Evaluation of adipose-derived stem cells (ASCS) exosome implantation and platelet-rich fibrin (PRF) on critical long bone defects in Sprague-Dawley rats.

INTRODUCTION: This study aimed to assess the efficacy of adipose-derived mesenchymal stem cell exosomes (ASCs exosome) and platelet-rich fibrin (PRF) in treating critical long bone defects in Sprague-Dawley rats. Critical long bone defects, defined as exceeding 2 cm or 50% of the bone diameter, often pose a healing challenge. While autologous bone grafts have been considered, they have shown unreliable results and donor-site complications, necessitating alternative treatments. METHODS: The research followed a quasi-experimental post-test only control group design involving 30 male Sprague-Dawley rats. The rats were divided into five groups and subjected to femur bone defect creation, internally fixed with a 1.4 mm K-wire, and treated with various combinations of hydroxyapatite (HA), bone graft (BG), ASCs exosome, and PRF. Histomorphometry and BMP-2 gene expression analysis were performed to evaluate bone healing. RESULTS AND DISCUSSION: The results indicated that the group treated with HA + BG + ASCs exosome (group IV) exhibited the highest BMP-2 gene expression, while group III (HA + BG + ASCs exosome + PRF) had the highest chordin level. Overall, groups receiving ASCs exosome or PRF intervention showed elevated BMP-2 expression compared to the control group. The use of ASCs exosome and PRF showed comparable outcomes compared to bone graft administration in terms of histomorphometry analysis. CONCLUSION: The administration of adipose tissue derived mesenchymal stem cells and PRF has a comparable outcome with the use of bone graft in terms of osseus area and expression of BMP-2 in critical bone defect.

Giant cell tumor with secondary aneurysmal bone cyst of the left calcaneus.

INTRODUCTION AND IMPORTANCE: Giant cell tumors (GCT) of the feet bones are rare, comprising of <1 % of cases. The lack of well-documented cases and similarity with other tumors under radiologic and histological evaluation makes diagnosis difficult. Current treatment modalities for GCT still result in a relatively high recurrence rate, making the overall management of the case a challenge. We reported a 27-year-old male diagnosed with GCT of the left calcaneus with secondary aneurysmal bone cyst (ABC) treated with curettage and femoral head allograft combined with bone cement application. CASE PRESENTATION: A 27-year-old male presented with lump on the left heel since seven months before admission. Physical examination demonstrated solid, palpable mass on the left heel region and limited ankle motion. Magnetic resonance imaging examination demonstrated expansile bone tumor at the left calcaneus with cystic components building fluid levels and hemorrhagic components, suggestive of giant cell tumors with secondary ABC. The patient is diagnosed with giant cell tumor with secondary ABC of the left calcaneus Campanacci grade 2. The patient was managed limb salvage surgery by curettage and subsequent mix of femoral head allograft and bone cement application to fill the defect. DISCUSSION: Conservative surgery via careful curettage is typically preferred for lower Campanacci grade lesions followed by bone reconstruction. In terms of filling bone defects, it is known that both bone cement and allografts have advantages and disadvantages. We hence decided to perform limb salvage surgery via curettage due to the size of the tumor and bone reconstruction using a mix of femoral head allograft and bone cement to fill the defect. CONCLUSION: Curettage and bone allograft with bone cement reconstruction is an option for surgical management of lower Campanacci grade 2 GCT of the calcaneus.