An os acromiale (OA) originates from failure of fusion of the anterior acromial apophysis (Kurtz et al.
This case report presents the results of successful management of a painful os acromiale associated with rotator cuff impingement in a competitive swimmer, based on ultrasonography diagnosis, a low cost and dynamic exam, and a specific conservative treatment.
Digital pressure over the os acromiale site was painful.
They described the downward motion of the acromial fragment during active shoulder elevation, linking the os acromiale hypermobility to the pathogenesis of the rotator cuff tear.
An examination of os acromiale
ties in nicely with a look at acromioclavicular joint injuries.
We discuss some of the more commonly symptomatic bones, namely the os acromiale, os styloideum, metacarpal and hallux sesamoids, patella, os trigonum, os calcaneus secundarius, accessory navicular, os peroneum, and os intermetatarseum.
An os acromiale results from the failure of 1 of these centers to fuse.
An os acromiale can contribute to shoulder impingement symptoms.
The diagnosis of os acromiale may be made on axillary projection radiographs, computed tomography (CT), or magnetic resonance imaging (MRI).
If there is a failure of the anterior acromial apophysis to unite, an os acromiale is present (Fig 2).
This condition was described as early as 1863, when Gruber noted the presence of an os acromiale with fibrocartilaginous union of the anterior acromial ossification centers in three out of 100 cadaveric specimens (in a review by Kurtz and colleagues (2)).
Os acromiale is often discovered as an incidental finding during the radiographic evaluation of a patient with shoulder pain, with the unfused acromial ossification centers being unrelated to the patient's symptomatology.