The geometric osteotomy: joint preservation in juxta-articular surface bone neoplasms.

Purpose. To present the oncologic and functional results of a consecutive series of patients treated by geometric osteotomy and allograft reconstruction for juxta-articular surface bone neoplasms.Patients. Twelve consecutive patients (mean age 28 years) underwent excision of benign aggressive or malignant juxta-articular surface bone neoplasms. In each case, only part of the circumference of the bone was excised, and the joint surface was preserved and kept in continuity with the remainder of the bone. The defects were filled with allograft or autograff, and internally fixed as appropriate.Methods. Patients were eligible for the study if they had a histologically proven, primary tumour of bone adjacent to a joint such that the turnout could be completely excised with a partial cortical resection and preservation of the joint. The database at the University Musculoskeletal Oncology Unit was used to identify all cases. Patient demographics and oncologic results were recorded. Functional assessment was performed using the Musculoskeletal Tumor Society rating scale and the Toronto Extremity Salvage Score.Results. Nine tumours were about the knee and three were in the proximal humerus. Negative margins were achieved in all cases. No patient had metastatic disease at a mean follow-up of 56.5 months. There was one local recurrence and this was managed by conversion to a Van Nes rotationplasty. Functional results were excellent in the proximal humeral cases and in cases about the knee where the stabilizing ligaments were preserved. Cases with post-operative knee instability were less successful but none the less were well controlled with bracing.Discussion. This technique offers an alternative to joint excision and prosthetic replacement in a group of young patients.