Skier's thumb

Original Editors - Alicia Keefe and Brenna Rutledge as part of the Temple University EBP Project

Top Contributors - Brenna Rutledge, Evi Peeters, Alicia Keefe, Khloud Shreif, Kim Jackson, Admin, Lieselot Longe, WikiSysop, Wendy Snyders, Scott A Burns, Max Louis, Claire Knott, Wanda van Niekerk and Lucinda hampton  

Search Strategy

Keywords:
Gamekeeper's thumb; Skier’s thumb; UCL injury of the thumb; Thumb injury; Ulnar collateral ligament injury; Stener lesion; Thumb sprain; Sprained thumb; Wackeldaum; Bennet fracture; Rolando fracture

Databases searched:
Medscape, Pedro, Google Scholar, Pubmed, Cochrane library, Web of Knowledge, Library of the VUB, ScienceDirect

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Definition/description

Skier's thumb is a acute partial or complete rupture of the ulnar collateral ligament (UCL) of the thumb’s metacarpophalangeal joint (MCPJ) due to a hyperabduction trauma of the thumb.

Whilst both terms are often used interchangeably, skier’s thumb refers to the cause being acute injury. Gamekeeper’s thumb specifically refers to the cause being chronic injury to the UCL in which it became attenuated through repetitive stress.
UCL damage caused by Chronic injury may have a serious risk of disabling instability, pinch strength, and pain-free motion if not treated adequately .[10][12][13]][38][41][42]

In 64–87% of total UCL tears, Stener lesion can occur. A Stener lesion occurs when the adductor aponeurosis becomes interposed between the ruptured UCL and its site of insertion at the base of the proximal phalanx. Hence making it impossible for the loosened ligament to reconnect with the site of insertion, necessitating surgery.[43]

Video illustration:
Stener lesion: https://www.youtube.com/watch?v=RLskrc7qifY
Skier’s thumb: https://www.youtube.com/watch?v=qFbxlgztK5U

Clinically Relevant Anatomy

The metacarpophalangeal joint of the thumb is a diarthrodial joint, reinforced by a capsule and by other soft tissue structures. The surrounding soft tissue offers both dynamic and static stability.[2]

The passive stability is provided by the following structures:
● Proper collateral ligament
● Accessory collateral ligament
● Volar plate
● Dorsal capsule[31]

The proper collateral ligament extends from a point slightly dorsal to the mid-axis of the metacarpal head to the palmar aspect of the proximal phalanx (Fig. 1). The proper collateral ligament prevents palmar subluxation of the proximal phalanx and serves as the primary restraint to valgus stress with the metacarpophalangeal joint in flexion. The accessory collateral ligament courses palmarly to insert onto the volar plate. The accessory collateral ligament is contiguous with the proper collateral ligament proximally. The volar plate and the accessory collateral ligament function as the principal restraints to valgus stress with the metacarpophalangeal joint in extension. [31]

Dynamic stabilizers to valgus stress consist of the intrinsic and extrinsic muscles of the thumb:
● Extensor pollicis brevis
● Extensor pollicis longus
● Flexor pollicis longus
● Adductor pollicis
● Flexor pollicis brevis

The adductor mechanism presents as an aponeurosis superficial to the metacarpophalangeal joint capsule and ulnar collateral ligament. The adductor mechanism maintains dual insertions. The superficial insertion of the adductor mechanism is the extensor expansion via the adductor aponeurosis; the deep insertion extends to the palmar aspect of the proximal phalanx via the ulnar sesamoid of the metacarpophalangeal joint. [2][13] [31]

The range of motion is highly variable at the thumb metacarpophalangeal joint. [31]
The movement association with the thumb MCPJ include flexion, extension, rotation, abduction and adduction. [2]

