ANTEROMEDIAL APPROACH

USES

This approach is useful exposure of the musculocutaneous nerve, or access to the anterior or medial humerus. It is a distal extension of the deltopectoral groove approach.

ADVANTAGES

This approach allows access to the medial side of the humerus without coming directly over the neurovascular bundle.

DISADVANTAGES

Because the anterior humerus is overlaid by the biceps and brachioradialis, this approach requires either splitting or retracting large muscles.

STRUCTURES AT RISK

The musculocutaneous nerve, which crosses from medial to lateral, innervating the biceps and the brachialis muscle and continuing down as the lateral antebrachial cutaneous nerve of the forearm, can be damaged in the more proximal part of this approach. The musculocutaneous nerve runs along the undersurface of the biceps in the region of the pectoralis major insertion and then innervates the biceps and the brachialis before moving in a lateral direction. If you are splitting the biceps down the middle, or retracting it in a medial direction and cutting down to the humerus, it is possible that you will damage this nerve.

The medial neurovascular bundle is potentially at risk with this approach. These structures lie just medial to the humerus and perhaps slightly posterior to it. They are clearly posterior to the biceps. By approaching the humerus through the biceps fascia, you have a layer protecting the neurovascular bundle.

TECHNIQUE

An incision is made, usually on the anterior medial aspect of the arm, just on the medial side of the biceps and carried through the subcutaneous tissue. The biceps can be retracted either medially or laterally. In the upper end of the approach in the region of the tendinous portion of the long head of the biceps, it is retracted medially. In the midshaft, it is retracted laterally. If the goal is to reach the proximal biceps for tenodesis, then you need to carry the incision into the deltopectoral groove area, retracting the deltoid laterally and the pectoralis medially. The biceps tendon will be seen underneath those muscles, directly anterior to the humerus.

If the goal is to reach the medial humerus in the midshaft region, then the biceps would be retracted laterally. The brachialis would be split as much as is necessary for the exposure. Ideally, the brachialis could also be retracted in its entirety in a lateral direction.