Biological reconstruction of the proximal femur after treatment of benign lesions: comparison of functional and oncological outcomes for children and adults.

PURPOSE Describe and compare the functional and oncological outcomes and complications between paediatric and adult patients after intra-lesional treatment of benign tumours of the proximal femur, stabilised with an autologous non-vascularised fibular strut graft (NVFSG). METHODS Retrospective review including 54 patients with a benign histopathological diagnosis treated between 1987 and 2018. The mean age at operation was 17 years (range, 3 to 37 years) with a median follow-up of 39.5 months (IQR 46.7 months). Patients were grouped according to their age at diagnosis (< 16 years versus ≥ 16 years). Data collection included weight-bearing status, Musculoskeletal Tumour Society (MSTS) score, local recurrence, revision surgery and complications. Local recurrence-free survival (LRFS) and revision-free survival (RFS) were calculated and compared between groups. RESULTS The median MSTS score for all patients was 98.3% (IQR 6.7%) without a statistically significant difference (p = 0.146) between both groups. The median time to full weight-bearing was 12 weeks (IQR 0 weeks). Local recurrence occurred in five (9%) patients. LRFS for all patients was 96% at 2 years and 88% at 5 years. Although local recurrence was more frequent in the paediatric group, LRFS did not significantly differ (p = 0.155, 95% CI 223.9 to 312.3) between both groups. Reoperation rate was 13% and was indicated for local recurrence, post-operative fracture, graft resorption and avascular necrosis. RFS for all patients was 90% at 2 years and 85% at 5 years. There was no statistically significant difference (p = 0.760, 95% CI 214.1 to 304.6) regarding RFS between both groups. CONCLUSION The use of an autogenous NVFSG after intra-lesional curettage of benign proximal femoral lesions allows for a biological, structural stabilisation without additional osteosynthesis, hastening weight-bearing and avoiding metalwork-related complications with minimal post-operative morbidity and complications and excellent functional and oncological outcome for both children and adults.