Sequence of reduction
Reduce and fix the tuberosity to the humeral head (thereby converting the 3-part fracture into a 2-part situation).
Reduce the proximal humeral segment to the shaft with the nail and fix it.
Suture fixation of the lesser tuberosity
Sutures in the subscapularis tendon insertion aid both reduction and fixation of the lesser tuberosity. Once reduced, lesser tuberosity sutures are tied to a similar suture in the infraspinatus tendon for provisional fixation. Ultimately, these sutures contribute significantly to primary stability of the lesser tuberosity.
Lesser tuberosity reduction
Proper reduction of the lesser tuberosity is difficult. Its position is hard to visualize with intraoperative image intensification.
Medial displacement of the lesser tuberosity (A) produces an intraarticular anterior step which can compromise internal rotation.
Lateral displacement of the lesser tuberosity (B) obstructs the bicipital groove and may compromise the bicipital tendon. If possible, correct reconstruction of the bicipital groove is desirable to allow sliding of the tendon. An alternative would be tenodesis of the long head of the biceps.
Reduction of the metaphyseal fracture component
If the entry point has been chosen correctly, insertion of the nail will help reduce the fracture.
Correct nail entrance point
A proper and precise entrance point of the humeral nail is crucial. An incorrect entry site results in malreduction of the metaphyseal fracture.
Preliminary reduction of the fracture helps with identification of the correct nail entry site. K-wire “joy-sticks” (as illustrated) or sutures through the rotator cuff insertions aid with reduction.
Risk of axillary nerve injury
The main structure at risk is the axillary nerve. The axillary nerve should be protected by limiting the incision to less than 5 cm distal to the acromial edge, by palpating the nerve, and by avoiding maneuvers that stretch the nerve during reduction and fixation.
Remember the course of the nerve when placing the distal screws.
Tension band sutures in addition to nail
Sutures placed through the insertions of each rotator cuff tendon increase stability, and should be used as well as the nail and screws, particularly for more comminuted and/or osteoporotic fractures. With osteoporotic bone, the tendon insertion is often stronger than the bone itself, so that sutures placed through the insertional fibers of the tendon may hold better than screws or sutures placed through bone.
These additional sutures are typically the last step of fixation.