Gracilis and Semitendinosus Autograft for Revision Elbow Ulnar Collateral Ligament and Flexor-Pronator Mass Reconstruction

Abstract

Elbow dysfunction due to medial ulnar collateral ligament (MUCL) insufficiency can be treated nonoperatively. However, in the setting of symptomatic medial elbow pain, surgery is considered. Techniques for addressing this injury include repair augmented with an internal brace, as well as reconstruction. Critical to the success of these surgical procedures is restoration of the static stabilizer of the medial elbow, the MUCL, and the integrity of the dynamic stabilizer, the flexor-pronator mass. This technique presents an approach to revision MUCL reconstruction using gracilis autograft, with reconstruction of the flexor-pronator mass using semitendinosus autograft.

The medial ulnar collateral ligament (MUCL) is one of the three components of the medial collateral ligament complex and is a primary valgus stabilizer of the elbow, in conjunction with the radial head and flexor-pronator mass.¹ Injury to the MUCL most commonly occurs in overhead athletes, but the incidence of MUCL injury—and surgery—has increased in recent years.²

MUCL reconstruction (Tommy John surgery) remains the gold standard of treatment for MUCL rupture in overhead athletes.³ Multiple techniques exist, with literature showing similar outcomes and stability between methods.4, 5, 6, 7 Two common techniques include MUCL reconstruction or repair with an internal brace and MUCL reconstruction alone.

The internal brace technique uses nonabsorbable suture tape tensioned to the sublime tubercle of the ulna and the medial epicondyle of the humerus, anatomically replicating the origin and insertion of the MUCL. This construct is used to augment the MUCL repair by acting as a load-sharing construct. The Jobe technique for ulnar collateral ligament (UCL) reconstruction involves a figure-of-8 autograft weaved through bone tunnels in the medial epicondyle and the sublime tubercle to re-create the MUCL with graft. The graft, typically palmaris longus or gracilis autograft, is secured by suturing its ends together. This method may necessitate ulnar nerve transposition to prevent postoperative neuropathy and requires extensive soft-tissue dissection, which can increase the risk of complications.⁸ The docking technique uses a graft that is docked into a single humeral tunnel with smaller ulnar tunnels for passage. The graft is anchored within the humeral tunnel using sutures tied over a bone bridge, potentially minimizing trauma to the ulnar nerve by allowing less dissection. This method preserves the graft’s isometry during flexion and extension and provides similar outcomes and return to function to the Jobe technique.⁷

Although there is evidence on outcomes across MUCL reconstruction techniques, there are few data on revision surgery.⁹ There has been an increase in the incidence of revision MUCL reconstruction, primarily in professional athletes.⁵ The purpose of this technical note is to present an approach to revision MUCL reconstruction and flexor-pronator mass reconstruction with hamstring autograft (Table 1).

Table 1.

Advantages and Disadvantages

Advantages

Reconstruction of MUCL (static stabilizer) and flexor-pronator mass (dynamic stabilizer) using autograft gracilis and semitendinosus tendons

Use of autograft tissue, avoiding complications of allograft tissue

Disadvantages

Donor-site morbidity to ipsilateral knee

Need for placement of anchor distal to site of humeral docking tunnel, increasing risk of fracture of distal lateral humerus

MUCL, medial ulnar collateral ligament.

Surgical Technique

Setup and Patient Positioning

The procedure is performed in the supine position. A thigh tourniquet is placed. After administration of general anesthesia, the affected arm and ipsilateral leg are prepared (Fig 1). A tourniquet is placed on the operative arm.

Fig 1.

Patient in supine position with right elbow and knee exposed. A nonsterile tourniquet is placed around the right thigh.

Autograft Hamstring Harvest

The leg is exsanguinated. A 4-cm longitudinal incision is made over the anteromedial leg. The interval between the pes anserinus tendons and the medial collateral ligament is identified. The gracilis and semitendinosus tendons are released from the tibia and are isolated by placing FiberLoop sutures (Arthrex) around the distal aspects of each tendon. They are mobilized by dissection of the gastrocnemius and soft-tissue attachments (Fig 2). A closed tendon stripper is used to harvest both tendons, and the muscle is cleaned off the tendons. The gracilis is used for MUCL reconstruction, and the semitendinosus tendon is prepared for later flexor-pronator mass reconstruction. The tourniquet is deflated, and the incision is closed.

