Reverse shoulder arthroplasty for malignant tumors of proximal humerus

Abstract

Background: Reverse shoulder arthroplasty (RSA) provides an alternative for shoulder girdle reconstruction after wide transarticular resection of the proximal humerus for malignant tumor. The aim of this study was to evaluate midterm outcomes of this therapeutic option.

Methods: Ten patients with RSA were included and reviewed with 24 months of minimum follow-up. Proximal resection of malignant tumor included the "V" deltoid insertion in 4 patients. The humeral stem was coated (with an allograft in 2 patients and a cement mantel in 3) or left uncoated (5 patients).

Results: At a mean follow-up of 42 months, among 8 prosthesis available for evaluation (2 patients died), the Constant and Murley score averaged 52 points, the 11-item version of the Disabilities of the Arm, Shoulder and Hand (QuickDASH) score averaged 29.5 points, the Subjective Shoulder Value averaged 58%, and the Musculoskeletal Tumor Society score averaged 20.25 points. Mean forward active elevation reached 122°, external rotation at side was -2°, and internal rotation was to L4. Three prostheses were unstable. The involvement of "V" deltoid insertion at surgery trended to worsen the clinical outcome. Atrophy of the anterior deltoid occurred in most of patients who had a previous transdeltoid biopsy. Radiographic evaluation found 1 stem loosening, 1 stem at risk, and 3 scapular notches without glenoid loosening.

Conclusion: Use of RSA after resection of a malignant tumor of the proximal humerus seems to be an acceptable option to preserve function. However, radiographic evolution is worrisome, and long-term study remains necessary to validate this therapeutic option with follow-up.

Keywords: Tumor; allograft; reverse arthroplasty; shoulder.