Skier’s Thumb (Ulnar collateral ligament Injury)

Introduction:

Skier’s Thumb, also known as an ulnar collateral ligament (UCL) injury of the thumb, is a common injury affecting the ligament on the inner side of the thumb’s metacarpophalangeal (MCP) joint. Usually, it occurs by a rapid, strong, outward bending of the thumb, like when you fall while carrying a basketball or a ski pole.

In severe cases, surgery may be required if the ligament is completely torn. Physical treatment may also be necessary to regain joint strength and mobility. A successful recovery and the avoidance of long-term consequences depend on early diagnosis and treatment.

Definition:

Injury to the thumb’s ulnar collateral ligament (UCL) (also known as the metacarpophalangeal joint, or MCPJ) increases the risk of chronic instability if left untreated. The lesion typically occurs when a skier’s thumb is forced to turn radially by the ski pole. An actual UCL rupture.

Clinical Relevant Anatomy:

The thumb’s diarthrodial metacarpophalangeal joint, which is supported by a capsule and other soft tissue elements, permits unhindered joint movement. Both dynamic and static stability are displayed by the nearby soft tissue.

The following constructions provide passive stability:

• Proper collateral ligament
• Supplementary collateral ligament
• Volar plate
• Posterior capsule

From a location just posterior to the metacarpal head’s mid-axis to the palmar part’s proximal phalanx, the correct collateral ligament extends.

The thumb’s intrinsic and extrinsic muscles are active stabilizers of valgus stress:

• Extensor pollicis brevis
• Extensor pollicis longus
• Flexor pollicis longus
• Adductor pollicis
• Flexor pollicis brevis

The thumb’s MCPJ is traversed by two main supporting ligaments:

• The ulnar collateral ligament (UCL)
• The radial collateral ligament (RCL)

The UCL and RCL attach to the base of the proximal phalanx on their respective aspects, below the adductor aponeurosis, after emerging from the medial and lateral tubercles of the metacarpal condyles.

Epidemiology:

The prevalence of this trauma during skiing varies from 7 percent to 32 percent of all skiing injuries, making it the most frequent upper limb injury suffered by skiers.

The most frequent cause of a skier’s thumb, which affects over 40% of patients, is a fall on the extended hand, typically from a bicycle or motorcycle (the thumb becomes stuck down the handlebars). An additional 30% of the causes are thought to be related to other sports, such as fighting or soccer. Hyperabduction trauma significantly causes a Salter-Harris III avulsion of the UCL insertion and invariably a genuine rupture of the UCL in children, who still have an adolescent skeleton.

Mechanism of Injury in Skier’s thumb:

It is important to note that this injury is not exclusive to skiers and can occur to anyone if the thumb experiences high valgus stress force during abduction and extension. While a forced abduction action would injure the RCL, an acute UCL injury occurs concurrently with rapid, hyper-abduction and hyper-extension stress at the MCP joint. Inappropriate treatment of the UCL injury may lead to arthritis, joint instability, pain, weakness, and persistent laxity in the MCPJ.

Pathophysiology:

Although the thumb’s anatomical function is complicated and outside the purview of this article, it is important to understand that the ulnar collateral ligament helps to stabilize the thumb at the metacarpophalangeal joint.

The thumb works in tandem with hand muscles, finger muscles, and ligamentous structures, such as the ulnar collateral ligament, to effectively grab and hold onto objects. One may see how severe hyperextension (or extreme abduction) might damage the ulnar collateral ligament by understanding this mechanism of thumb function. The patient may experience pain and edema in the first metacarpophalangeal joint, as seen in other acute joint injuries.

Cause of Skier’s thumb:

When the thumb is directly traumatized, it frequently twists or bends abruptly to the side or back. Imagine your hand exerting too much energy to bend your thumb in an unusual manner. That is the exact mechanism by which a UCL rupture occurs.

You have a higher chance of suffering a UCL injury if you are an athlete or frequently engage in high-impact sports like baseball, basketball, football, racquet sports, or snowboarding.

• Excessive thumb abduction and hyperextension cause it.
• Thumb hyperextension that causes trauma

Symptoms of Skier’s thumb:

Inflammation and bruises will be seen if the damage is recent. Patients in more chronic conditions typically report thumb instability when doing these ADLs, as well as pain and weakness in the pincer grip. A palpable lump that is situated close to the adductor aponeurosis is present in the Stener lesion example.

