Ulnar Collateral Ligament Reconstruction

Ulnar collateral ligament (UCL) injuries can significantly impair the overhead athlete. Reconstruction of the anterior bundle of the UCL (UCL-R) has allowed a high proportion of these individuals to return to their previous level of play. Several techniques for UCL-R are described that produce acceptable results with an overall low complication rate. Transient ulnar neuritis is the most common complication following UCL-R. The rate of UCL injury in young athletes is rising with increased youth involvement and year-round participation in overhead sports. The sports medicine community must broaden its focus to not only treat UCL injuries but also prevent them.

Key points

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Increased involvement, poorly defined pitch counts, and year-round play are risk factors contributing to the rising frequency of ulnar collateral ligament (UCL) tears in young athletes.
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History, physical examination, and appropriate imaging are required to appropriately diagnose a UCL tear.
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There are multiple surgical techniques for UCL reconstruction that have successfully returned overhead athletes to their sport.
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The most common complication following UCL reconstruction is transient ulnar neuritis.
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Revision UCL reconstruction has poorer outcomes with a higher complication rate when compared with the index procedure.

Introduction

Atraumatic ulnar collateral ligament (UCL) injuries most commonly occur in overhead athletes. The player with a UCL injury often presents with loss of throwing speed and control. There is a spectrum of clinical presentation, ranging from acute injuries to a more gradual onset of progressive pain with throwing and diminished performance. Although rest and rehabilitation are a reasonable option when treating UCL injuries, ligament reconstruction has resulted in return to prior competition level for most athletes.

Anatomy

The UCL consists of 3 substructures: the anterior, posterior, and oblique bundles. The anterior bundle primarily resists valgus stress from 30° to 120° of flexion and is the most important restraint to valgus during a pitcher’s throwing motion. The posterior bundle is fan shaped and provides minimal stability to the elbow. In a cadaveric study, Dugas and colleagues examined the origin and insertion of the anterior bundle of the UCL. The anterior bundle originates at the anteroinferior aspect of the medial humeral epicondyle with an average footprint of 45.5 mm ² . The insertion is located 2.8 mm ² distal to the ulnohumeral joint on the sublime tubercle with an average footprint of 29.2 mm ² . Within the sublime tubercle exists a ridge, which further divides the anterior bundle into an anterior and posterior band. Successful surgical reconstruction relies on repair of the anterior band, which provides most of the valgus restraint at 60° to 90° of flexion. The posterior band is a secondary valgus restraint at 90° to 120° of elbow flexion.

Clinical presentation

Risk Factors

Several risk factors for UCL injury exist. Younger throwers are at an increased risk for UCL injury. In fact, throwers 15 to 19 years in age account for most surgical reconstructions and are the fastest growing group undergoing surgical intervention. The higher prevalence of UCL injuries in younger patients has garnished recent attention. Olsen and colleagues found a correlation between increased pitch count and injury in adolescent baseball players. The study participants were also taller, heavier, participated in showcases, played for multiple teams, and pitched while in a fatigued state. Fleisig and colleagues also identified increased pitch volume, longer seasons, year-round participation, and pitching while fatigued as risk factors for UCL injury. In addition, they identified athletes who play both catcher and pitcher are at even more risk, given that they have more total throws than pitchers alone.

History

A thorough history is crucial when examining the athlete with a suspected UCL injury. In overhead athletes, it is important to determine what point during a throwing motion elicits pain. Of individuals with a UCL injury, 96% report pain during late cocking and early acceleration. The onset of symptoms may be variable. Cain and colleagues reported that 47% of patients experience an acute onset of pain, whereas the remaining 53% of patients experienced a gradual onset of symptoms. Three out of 4 athletes were injured during competition, and of those with an injury, almost a quarter experienced ulnar nerve paresthesias during the throwing motion.

Physical Examination

Most athletes with a UCL injury present without visual signs of trauma or swelling. A small deficit of elbow range of motion (ROM) may exist. Upon palpation, subjects may be tender over the humeral medial epicondyle or ulnar sublime tubercle. A thorough examination of all palpable landmarks of the elbow precludes missing a coexisting injury. Specific physical examination maneuvers help facilitate diagnosing a UCL injury. The moving valgus stress test ( Fig. 1 ) is performed with the forearm supinated and elbow fully flexed. A valgus force is applied as the elbow is extended. Elicitation of medial pain as the elbow is moved from 120° to 70° of flexion is considered a positive test. The milking maneuver ( Fig. 2 ) tests for UCL injury with the elbow in the overhead throwing position. The shoulder is abducted to 90° and the elbow is flexed to 90° with the forearm in a supinated position. The examiner pulls the subject’s thumb posteriorly, eliciting pain or apprehension. Evaluation of the elbow at 30° of flexion allows for the assessment of increased valgus instability. Instability is difficult to detect clinically, even when dealing with complete UCL tears, because only 1 to 2 mm of laxity is typically present. Overhead athletes sometimes develop a painful posteromedial olecranon osteophyte as a result of repetitive throwing. The valgus extension overload test identifies the presence of this osteophyte by passively extending the elbow quickly with a valgus force. Elicitation of posteromedial elbow pain with this examination maneuver is a positive test, and the surgeon may remove this osteophyte during reconstruction of the ulnar collateral ligament (UCL-R). The examiner must perform a neurovascular assessment of the upper extremity, with a diligent evaluation of ulnar nerve function. Oftentimes, players with ulnar nerve pathologic condition will have a positive Tinel test at the cubital tunnel. It is imperative to document strength and ROM of the shoulder and wrist because pathologic condition of these structures can occur concomitantly with UCL injuries.

