcohol-induced osteonecrosis of the femoral head

Alcohol-induced osteonecrosis of the femoral head (ONFH) is a disabling disease with a high incidence and elusive pathogenesis. Here, we used single-cell RNA sequencing to explore the transcriptomic landscape of mid- and advanced-stage alcohol-induced ONFH. Cells derived from age-matched hip osteoarthritis and femoral neck fracture samples were used as control. Our bioinformatics analysis revealed the disorder of osteogenic-adipogenic differentiation of stromal cells in ONFH and altered regulons such as MEF2C and JUND. In addition, we reported that one of the endothelial cell clusters with ACKR1 expression exhibited strong chemotaxis and a weak angiogenic ability and expanded with disease progression. Furthermore, ligand-receptor-based cell-cell interaction analysis indicated that ACKR1+ endothelial cells might specifically communicate with stromal cells through the VISFATIN and SELE pathways, thus influencing stromal cell differentiation in ONFH. Overall, our data revealed single cell transcriptome characteristics in alcohol-induced ONFH, which may contribute to the further investigation of ONFH pathogenesis.

Single-cell RNA-seq of bone from patients with osteonecrosis of the femoral head (ONFH) highlights the relevance of stromal and endothelial cells to disease pathogenesis, and provides a resource for developing cell type-specific therapeutic strategies.

Nonoperative and Operative Bone and Cartilage Regeneration and Orthopaedic Biologics of the Hip: An Orthoregeneration Network (ON) Foundation Hip Review

Orthoregeneration is defined as a solution for orthopaedic conditions that harnesses the benefits of biology to improve healing, reduce pain, improve function, and, optimally, provide an environment for tissue regeneration. Options include drugs, surgical intervention, scaffolds, biologics as a product of cells, and physical and electromagnetic stimuli. The goal of regenerative medicine is to enhance the healing of tissue after musculoskeletal injuries as both isolated treatment and adjunct to surgical management, using novel therapies to improve recovery and outcomes. Various orthopaedic biologics (orthobiologics) have been investigated for the treatment of pathology involving the hip, including osteonecrosis (aseptic necrosis) involving bone marrow, bone, and cartilage, and chondral injuries involving articular cartilage, synovium, and bone marrow. Promising and established treatment modalities for osteonecrosis include nonweightbearing; pharmacological treatments including low molecular-weight heparin, prostacyclin, statins, bisphosphonates, and denosumab, a receptor activator of nuclear factor-kB ligand inhibitor; extracorporeal shock wave therapy; pulsed electromagnetic fields; core decompression surgery; cellular therapies including bone marrow aspirate comprising mesenchymal stromal cells (MSCs aka mesenchymal stem cells) and bone marrow autologous concentrate, with or without expanded or cultured cells, and possible addition of bone morphogenetic protein-2, vascular endothelial growth factor, and basic fibroblast growth factor; and arterial perfusion of MSCs that may be combined with addition of carriers or scaffolds including autologous MSCs cultured with beta-tricalcium phosphate ceramics associated with a free vascularized fibula. Promising and established treatment modalities for chondral lesions include autologous platelet-rich plasma; hyaluronic acid; MSCs (in expanded or nonexpanded form) derived from bone marrow or other sources such as fat, placenta, umbilical cord blood, synovial membrane, and cartilage; microfracture or microfracture augmented with membrane containing MSCs, collagen, HA, or synthetic polymer; mosaicplasty; 1-stage autologous cartilage translation (ACT) or 2-stage ACT using 3-dimensional spheroids; and autologous cartilage grafting; chondral flap repair, or flap fixation with fibrin glue. Hip pain is catastrophic in young patients, and promising therapies offer an alternative to premature arthroplasty. This may address both physical and psychological components of pain; the goal is to avoid or postpone an artificial joint. LEVEL OF EVIDENCE: Level V, expert opinion.

