Subscapularis Tendon Tears

The subscapularis muscle is one of the four muscles that arise from the shoulder blade and attach to the humeral head. The tendons of these four muscles make up the rotator cuff. The subscapularis muscle comes off the front of the shoulder blade and helps you reach behind your back. Subscapularis tears are not as common as tears of the supraspinatus tendon. Subscapularis tendon tears may be isolated or in conjunction with supraspinatus and infraspinatus tendon tears. Tears of the subscapularis tendon are often associated with tears or instability of the long head of biceps tendon.

Subscapularis tendon tears may be partial or full thickness. The tears may be due to chronic overload or acute trauma. Complete tears in active individuals that are causing pain or disability are considered for surgical treatment. An MRI scan is generally performed prior to surgery, to assess the size of tear, degree of retraction, degree of muscle wasting and likelihood of successful repair. Subscapularis tendon tears may be repaired by arthroscopic or open techniques.

The risks of surgery are small but include infection, stiffness, nerve injury, failure of tendon healing and re-rupture.

Following a subscapularis tendon tear patients require 6 weeks immobilisation in a sling. Gentle range of motion exercises can be performed after 6 weeks. A strength program commences from 3 months post surgery. The benefits of surgery may take 6-12 months to be fully realised.

Some subscapularis tendon tears are irreparable due to marked tendon retraction and muscle atrophy. A tendon transfer procedure using the pectoralis major muscle tendon unit can be considered for salvage cases.