REVERSE SHOULDER ARTHROPLASTY IN PROXIMAL HUMERUS GIANT CELL TUMOUR

Abstract

BACKGROUND Giant cell tumour is a locally aggressive tumour that occurs close to the joint of a skeletally mature bone. It usually affects young adults aged 18 to 40 years with a slight female preponderance. Proximal humerus is a rare site of involvement accounting for only around 4\% of the disease. Campanacci grade 1 and 2 lesions where there is no extraosseous extension, treated with intralesional extended curettage, having a recurrence rate of 17\% has been reported. Wide resection and reconstruction is reserved for Campanacci grade 3 tumour, where these are breach of cortical bone. Goal of surgery was to prevent recurrence by completely removing the tumour and reconstruction of proximal humerus tumour with wide resection and reconstruction results in poor functional outcome. Reconstruction of proximal humerus with an osteoarticular allograft, endoprosthesis or allograft-prosthetic composite are available but offers poor outcome. Here, in this study we have used reverse shoulder arthroplasty for reconstruction of proximal humerus giant cell tumours for good functional outcome. MATERIALS AND METHODS It was a retrospective, descriptive study which consisted of 30 patients (11 females and 19 males). Selection criteria of patients were patients with Campanacci grade 3 lesion and metastasis. All patients were operated under general anaesthesia positioned in beach chair position. Deltopectoral standard approach was used in all patients and whole of tumour was resected en bloc. Reconstruction of shoulder joint was done by reverse shoulder prosthesis (Depuy). Postoperatively, patients' shoulder was immobilised in an abduction splint for 1 week. Passive range of movements were started as per the patient's tolerance over the next 4-6 weeks. Patients were evaluated by Constant Murley Score, American Shoulder and Elbow Surgeon and Disability of Arm, Shoulder and Hand Score. RESULTS The mean follow-up period was 20 (range of 12-26) months. All patients were evaluated clinically. None of the patients had recurrence. The mean forward elevation was 80, mean abduction was 75, external rotation and internal rotation was 20. There was no evidence of loosening of components. All the patients were evaluated clinically. None of the patients had recurrence. Active shoulder abduction ranged from 40 to 110 degrees (mean 78.3 degrees). The mean functional Constant-Murley score was 71\% (range from 38\%-88\%). The Musculoskeletal Tumour Society (MSTS) score as proposed by Enneking averaged 81.2\% (ranging from 61\%-90\%). Patients with history of dislocation (2 patients) performed worse. Even patients with generalised tumour disease had a significant improvement in comfort and function, increasing their quality of life. Scapular notching was not seen in our cases. CONCLUSION Reverse shoulder prosthesis compared to other modalities of shoulder reconstruction after tumour resection provides a good range of movement, stability and patient satisfaction. Complication can only be better assessed with a long follow-up. But we believe reverse shoulder is the prosthesis for reconstruction of proximal humerus GCT resection. Young patient undergoing RSA require counselling of their post-operative limitation and functional capacities.