Core decompression and bone marrow aspirate concentrate injection for Avascular Necrosis (AVN) of the femoral head: A scoping review

BACKGROUND

Various joint preserving treatments are available for use in Avascular Necrosis of the femoral head. Most of these are effective in the pre-collapse stage of the disease. This review aimed to evaluate the effectiveness of core decompression and Bone Marrow Aspirate Concentrate in various stages of AVN, in modifying the progression of the disease and the need for hip replacement.

MATERIAL AND METHODS

The Preferred Reporting Items for Systematic reviews and Meta-Analysis Extension for Scoping Reviews reporting guidelines were followed. The literature search was conducted from inception till 2nd May 2021, on the PUBMED, SCOPUS, and Google Scholar search engines, using "bone marrow aspirate concentrate osteonecrosis femur" and "bmac osteonecrosis femur" as the keywords. In all these studies, Core Decompression with Bone marrow Aspirate concentrate was performed. The evaluation was done based on the progression of osteonecrosis, improvement in functional outcomes and the conversion to total hip arthroplasty.

RESULTS

We have analyzed 612 hips from11 studies, based on our inclusion and exclusion criteria. The mean age of the patients was 38.27 years. There was a predominance of males. The grade of AVN ranged from grade 1 to 4. The average follow-up period of the cases ranged from 2 to 12 years (average: 4.38 years). The functional scores were improved in the majority of cases. Radiographic progression occurred in 23.5% of hips, and the Total Hip Arthroplasty was performed in 14.9% of hips.

CONCLUSIONS

Core decompression with Bone Marrow Aspirate Concentrate in pre-collapse stages of the disease is beneficial in improving the functions scores and for reducing the radiological progression of the disease and need for total hip arthroplasty, in the majority of cases.

Lack of Conclusive Evidence of the Benefit of Biologic Augmentation in Core Decompression for Nontraumatic Osteonecrosis of the Femoral Head: A Systematic Review

PURPOSE

To assess whether biologic augmentation in addition to core decompression (CD), compared with CD alone, improves clinical and radiographic outcomes in the treatment of nontraumatic osteonecrosis of the femoral head (ONFH). Our hypothesis was that biologic augmentation would reduce the progression of osteonecrosis and therefore also the rate of conversion to total hip arthroplasty (THA).

METHODS

A systematic review was performed in accordance with the Preferred Reporting Items of Systematic Reviews and Meta-analysis (PRISMA) statement. Six databases were searched: Central, MEDLINE, Embase, Scopus, AMED, and Web of Science. Studies comparing outcomes of CD versus CD plus biologic augmentation (with or without structural augmentation), with a reported minimum level of evidence of III and ≥24 months of follow-up, were eligible. Procedural success was conceptualized as (1) avoidance of conversion to THA and (2) absence of radiographic disease progression. Risk of bias was assessed using the Joanna Briggs Institute critical appraisal checklists. A quantitative analysis of heterogeneity was undertaken.

RESULTS

We included studies reporting on 560 hips in 484 patients. Biologic augmentation consisted of bone marrow stem cells in 10 studies, bone morphogenic protein in 2, and platelet-rich plasma in 1. Three studies used additional structural augmentation. The median maximum follow-up time was 45 months. Only 4 studies reported improvement in all clinical scores in the augmentation group. Seven studies observed a reduction in the rate of radiographic progression, and only 5 found reduced rates of conversion to THA when using augmentation. A high risk of bias and marked heterogeneity was found, with uncertainty about the study designs implemented, analytical approaches, and quality of reporting.

CONCLUSION

Current evidence is inconclusive regarding the benefit of biologic augmentation in CD for nontraumatic ONFH, because of inconsistent results with substantial heterogeneity and high risk of bias.

LEVEL OF EVIDENCE

III, systematic review of level I, II, and III studies.

Cell therapy for osteonecrosis of femoral head and joint preservation

Osteonecrosis of femoral head (ONFH) is a disease of the femoral head and can cause femoral head collapse and arthritis. This can lead to pain and gait disorders. ONFH has various risk factors, it is often progressive, and if untreated results in secondary osteo-arthritis. Biological therapy makes use of bone marrow concentrate, cultured osteoblast and mesenchymal stem cell (MSC) obtained from various sources. These are often used in conjunction with core decompression surgery. In this review article, we discuss the current status of cell therapy and its limitations. We also present the future development of biological approach to treat ONFH.

