Curettage, phenolization, and cementation in paediatric Ewing's sarcoma with a complete radiological response to neoadjuvant chemotherapy.

PURPOSE: Although wide resection is the standard treatment for Ewing's sarcoma (ES), it has complications especially in children. In this study, we compared the oncologic and functional outcomes of wide resection with extended curettage and local adjuvant therapy (phenolization and cementation), as a less extensive surgery for paediatric ES with a complete radiologic response to neoadjuvant chemotherapy. METHODS: Children aged ≤ ten years, with ES of non-expendable long-bones and complete radiologic response to neoadjuvant chemotherapy, were included in this case-control study. Twenty-six patients were treated with extended curettage and local adjuvant therapy (case group) and 17 were managed with wide resection (control group). The average follow-up period was 60.1 ± 28.7 months (range 30-168 months). Functional outcome was assessed with the Musculoskeletal Tumor Society (MSTS) scoring system. RESULTS: Three local recurrences (11.5%) and three distant metastases (11.5%) were observed in the case group. Two local recurrences (11.7%) and two metastases (11.7%) were recorded in the control group. The rate of local recurrence was not statistically different between the two study groups (p = 0.668). The rate of metastasis was not statistically different between the two study groups as well (p = 0.668). The complication rates were 15% in the case group and 53% in the control group (p = 0.005). The mean MSTS score was 98.3% and 74% in the case and control group, respectively (p < 0.001). CONCLUSION: The oncologic outcome of extended curettage and local adjuvant therapy in paediatric ES with complete radiological response to neoadjuvant chemotherapy is comparable to wide resection, yet it offers considerably better functional results.

The effect of cement augmentation and anteromedial plating on proximal humerus allograft reconstruction.

BACKGROUND: Limb salvage following the resection of tumor from the proximal part of the humerus, poses many challenges, and there is no consensus regarding the best reconstructive technique after proximal humerus resection. The aim of this study was to evaluate the effect of anteromedial placing of the plate in the absence of deltoid muscle and cement augmentation on the functional outcome, complication rate and survival of proximal humerus allograft reconstruction. PATIENTS AND METHODS: A number of 36 osteoarticular allograft reconstructions of proximal humerus were included in final study. In 26 cases, medullary canal of the allograft was filled by cement and the complication rate and survival was compared to non-cemented allografts. In addition, anteromedial placement of plate was applied for all resection type IB (18 cases), in which the deltoid muscle was resected. The mean follow-up of patients was 46 months. RESULTS: In total, 12 complications including 3 fractures, 4 resorptions, 3 infections and 2 nonunions were reported. Complication rates were significantly lower in cemented allografts (p = 0.001). Five year survival rates of cemented and non-cemented allografts were found to be 82% and 70%, respectively. The mean MSTS score was 84.9%, ranging 76-90. CONCLUSION: According to our results, cement augmentation improves survival and reduces the complication rate of allografts. Moreover, our results showed that anteromedial placing of the plate in resection type IB could improve the functional outcome of allografts. However, the detailed effect of anteromedial plating should be further investigated in future studies.

Fibular strut allograft or bone cement for reconstruction after curettage of a giant cell tumour of the proximal femur : a retrospective cohort study.

AIMS: Giant cell tumours (GCTs) of the proximal femur are rare, and there is no consensus about the best method of filling the defect left by curettage. In this study, we compared the outcome of using a fibular strut allograft and bone cement to reconstruct the bone defect after extended curettage of a GCT of the proximal femur. METHODS: In a retrospective study, we reviewed 26 patients with a GCT of the proximal femur in whom the bone defect had been filled with either a fibular strut allograft (n = 12) or bone cement (n = 14). Their demographic details and oncological and nononcological complications were retrieved from their medical records. Limb function was assessed using the Musculoskeletal Tumor Society (MSTS) score. RESULTS: Mean follow-up was 116 months (SD 59.2; 48 to 240) for the fibular strut allograft group and 113 months (SD 43.7; 60 to 192) for the bone cement group (p = 0.391). The rate of recurrence was not significantly different between the two groups (25% vs 21.4%). The rate of nononcological complications was 16.7% in the strut allograft group and 42.8% in the bone cement group. Degenerative joint disease was the most frequent nononcological complication in the cement group. The mean MSTS score of the patients was 92.4% (SD 11.5%; 73.3% to 100.0%) in the fibular strut allograft group and 74.2% (SD 10.5%; 66.7% to 96.7%) in the bone cement group (p < 0.001). CONCLUSION: Given the similar rate of recurrence and a lower rate of nononcological complications, fibular strut grafting could be recommended as a method of reconstructing the bone defect left by curettage of a GCT of the proximal femur. Cite this article: Bone Joint J 2022;104-B(2):297-301.

Cartilage tissue engineering by co-transplantation of chondrocyte extracellular vesicles and mesenchymal stem cells, entrapped in chitosan-hyaluronic acid hydrogel.

Mesenchymal stem cells (MSCs) on injectable hydrogels are mostly used to regenerate articular cartilage, which would have a variety of outcomes. Chondrocyte extracellular vesicles (EVs) have attracted many attentions for their chondrogenic differentiation capacity; however, the roles of EVs in both chondrogenic differentiation of MSCs and cartilage regeneration are poorly understood yet. In the current study, to investigate the differentiation effects of human articular chondrocyte EVs on adipose-derived MSCs, they were cultured in injectable chitosan-hyaluronic acid (CS-HA) hydrogel and then treated with chondrocyte EVs for 21 days. The continuous treatment of EVs performed on MSCs increased chondrogenic genes' expressions ofSOX9andCOL2A1and induced expression of Col II protein. In addition, glycosaminoglycans secretion was detected in the EV-treated MSCs after about 14 days. The therapeutic efficiency of this hydrogel and EVs was studied in a rabbit osteochondral defect model. MRI results revealed that the cartilage regeneration capacity of EV-treated MSCs with CS-HA hydrogel was greater than the untreated MSCs or the EV-treated MSCs without hydrogel. Moreover, histological results showed hyaline-like cartilage in the CS-HA/MSC and CS-HA/EV/MSC groups in the cartilage defect sites. These findings suggested that the chondrocyte-EVs and CS-HA hydrogel could provide the preferable niche for chondrogenic differentiation of MSCs and cartilage regeneration in osteoarthritis cartilage injuries.