Shoulder arthroplasty for atraumatic osteonecrosis of the humeral head.

BACKGROUND: Osteonecrosis (ON) of the humeral head represents <5% of the shoulder arthroplasty population. Depending on the stage of disease, surgeons must decide between hemiarthroplasty (HA) and total shoulder arthroplasty (TSA). To date, the peer-reviewed literature offers minimal insight into the best form of treatment of this population of patients.

METHODS: Between August 1973 and November 2010, 141 shoulder arthroplasties were performed for operatively confirmed ON of the humeral head; 67 HAs and 71 TSAs were observed for at least 2 years (mean, 9.3 years) or until reoperation. Indications for surgery included imaging-confirmed ON in a patient who had failed to respond to conservative treatment modalities.

RESULTS: Shoulder arthroplasty provided significant improvements in pain scores (P < .001), elevation (P < .01), and external rotation (P < .01) for both the HA and TSA populations. Both groups showed similar patient-reported satisfaction (>75%) and excellent/satisfactory Neer ratings (>65%). Eleven percent of HAs had moderate to severe glenoid erosion at follow-up, and 25% of glenoid components were radiographically at risk. Eight HAs and 11 TSAs underwent reoperation. The most common cause for reoperation was painful glenoid arthrosis in the HA group (7) and aseptic loosening (4) in the TSA group. The estimated 20-year survivorship of HA and TSA was 87% and 79%, respectively.

CONCLUSIONS: In patients with atraumatic ON of the humeral head, both HA and TSA can be expected to provide lasting pain relief and improved range of motion, with HA having longer follow-up. HA should be strongly considered in patients with atraumatic ON of the humeral head and preserved glenoid cartilage.