Skier's Thumb 

Updated: Sep 15, 2019
Author: Patrick M Foye, MD; Chief Editor: Sherwin SW Ho, MD 

Overview

Background

Injuries to the ulnar collateral ligament (UCL) of the thumb were first recognized as an occupational condition in European gamekeepers. By repetitively wringing the necks of game (eg, chickens) between their thumb and index finger, these workers produced a chronic stretching of the UCL that resulted in instability at the first metacarpophalangeal (MCP) joint. The condition became known as gamekeeper's thumb. Today, the injury is primarily caused by acute (rather than chronic and repetitive) damage to the UCL, most often due to a skiing accident; hence, the condition is now commonly referred to as skier's thumb.

For patient education resources, see the Hand, Wrist, Elbow, and Shoulder Center and Sports Injury Center, as well as Skier's Thumb and Repetitive Motion Injuries.

Epidemiology

Frequency

United States

Skier's thumb represents 5-10% of all skiing injuries; this condition is the most frequent injury of the upper extremity that skiers experience.[1, 2, 3, 4]

Functional Anatomy

The MCP joint of the thumb is primarily stabilized by the UCL. The origin of this ligament is found on the ulnar aspect of the metacarpal head, whereas the insertion of the UCL is located distally on the proximal phalanx.

Sport-Specific Biomechanics

The most common cause of UCL injury is an acute abducting (radially directed) force upon the thumb.[5] Damage may also result from a combination of torsion, abduction, and hyperextension at the first MCP joint. Depending on the degree of impact of these forces at the MCP joint, the UCL may either tear partially or completely (see the images below).[1, 2, 3, 4, 6]

Anteroposterior radiograph displaying a gamekeeper Anteroposterior radiograph displaying a gamekeeper's fracture.
Lateral radiograph displaying a gamekeeper's fract Lateral radiograph displaying a gamekeeper's fracture.

A large number of skiing injuries are attributed to ski poles, in which the strap or sword grip lies across the palm and transmits the damaging force to the thumb during a fall. Football players may develop UCL damage either traumatically (eg, while making a tackle, falling on an outstretched hand [FOOSH injury]), or chronically (eg, linemen, who repetitively stress the thumb radially while blocking). The injury is also common among athletes who handle balls (eg, basketball, football) and among those who use sticks (eg, hockey, lacrosse), in which the sporting equipment can forcefully abduct the thumb during sport activity.

 

Presentation

History

See the list below:

  • Patients with skier's thumb often describe jamming their thumb, either during a fall or with an object such as a ski pole or ball.

  • Pain is reported along the ulnar side of the MCP joint.

  • In cases of UCL laxity, patients often report weakness in their grasping or pinching ability; patients with UCL tears may report inability to perform these movements.

Physical

See the list below:

  • Inspection and palpation of a skier's thumb

    • Examination of the injured thumb may reveal swelling at the MCP joint, as well as discoloration and tenderness to palpation along the ulnar aspect. Marked swelling and ecchymosis are suggestive of severe UCL damage. Practitioners should also be aware that swelling and ecchymosis can be indicative of a sesamoid fracture, as this is a commonly overlooked cause of UCL instability. [7]

    • Sometimes a lump at the ulnar aspect of the metacarpophalangeal joint is indicative of a Stener lesion and suggests a rupture of the ulnar collateral ligament.[8]

    • The location at which the patient has maximal tenderness indicates the site of the ligament injury. Most UCL tears occur distally, near the insertion of the ligament into the proximal phalanx, but proximal rupture also occurs (near the origin on the metacarpal head).

  • Strength

    • The patient's pinch may be markedly weakened, and the thumb may deviate radially.

  • Stress testing

    • In traumatic cases, to avoid inadvertent displacement of the involved bone, stress testing should not be performed until radiographs have ruled out the presence of an undisplaced fracture (see the image below).

      Radiograph displaying a stress test of a torn ulna Radiograph displaying a stress test of a torn ulnar collateral ligament.
    • To appreciate any instability of the MCP joint, a radially directed force is applied to the thumb whose mobility is compared with that of the uninjured hand. There are varying opinions regarding the proper thumb positioning during stress testing. Although the preferred technique is to examine the thumb in full extension, a complete evaluation of the UCL should also include assessment of the thumb in full flexion (when the ligament is maximally taut) (see the images below).

