Treatment of osteonecrosis of the humeral head with cementless surface replacement arthroplasty.

BACKGROUND: Osteonecrosis of the humeral head is a disabling condition that can lead to joint destruction with persistent pain and dysfunction. The aim of the present study was to examine cementless humeral surface replacement arthroplasty as a treatment option for posttraumatic and nontraumatic osteonecrosis.

METHODS: Between 2002 and 2005, seventeen shoulders with posttraumatic (n = 8) or nontraumatic (n = 9) osteonecrosis of the humeral head were treated with cementless humeral replacement arthroplasty. The mean proportion of the humeral head that was occupied by necrotic bone was 18.6% (range, 8.9% to 30.9%). The mean duration of follow-up was three years. Constant scores, patient satisfaction, and complications were recorded. Volumetric measurements of the necrotic areas and signs of implant loosening were analyzed with use of standardized radiographs.

RESULTS: The mean Constant score for the entire cohort improved significantly from 31 to 62 points (34% to 75% when adjusted by age and sex) (p < 0.0001). There were also significant improvements in mean shoulder flexion (from 87 degrees to 139 degrees), abduction (from 64 degrees to 120 degrees), and external rotation (from 2 degrees to 27 degrees). The final values for the Constant score, abduction, and power were significantly higher for the nontraumatic group than for the posttraumatic group. Fourteen patients (fifteen shoulders) were very satisfied (eleven shoulders) or satisfied (four shoulders), and two patients (two shoulders) were somewhat disappointed with the postoperative result. Signs of implant loosening were not observed. One patient had a wound infection that required surgical débridement and antibiotic therapy. To date, no implant revisions have been necessary.

CONCLUSIONS: Cementless humeral surface replacement arthroplasty is a potentially bone-preserving option for patients with posttraumatic and nontraumatic osteonecrosis of the humeral head. Even in the presence of bone loss of as much as 31% of the humeral head, implant loosening was not observed. Good functional results and relief of pain in combination with a low complication rate can be achieved in the short term.