Impingement syndromes of the shoulder are caused by anatomic crowding between the upper arm bone (humeral head), the rotator cuff tendon and the summit of the shoulder (acromion, acromioclavicular joint, coracoid process). Complaints can be caused by the following:
- Arthrosis of the acromioclavicular joint or a bony spur at the lower end of the shoulder summit, thus further decreasing the sub-acromial space between the head of the upper arm bone (humeral head) and the shoulder summit.
- Tears of the rotator cuff (supraspinatus and infraspinatus tendons, subscapularis tendon). The supraspinatus tendon, in particular, is prone to early degeneration, accompanied by tears (ruptures), but tears can also happen as the result of accidents. The rupture disturbs the bio-mechanics of the shoulder joint and results in a painful impairment to mobility with a loss of strength (see also ‘Rotator cuff’).
- Calcification of the rotator cuff tendon (tendinitis calcarea), particularly around the supraspinatus tendon (see also ‘Calcific tendinitis of the shoulder’)
- Inflammations of the lubricating sac (synovial bursa), mainly as an accompanying symptom.
- Frozen shoulder, occurring spontaneously or after injuries.
Surgical treatment of impingement syndromes
Subacromial decompression (SAD)
Across the world, Neer acromioplasty has become the prevailing technique. In this endoscopic procedure, the bony outgrowths (osteophytes) at the lower end of the acromion and also any arthrosis in the acromioclavicular joint are elegantly ground down using miniature cutters, and the infected lubricating sac is removed. In this way, sufficient space is restored for the supraspinatus tendon to move underneath, and any inflammatory irritations can heal over time. In the case of advanced arthrosis of the acromioclavicular joint, the outer end of the clavicle is also removed without any expected loss in functionality.
Arthroscopic subacromial decompression (SAD) according to Neer. Removal of bony outgrowths (osteophytes) from the lower edge of the acromion.
Aftercare
If the surgical procedure only involves cleaning and widening below the acromion, post-operative positioning is not critical. Only a few days of inactivation in an arm sling are enough, because there are no tissue structures that have to bond in healing. This can be followed by light mobility training with gentle swinging in the pain-free range of motion, with physiotherapeutic mobilization starting from week 2 after the operation. If stiffness of the shoulder was persistent for a longer period of time prior to the operation, a thorax abduction brace should be worn for about 2 weeks. However, the brace may be removed for washing and for mobility exercises.