Long-Term Results of a Phase I/II Clinical Trial of Autologous Mesenchymal Stem Cell Therapy for Femoral Head Osteonecrosis

Molecular Prospective on Malignant Transformation of Mesenchymal Stem Cells: An Issue in Cell Therapy

Mesenchymal stem cell (MSCs) therapy, as a rapidly developing area of medicine, holds great promise for the treatment of a variety of medical conditions. MSCs are multipotent stem cells that can be isolated from various tissues and could self-renew and differentiate. They secrete cytokines and trophic factors that create a regenerative microenvironment and have immunomodulatory properties. Although clinical trials have been conducted with MSCs in various diseases, concerns regarding the possibility of malignant transformation of these cells have been raised. The studies showed a higher rate of hematological malignancy and carcinogenesis in experimental models after MSC transplantation. The mechanisms underlying malignant transformation of MSCs are complex and not fully understood, but they are believed to involve the presence of special signaling molecules and alterations in cell behavior regulation pathways. Possible pathways that lead to MSCs' oncogenic transformation occur through two mechanisms: spontaneous and stimulated malignant transformation, including cell fusion, fusion proteins, and the tumor microenvironment. MSC-based therapies have the potential to revolutionize medicine, and addressing the issue of malignancy is crucial to ensure their safety and efficacy. Therefore, the purpose of the present review is to summarize the potential mechanisms of the malignant transformation of MSCs. [Figure: see text].

Mesenchymal Stem Cell Therapy for Bone Repair of Human Hip Osteonecrosis with Bilateral Match-Control Evaluation: Impact of Tissue Source, Cell Count, Disease Stage, and Volume Size on 908 Hips

We investigated the impact of mesenchymal stem cell (MSC) therapy on treating bilateral human hip osteonecrosis, analyzing 908 cases. This study assesses factors such as tissue source and cell count, comparing core decompression with various cell therapies. This research emphasizes bone repair according to pre-treatment conditions and the specificities of cell therapy in osteonecrosis repair, indicating a potential for improved bone repair strategies in hips without femoral head collapse. This study utilized a single-center retrospective analysis to investigate the efficacy of cellular approaches in the bone repair of osteonecrosis. It examined the impact on bone repair of tissue source (autologous bone marrow concentrate, allogeneic expanded, autologous expanded), cell quantity (from none in core decompression alone to millions in cell therapy), and osteonecrosis stage and volume. Excluding hips with femoral head collapse, it focused on patients who had bilateral hip osteonecrosis, both pre-operative and post-operative MRIs, and a follow-up of over five years. The analysis divided these patients into seven groups based on match control treatment variations in bilateral hip osteonecrosis, primarily investigating the outcomes between core decompression, washing effect, and different tissue sources of MSCs. Younger patients (<30 years) demonstrated significantly better repair volumes, particularly in stage II lesions, than older counterparts. Additionally, bone repair volume increased with the number of implanted MSCs up to 1,000,000, beyond which no additional benefits were observed. No significant difference was observed in repair outcomes between different sources of MSCs (BMAC, allogenic, or expanded cells). The study also highlighted that a 'washing effect' was beneficial, particularly for larger-volume osteonecrosis when combined with core decompression. Partial bone repair was the more frequent event observed, while total bone repair of osteonecrosis was rare. The volume and stage of osteonecrosis, alongside the number of injected cells, significantly affected treatment outcomes. In summary, this study provides comprehensive insights into the effectiveness and variables influencing the use of mesenchymal stem cells in treating human hip osteonecrosis. It emphasizes the potential of cell therapy while acknowledging the complexity and variability of results based on factors such as age, cell count, and disease stage.

Hip Arthroscopy Debridement Combined with Multiple Small-Diameter Fan-Shaped Low-Speed Drilling Decompression in the Treatment of Early and Middle Stage Osteonecrosis of the Femoral Head: 14 Years Follow-Up

OBJECTIVE

Osteonecrosis of the femoral head (ONFH) is a disease that occurs frequently in young and middle-aged people. Because of its high disability rate, it affects the ability to work, so the early treatment of this disease is particularly important. This retrospective study aimed to evaluate the clinical efficacy of hip arthroscopy combined with multiple small-diameter fan-shaped low-speed drilling decompression (MSFLD) in treating early-mid stage ONFH (ARCO II-IIIA) compared to MSFLD, with at least 10-year follow-up.

METHODS

A total of 234 patients who underwent hip arthroscopy and MSFLD for ONFH from 1998 to 2012 were analyzed retrospectively. This study enrolled patients between 18 and 60 years old with ARCO stage II-III A, diagnosed clinically and through imaging, in accordance with the 2021 guidelines for the treatment of ONFH. Clinical data, including demographics, operation mode, BMI, pre- and postoperative Harris score, and femoral head survival rate, were collected. Patients were divided into hip arthroscopy + MSFLD and MSFLD groups based on the operation mode. The t-test was used to compare the postoperative efficacy, Harris scores, and survival rates of the femoral head between the two groups.

RESULTS

Among the 234 patients, 160 cases were followed up, including 92 cases in the hip arthroscopy + MSFLD group and 68 cases in MSFLD group, the follow-up rate was 68.38%, and the follow-up time was (10-22)14.11 ± 3.06 years. The Harris score (80.65 ± 6.29) in the hip arthroscopy + MSFLD group was significantly higher than that in the MSFLD group (p = 0.00), and the survival rate of femoral head (5-year survival rate was 84.78%, 10-year survival rate was 23.91%) was also higher than that in the MSFLD group (5-year survival rate was 63.24%, 10-year survival rate was 8.82%). The 5-year and 10-year survival rates of patients with ARCO II were 82.11% and 28.42%, which were better than 54% and 33% for ARCO III A. The femur head survival rate of alcoholic ONFH (5-year survival rate 61.54%, 10-year survival rate 9.23%) was significantly higher than that of other types of ONFH.

CONCLUSION

Clinical follow-up of at least 10 years suggests that hip arthroscopy combined with MSFLD is an effective treatment for early-mid stage ONFH, with good clinical effect and high survival rate of femoral head.