The patient is positioned supine on an operating table with a hand-table attachment. A sterile tourniquet is placed as proximal on the brachium as the sterile field will allow. An Esmarch bandage is used to exsanguinate the limb, and the tourniquet is inflated. A 12-cm incision is made over the cubital tunnel, centered at the medial epicondyle (Fig. 1). Sharp dissection is carried through the dermis only, and then blunt dissection is utilized to identify and preserve branches of the medial antebrachial cutaneous nerve. These branches will travel perpendicular to the skin incision superficial to the fascia. While there are anatomic variations, it is common to find one branch proximal and one branch distal to the medial epicondyle.
Two self-retaining retractors are placed to reveal the medial elbow structures. Inspection of the musculature uniformly demonstrates disruption and distal retraction of the superficial layer of the flexor-pronator muscles (Fig. 2). Typically, the pattern of injury is along the anterior two-thirds of the muscle origin. It is not uncommon to find a hematoma within the cubital tunnel.
The floor of the cubital tunnel is the posterior band of the medial collateral ligament. Therefore, the ulnar nerve must be mobilized to expose the underlying medial collateral ligament. We routinely perform an anterior transposition of the ulnar nerve. The nerve is most easily identified proximal to the cubital tunnel, where it lies just posterior to the medial intermuscular septum. If it is not readily visualized, its cord-like structure can be palpated easily with a finger moving in an anterior-to-posterior direction just proximal to the medial epicondyle. The ulnar nerve is exposed proximally, and a vessel-loop is placed around it. To minimize inadvertent traction on the nerve, surgical clamps should never be used to secure the vessel-loop. The ulnar nerve is then mobilized distally through the cubital tunnel with the release of the Osborne ligament. The dissection is carried distally through the fascia overlying the flexor carpi ulnaris until the nerve is visualized passing deep to the two heads of the muscle.
The ulnar nerve is gently retracted, and the medial collateral ligament is inspected. It is consistently avulsed in a sleeve-like fashion from a denuded medial epicondyle (Figs. 3-A, 3-B, and 3-C). Typically, concomitant injury to the flexor-pronator muscles affords an excellent exposure of the medial collateral ligament without the need for any further dissection. We have found that the medial collateral ligament can be infolded into the ulnohumeral joint. With the medial collateral ligament retracted, the medial aspect of the joint is inspected for articular damage. At this point, the medial collateral ligament is prepared for repair to the medial epicondyle.
A double-armed number-2 nonabsorbable suture is used to repair the ligament (Fig. 4). The transverse limb of the suture is placed as distal as possible in the anterior bundle of the medial collateral ligament, near its insertion onto the sublime tubercle of the ulna. After it is confirmed that the suture limbs are of equal length, the suture is passed in a parallel running, locked fashion from distal to proximal along the anterior and posterior margins of the medial collateral ligament. It is critical to eliminate any laxity in the sutures with each throw so that there is no relaxation of the repair after the sutures are secured over the bone bridge. The final pass of each arm of the suture is through the proximal end of the ligament such that one limb is anterior and the other limb is posterior.
The bone tunnels are prepared with use of a 2.0-mm drill-bit. The entry point for the repair is created first at the footprint of the ligament on the inferior aspect of the epicondyle (Figs. 5-A, 5-B, and 5-C). The drill-hole is placed as deep on the medial epicondyle as possible at its junction with the medial wall of the trochlea. A drill sleeve is used at all times to minimize the risk of injury to the ulnar nerve. Through the same entry point, two bone tunnels are drilled proximally to create a bone bridge over which the sutures will be tied. One tunnel is created to exit anterior to the supracondylar ridge, and the other is drilled to exit posteriorly. A bone bridge of approximately 2 cm is desired to avoid fracture during fixation.
The anterior and posterior suture limbs are passed through their respective bone tunnels. While the position of the elbow and forearm is critical to the tensioning of a reconstruction of the medial collateral ligament, these concerns are minimized with this technique because it is an anatomic repair of the native tissues. We choose a relatively small drill-bit to avoid advancing the medial collateral ligament into the bone tunnel. We place the elbow in approximately 70° of flexion and the forearm in supination while applying a slight varus stress on the elbow during suture tying (Fig. 6). Once the sutures are secured, the flexor-pronator musculature is repaired with use of nonabsorbable sutures in a figure-of-eight fashion.