These signs and symptoms may appear minutes to hours after the injury-causing fall:

• Swelling in the thumb.
• Sensitivity when your thumb’s index fingers are palpated.
• The skin around the thumb appears discolored, either blue or black.
• Pain in the thumb that gets worse when you move in practically every direction.
• The pain that comes from your thumb may be referred to as wrist ache.

Type-Injury Examination:

• I had a fracture that moved. Stable in flexion
• II Fracture displacement No special test
• III No fracture In flexion, stable (<30°) IV Not a fracture In flexion, unstable (>30°)

Differential Diagnosis:

Bony structures, tendons, neurological tissues, the auxiliary collateral ligament, and the adductor aponeurosis are among the various structures that may be impacted. The area of soreness, however, may determine them.

• Stener lesion: A sterner lesion occurs when the thumb is violently abducted, causing the distal ulnar collateral ligament to avulsion from the bone beneath the thumb’s proximal phalanx.
• Bennett or Rolando fracture.
• Avulsion fracture.
• Wrist fracture.
• Dislocation of the first metacarpophalangeal joint.
• Lunate dislocation.
• Rheumatoid arthritis or osteoarthritis.
• Wrist sprain.
• Prolonged instability of the first MCP joint: If left untreated, damage to the two main assistive ligaments that cross the thumb’s metacarpophalangeal (MCP) joint can cause symptomatic joint fluctuation, including pain, weakness, and arthritis.
• Neuropraxia.

Diagnosis:

• X-rays: Avulsion fractures with displacement greater than 5 mm or any fracture involving at least 25% of the MCP joint surface are not indicated for surgical therapy backed by imaging.
• MRI: Many people recommend it as the most effective method for identifying UCL trauma, especially in cases with chronic UCL injury.
• Ultrasound: Before using a glove spica cast as part of conservative therapy, the US must make the diagnosis.
• Arthrography: In practically all MCPJ sprains, stability testing (done with the joint in full flexion) and additional routine radiographs continue to be the cornerstones of decision-making, according to clinical and anatomical findings.

Physical Examination:

Regarding measuring the hand at rest and in flexion in order to detect deformity. After doing an active range of motion (AROM), passive range of motion (PROM), and resisted movement to assess tendon integrity, if manageable, examine the hand’s feeling.

X-rays and clinical examinations are sensitive methods for identifying UCL injuries. The thumb MCP joint stability is assessed using a stress test if there isn’t a shaft fracture associated with it; the steady endpoint is shown below:

• To prevent strain, the thumb’s proximal phalanges are supported by the metacarpal, which is stabilized with the aid of a second hand.
• It is possible to detect the steady endpoint by repeating the radial focus in the extended position while the proximal phalanges are in a 30-degree flexion.
• The tester will detect a ligamentous bulge if there is a stener lesion.

Stress tests can be painful, and in order to do the test without causing tension in the surrounding muscles, the tester may need to administer local anesthesia.

Usually, there is a history of trauma or falls that resulted in hyperextension or excessive thumb abduction. Acute presentations may occur shortly after the injury, or if the injury is more persistent, the patient may not show up for a while. Pain and sometimes weakness may be experienced in both cases, particularly when trying to grab objects, especially with a pincer grasp.

Making this diagnosis can be particularly aided by the physical examination. Establishing a baseline to indicate the extent of the tear or injury can be aided by comparison with the thumb that is unaffected. There will be more laxity or movement on valgus stress tests when there are partial tears present.

According to orthopedic research, any laxity on abduction or valgus stress testing that is greater than 15 to 20 degrees is considered to be indicative of ulnar collateral ligament damage. Although the orthopedic literature describes this, the physician can find it challenging to measure the degree of ulnar collateral ligament laxity in the real-world clinical setting.

Evaluation:

When there is acute damage to the ulnar collateral ligament, imaging is usually not beneficial. Plain X-ray imaging, however, is typically unrevealing in fact, it may be normal in these patients. Similar to the physical examination, both thumbs can undergo ultrasound imaging to compare the two and create a baseline on the unaffected side.

