Thumb Ulnar Collateral Ligament Tear Repair

Abstract

Ulnar collateral ligament (UCL) injuries of the thumb are among the most common injuries of the hand. Whether the injury is acute or chronic, a complete rupture of the ligament is usually managed with operative repair to restore thumb stability with pinch and grip, as well as to avoid arthritic changes. Here we present a patient who underwent UCL repair. We will discuss the natural history, preoperative care, intraoperative technique, and postoperative considerations.

Case Overview 

Background

Ulnar collateral ligament (UCL) injuries of the thumb occur when there is an excessive valgus or hyper-abducted force applied to the metacarpophalangeal (MCP) joint. Acute UCL injuries, also known as “skier’s thumb,” usually occur from a fall on an outstretched hand. The name skier’s thumb originated from when a skier fell while holding onto their ski poles. This nomenclature may be misleading because they are noted in multiple sporting activities such as basketball, hockey, football, etc. Furthermore, manual laborers are at risk for these types of injuries. Chronic injuries are more commonly associated with repetitive valgus stress to the UCL and are referred to as “Gamekeeper's thumb.” Any partial tear of the UCL is usually managed conservatively with a splint, whereas a complete tear is indicative of operative intervention. Suturing the torn ligament to its anatomical footprint successfully repairs the ligament and allows restoration of thumb stability. 

Focused History of the Patient

A 35-year-old male patient presented to the clinic after a fall onto an outstretched hand resulting in forced hyperabduction of the thumb. The patient complained of swelling and pain of the thumb but no numbness. 

Physical Exam

There was swelling and bruising localized to the injured MCP joint, along with tenderness to palpation along the medial or ulnar side of the thumb MCP joint. The thumb was placed into extension with the application of a valgus force, and the patient exhibited a metacarpal-phalangeal deviation greater than 35 degrees, which is indicative of a complete UCL tear. However, in recent literature, Ritting et al. suggested that the absence of a firm endpoint on physical exam is more indicative of a complete tear.¹ If the pain interferes with the quality of the physical exam, local lidocaine may be used. The patient also demonstrated a palpable mass along the medial side of the MCP, which is suggestive of a “Stener’s” lesion (which is representative of a retracted UCL). There was also mild weakness with thumb adduction due to significant pain, but there was no evidence of median or radial nerve injury and the radial pulses were intact. 

Imaging

The first step in evaluating a complete UCL tear is to obtain lateral and anteroposterior view radiographs of the first metacarpal. This is to rule out an avulsion fracture of the proximal phalanx base, which can be associated with UCL injuries.² Furthermore, stress radiographs may be obtained, but there is a concern for further damaging the UCL so imaging is typically recommended before applying valgus stress on a suspected UCL injury. If an X-ray is inconclusive, alternative imaging modalities include ultrasound, CT, or MRI. MRIs have a 96–100% sensitivity and a 95–100% specificity when diagnosing UCL tears.³ This makes it one of the best imaging techniques to use, but due to its high cost and long waiting times, it may not always be as practical. 

Natural History

A complete tear of the UCL of the thumb can have long term complications without intervention. Patients may report chronic pain and instability in the MCP joint in addition to decreased grip and pinch strength. Furthermore, chronic MCP joint instability can result in osteoarthritis of the MCP as well. 

Options for Treatment

Management of a UCL tear is dependent on whether the tear is complete or partial. Partial tears may be managed conservatively with a splint or cast immobilization. In a study by Landsman et al., 84% of patients treated with a splint after a partial tear for 8–12 weeks healed without significant instability, as opposed to 16% who needed further surgical intervention.⁴ Surgical repair is considered to be the gold standard for a complete tear of the UCL and has proven to be superior to conservative management such as splinting. Recent studies have shown that without operative intervention for a complete tear, there is an increased risk of instability of the MCP joint in addition to decreased pinch strength.⁵ However, one study showed promising results for treating an avulsion injury without instability on the exam with conservative management such as splinting, but any instability of the MCP warrants surgical intervention.⁴

Rationale for Treatment

Without surgical repair of a thumb UCL tear, a patient may experience thumb pain, weakness, instability, and osteoarthritis later. Grip and pinch strength is frequently used in occupational or activities of daily living, such as using tools or grabbing smaller objects in one’s typical environment.⁶ This makes operative repair pragmatic for any range of patients because any decrease in activities of daily living can affect one’s quality of life. 