Finally, the ulnar nerve is assessed for potential transposition. If there is any concern about instability at the cubital tunnel or potential irritation by the sutures at the repair site, the ulnar nerve is transposed anteriorly (Fig. 7). We have typically performed transposition using a subfascial technique, directing attention to release of the arcade of Struthers and excision of a portion of the medial intermuscular septum to avoid compression of the ulnar nerve. Anterior and posterior fascial flaps are elevated off of the flexor-pronator musculature (Figs. 8-A, 8-B, and 8-C). The anterior fascial flap is distally based, and the posterior flap is proximally based. The flaps are created so that they are of sufficient length to avoid constricting the ulnar nerve once they are secured with number-2-0 absorbable sutures. After the transposition is performed, the elbow is placed through an arc of flexion and extension to confirm that the nerve glides without compression. The tourniquet is released, and the site is copiously irrigated. Meticulous hemostasis is achieved with bipolar cautery, and the incision is closed with interrupted absorbable sutures in the subcutaneous layer and nylon sutures in the skin.
A well-padded splint is applied with the elbow in 90° of flexion and the forearm in neutral rotation. At the first follow-up visit, the sutures are removed and the splint is converted to a hinged elbow orthosis. The elbow is maintained at 90° with the forearm in neutral rotation until three weeks postoperatively. At three weeks, the orthosis is unlocked and a full range of elbow motion is encouraged. At six weeks, use of the brace is discontinued and progressive strengthening is initiated with the forearm in neutral rotation. Flexor-pronator strengthening is deferred until full forearm rotation is achieved. At twelve weeks, mock throwing is initiated for throwing athletes with attention to shoulder mobility and strength. Athletes who engage in overhead throwing are permitted to throw after they have regained a full range of motion of the elbow, have performed flexor-pronator strengthening, and demonstrate no pain with valgus stress on clinical examination. Athletes were allowed to resume throwing at a mean of nineteen weeks (range, eighteen to twenty-two weeks) in our series.
INDICATIONS:
The principal indication for direct repair of the medial collateral ligament is acute traumatic valgus instability of the elbow. In the clinical setting of valgus instability resulting from acute trauma, magnetic resonance imaging is useful to confirm the pathoanatomy of avulsion of the medial collateral ligament from the medial epicondyle and disruption and retraction of the overlying flexor-pronator muscles (Figs. 9-A and 9-B). The pathological findings are confirmed by the history, imaging studies, and operative findings. Patients who report a history of medial elbow pain raise the possibility of an acute-on-chronic injury. In this setting, the abnormal medial collateral ligament is not suitable for direct repair. Magnetic resonance imaging is helpful in identifying the site of disruption9,10. A previously injured medial collateral ligament may rupture through the midsubstance of the ligament, which would not be amenable to direct repair. Finally, operative findings should confirm the expected injury pattern. If the medial collateral ligament appears attenuated, the surgeon should be prepared to convert the procedure to a reconstruction of the medial collateral ligament. Direct repair of the medial collateral ligament is indicated for physiologically young, active patients who wish to return to activities that require valgus stability of the elbow.
CONTRAINDICATIONS:
Contraindications include evidence of preexisting insufficiency of the medial collateral ligament such that the medial soft tissues would be inadequate for repair. A relative contraindication is evidence of either posterolateral or varus instability as seen with an associated radial head or coronoid fracture. Careful review of the imaging studies is required to rule out these injury patterns. In this setting, we recommend primary attention to the fractures and the lateral ligaments, with consideration of repair of the medial side if that is required.
PITFALLS:
Care must be taken to protect the ulnar nerve throughout the procedure. Consideration should be given to transposition of the ulnar nerve if there is subluxation or the potential for irritation after the repair. As the sutures are passed through the medial collateral ligament in a running, locked fashion, each throw should be preloaded to eliminate any laxity in the repair when the sutures are ultimately tied over the bone bridge. Placement of the bone tunnels should ensure an anatomic repair onto the medial epicondyle with a bone bridge of sufficient width to minimize the risk of fracture when the sutures are tied.
AUTHOR UPDATE:
There have not been any important changes in the surgical technique since the original publication of our article.