Combining autologous bone marrow buffy coat and angioconductive bioceramic rod grafting with advanced core decompression improves short-term outcomes in early avascular necrosis of the femoral head: a prospective, randomized, comparative study

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.

Cross Talk Between Cells and the Current Bioceramics in Bone Regeneration: A Comprehensive Review

The conventional approach for addressing bone defects and stubborn non-unions typically involves the use of autogenous bone grafts. Nevertheless, obtaining these grafts can be challenging, and the procedure can lead to significant morbidity. Three primary treatment strategies for managing bone defects and non-unions prove resistant to conventional treatments: synthetic bone graft substitutes (BGS), a combination of BGS with bioactive molecules, and the use of BGS in conjunction with stem cells. In the realm of synthetic BGS, a multitude of biomaterials have emerged for creating scaffolds in bone tissue engineering (TE). These materials encompass biometals like titanium, iron, magnesium, and zinc, as well as bioceramics such as hydroxyapatite (HA) and tricalcium phosphate (TCP). Bone TE scaffolds serve as temporary implants, fostering tissue ingrowth and the regeneration of new bone. They are meticulously designed to enhance bone healing by optimizing geometric, mechanical, and biological properties. These scaffolds undergo continual remodeling facilitated by bone cells like osteoblasts and osteoclasts. Through various signaling pathways, stem cells and bone cells work together to regulate bone regeneration when a portion of bone is damaged or deformed. By targeting signaling pathways, bone TE can improve bone defects through effective therapies. This review provided insights into the interplay between cells and the current state of bioceramics in the context of bone regeneration.

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.

Stem cell therapy combined with core decompression versus core decompression alone in the treatment of avascular necrosis of the femoral head: a systematic review and meta-analysis

INTRODUCTION

Accumulated clinical trials had been focused on stem cell therapy in combination of core decompression (CD) in the treatment of avascular necrosis of the femoral head (ANFH). Nonetheless, the results were inconclusive. Here, we performed a systematic review and meta-analysis of previous randomized controlled trials (RCTs) and retrospective studies to assess whether combined stem cell augmentation with CD improved the outcomes of ANFH compared with CD alone.

METHODS

The current study included 11 RCTs and 7 retrospective studies reporting the clinical outcomes of a total of 916 patients and 1257 hips. 557 and 700 hips received CD and CD plus stem cell therapy, respectively. To compare CD with CD plus stem cell therapy, we examined the clinical evaluating scores, the occurrence of the femoral head, radiologic progression and conversion to total hip arthroplasty (THA).

RESULTS

Only 10 studies reported significantly greater improvement in hip functions while combining stem cell procedure with CD. The pooled results in subgroup analysis indicated that stem cell group had a lower collapse rate on a mid-term basis (P = 0.001), when combined with mechanical support (P < 0.00001), and with extracted stem cells (P = 0.0002). Likewise, stem cell group had a lower radiographic progression rate at 2- to 5-year follow-up [P = 0.003], when combined with structural grafting (P < 0.00001), and with extracted stem cells (P = 0.004). Stem cell therapy resulted in an overall lower THA conversion rate (P < 0.0001) except that at a follow-up longer than 5 years.

CONCLUSION

Stem cell therapy combined with core decompression was more effective in preventing collapse, radiographic progression and conversion to THA. Trial Registration The current protocol has been registered in PROSPERO with the registration number: CRD42023417248.

Application of Biomaterials in Treating Early Osteonecrosis of the Femoral Head: Research Progress and Future Perspectives

Osteonecrosis of the femoral head (ONFH), a progressive pathological process of femoral head ischemia and osteocyte necrosis, is a refractory orthopedic disease caused by multiple etiologies and there is no complete cure at present. With the extension of ONFH duration, osteocyte apoptosis and trabecular bone loss can decrease the load-bearing capacity of the femoral head, which leads to the collapse of the articular cartilage and subchondral bone. Therefore, an urgent clinical need exists to develop effective treatment strategies of early-stage ONFH for maintaining the hip joint function and preventing femoral head collapse. In recent years, extensive attention has been paid to the application of diverse biomaterials in treating early ONFH for sustaining the normal morphology and function of the autologous femoral head, and slowing disease progression. Herein, we review the research progress of bone grafts, metallic materials, bioceramics, bioglasses and polymer materials for early ONFH treatment, and discuss the biological mechanisms of bone repair and regeneration in the femoral-head necrotic area. We propose suggestions for future research directions, from a special perspective of improving the local microenvironment in femoral head by facilitating vessel-associated osteoclasts (VAOs) generation and coupling of bone-specific angiogenesis and osteogenesis, as well as inhibiting bone-associated osteoclasts (BAOs) and BAO-mediated bone resorption. This review can provide ideas for the research, development, and clinical application of biomaterials for treating early ONFH. STATEMENT OF SIGNIFICANCE: We believe that at least three aspects of this manuscript make it interesting to readers of the Acta Biomaterialia. First, we briefly summarize the incidence, pathogenesis, risk factors, classification criteria and treatment of early osteonecrosis of the femoral head (ONFH). Second, we review the research progress in biomaterials for early ONFH treatment and the biological mechanisms of bone repair and regeneration in femoral-head necrotic area. Third, we propose future research progress on improving the local microenvironment in femoral head by facilitating vessel-associated osteoclasts generation and coupling of bone-specific angiogenesis and osteogenesis, as well as inhibiting bone-associated osteoclasts and bone resorption. We hope this review can provide ideas for the research, development, and clinical application of biomaterials for treating early ONFH.

