The Effect of Autologous Adipose Tissue Derived Mesenchymal Stem Cell Implantation for Osteonecrosis of the Femoral Head

Abstract

Introduction Outcomes of traditional treatment for osteonecrosis of femoral head (ONFH) like core decompression or multiple drilling are not always satisfactory, and cell supplementation therapy has been recently attempted to facilitate the regeneration of the necrotic tissue. Adipose-derived mesenchymal stem cell (AD MSC) has several potential advantages over bone marrow-derived MSCs, but the outcomes of AD MSC implantation for ONFH has not well been investigated. The current study sought to determine the 2-year radiologic and clinical outcomes of the of AD MSC implantation combined with core decompression in ONFH. Materials & Methods Eighteen hips with large ONFH (≥30% of femoral head) were included in the study. AD MSCs were harvested with liposuction and culture-expanded for 3weeks and 3 passages. With core decompression, AD MSCs were implanted into the necrotic zone of the femoral head. All patients underwent MRI, SPECT/CT at screening, 6 months, 12 months and 24 months after surgery. Clinical scores were also measured at each visit. The primary outcome of was the change in lesion size on MRI. Secondary outcomes were changes in clinical scores and radioisotope uptake on SPECT/CT. Conversion to total hip arthroplasty was defined as the endpoint. Results Preoperatively, the mean extent of the necrotic lesions was 63.0% (range, 38.4% to 96.7%) of the femoral head. The mean Harris hip score was 89.2 ± 8.2. The mean UCLA score was 5.6 ± 2.4, and the mean WOMAC score was 79.4 ± 14.7. Three patients received total hip arthroplasty during follow-up, and one patient died in an accident in the course of the study. Finally, 11 patients (14 hips) were available for 2-year follow-up evaluations. At the latest follow-up, there were no surgery-related complications, and 14 of 17 hips (82%) were able to perform daily activities without the need for total hip arthroplasty. There was no significant decrease in lesion size between any two intervals on MRI. Eleven of 14 hips (79%) showed increased vascularity in SPECT/CT at 2 years after surgery. There was no significant difference between preoperative and 24-month mean HHS (89.2 to 88.6), WOMAC (79.4 to 75.7), and UCLA score (5.6 to 6.2). Conclusions At 2-year follow-up, autologous AD MSCs implantation for ONFH with a large necrotic lesion was safe without any complications. The majority of the cases (82%) did not show symptomatic femoral head collapse and did not require additional surgery. Although there was no significant lesion size change on MRI, increased uptake on SPECT/CT observed in the majority of cases may indicate increased vascularity in the necrotic area. Despite limitations, the outcomes of the current study suggest that AD MSC implantation in ONFH could be a viable option.