There are two main supporting ligaments traversing the MCPJ of the thumb:
1) the UCL ligament
2) the radial collateral ligament (RCL)
The UCL and RCL arise from the medial and lateral tubercles of the metacarpal condyles and insert into the base of the proximal phalanx on their respective sides, beneath the adductor aponeurosis (Figure 1b).[2][3] The UCL prevents the thumb from pointing too far away from the hand.[10]

Epidemyology/ etiology

Skier’s thumb is caused by forced abduction and hyperextension of the thumb. [9] The UCL tears mostly find place at the distal attachment of the proximal phalange. But proximal avulsion, proximal and distal bony avulsion, isolated mid-substance tears and mid-substance tears with bony avulsion do also occur. [8

● Mechanism of injury.
It is important to note that this injury is not exclusive to skiers and can occur to anyone where there is an extreme valgus stress force applied to the thumb in abduction and extension. [18]
An acute UCL injury occurs following a sudden, hyperabduction and hyperextension forces[8] at the MCP joint, whereas a forced adduction movement would cause injury to the RCL (Figure 2A).[2] With regards to skiing, the injury often occurs when a person lands on an outstretched hand while holding a ski pole, which causes forced abduction of the thumb with extension (Figure 2B).[1] It is called skier’s thumb but can also occur in football, handball, basketball, rugby, soccer and even a handshake. [8] If the injury to the UCL is not treated properly this can lead to chronic laxity, joint instability, pain, weakness and arthritis in the MCPJ.

● Frequency.
An often-encountered problem. It concerns 86% of all injuries to the base of the thumb.
Injuries to the ulnar collateral ligament of the thumb are the second most common ski-related injury. Prevalence of this injury during skiing varies from 7% up to as high as 32% of all skiing injuries and is the most frequent injury of the upper extremity that skiers experience.(figure 2C)[18][19][38]
This type of injury is also seen in other sports, especially those that use a stick or ball, such as hockey or basketball. Only an estimated 10% of the patients diagnosed with a skier’s thumb had acquired this injury skiing. A fall on the hand, usually from a bicycle or motorcycle (in which the thumb gets stuck behind the handlebars), is a much more common cause of skier’s thumb, seen in approximately 40 % of all patients(figure 2B). Other sports such as soccer or fighting are responsible for another estimated 30% of the causes(figure 2A).
In children, who still have an immature skeleton, hyperabduction trauma mostly leads to a Salter-Harris III avulsion of the UCL insertion and rarely to a true rupture of the UCL. [38]

Mechanism of injury by falling.

Figure 2A. Mechanism of injury by falling.

Mechanism of injury by skiing

Figure 2B. Mechanism of injury by skiing.

● Prevention.
Preventive measures should include instruction in proper pole technique for powder skiing, avoidance of pole dragging and deep pole plants and downsizing baskets from the standard 4-inch diameter to 2.5-inches. Pole length should be 2 inches shorter than the recommended length for that skier. [17]

Strapless poles do not reduce the chance of injuries, but if skiers are trained to discard the pole during a fall the risk might be reduced. [41]

Risk of injury can be further reduced by wearing a properly designed ski-glove which not only prevents extreme movement of the thumb, but also incorporates a mechanism for the ejection of the ski-pole. [20]

Characteristics/Clinical Presentation

The most common presentation is pain over the ulnar aspect of the MCPJ of the thumb. If the injury is acute there will be bruising and inflammation (Figure 4). There may be tenderness with palpation, which localizes the injury to the ulnar aspect of the thumb where the UCL is lesioned. In more chronic cases the patients typically complain of pain and weakness when using a pincer grip. There also can be instability of the thumb while doing these tasks. [8][2] In the instance of a Stener lesion, there may also be a palpable mass proximal to the adductor aponeurosis.[1]

● Symtoms.
These symptoms may occur minutes to hours after the fall that created the injury:[29]
‒ Pain at the base of the thumb in the web space between thumb and index finger.
‒ Swelling of your thumb.
‒ Inability to grasp or weakness of grasp between your thumb and index finger.
‒ Tenderness to the touch along the index finger side of your thumb.
‒ Blue or black discoloration of the skin over the thumb.
‒ Thumb pain that worsens with movement in any or all directions.
‒ Pain in the wrist (which may be referred pain from your thumb).