LncAABR07053481 inhibits bone marrow mesenchymal stem cell apoptosis and promotes repair following steroid-induced avascular necrosis

The osteonecrotic area of steroid-induced avascular necrosis of the femoral head (SANFH) is a hypoxic microenvironment that leads to apoptosis of transplanted bone marrow mesenchymal stem cells (BMSCs). However, the underlying mechanism remains unclear. Here, we explore the mechanism of hypoxic-induced apoptosis of BMSCs, and use the mechanism to improve the transplantation efficacy of BMSCs. Our results show that the long non-coding RNA AABR07053481 (LncAABR07053481) is downregulated in BMSCs and closely related to the degree of hypoxia. Overexpression of LncAABR07053481 could increase the survival rate of BMSCs. Further exploration of the downstream target gene indicates that LncAABR07053481 acts as a molecular "sponge" of miR-664-2-5p to relieve the silencing effect of miR-664-2-5p on the target gene Notch1. Importantly, the survival rate of BMSCs overexpressing LncAABR07053481 is significantly improved after transplantation, and the repair effect of BMSCs in the osteonecrotic area is also improved. This study reveal the mechanism by which LncAABR07053481 inhibits hypoxia-induced apoptosis of BMSCs by regulating the miR-664-2-5p/Notch1 pathway and its therapeutic effect on SANFH.

Core decompression with β-tri-calcium phosphate grafts in combination with platelet-rich plasma for the treatment of avascular necrosis of femoral head

BACKGROUND

This study was aimed to investigate whether the application of platelet-rich plasma (PRP) combined with β-tri-calcium phosphate (β-TCP) grafts after core decompression (CD) could improve the clinical outcomes of early stage of avascular necrosis of femoral head.

METHODS

Forty-five (54 hips) patients with Ficat-Arlet classification stage I-II treated by CD with β-TCP grafts with or without the application of PRP from July 2015 to October 2020 were reviewed. Group A (CD + β-TCP grafts) included 24 patients (29 hips), while group B (CD + β-TCP grafts + PRP) included 21 patients (25 hips). Visual analogue scale (VAS) score, Harris hip score (HHS), change in modified Kerboul angle and the hip joint survival were evaluated and compared between the groups. Patients had a mean follow-up period of 62.1 ± 17.2 months and 59.3 ± 14.8 months in group A and group B, respectively.

RESULTS

The mean VAS scores in group A was significantly higher than group B at the 6 months (2.9 ± 0.7 vs 1.9 ± 0.6, p < 0.01) and final follow up postoperative (2.8 ± 1.2 vs 2.2 ± 0.7, p = 0.04). The mean HHS in group A was significantly lower than group B at the 6 months (80.5 ± 13.8 vs 89.8 ± 12.8, p = 0.02). However, at the final follow up, there is no significant difference between the groups (77.0 ± 12.4 vs 83.1 ± 9.3, p = 0.07). The mean change in modified Kerboul angle was -7.4 ± 10.6 in group A and -19.9 ± 13.9 in group B which is statistically significant (p < 0.01). Survivorship from total hip arthroplasty were 86.2%/84% (p = 0.86) at the final follow up, which was not statistically significant. No serious complications were found in both groups.

CONCLUSIONS

A single dose of PRP combined with CD and β-TCP grafts provided significant pain relief, better functional outcomes, and delayed progression in the short term compared to CD combined with β-TCP grafts. However, the prognosis of the femoral head did not improve significantly in the long term. In the future, designing new implants to achieve multiple PRP injections may improve the hip preservation rate.