Discussion

This is a 35-year-old patient who presented with a complete UCL tear of the right thumb. This patient underwent repair of the UCL with the use of a 3-0 suture anchor placed in the anatomical footprint. The author typically uses a “mini” anchor with either a 3-0 or 4-0 non-absorbable suture with a tapered needle placed at the volar base of the ulnar aspect of the proximal phalanx. The ligament was held down to the anatomical footprint and was subsequently repaired. The repair was subsequently augmented with a temporary 0.045 K-wire across the MCP joint to reinforce the UCL repair. 

Application of a 0.045 K-wire was used prior to UCL repair to stabilize the MCP joint and protect the repair. The K-wire is left in place for 3–4 weeks, after which it will be subsequently removed in the office upon follow-up. In a prospective study conducted by Picard et al., they found that the application of a K-wire resulted in a decreased recovery time and an early return to work. However, it is significant to note that manual laborers were not included in this study.⁶ K-wire immobilization has proved to be effective in treating avulsion injuries, whereas free tendon reconstruction has been just as effective for UCL ruptures. Thus, it seems that the use of a K-wire depends on the type of UCL injury (avulsion vs rupture) and is up to the surgeon's discretion.⁷

In this case, we are using a suture augmentation to help expedite the healing process. The benefits of faster healing time and increased stability of repair make suture augmentation one of the most effective treatments to date. Historically, the UCL was repaired using wire or suture pull-out techniques through a bone tunnel.⁸ Suture tape is also a popular technique used because it removes the need for drilling a bone tunnel or exposing the suture material as required in suture/wire pull‐out techniques.⁹ The suture augmentation tape allows for a faster clinical recovery in addition to a decreased postoperative time in an immobilization cast. Another factor that makes this tape appealing is the increased stability and ability to withstand a higher workload as opposed to repair without suture augmentation.¹⁰

It is important to note that partial tears are treated conservatively with a plaster cast or splint. One study showed that there was no difference in time or efficiency in recovery between the two, which leaves it to the discretion of the patient if one is more comfortable than the other.¹¹

A complete tear of the UCL is best managed operatively. There runs some risk with operative intervention, such as neuropraxia (sensory branch of the radial nerve), stiffness, persistent pain, the persistent weakness of grip, and cold intolerance.⁷ Unfortunately, without an experienced clinician, a complete UCL tear can easily be missed on a physical exam. Any delay in operative intervention may interfere with postoperative outcomes such as the return of MCP stability. Studies have shown that repair within 1–3 weeks of an acute UCL tear clinical diagnosis yielded better recovery time in addition to increased stability of the UCL when compared with those who received a delay in diagnosis.^7, 12 Therefore, any inaccuracy or missed diagnosis could become crucial to the prognosis of the patient. 

This patient will return to the clinic in approximately 4–6 weeks to assess the healing of the UCL repair. After the cast is removed, patients typically participate in physical therapy exercises such as range of motion and grip strength exercises. Once the pain has subsided and the range of motion is restored, the hand can be completely used again.¹³ Unfortunately, some follow-up studies have shown some degree of osteoarthritis in patients who underwent ligamentous repair.¹⁴ However, all of these patients had a chronic UCL injury as opposed to an acute injury. It seems that there is insufficient literature on postoperative osteoarthritis following the repair of acute tears, and it would be beneficial to further investigate. 

Equipment 

• 3-0 suture anchor
• 0.045 K-wire (optional)

Disclosure

Nothing to disclose.

Statement of Consent 

The patient referred to in this video article has given their informed consent to be filmed and is aware that information and images will be published online.