Background: The purpose of this study was to evaluate the functional outcome and the complications of reconstruction with an osteoarticular allograft in patients who had had intra-articular resection of the proximal aspect of the humerus.Methods: Sixteen patients who had had intra-articular resection and reconstruction of the proximal aspect of the humerus for the treatment of a tumor between 1986 and 1996 were evaluated. The length of the resected part of the humerus ranged from eight to 27.5 centimeters. The resections were classified as either S34A or S345A resections of the shoulder girdle on the basis of the Musculoskeletal Tumor Society classification system. Reconstruction was performed with use of a nonirradiated, frozen osteoarticular allograft with intact capsular and rotator cuff attachments. Dual orthogonal dynamic compression plates were used for internal fixation of the allograft to the host bone. The oncological parameters that were evaluated included survival of the patient, local recurrence, and metastasis. The radiographic parameters included time to union, stability of the joint, fracture of the allograft, and fragmentation of the epiphysis of the allograft (subchondral collapse). Survival of the graft was assessed with Kaplan-Meier survival analysis. The modified Musculoskeletal Tumor Society evaluation system was used to assess functional outcome.Results: At a median of forty-seven months (range, fourteen to 130 months) after the operation, fourteen of the patients in the study group were free of disease and two had died of disease. No patient had local recurrence or nonunion. Late complications included four fractures of the allograft and one infection of the graft. A Kaplan-Meier survival curve demonstrated a 68 percent rate of survival of the allograft at five years. Instability of the glenohumeral joint in the form of ptosis and anterior subluxation was noted in three patients, and dislocation of the glenohumeral joint was seen in eight patients. On the basis of the modified Musculoskeletal Tumor Society functional evaluation, the mean score at the most recent follow-up evaluation (at a mean of thirty-four months) was 70 percent. This score was lower than the mean score of 81 percent at a mean of fourteen months. All patients had normal manual dexterity and had mild or no pain at the most recent follow-up evaluation. However, all had restriction of recreational activities or partial disability in addition to limitations with regard to placement of the hand and the ability to lift.Conclusions: Reconstruction of the proximal aspect of the humerus with an osteoarticular allograft is an option that provides good relief of pain and preserves manual dexterity. However, in our study, function was limited by impairment of elevation of the shoulder and hand as well as by decreased strength of the shoulder. There was an extremely high rate of complications, including joint instability, fracture of the allograft, and infection of the allograft. We no longer routinely perform this reconstruction at our institution.