Functional Outcomes of Reverse Shoulder Arthroplasty and Allograft-Prosthetic Composite in Oncologic Patients

Introduction: Reverse total shoulder arthroplasty (rTSA) is a feasible reconstruction technique for proximal humerus tumors and can be combined with allograft-prosthetic composite (rTSA-APC) for extensive lesions. We assessed postoperative complications and functional outcomes after rTSA with and without allograft prosthetic composites for oncologic indications, comparing them with a matched nononcologic cohort. Methods: Twenty-three patients who underwent rTSA with or without allograft prosthetic composites after proximal humerus tumor resection between 2010 and 2022 were included. We defined two groups in the oncologic cohort: rTSA (15 patients) and rTSA-APC (8 patients). Implant failure was assessed using the Henderson classification and outcomes with the Musculoskeletal Tumor Society score. Outcomes were compared with those of a propensity score–matched nononcologic cohort. Results: Oncologic patients exhibited higher rates of dislocation (22% vs. 0%), axillary nerve resection (13% vs. 0%), reoperation (52% vs. 10%), and revision surgery (30% vs. 5%) compared with nononcologic patients. Within the oncologic cohort, axillary nerve resection was more frequent in the rTSA-APC group (38% vs. 0%, P = 0.01); no other differences were seen between groups. Two-year dislocation-, reoperation-, and revision-free survival rates were higher in the nononcologic cohort. No differences in survival rates were observed between the rTSA and rTSA-APC groups. Shoulder range of motion was similar between groups. Median Musculoskeletal Tumor Society scores were higher in nononcologic patients compared with oncologic ones (90% vs. 70%; P = 0.001) and in rTSA-APC patients compared with rTSA patients (80% vs. 37%; P = 0.04). Conclusion: Oncologic patients overall had more complications and lower functional scores compared with nononcologic patients. Within the oncologic cohort, rTSA-APC patients achieved better functional outcomes than rTSA-only patients, despite experiencing higher complication rates. Surgical approaches should be individualized based on the anatomic defect.