Abstract
Purpose:
To determine the insertion of the different layers of the rotator cuff and apply it to rotator cuff tears. Anatomical insertion of the rotator cuff holds the key to a proper anatomical repair.
Method:
A study of the rotator cuff insertion was done in conjunction with MSc student department Anatomy. The rotator cuff consists of a capsular and tendinous layer. They have different mechanical properties. The capsular layer inserts ± 3 mm more medially on the tuberosity and the tendinous layer more laterally. It was shown that the superficial layer extends beyond the greater tuberosity and connects the supra-spinatus tendon to the sub-scapularis tendon via the bicepital groove. This connection was called the “rotator hood”. The “rotator hood” has a mechanically advantageous insertion, is a strong structure with a compressive force on the proximal humerus.
Conclusion:
-
1.
The rotator cuff inserts on the greater tuberosity as two separate entities.
-
2.
The capsular layer inserts on the more medial 2–3 mm.
-
3.
The tendinous layer is attached over a broader more lateral area giving it a mechanical advantage.
-
4.
The tendinous layer of supra-spinatus extends beyond the tuberosity to connect to the sub-scapularis tendon providing an even greater mechanical advantage.