During a 4-year period, 14 individuals (15 shoulders) who had been seen at the shoulder service of our institution because of pain in the shoulder had a radiographic finding of an os acromiale. On clinical examination, the pain appeared to be due to an unstable os acromiale because the patients had point tenderness over the acromion and pain on forward elevation of the shoulder. The diagnosis of an os acromiale was confirmed on radiographs, magnetic resonance images, or a bone scan. 8 patients had an associated tear of the rotator cuff. The os acromiale was located in the pre-acromion in one shoulder, the meso-acromion in 11 shoulders, and the meta-acromion in 3 shoulders. At the operation, the anterior aspect of the acromion was found to be unstable in all shoulders. 11 patients (12 shoulders) had open reduction of the os acromiale and insertion of an autogenous iliac-crest bone graft. Of those patients, 4 (5 shoulders) had open reduction and internal fixation with a tension-band procedure with use of pins and wires. Only one of those shoulders had a solid osseous union, and the other 4 shoulders had a non-union that was due to a disruption of the fixation. The remaining 7 patients (7 shoulders) had open reduction and internal fixation with use of cannulated screws and a tension-band construct; a solid osseous union was achieved in all but one of them. One patient had excision of the pre-acromion, which relieved the pain. 2 patients who had had failed open reduction and internal fixation had excision of a grossly unstable os acromiale in the meso-acromion; both patients had pain and weakness after this procedure. Of the 12 shoulders that had open reduction and bone-grafting, 7 had union of the os acromiale; the average time to radiographic and clinical union was 9 weeks (range, 7 to 20 weeks). We concluded that, although it is rare, symptomatic unstable os acromiale does occur and can be effectively treated with use of autogenous bone-grafting and internal fixation with a rigid tension-band construct and cannulated screws.
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During a 4-year period, 14 individuals (15 shoulders) who had been seen at the shoulder service of our institution because of pain in the shoulder had a radiographic finding of an os acromiale. On clinical examination, the pain appeared to be due to an unstable os acromiale because the patients had point tenderness over the acromion and pain on forward elevation of the shoulder. The diagnosis of an os acromiale was confirmed on radiographs, magnetic resonance images, or a bone scan. 8 patients had an associated tear of the rotator cuff. The os acromiale was located in the pre-acromion in one shoulder, the meso-acromion in 11 shoulders, and the meta-acromion in 3 shoulders. At the operation, the anterior aspect of the acromion was found to be unstable in all shoulders. 11 patients (12 shoulders) had open reduction of the os acromiale and insertion of an autogenous iliac-crest bone graft. Of those patients, 4 (5 shoulders) had open reduction and internal fixation with a tension-band procedure with use of pins and wires. Only one of those shoulders had a solid osseous union, and the other 4 shoulders had a non-union that was due to a disruption of the fixation. The remaining 7 patients (7 shoulders) had open reduction and internal fixation with use of cannulated screws and a tension-band construct; a solid osseous union was achieved in all but one of them. One patient had excision of the pre-acromion, which relieved the pain. 2 patients who had had failed open reduction and internal fixation had excision of a grossly unstable os acromiale in the meso-acromion; both patients had pain and weakness after this procedure. Of the 12 shoulders that had open reduction and bone-grafting, 7 had union of the os acromiale; the average time to radiographic and clinical union was 9 weeks (range, 7 to 20 weeks). We concluded that, although it is rare, symptomatic unstable os acromiale does occur and can be effectively treated with use of autogenous bone-grafting and internal fixation with a rigid tension-band construct and cannulated screws.
Copyright remains with the authors and publisher.