Isoelastic shoulder prostheses. Considerations on use and results.

The principles underlying the use of isoelastic shoulder prostheses are discussed and the results obtained in 8 patients are reported. Two operations were for pseudarthrosis of the humeral neck and 6 for osteolytic neoplasms. The results were assessed after an average follow-up of 4 years. Full movement was never recovered; there was partial recovery in 6 cases, and no significant recovery in 2. The extent of the surgical resection was determined by the type of lesion; in more conservative resections which allowed for the reconstruction of tendinous insertions, the functional results were better than in wide resections. The difficulty of recovering good movement was related to the limited possibilities of reconstructing the insertions of the external rotator muscles.