Late prosthetic shoulder arthroplasty for displaced proximal humerus fractures.

Twenty-three shoulders in 23 patients with failed treatment of three- and four-part proximal humerus fractures subsequently treated with prosthetic arthroplasty were reviewed. The initial treatment was closed in 10 cases and open in 13. The complications of treatment included malunions in 17, nonunions in four, traumatic arthritis in 14, avascular necrosis in nine, humeral shortening in six, and deltoid paresis in four. In 20 cases prosthetic arthroplasty was performed an average of 15.8 months after injury. Three other cases had arthroplasty 19, 20, and 22 years after the original fracture. Seventeen were treated with a total shoulder arthroplasty, and six had a humeral head replacement. Thirteen had a tuberosity osteotomy, and eight had lengthening of the subscapularis tendon. Prosthetic arthroplasty reduced the shoulder pain in 22 (95%). Average active forward elevation increased from 68 degrees to 92 degrees, and active external rotation increased from 6 degrees to 27 degrees. After arthroplasty 53% of the patients were able to do activities at or above shoulder level compared with 15% before arthroplasty. Late surgery for failed early treatment is technically difficult, and the results are inferior to those reported for acute humeral head replacement. These findings should be considered when treatment is selected for acute three- and four-part proximal humerus fractures. Nonetheless late arthroplasty is a satisfactory reconstructive option when primary treatment of proximal humerus fractures fails.