Risk of local recurrence after deltoid-sparing resection for osteosarcoma of the proximal humerus

The anatomy of the shoulder poses special challenges with regard to limb-sparing surgery. Resection of the deltoid muscle is considered by some surgeons to be necessary to achieve adequate margins for osteosarcoma of the proximal humerus. However, this can compromise the functional results after reconstruction of the shoulder. The goal of the current study was to determine whether deltoid-sparing resection can be safely performed for osteosarcoma of the proximal humerus.

Between 1978 and 2005, 23 consecutive patients with high-grade nonmetastatic osteosarcoma of the proximal humerus underwent limb-sparing surgery with preservation of the deltoid muscle. All patients received neoadjuvant chemotherapy followed by surgery and postoperative chemotherapy. The mean follow-up was 90 months (range, 7 months-279 months).

The overall survival at 5 years was 77%. At the time of last follow-up, 14 (61%) of 23 of patients were alive without evidence of disease. Three (13%) patients developed local recurrence. Two of these patients had poor responses to chemotherapy, with tumor necrosis of 50% and 70%. The third patient had a pathologic fracture of the humerus. Positive surgical margins were associated with local recurrence, and 2 of 4 patients with a positive surgical margin developed local recurrence (P = .01).

Preservation of the deltoid muscle can be performed for carefully selected patients with osteosarcoma of the proximal humerus. Routine use of the procedure is not justified, because it may be associated with an elevated risk of recurrence. The risk of local recurrence appears to be related to positive surgical margins and possibly the percentage of tumor necrosis.