● Grades of thumb sprains.
Thumb sprains are ranked by how much the ligament is pulled or torn away from the bone. [31]
‒ Grade 1: Ligaments are stretched, but not torn. This is a mild injury. It can improve with some light stretching.
‒ Grade 2: Ligaments are partially torn (less than 3mm) [5]. This injury may require wearing a splint or a cast for 5 to 6 weeks.
‒ Grade 3: Ligaments are completely torn or more than 3mm[5]. This is a severe injury that usually requires surgery.
‒ Grade 4: Failed immobilization and required surgery as did all of those with a Stener lesion[5].

Haley-resized.jpg

Figure 4. Presentation of an ulnar collateral ligament injury with an avulsion fracture. Photo courtesy H. Stevenson.

Differential Diagnosis

The injury can involve other structures such as the adductor aponeurosis, the accessory collateral ligament, bony structures, tendons and neurological tissues.[1] The injuries all present with pincer grasp weakness. However they may be differentiated by the location of tenderness.
For al thumb injuries, radiographs should be obtained of the patient suspected to have a skier’s thumb. It’s important to remember that a skier’s thumb may or may not be visible on X-ray and the most common radiographic finding is an avulsion fracture of the proximal thumb phalanx at the site of UCL attachment. MRI can be usefull because it has the highest spicificity and sensivisity.[12]

•  Skier’s thumb (UCL tear):

is characterized by point tenderness and instability at the thumb MCP joint, while

•  Stener lesion:

is a particular type of UCL injury with palmar subluxation of the base of the proximal phalanx.

•  Bennett or Rolando fracture:

Is an intra-acticular fracture luxation at the base of MC I in the CMC joint.[8]

•  Avulsion fracture:

An avulsion fracture is an injury to the bone in a location where a tendon or ligament attaches to the bone. When an avulsion fracture occurs, the tendon or ligament pulls off a piece of the bone. [37] In children, who still have an immature skeleton, hyperabduction trauma mostly leads to a Salter-Harris III avulsion of the UCL insertion and rarely to a true rupture of the UCL. [38]

•  Wrist sprain:

When a wrist sprain injury occurs, the ligaments of the wrist are stretched beyond their normal limits. [35]
Wrist sprains are graded according to severity:
Grade 1 (mild)
Grade 2 (moderate)
Grade 3 (severe)
Grade 4 (surgery)

•  Wrist fracture:

A broken wrist (wrist fracture) can involve the small bones in the wrist or the ends of the forearm bones. [35]

•  Dislocation of 1st MCP joint:

A dislocation is an injury to a joint — a place where two or more of your bones come together — in which the ends of your bones are forced from their normal positions. [33] [34]

•  Chronic instability of the 1ste MCP joint:

Injuries to the two main supporting ligaments traversing the metacarpophalangeal (MCP) joint of the thumb can lead to symptomatic joint instability with subsequent pain, weakness and arthritis if ignored. These two ligaments are the ulnar and radial collateral ligaments. [36]

•  Lunate dislocation:

A lunate dislocation is an injury to one of the small bones of the wrist. Lunate dislocations usually occur as part of a major injury such as a fall from a height or an automobile collision. When a lunate dislocation occurs, one of the small bones of the wrist, called the carpal bones, comes out of its normal position. [30]

•  Neuropraxia of the radial nerve

arises secondary to traction, swelling or stiffness.

Complications

If the UCL is ruptured there is a possibility that the distal end may become interposed by the adductor aponeurosis, which is referred to as a Stener lesion (Figure 5). A Stener lesion is difficult to diagnose but leads to poor healing and usually indicates operative management. If left untreated, a torn UCL can lead to joint instability and a weak pinch grip.

