'Umbrella construct' - an innovative technique for reconstruction of the proximal humerus after curettage in locally aggressive benign bone tumours.

Abstract

Reconstructing locally aggressive benign bone tumours of the proximal humerus after intralesional curettage is a challenge. We present a novel reconstruction technique '<i>Umbrella construct</i>' where a femoral head and a strut allograft are combined to reconstruct the cavity. Complications, graft incorporation time, functional (Musculoskeletal Tumor Society score [MSTS]) and oncological outcomes were evaluated. Between January 2006 and June 2017, 11 cases (10 giant cell tumours, 1 chondroblastoma) underwent curettage followed by reconstruction with Umbrella construct. There were six females and five males with a mean age of 23 years (range 14-36 years). The maximum longitudinal extent of disease was 9 cm (range 5-9 cm). The median follow-up was 54 months (range 34-122 months). The mean allograft incorporation time was 7 months (5-8 months). One patient had a graft fracture which was managed conservatively. Two cases developed local recurrence and the construct was revised to a prosthesis in both. The mean MSTS score for the nine cases with retained graft was 27 (23-29). Umbrella construct is an effective reconstruction modality which helps to maintain joint congruity and limb length. It has acceptable oncological outcomes with good function.