Medial ulnar collateral ligament (MUCL) insufficiency is becoming common in younger, nonprofessional athletes. In contrast to elite athletes who develop valgus extension overload syndrome and associated chronic pathologic changes in the MUCL, younger patients present with sprains and partial tears that can often be managed non-operatively with successful outcome and rapid return to play. In the younger throwing athlete with medial-sided elbow pain, a hinged elbow brace and rehabilitation of dysfunctional muscles often lead to successful recovery and return to play within 1-2 months. In more severe injuries, direct repair of the partial tear with or without added internal bracing supplementation allows restoration of stability with a return to play with 4 to 6 months.
Key points
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Strains and partial tears are more common injuries than complete tears in non- professional athletes.
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These lower grade injuries are best managed more conservatively than immediate surgery in young athletes.
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If surgery is required, repair with or without an internal brace is a much better option in non-professional athletes.
Introduction
The anterior bundle of the ulnar collateral ligament (UCL) complex is the primary stabilizer of the elbow to valgus stress from 20° to 120° of flexion, the primary arc of motion used in overhead throwing. Isolated UCL deficiency was first identified in javelin throwers by Waris in 1946, and was once thought to be a career-ending injury. The initial operative intervention for the condition involved repair of the native ligament, which was supported by Barnes and Tullos, who noted that athletes with UCL injury had better clinical outcomes after repair in comparison with nonoperative treatment. Much of the current operative management of UCL deficiency is focused on symptomatic valgus instability in the high-level throwing athlete and usually requires some variation of the reconstructive procedure pioneered by Jobe in 1974 for return to play. However, there has been a substantial increase in the number of patients sustaining a more acute form of this injury at younger ages, , for which a reconstruction may not be warranted. In contrast to elite athletes who have sustained repetitive microtrauma over years of high-level competition with resultant ligament damage through its length and secondary pathologic changes in the elbow from chronic valgus extension overload syndrome, , the younger or acutely injured athlete can be expected to have a ligament of better quality, with isolated damage to one area, and a more biomechanically stable joint. In these patients the injury is more likely to be a sprain or partial tear. If the tear is complete, it only involves a single area of injury at the proximal or distal end of the ligament. In these young patients nonoperative treatment can be very successful, and in most cases if surgery is needed primary repair of the UCL has proved to be a viable option, with reliable results and a quicker return to sports than the standard reconstruction.
Examination and imaging
In many young overhead athletes, medial elbow pain signifies an injury to the anterior band of the medial ulnar collateral ligament (MUCL). The patient may report a slow onset of pain with repetitive use of the arm or may have a history of a single “pop” followed by an inability to throw accurately or with velocity.
Examination of the athlete starts from the ground up. The patient’s stance, body habitus, and resting posture are noted. A single leg squat can test hip and core strength. Hip internal and external rotation on both the plant leg and lead leg should be measured and recorded. The shoulder is evaluated with Whipple, O’Brien, and Dynamic Label Shear tests both without and then with scapular assist.
The elbow is then evaluated for alignment and motion. Tender areas are noted. It is crucial to palpate the proximal and distal ends of the MUCL, the ulnar nerve, the capitellum, and plica during the examination. Valgus and varus testing at 30°, 70°, and 90° of flexion can be compared with the opposite side. Valgus extension overload testing and moving valgus stress test may confirm the diagnosis. As described by O’Driscoll and colleagues, the moving valgus stress test is performed on a patient in the upright position with the shoulder abducted to 90°, in maximal external rotation with the elbow fully flexed. The examiner then extends the elbow while applying a constant valgus load. A positive test will reproduce medial elbow pain that the patient experiences with provocative activities and should be maximal between the positions of 120° and 70° of elbow extension, correlating with the late cocking and early acceleration phases of throwing. Other physical examination findings that are usually positive include the Milk test and the valgus extension overload test.
Imaging should include standard radiographs to evaluate for bony changes, loose bodies, and osteochondritis dissecans. Standard radiographic evaluation of the elbow begins with anteroposterior, lateral, and oblique views. A true lateral view of the hyperflexed elbow or an axial olecranon view in 110° of flexion may identify posteromedial osteophytes, suggestive of a chronic valgus extension overload syndrome. Comparative stress radiographs may help identify ligamentous laxity, and a greater than 5-mm side-to-side difference may be sufficient as a diagnostic study. In younger patients, contralateral comparison views may be helpful to identify growth disturbances and variant ossification centers.