Image:Stener_lesion.gif

Figure 5. Stener lesion.

Examination

Begin looking for deformities with observation of the hand at rest and in flexion. Then test the sensation in the hand followed by active range of motion (AROM). AROM should be followed by passive range of motion (PROM) and resisted movement to assess tendon integrity, if possible. To test the UCL, apply a valgus stress to the thumb in 30 degrees of flexion (Figure 4). This test is referred to as the Valgus Stress to UCL test. A rupture is likely if there is more than 30 degrees of laxity in the injured thumb or 15 degrees more laxity than on the noninjured side. To test the accessory UCL, apply a valgus stress to the thumb in full extension. A rupture is likely if there is more than 30 degrees of laxity in the injured thumb or 15 degrees more laxity than on the noninjured side. When the accessory UCL is still intact a Stener lesion is less likely. If there is any concern about the possibility of fractures to the first metacarpal or proximal phalanx of the thumb, plain radiographs are indicated prior to stress testing of the UCL. It is important to note that pain when examining can cause apprehension with subsequent tensing of surrounding muscles and can lead to a false negative.

Figure 6. Valgus stress to UCL - compare stability in injured thumb to uninjured thumb.

Management/Intervention

A UCL injury may be managed conservatively or surgically depending on the severity of the injury, location of injury, and the patient’s goals. Chronic instability of the MCPJ can occur if the injury is not managed properly.

Physical Therapy Management

Nonoperative treatment is reserved for ligament strains, partial tears, low-demand patients and poor-operative candidates, including patients with degenerative MCP joint disease. More specifically, conservative management is appropriate for patients with less than 30 degrees of valgus laxity of extension of the MCPJ, less than 15 degrees difference between sides, and no signs of avulsion fracture on radiographs. Conservative treatment typically starts with some sort of immobilization process. A thumb spica cast, including the wrist, may also be worn until the initial inflammation is resolved, typically within a week (Figure 7). Swelling can be controlled with elevation while supine, and the use of cold compresses as needed.

Once the inflammation has resolved, the patient is advised to start wearing a thermoplastic splint. The thermoplastic splint allows for the patient to begin movement of the interphalangeal joint. Thermoplastic splinting can be used initially for less severe incomplete ligamentous injuries. Wearing a splint will avoid putting radial stress on the thumb and gives the ligament time to heal. The optimal positioning for the splint involves holding the MCPJ in slight flexion with a slight ulnar deviation; the interphalangeal joints should not be immobilized in the splint. The patient should begin supervised hand therapy during the period of immobilization. The splint should be worn at all times, except for therapy sessions, for at least 6 weeks, after which the splint should only be worn during high risk situations, such as manual labor.

Figure 7. Thumb spica splint.

Gentle flexion and extension range of motion exercises can begin after about four weeks, with the patient continuing to wear the splint between therapy sessions. After 8 weeks progressive strengthening exercises may begin, but unrestricted activity is not allowed until after 12 weeks. Gripping and pinching activities should not started until 10-12 weeks and should be advanced as tolerated; forceful gripping activities are typically not tolerated until about week 12.

Surgical Management

Operative management depends on a timely diagnosis of the injury; chronic lesions become more difficult to repair with increased time since injury since remaining tissue becomes attenuated not robust enough to provide adequate support to the joint. There are multiple methods of repair, which can be categorized into dynamic or static.

Dynamic
● Extensor indicis proprius tendon transfer
● Extensor pollicis brevis tendon transfer
● Adductor pollicis brevis tendon transfer

Static
● Figure-of-eight grafting
● Parallel configuration graft
● Triangular configuration with proximal apex graft
● Triangular configuration with distal apex graft
● Dually opposed biotenodesis fixation of tendon graft
● Tendon graft weaves
● Dually opposed suture anchor fixation
● Hybrid technique

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References

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