Salvage of the upper extremity in cases of tumorous destruction of the proximal humerus

Malignant bone rumours or metastasis of the upper humerus may cause signifi cant loss of function especially in those patients with resectional arthrop lasty of the shoulder. One method for achieving functional reconstruction o f the humerus concerned is replacement with a modular endoprosthesis. Littl e is known about clinical and radiologicial results in these rare circumsta nces. Between 1993 and 1997 we treated 21 patients (22 shoulders) with enla rged osteolytic destructions of the proximal humerus caused by metastatic s pread or primary malignant rumours. Patients with additional involvement of the glenoid were excluded from this study. The average follow-up was 3.9 y ears. Every 3 months all patients were followed-up clinically and radiograp hically. Prior to surgery, diagnosis was established by incisional biopsy a nd the outcome determined the therapeutic algorithm (radiotherapy, chemothe rapy, surgery). In most cases of metastatic lesions, surgery was the first treatment. According to the regional spread of the tumour, various amount o f bone and soft tissues had to be removed. The distal stem of the prosthesi s was inserted in a cementless way and secured to bone with two interlockin g screws. The length of the diaphyseal part depended on the site of osteoto my. Soft-tissue coverage of the large implant was achieved in all patients. Early complications were lymphogenic oedema and superficial wound dehiscen ce. One patient developed a deep infection, which had to be managed surgica lly. According to the functional rating system of the Musculoskeletal Tumou r Society for the upper extremity the overall results were inversely propor tional to the extent of resection. None of our patients achieved unrestrict ed motion of the shoulder concerned. The most important finding was a proxi mal migration of the prosthesis causing a painful subacromial impingement, mainly a consequence of the resection of the deltoid muscle and the rotator cuff. In summary, a modular endoprosthesis cannot be recommended generally as the method of choice. If the muscular balance of the shoulder is too we ak to act as a joint centralizer the endoprosthesis has no advantage over a simple diaphyseal spacer.