The short- term function of reverse shoulder arthroplasty after resection of the proximal humerus bone tumour

Objective To explore the short-term functional outcomes of the reconstruction of the proximal humerus by reverse shoulder arthroplasty after tumor rescetion. Methods 8 patients who underwent reverse shoulder arthroplasty after tumor resection between January 2013 and December 2014. 5 were female and 3 were male, mean aged was 38 years old (25-61). 2 chondrosarcomas and 6 giant cell tumors. Enneking stageing of 2 cases with chondrosarcoma were stage ⅠB and stage ⅡB. 6 giant cell tumors were Campanacci stage 3, meanwhile 3 cases had pathological fractures. The deltoid and axillary nerve were intact in all patients by image analysis before the operation. The proximal humerus was resected according to Malawer type Ⅰ resection. Then reverse shoulder arthroplasty reconstruction and bone graft was performed. The follow-up was scheduled, and the patient received X-ray examination of the shoulder. The range of motion of the shoulder was measured, the Constant-Murley score and musculoskeletal tumor society(MSTS) score was recorded. Results The mean duration of the operation was 2.7 h (2-3.5 h). The bleeding in the operation was 510 ml (300-850 ml). The mean length of humerus resection was 8 cm (6-10 cm). The allografts were used in 7 cases and reimplantation after tumor bone deactivation was used in one. The latissimus dorsi transfer were performed in 2 cases. The rotator cuff were resected 1-1.5 cm from the great and lesser tubercles. The follow-up was 13 months (3-26 months). No infection, dislocation, or loosening of prosthesis was found by the last follow-up. The X-ray showed the case who received reimplantation after tumor bone deactivation had achieved bone union 1 year postoperation, 7 cases received allograft had still nonunion at the host-graft junction. Bone resorption were found in all cases in different extent but the prosthesis were stable. No local recurrence of the tumor was found. At last follow-up, active abduction was 155° (100°- 175°) and active forward elevation was 150°(115°-170°) and Constant-Murley score was 76% (68%-87%). The MSTS score was 92% (87%-97%). Conclusion The functional outcomes of the reconstruction of the proximal humerus by reverse shoulder arthroplasty after tumor rescetion was satisfied in early period. The reverse shoulder arthroplasty can be used in younger patient, but long-term results need further study. Key words: Shoulder; Bone neoplasms; Arthroplasty, replacement