Radiographic evaluation

Radiographs including anteroposterior, lateral, medial, and lateral obliques and axial olecranon views are typically obtained when evaluating the thrower’s elbow. More than half of patients with UCL pathologic condition have abnormal radiographs, either in the form of a posteromedial olecranon osteophyte or ossicle formation within the UCL. Valgus stress radiographs may be performed, but are uncomfortable and provide limited diagnostic benefit. Ellenbecker and colleagues reported a baseline increase in medial joint laxity when comparing the stress radiographs of the throwing arm to nondominant arm in professional pitchers. MRI arthrography is the gold standard for diagnosing a suspected UCL tear. When compared with noncontrasted studies, the addition of contrast fluid helps better visualize partial-thickness under-sided tears. Schwartz and colleagues successfully identified 83% of partial UCL tears when using a contrasted MRI study, compared with only 14% when using a noncontrast MRI ( Fig. 3 ). Timmerman and colleagues coined the term T sign ( Fig. 4 ) for this tear pattern, originally describing it in computed tomographic (CT) arthrography. However, MRI arthrography is routinely performed in lieu of CT arthrography given the superior visualization of soft tissue structures and lower radiation doses required.

Nonsurgical management

There is no consensus algorithm for operative versus nonoperative management of UCL injuries. Those athletes who are not adamant about returning to play a sport requiring valgus stability have radiographic indications of ulnohumeral arthritis, or those who are unwilling to comply with the UCL-R rehabilitation protocol are often better suited for nonoperative management. Even if surgical reconstruction is ultimately chosen, the athlete generally should attempt 3 months of conservative therapy before an operation. However, elite athletes often experience a shorter trial of nonsurgical management to meet season schedules and time-sensitive requirements. Nonoperative management begins with 3 months of rest from overhead throwing. During this timeframe, the patient undergoes shoulder- and elbow-directed rehabilitation. At the 3-month mark, the asymptomatic player begins a gradual throwing protocol, and upon completion, may return to play.

Historically, conservative treatment of UCL injuries has resulted in poor outcomes. Rettig and colleagues described a 42% success rate with 6 months of rest and rehabilitation. Conversely, Ford and colleagues reported an 84% success rate with nonoperative management of 31 partial-thickness UCL injuries in professional baseball players. However, if a patient failed to respond to rehabilitation at 6 to 8 weeks, the investigators recommended surgical reconstruction. Cascia and colleagues performed a systematic review examining the nonsurgical treatment of UCL injuries in overhead athletes. They reported a range from 42% to 100% return to play (mean 78% ± 20%).

Tear location may also play a role in the success of nonoperative treatment. Frangiamore and colleagues identified higher failure rates in ulnar insertional injuries (82%) when compared with humeral-sided injuries (19%). These findings argue for aggressive operative intervention when managing ulnar-sided tears versus humeral tears.

Orthobiologics have recently shown promise as a potential adjuvant to nonoperative management of partial UCL injuries. Platelet-rich plasma (PRP) is an orthobiologic that promotes angiogenesis and endothelial proliferation. It is an autologous blood product that contains several growth factors, like vascular endothelial growth factor, transforming growth factor-beta, and platelet-derived growth factor. Podesta and colleagues examined overhead athletes who received an ultrasound-guided injection of PRP after failing a trial of nonoperative treatment of partial-thickness UCL tears. Of these athletes, 88% were able to return to play at an average of 12 weeks after injection. Although promising, better evidence, including randomized controlled trials, is needed to solidify the role of PRP in managing UCL injuries.

Operative management

The most commonly selected graft for UCL-R is the palmaris longus tendon. The clinician must evaluate the presence of this structure in the preoperative setting because 16% of individuals have a unilateral congenital absence, and 9% have bilateral absence. Identification of the tendon’s presence is performed by having the patient oppose the thumb and small finger during resisted wrist flexion. In preparation for surgical harvest, the course of the tendon should be marked with a marking pen in the preoperative holding bay ( Fig. 5 ). If palmaris longus is absent, or if there is a bony ossicle within the ligament, the gracilis tendon may be used. The authors prefer the contralateral gracilis tendon for ease of surgeon position during graft harvest. Other graft options include toe extensors, the plantaris tendon, a portion of the Achilles tendon, and allograft. For the modified Jobe technique, a minimum graft length of 13 cm is required to successfully pass through the ulnar and humeral tunnels and to ensure good fixation.