Application of reverse shoulder prosthesis combined with ligament advanced reinforcement system in resection and reconstruction for proximal humerus malignant tumors

Abstract Background Evaluation of the application value of reverse shoulder prosthesis combined with ligament advanced reinforcement system (LARS) in reconstruction following resection of proximal humerus malignant tumors. Methods We retrospectively analyzed ten patients with proximal humerus malignant tumors who underwent reconstruction using reverse shoulder prosthesis combined with LARS at our institution from March 2021 to May 2023. The cohort included six males and four females, with a mean age of 38.6 ± 18.7 years. Preoperative core needle biopsy confirmed pathological diagnoses in all patients: osteosarcoma (n = 5), chondrosarcoma (n = 2), solitary metastatic squamous cell carcinoma (n = 1), Ewing sarcoma (n = 1), and synovial sarcoma (n = 1). Surgical procedures involved en bloc resection of the proximal humeral tumor segment followed by reverse shoulder arthroplasty. Postoperative radiographic assessment included X-ray and CT. Shoulder range of motion (ROM) was measured quantitatively. Functional outcomes were evaluated using the Musculoskeletal Tumor Society (MSTS-93) Score and Constant-Murley Shoulder Score. Results All ten patients underwent uneventful procedures. The mean osteotomy length was 15.3 ± 5.1 cm. All patients were followed up for a mean duration of 28.1 ± 14.1 months. At final follow-up, the mean shoulder ROM measurements were: abduction 105.3° ± 13.1°, forward flexion 120.5° ± 16.2°, external rotation 75.3° ± 6.8°, and internal rotation 48.2° ± 3.5°. Functional outcomes averaged 24.5 ± 2.6 points on the MSTS-93 score and 74.6 ± 3.4 points on the Constant-Murley Score. Postoperative complications included shoulder instability in one patient. Conclusions Reinforcement of the deltoid insertion and rotator cuff reconstruction using LARS following resection of proximal humerus malignant tumors contributes to improved postoperative forward flexion, abduction, and rotational function while reducing prosthetic dislocation rates. However, long-term functional outcomes and implant stability require further follow-up observation.