      Stress testing of the metacarpophalangeal joint of Stress testing of the metacarpophalangeal joint of the thumb in flexion.
      Stress testing of the metacarpophalangeal joint of Stress testing of the metacarpophalangeal joint of the thumb in extension.
    • Local anesthetic can be injected into the joint if provocative maneuvering proves to be too painful. If the stress-induced angulation of the injured thumb demonstrates an instability that differs by greater than 30° relative to the uninjured thumb, it can be assumed that the UCL is completely ruptured.[9] In cases in which the UCL insufficiency is a result of chronic damage, patients may be minimally symptomatic but demonstrate UCL laxity during stress testing. UCL injuries of the thumb can be misdiagnosed or the severity underestimated in part because assessment of the injury is limited by patient discomfort. The infiltration of local anesthetic around the injury site can make the physical examination more tolerable for the patient and enable the physician to make a more accurate diagnosis. This simple technique may be a useful adjunct to the standard physical examination.

    • A cadaveric study done by Lankachandra et al demonstrated that an iatrogenic Stener lesion could be created inadvertently during physical examination. This complication can occur via thumb supination and 30˚ of flexion of the MCP joint, provided that prior to physical exam there was already a deficiency in the fascia overlying the UCL.[10]

  • Classification

    • Skier's thumb can be classified into 3 grades. Grade 1 is a thumb sprain without instability of the metacarpophalangeal joint. Grade 2 is an incomplete tear with joint laxity. Grade 3 is a complete tear with instability of the joint.[11]

Causes

Traumatic injuries in cases of skier's thumb occur more often and result more commonly in UCL ruptures. In addition, UCL injuries from chronic repetitive radial stresses typically lead to UCL laxity and thumb instability but without complete UCL rupture.

 

DDx

 

Workup

Laboratory Studies

See the list below:

  • Laboratory studies are not indicated for the diagnosis of skier's thumb.

Imaging Studies

See the list below:

  • Clinical examination of the thumb still remains the criterion standard in the diagnosis of a UCL rupture of the thumb.[12] If the diagnosis of skier's thumb is uncertain or if a concomitant fracture is suspected, additional diagnostic tools may be used, such as imaging studies.[12]

  • Plain radiographs of the thumb are first obtained to assess for possible thumb fracture or subluxation (see the images below). An avulsion fracture of the volar base of the proximal phalanx commonly accompanies UCL injuries. The thumb is considered dislocated when it is malrotated or displaced by more than 1 mm.[8]

  • Recent research describes the "sag sign" as a reliable indicator of thumb UCL underlying injury. The sag sign is volar subluxation of the proximal phalanx relative to the metacarpal at the MCP joint, evident on plain film.[13]

    Anteroposterior radiograph displaying a gamekeeper Anteroposterior radiograph displaying a gamekeeper's fracture.
    Lateral radiograph displaying a gamekeeper's fract Lateral radiograph displaying a gamekeeper's fracture.
  • Stress radiographs of the MCP joint are used to assess the severity of damage to the thumb and UCL. A joint opening that is greater than 30º while the MCP is fully flexed is consistent with complete rupture of the UCL; if the joint opening is less than 30°, one can assume that part of the ligament remains intact (see the image below). If questions arise regarding the degree of joint opening and the severity of damage, stress radiographs of the uninjured thumb can be obtained for comparison.

    Radiograph displaying a stress test of a torn ulna Radiograph displaying a stress test of a torn ulnar collateral ligament.
  • Magnetic resonance imaging (MRI) is useful for evaluating UCL injuries,[14] but it is expensive and not always necessary. A study by Plancher et al showed that MRI has a greater than 90% sensitivity and a greater than 90% specificity for identifying UCL tears.[14]

  • Ultrasonography is less expensive than MRI. Shortly after presentation, ultrasonography yields higher positive predictive values than clinical examination for ruptures of the UCL.[15] Diagnostic musculoskeletal ultrasound can help to distinguish between full thickness versus partial thickness tear of the UCL. A partial thickness tear can show up on longitudinal views as a focal hypoechoic area with partial fiber disruption, typically close to the distal insertion of the UCL. Also, Doppler imaging studies may show hyperemia at the region of partial tear. Conversely, ultrasound findings with a full-thickness UCL tear can show retraction of the UCL where the retracted UCL appears as a hypoechoic mass-like structure.[16]  However, some discrepancies can be found in the medical literature as to whether ultrasonography is helpful[12, 17] or misleading[18, 19] in the diagnosis of a UCL injury.

    Radiograph displaying a stress test of a torn ulna Radiograph displaying a stress test of a torn ulnar collateral ligament.
 