Advanced imaging is usually needed, and the authors prefer magnetic resonance arthrograms in these patients. The advanced imaging will show strains, partial tears, or complete tears and also allow an accurate assessment of the quality of the noninjured ligament.
Ultrasonography can also provide an excellent image of the ligament, delineating both the area of injury and evaluating the body’s response to the injury with Doppler assessment of the vascular response. Dynamic ultrasonography, performing the examination while doing a moving valgus stress test, has been shown to be an effective tool in evaluating injuries of the MUCL.
Nonoperative management
Sprains
In many young overhead athletes, the MUCL may only have interstitial damage (sprain) or have a small partial tear. In the first group (sprains) an aggressive form of nonoperative treatment has been reasonably successful in the authors’ patients. The patient is placed in a hinged elbow brace set to allow a pain-free range of motion, usually 30° to 90° on the first visit. The patient is referred to physical therapy for leg, hip, core, scapula, and shoulder rehabilitation, maintaining the brace at all times. Once the entire body is balanced, the elbow is added to the rehabilitation. A full, pain-free range of motion must be achieved before the patient is allowed to start a return to hit and throw program in the brace, usually 3 to 4 weeks. As this progresses and the instability examination normalizes negative, the brace is discontinued and the patient is allowed to return to full sports. The entire recovery time from a sprain is usually 6 to 8 weeks.
Partial Tears
Partial MUCL tears can also be managed nonoperatively with a program similar to that for MUCL sprains. In these cases, supplementation with biologics is also discussed. The authors have previously published results on the use of leukocyte-rich platelet-rich plasma (PRP) (Harvest; Terumo BCT, Lakewood, CO), which produced excellent healing in both proximal and distal partial tears ( Fig. 1 ).
In these cases, the history and imaging confirm a partial tear and its location. PRP injections are offered as an option to add to the nonoperative treatment. A series of 2 injections 2 weeks apart are administered while continuing the physical therapy and bracing program described for sprains. A “study” MRI of a few coronal cuts is performed 2 to 4 weeks after the second PRP and thereafter, dynamic ultrasonography is used to monitor the status of the ligament. The brace is continued for a minimum of 6 weeks and the usual return to play without the brace is 12 weeks. The program has allowed successful return to play in 85% of injured athletes with partial MUCL tears.
Indications and contraindications for surgical repair
Indication for surgery is the presence of a significant proximal or distal tear in an older (age >15 years) athlete. Contraindications include ligaments with midsubstance injuries, evidence of damage over an extended length of the ligament, and a ligament of general poor quality with calcifications or defects noted on MRI or ultrasonography. In these cases, a standard graft reconstruction procedure is required.
Patient positioning in surgery
For the authors’ UCL repair protocol, preference is to place the patient in the standard prone arthroscopy position with the shoulder abducted to 90° and the elbow flexed to 90° over a block. This position eliminates the need for traction, allows for easier intraoperative manipulation of the elbow, permits access to the posterior aspect of the joint, and affords a more stable position to the elbow. Following the arthroscopic portion of the procedure, this position allows the surgeon to convert to an open procedure by internally rotating the shoulder and placing the hand on an arm board near the patient’s hip, exposing the medial side of the elbow while providing a constant varus stress for the repair.
Surgical technique
With the patient in the prone arthroscopy position already described, a thorough examination under anesthesia is performed to evaluate the elbow for instability and motion, comparing the injured elbow with the opposite, uninjured side. A standard diagnostic arthroscopy is then performed to evaluate the articular cartilage, specifically of the capitellum and the posterolateral plica. Although rare in these young athletes, additional pathologic features including loose bodies and ulnohumeral spurs can be addressed if present. The arthroscopic stress test of Field and Altchek can also be performed at this time, which produced positive findings of medial opening 3 mm or greater in all of the authors’ 60 patients investigated in a previously reported case series on MUCL repair.
With the arthroscopic portion of the case complete, the surgery is converted to an open procedure with the arm positioning change already described. A skin incision is made on the tip of the medial epicondyle and extended distally 5 cm ( Fig. 2 ). A pronator muscle-splitting approach as described by Smith and colleagues is then used to expose the UCL ( Fig. 3 A–C). The outer surface of the UCL is evaluated for tissue quality and the location of the tear (see Fig. 3 A). Depending on the tear location and extent, a longitudinal incision is then made along either the anterior border (for a simple repair) or in the middle (for a repair + internal brace [Arthrex, Naples, FL]) of the MUCL and the remainder of the ligament inspected (see Fig. 3 B).