Fig 2.

Right knee flexed to 90°. The gracilis (blue star) and semitendinosus (yellow star) autograft tendons have been isolated and secured with 2 heavy sutures and are ready for harvesting.

Medial Elbow Exposure

The arm is exsanguinated. A posteromedial incision is made with care taken to preserve the medial antebrachial cutaneous nerve. This is followed by dissection to identify the ulnar nerve (Table 2). Depending on the patient’s prior injury and extent of primary reconstruction, the joint capsule may or may not be present. In the case of chronic UCL insufficiency with flexor-pronator mass rupture and retraction, there is minimal soft tissue over the medial elbow deep to the subcutaneous fat layer. The ulnar nerve is decompressed. Remnant suture and suture anchors are removed (Fig 3).

Table 2.

Pearls and Pitfalls

Pearls

The surgeon should ensure that the ulnar nerve is decompressed at the flexor carpi ulnaris and protected while suturing the semitendinosus autograft to the flexor-pronator myotendinous junction.

Suture anchors should be placed in the distal humerus, distal to the humeral docking tunnel, to allow for flexor-pronator reconstruction anchoring.

Pitfalls

Owing to the significant elbow instability in these cases, immobilization for 6 wk should be considered to allow healing and prevent early failure.

Transposition of the ulnar nerve is necessary to prevent postoperative ulnar neuropathy in cases with flexor-pronator mass reconstruction.

Fig 3.

Exposure of ulnohumeral joint in right elbow with protection of ulnar nerve (yellow arrow) after removal of original internal brace. Anchor points are annotated by the blue and green arrows.

The flexor-pronator mass is identified, and sharp dissection is used to excise any avulsed bone attachments. The flexor-pronator mass is tagged with a No. 2 FiberWire (Arthrex) (Fig 4). The medial epicondyle of the humerus and sublime tubercle of the ulna are exposed and debrided of soft tissue.

Fig 4.

Flexor-pronator mass (blue arrow) tagged with No. 2 FiberWire suture. The ulnar nerve (yellow arrow) is decompressed through the cubital tunnel and the 2 heads of the flexor carpi ulnaris and is isolated with a Penrose drain. The medial epicondyle (green arrow) is exposed.

Tunnel Preparation for Graft Docking

The ulnar reconstruction tunnels are prepared with a 3.5-mm drill on the anterior and posterior aspects of the sublime tubercle, which are then connected with a curette. A looped passing suture is placed through the tunnel for graft passage. The medial epicondyle tunnel is prepared using a 4.5-mm drill and drilled into the lateral column of the humerus (Fig 5). A 2.0-mm drill is used on the anterior and posterior aspects of the medial epicondylar ridge forming the bone bridge for future graft docking. If the patient underwent a prior primary repair with an internal brace, the humeral and ulnar drill holes from the internal brace anchors are re-prepared using the appropriate drill sizes. Often the prior internal brace ulnar anchor site is more proximal to the anterior and posterior UCL reconstruction tunnels. Additionally, if the prior humeral anchor site for the internal brace is more distal than the UCL reconstruction tunnel, then it can be used for internal brace augmentation of the UCL reconstruction. The sites are re-prepared with a punch for the placement of two 4.75-mm SwiveLock anchors (Arthrex) with an internal brace FiberTape suture.

Fig 5.

In the right elbow, the medial epicondyle (white star) is isolated and the humeral tunnel for docking is drilled up the lateral column with a 4.5-mm drill.

Graft Insertion and Internal Brace Fixation

The gracilis autograft is lubricated with mineral oil and passed through the ulnar tunnels using the passing suture. Each end of the gracilis is docked into the medial epicondyle (Fig 6).

Fig 6.

The gracilis autograft tendon (white arrows) is docked into the distal humeral tunnel. The yellow arrow annotates the distally retracted flexor-pronator mass, which is chronically torn. Right medial elbow exposed.

