Impingement syndrome, arthroscopic subacromial decompression

The term "impingement syndrome" summarizes various causes impeding the gliding of the supraspinatus tendon below the acromion. The cause of the impaired gliding movement may be an abnormal shape of the acromion which can be congenital or acquired. Bone projections at the acromioclavicular joint (A/C joint) as an expression of arthrosis of the A/C joint can also lead to a narrowing of the subacromial space and thus impede the gliding of the supraspinatus tendon. Further, changes originating in the tendon such as shoulder calcification (tendinosis calcarea) may impede the gliding movement of the tendon below the acromion. The constant friction of the tendon against the bone results in damage (so-called tendinopathy) which may lead to a complete rupture of the tendon.

Fig. 19: Posterior view of the tendon

Fig. 20: Subacromial impingement

Treatment objective

If the symptoms cannot be treated using conservative measures, surgical intervention is indicated. The objective of a surgical treatment is to restore the free gliding movement of the tendon below the acromion in order to prevent rupture of the tendon.

Surgery technique

The therapy of choice is arthroscopic subacromial decompression. During this arthroscopic (closed) intervention, the subacromial space is enlarged by removing the inflamed soft tissue below the acromion (removal of the pathologically altered bursa which grows back) and the bony alterations of the acromion using a motor-driven precision mill.

Fig. 21: Arthroscopic subacromial decompression.

Arthroscopic A/C joint resection

Fig. 22: The inferior part of the joint capsule and the joint surfaces of the acromion and the lateral clavicle are resected using an engine-driven mill until there is no bony contact between both joint partners.

Follow-up treatment

From the first day after surgery, the arm may be moved within the painless range on a physiotherapist's instructions. This is necessary in order to prevent adhesions. A return to work is possible after 3 - 4 weeks. Patients performing heavy physical work or predominantly work above their head will need prolonged rehabilitation of 6 - 12 weeks.
With the ability to work, recreational activities may usually be resumed as well. The time of resuming an individual sport depends on the specific strain on the shoulder girdle.