Secondary to supraspinatus tendon and subacromial bursal pathology.
Restricted subacromial space due to degeneration and swelling of supraspinatus tendon is results in impingement of tendon against acromium and coracoacromial ligament
Late features include spur in under surface of acromium, thickening of coracoacromial ligament
Eventually partial and full thickness tears of supraspinatus tendon; may involve other rotator cuff tendons.
Finally migration of humeral head superiorly to articulate with acromium and secondary OA
Clinical features:
Insidious or following direct trauma.
Pain on abduction of shoulder
Management:
Initially conservative management
Steroid injections into subacromial bursa
Arthroscopic subacromial decompression - shaving underside and anterior tip of acromium and dividing coracoacromaial ligament, thus widening subacromial space
References:
1. Ostlere S. Imaging the shoulder.Imaging 15:162-173 (2003)