Treatment

Acute Phase

Rehabilitation Program

Occupational Therapy

Patients with hand injuries are sometimes treated by a physical therapist, but these individuals are more frequently referred to an occupational therapist, particularly one with special training in hand therapy. During the acute injury phase, local modalities (eg, icing) may be helpful to decrease the pain of patients who have nonsurgical cases of UCL injuries.

Medical Issues/Complications

When the UCL is completely ruptured, the adductor pollicis muscle can interpose between the fragments and hinder ligament healing (see the image below). This is referred to as a Stener lesion and results in permanent instability at the MCP joint if treated conservatively. Therefore, the presence of a Stener lesion, although difficult to identify clinically, is an indication for surgical repair (see the image or below).[1, 2, 3, 4, 20]

Ruptured ulnar collateral ligament. Ruptured ulnar collateral ligament.
Completed repair using suture anchors for fixation Completed repair using suture anchors for fixation.

Stress testing, or clinical stability testing, is key to making the diagnosis of UCL injury; however, it is theoretically possible that this provocative maneuver could cause a Stener lesion.

A recent study investigated this with 10 Thiel fixated cadaveric hands.[21] Clinical stability testing was performed in 30° of flexion and extension by 2 hand surgeons using maximum strength. When only the UCL was disrupted, only mild MCP joint instability was noted in flexion and the joint was stable in extension. After disruption of the UCL and the accessory collateral ligament (ACL), clinically significant instability was present in both flexion and extension; however, no Stener lesions were provoked. The only way the researchers were able to simulate a Stener lesion was by cutting the UCL, ACL, and the adhesive fibers connecting these ligaments to the joint capsule and adductor aponeurosis and then pulling directly on the cut fibers of the ligaments to displace them. When the ligaments were then returned back to normal position, repeat clinical stability testing did not reproduce the displacement.

Thus, since no clinical stability testing was able to produce a Stener lesion, it was concluded that only high-energy injuries that disrupted the UCL, ACL, and adductor aponeurosis would cause enough damage to cause a Stener lesion.[21]

Surgical Intervention

Primary surgical repair is indicated for the following:

  • Complete rupture of the UCL, as evidenced by joint instability

  • UCL damage with any accompanying fracture that is displaced, rotated, or intra-articular

  • Presence of a Stener lesion

  • Grade 3 classification[11]

To prevent chronic painful instability, weakness of pinch, and arthritis, surgical treatment is recommended for fractures with 2 mm or more of displacement, or significant articular involvement with incongruency or rotation.[22]

A study by Milner et al that developed a 4-stage treatment-oriented classification of thumb UCL injury found that partial and minimally displaced UCL tears and tears displaced less than 3 mm typically healed by immobilization alone, whereas 90% of tears displaced more than 3 mm failed immobilization and required surgery as did all of those with a Stener lesion.[23]

Direct reinsertion of the ligament onto the bone is the most secure method of fixation. In cases of fracture, a fragment accompanying a ruptured ligament can be excised if it constitutes less than 15% of the articular surface; otherwise, the fragment is also reinserted.

In addition to ligament reconstruction, thumb-MCP arthrodesis has been shown to produce good outcomes in pain scores and tip-pinch strength. Similarly, patients post-arthrodesis had similar disability scores as patients who underwent primary repair. [24]

Consultations

Cases of skier's thumb that meet the clinical criteria for surgical repair should be promptly sent for consultation with an orthopedic hand surgeon.

Other Treatment

Grades 1 and 2 skier's thumbs and incomplete UCL ruptures can be treated conservatively (nonsurgically) with proper immobilization.[11] The patient is placed in a forearm cast or splint with a thumb spica for 3-4 weeks (see Images 8-9 or below). The MCP joint is left in 20° of flexion with mild ulnar deviation (adduction) to reduce stress on the ligament, and the interphalangeal joint is also placed in slight flexion.

Anterior view of a hand in a thumb spica splint. Anterior view of a hand in a thumb spica splint.
Lateral view of a hand in a thumb spica splint. Lateral view of a hand in a thumb spica splint.

During management of acute UCL injuries during competition (or for avid recreational skiers who are reluctant to forego their time on the slopes), a decision must be made as to whether the patient should continue to ski. No firmly established criteria exist for making this clinical decision, although the severity of the symptoms and the degree of joint laxity may be important considerations.

