Anteromedial Approach to the Elbow

The anteromedial approach gives good exposure of the medial compartment of the joint.8,9 It also can be enlarged to expose the anterior surface of the distal fourth of the humerus. The ulnar nerve (which runs across the operative field), median nerve, and brachial artery may be at risk in this exposure. The uses of the medial approach include the following:

1. Removal of loose bodies (now more commonly removed arthroscopically).

2. Open reduction and internal fixation of fractures of the coronoid process of the ulna especially if associated with repair of the medial supporting structures of the elbow.

3. Open reduction and internal fixation of fractures of the medial humeral condyle and epicondyle.

4. The medial approach provides poor access to the lateral side of the joint and should not be used for routine exploration of the elbow. The joint may be dislocated during the procedure, however, to gain access to the lateral side of the elbow, if necessary.

Position of the Patient

Place the patient supine on the operating table, with the arm supported on an arm board or table. Abduct the arm and rotate the shoulder fully externally so that the medial epicondyle of the humerus faces anteriorly. Flex the elbow to 90 degrees. Alternatively, flex the patient’s shoulder and elbow such that the forearm comes to lie over the front of the face. This allows easier exposure of the medial side of the elbow, but requires an assistant to hold the forearm to provide adequate exposure (Fig. 3-11).

Exsanguinate the limb either by elevating it for 5 minutes or by applying a soft rubber bandage (or exsanguinator). Then, inflate a tourniquet.

Landmarks and Incision

Landmarks

Palpate the medial epicondyle of the humerus, the large subcutaneous bony mass that stands out on the medial side of the distal end of the humerus.

Figure 3-11 Position of the patient on the operating table.

Figure 3-12 Incision for the medial approach to the elbow, centered on the medial epicondyle.

Incision

Make a curved incision 8 to 10 cm long on the medial aspect of the elbow, centering the incision on the medial epicondyle (Fig. 3-12).

Internervous Plane

Proximally, the internervous plane lies between the brachialis muscle (which is supplied by the musculocutaneous nerve) and the triceps muscle (which is supplied by the radial nerve) (Fig. 3-13).

Distally, the plane lies between the brachialis muscle (which is

supplied by the musculocutaneous nerve) and the pronator teres muscle (which is supplied by the median nerve; see Fig. 3-13).

Superficial Surgical Dissection

Palpate the ulnar nerve as it runs in its groove behind the medial condyle of the humerus. Incise the fascia over the nerve, starting proximal to the medial epicondyle; then, isolate the nerve along the length of the incision (Fig. 3-14).

Figure 3-13 Internervous plane. Proximally, the plane is between the brachialis (musculocutaneous nerve) and the triceps (radial nerve); distally, it is between the brachialis and the pronator teres (median nerve).

Figure 3-14 Superficial surgical dissection. Isolate the ulnar nerve along the length of the incision.

Retract the anterior skin flap, together with the fascia overlying the pronator teres. The superficial flexor muscles of the forearm now are visible as they pass directly from their common origin on the medial epicondyle of the humerus (Fig. 3-15).

Define the interval between the pronator teres and brachialis muscles, taking care not to damage the median nerve, which enters the pronator teres near the midline. Gently retract the pronator teres medially, lifting it off the brachialis (Fig. 3-16). Make sure that the ulnar nerve is retracted inferiorly; then, perform an osteotomy of the medial epicondyle. Place a periosteal elevator beneath the medial collateral ligament in order to be certain that when the medial epicondyle is osteotomized the ligament remains attached to the medial epicondyle. Reflect the epicondyle with its attached flexors distally, avoiding traction that might damage the median or anterior interosseous nerves. Superiorly, continue the dissection between the brachialis, retracting it anteriorly, and the triceps, retracting it posteriorly (Fig. 3-17). The medial collateral ligaments must be preserved during osteotomy of the medial epicondyle. Division of this ligament will result in valgus instability of the elbow.

Figure 3-15 Retract the skin anteriorly with the fascia to uncover the common origin of the superficial flexor muscles from the medial epicondyle.

Figure 3-16 Enter the interval between the pronator teres and the brachialis. Retract the pronator teres medially.

Deep Surgical Dissection

The medial side of the joint now can be seen. Incise the capsule and the medial collateral ligament to expose the joint (Fig. 3-18).

Figure 3-17 Subject the medial epicondyle to osteotomy and retract it (gently) with its attached flexors. Vigorous retraction of the epicondyle and its attached muscles may stretch the branch of the median nerve to the flexors.

Figure 3-18 Incise the joint capsule and the medial collateral ligament to expose the joint.

Dang

Nerves

The ulnar nerve must be dissected out and isolated before the medial epicondyle undergoes osteotomy (see Fig. 3-16).

The median nerve can suffer a traction lesion, with special damage to its multiple branches to the pronator teres muscle, if the medial epicondyle and its superficial flexor muscles are retracted too vigorously in a distal direction. Its major branch, the anterior interosseous nerve, also may suffer a traction lesion (see Fig. 3-17).

How to Enlarge the Approach

Local Measures

If a better view of the joint is required, the forearm can be abducted to open its medial side. To dislocate the elbow, the joint capsule and periosteum should be stripped off the distal humerus, working from within the joint. By this means, the mobility of the proximal ulna will be increased significantly. This increased mobility then will allow dislocation of the joint laterally, thereby opening all the surfaces of the joint to inspection.

Extensile Measures

Proximal Extension. Enlarge the exposure proximally by developing the plane between the triceps and brachialis muscles. Subperiosteal dissection and elevation of the brachialis expose the anterior surface of the distal fourth of the humerus (see Figs. 3-18 and 3-48).

Distal Extension. The medial epicondyle of the humerus, with its attached flexor muscles, can be retracted only as far as the branches from the median nerve allow. Thus, although the exposure provides an adequate view of the brachialis inserting into the coronoid, it cannot offer a more distal exposure of the ulna.