Prior to tying and tensioning of the graft, the internal brace is placed. A 4.75-mm SwiveLock anchor with FiberTape and a No. 2 FiberWire free suture are placed in the distal humeral tunnel prepared from the prior internal brace. The FiberWire suture will be used for flexor-pronator mass reconstruction, and the FiberTape, for internal brace fixation. Therefore, the FiberTape should be appropriately tensioned by bringing the arm through flexion and extension, ensuring isometry of the internal brace. Once tensioned, the FiberTape and a SwiveLock anchor are inserted into the drill hole of the ulna that was prepared from the prior surgical procedure, completing fixation of the internal brace (Fig 7).

Fig 7.

Right medial elbow exposed. The 2 tails of the gracilis autograft are docked in the humeral tunnel (white arrows), and the internal brace is placed (seen between each strand of gracilis autograft and annotated with yellow arrow). A free No. 2 suture (blue arrow) for flexor-pronator reconstruction and a suture tag (white star) on the flexor-pronator mass are also shown.

The gracilis graft can now be tensioned. With the arm in 50° of flexion and a slight varus force applied, the sutures from each end of the graft are tied across the bone bridge to complete the revision MUCL reconstruction.

Flexor-Pronator Mass Reconstruction and Ulnar Nerve Transposition

One end of the semitendinosus tendon graft is sutured to the myotendinous junction of the flexor-pronator mass using a No. 2 FiberWire suture. This can be achieved via a Pulvertaft technique or simply laying the graft over the flexor-pronator mass and suturing it over the top. Once the flexor-pronator mass and the semitendinosus autograft are unitized, one limb of the free No. 2 FiberWire suture from the distal humerus internal brace anchor is used to place a Krackow stitch down and back up the tendon. The flexor-pronator mass reconstruction is tied down to the distal humerus (Fig 8). The ulnar nerve is then transposed anterior to the medial epicondyle. The arm is taken through the range of motion to assess stability (Video 1).

Fig 8.

Right medial elbow exposed. Final fixation including autograft gracilis docked in distal humerus (white arrow), semitendinosus flexor-pronator mass reconstruction with autograft semitendinosus tendon (yellow star), and site of anchoring of flexor-pronator mass reconstruction (blue arrow).

The tourniquet is then deflated, and hemostasis is achieved. Final fluoroscopic images are taken to ensure anatomic reduction and stability with gentle valgus stress. The wound is closed in layers, and the patient is placed in a long-arm plaster splint in approximately 90° of flexion and neutral rotation.

Postoperative Care

Patients should be non–weight bearing and should undergo follow-up at approximately 2 weeks postoperatively for a wound check with appropriate neurovascular evaluation. At 6 weeks, patients progress to the use of a hinged elbow brace with full range of motion and occupational therapy.

Discussion

MUCL rupture can impact the general population and overhead athletes. Several operative techniques have been described to treat these injuries. Although these techniques for primary reconstruction have been reported in the literature, there are few data regarding revision MUCL reconstruction techniques after failed primary repair. Additionally, even more rare is the combined injury of MUCL and flexor-pronator mass insufficiency.

The flexor-pronator mass is a dynamic stabilizer of the medial elbow to valgus. Biomechanical studies have highlighted the importance of the flexor-pronator mass to elbow stabilization at varying degrees of elbow flexion and in varying MUCL conditions. Udall et al.¹⁰ showed that at various elbow flexion angles, loading of the flexor-pronator mass resulted in a decreased valgus angle of the elbow when stressed in all conditions of the MUCL. This was supported by Lin et al.,¹¹ who showed that flexor-pronator mass loading provided significant MUCL valgus stress relief in elbow flexion. With data supporting the importance of the flexor-pronator mass in dynamic elbow stability, this technique emphasizes the importance of flexor-pronator mass reconstruction in patients with chronic elbow instability due to combined chronic MUCL and flexor-pronator mass rupture with retraction.

Disclosures

All authors (C.D., G.V.C., J.V.N., B.M.P., J.W.G.) declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Supplementary Data

Video 1

Technique of medial ulnar collateral ligament (MUCL) and flexor-pronator mass reconstruction with autograft gracilis and semitendinosus. Patient is positioned in the supine position with the right elbow and ipsilateral leg prepped and draped.