If there is a clinical decision to allow the patient to continue skiing after a recent injury to the UCL at the thumb, then protective splinting should be considered. Options include moldable fiberglass splints (which can be adapted to the ski pole) or athletic taping, either in wrist/thumb spica style, or the athletic trainer's figure-8 approach.

Before these interventions, the patient should have a clear understanding that there is a potential for worsening of their condition from further injury. Always include proper documentation of the patient's severity of symptoms and degree of joint laxity, as well as documentation of discussions with the patient regarding recommendations, interventions, prognosis, and activity.

Recovery Phase

Rehabilitation Program

Occupational Therapy

After 3-4 weeks of immobilization for an incomplete UCL tear, reassess the thumb. If swelling and tenderness have diminished and the joint remains stable, the patient should continue to wear either a volar gutter or thumb spica splint for an additional 2-4 weeks, with removal of the splint several times daily for the performance of active-range-of-motion (AROM) exercises.

Surgical Intervention

In surgically repaired skier's thumb injuries, a volar plaster splint is used to immobilize the thumb and wrist for 4-5 weeks following the operation. After this period, the splint should be worn for an additional week, but it can be removed several times a day for AROM exercises. The splint is then discontinued and the frequency of exercises is increased to an hourly basis.

In the reevaluation of an incomplete UCL tear, if the joint is significantly unstable, operative repair should be considered. In the weeks following the initial injury, a ligament that folds upon itself may develop scarring that precludes primary repair and may require reconstruction with the use of a tendon graft.

Maintenance Phase

Rehabilitation Program

Occupational Therapy

If necessary (such as after prolonged immobilization), the patient with skier's thumb can be instructed in the use of stretching exercises to assist with a full return of ROM. Also, strengthening exercises can be used to help the return of strength and functioning. The strengthening program should be well rounded but should also focus particularly on the strength components that are necessary to the athlete's particular sport (eg, grip strength in a hockey player or a lacrosse player, both sports that require a firm hold onto a stick).

 

Medication

Medication Summary

Medications are primarily used to decrease pain and inflammation in cases of skier's thumb. Thus, the most commonly used medications are oral nonsteroidal anti-inflammatory drugs (NSAIDs) in conjunction with the rest of the rehabilitation plan.

Nonsteroidal Anti-inflammatory Drugs (NSAIDs)

Class Summary

Various oral NSAIDs can be used to decrease pain and inflammation for this musculoskeletal condition, and the drug of choice (DOC) is largely a matter of convenience (eg, what is the best dosing frequency to achieve adequate analgesic and anti-inflammatory effects?), the safety profile, and cost.

Ibuprofen (Motrin, Advil, Nuprin, Rufen)

A commonly used NSAID. DOC for patients with mild to moderate pain. Inhibits inflammatory reactions and pain by decreasing prostaglandin synthesis. Many doses are available without a prescription.

Ketoprofen (Orudis, Actron, Oruvail)

For the relief of mild to moderate pain and inflammation.

Small dosages are initially indicated for small and elderly patients and in those with renal or liver disease.

Doses over 75 mg do not increase therapeutic effects. Administer high doses with caution, and closely observe the patient for response.

Naproxen (Aleve, Naprelan, Anaprox, Naprosyn)

For the relief of mild to moderate pain; inhibits inflammatory reactions and pain by decreasing cyclooxygenase activity, which results in a decrease of prostaglandin synthesis.

Nonsteroidal Anti-inflammatory Drug (NSAIDs), Topical

Class Summary

Topical NSAIDs are able to deliver a large dose of anti-inflammatory medication to a focal painful area with minimal systemic effects.

Diclofenac topical (Flector)

Inhibits inflammatory reactions and pain by decreasing prostaglandin synthesis.

 

Follow-up

Return to Play

In addition to the 6-8 weeks of immobilization with casting or splinting, the patient with skier's thumb should avoid activities that risk reinjury for approximately another 6 weeks. An orthosis can be fitted to protect the patient's thumb to prevent further delay in return to activity.

Complications

Osteoarthritis of the first MCP joint may occur in patients with skier's thumb.

Prevention

A small dorsal (or radial) gutter splint can be designed to fit within the glove of skiers and other athletes.

Prognosis

When properly treated, patients with a UCL injury have a good prognosis for returning to their premorbid level of functioning. A missed diagnosis that delays the repair of a complete UCL rupture leads to a less favorable prognosis. Complications from delayed treatment of a complete tear may include neurapraxia (secondary to injury of the radial sensory nerve), stiffness (which usually improves with time), and persistent instability (which can eventually lead to MCP joint arthritic changes).[25]