Proteomic Comparison of Bone Marrow Derived Osteoblasts and Mesenchymal Stem Cells

Mesenchymal stem cells (MSCs) can differentiate into osteoblasts, and therapeutic targeting of these cells is considered both for malignant and non-malignant diseases. We analyzed global proteomic profiles for osteoblasts derived from ten and MSCs from six healthy individuals, and we quantified 5465 proteins for the osteoblasts and 5420 proteins for the MSCs. There was a large overlap in the profiles for the two cell types; 156 proteins were quantified only in osteoblasts and 111 proteins only for the MSCs. The osteoblast-specific proteins included several extracellular matrix proteins and a network including 27 proteins that influence intracellular signaling (Wnt/Notch/Bone morphogenic protein pathways) and bone mineralization. The osteoblasts and MSCs showed only minor age- and sex-dependent proteomic differences. Finally, the osteoblast and MSC proteomic profiles were altered by ex vivo culture in serum-free media. We conclude that although the proteomic profiles of osteoblasts and MSCs show many similarities, we identified several osteoblast-specific extracellular matrix proteins and an osteoblast-specific intracellular signaling network. Therapeutic targeting of these proteins will possibly have minor effects on MSCs. Furthermore, the use of ex vivo cultured osteoblasts/MSCs in clinical medicine will require careful standardization of the ex vivo handling of the cells.

Efficacy and safety of stem cell therapy for the early-stage osteonecrosis of femoral head: a systematic review and meta-analysis of randomized controlled trials

Background

Osteonecrosis of femoral head (ONFH) is a seriously degenerative disease with no effective therapies to slow its progression. Several studies have reported short-term efficacy of stem cells on early-stage ONFH. However, its long-term effect was still unclear especially on progression events. This study was performed to evaluate the long-term efficacy and safety of stem cells and analyze its optimal age group and cell number.

Methods

Our review was registered on PROSPERO (http://www.crd.york.ac.uk/PROSPERO), registration number CRD42020136094. Following PRISMA guideline, we searched 8 electronic databases on January 5, 2020, and rigorous random controlled trials (RCTs) utilizing stem cell therapy on early-stage ONFH were included. Quality and bias were analyzed. Pooled analysis was performed to assess difference between various outcomes.

Results

A total of 13 RCTs (619 patients with 855 hips) were included. The application of stem cells significantly delayed collapse of femoral head(I², 70%; RR, 0.54; 95% CI, 0.33 to 0.89; P < .00001) and total hip replacement (THR) (I², 68%; RR, 0.55; 95% CI, 0.34 to 0.90; P = .02) in the long term. It effectively decreased the events of collapse of femoral head (≥ 60 months) (I², 0%; RR, 0.37; 95% CI, 0.28 to 0.49; P < .00001) and THR (> 36 months) (I², 0%; RR, 0.32; 95% CI, 0.23 to 0.44; P < .00001). There existed a beneficial effect for patients under 40 (Collapse of femoral head: I², 56%; RR, 0.41; 95% CI, 0.23 to 0.76; P = .004) (THR: I², 0%; RR, 0.31; 95% CI, 0.23 to 0.42; P < .00001). In addition, quantity of stem cells at 10⁸ magnitude had better effects on disease progression events (I², 0%; RR, 0.34; 95%CI, 0.16 to 0.74; P = .007). Besides, there were no significant differences on adverse events between the stem cell group and control group (I², 0%; RR, 0.82; 95% CI, 0.39 to 1.73; P = .60).

Conclusion

Our findings build solid evidence that stem cell therapy could be expected to have a long-term effect on preventing early-stage ONFH patients from progression events, such as collapse of femoral head and total hip replacement. Furthermore, patients under 40 may be an ideal age group and the optimal cell number could be at 10⁸ magnitude for this therapy. Further studies including strict RCTs are required to evaluate a clear effect of stem cells on ideal patient profile and the procedures of implantation.