Acute magnetic resonance imaging can be difficult to obtain. This method, however, offers the highest sensitivity and specificity (almost 100%) for identifying injuries to the ulnar collateral ligament, including ruptures or tears.

Treatment of Skier’s thumb:

Medical methods or conservative treatment for a UCL injury depend on the following factors, which are primarily present:

• Timing of presentation (acute or chronic)
• Grade (severity of injury)
• Trauma site (peripheral or mid-substance) concussions of large tissues, such as the volar plate, anterior plate, or bone, occur together or in association. Aspect connected to the patient (demands of the workplace, etc.)

The following describes the suggested care of UCL injuries based on Hintermann’s classification:

• Cast immobilization is required for approximately four weeks for type I injuries.
• Cast immobilization is required for approximately three weeks for Type III and Type V injuries.
• Surgery is required for types II and IV injuries.

Medical Treatment:

R-I-C-E therapy—rest, ice, compression, and elevation can be used to treat ulnar collateral ligament injuries acutely, much like it is for the majority of musculoskeletal injuries.

The patient should be referred immediately to an orthopedic or hand specialist if they have a bone injury, such as an avulsion fracture in the context of an ulnar collateral ligament injury.

According to one study on sports-related injuries, there was a 10.3% postoperative complication rate and an overall 98.1% successful return to play following surgery without a discernible decline in performance. Surgery is advised as the final course of treatment since the ligament cannot recover properly due to this changed anatomy.

Immobilization:

Depending on the level of laxity during the early evaluation, from 10 days to 6 weeks. The following recommendations, which the investigator was persuaded to make after four to six weeks and up to twelve weeks, depend on the extent of the lesion:

• A thumb spica cast for short arms
• With a thermoplastic splint, the patient can begin using their interphalangeal joint.
• A removable thumb spica orthosis that is hand-based.
• The MCPJ in mild flexion with a small ulnar deviation is the ideal orientation for splint respect retention because it brings the torn ligament segments closer together and aids in healing.

Surgical Treatment:

Prolonged lesions become significantly more difficult to repair with increased duration after damage because the remaining tissue becomes less robust to provide enough support to the joint. Operative consideration is excluded if the trauma is grade 1 or 2 and radiographs show volar subluxation, a present unstable joint, a Stener lesion, or a displaced avulsion fracture.

Dynamic Static:

• 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
• Tendon graft weaves
• Hybrid technique
• Free tendon graft

A better result can still be obtained after three to four weeks, as long as the procedure was performed on time (delaying surgery reduces the choice of outcome). Immobilization is necessary for approximately six weeks, after which a fresh radiograph is taken and physical therapy can begin. This typically takes about three months. Furthermore, no studies have yet been established to examine if surgical intervention is indeed better than non-operative treatment.

Follow up:

Following a surgical fix or a period of immobilization in a cast, the patient will be seen by the operative surgeon. A second examination of the patient’s thumb will be performed.

Physical Therapy Treatment:

Conservative management is used for incomplete ruptures. Elevating the body above the level of the heart when in a supine position and applying cold compresses as necessary can help control swelling.

Enhancing function and minimizing the duration of functional recovery are the main goals of rehabilitation; the suggested treatment offers prospective benefits in the treatment of this frequent acute hand injury.

Exercise therapy:

The patient must begin hand rehabilitation under supervision while they are immobilized. It is possible to begin advanced strengthening exercises after 8 weeks, however, full activity is not allowed until 12 weeks.

Thumb active range of motion:

• Then make a handshaking motion with your hand resting on the table.
• Stretch your thumb as far away from your palm as you can.
• Hold on for five seconds.
• Take your thumb and palm side by side and move them toward your little finger.
• For five seconds, maintain this posture. 15 times, repeat this entire sequence. Perform two sets of fifteen.

Wrist range of motion:

• Flexion: Bend your wrist forward slightly. Hold for five seconds. Perform two sets of fifteen.
• Extension: Bend your wrist back slightly. For five seconds, maintain this posture. Perform two sets of fifteen.
• Side to side: Shake your hands by lightly moving your wrist from side to side. Hold in each direction for 5 seconds. Perform two sets of fifteen.
• Spend five to ten minutes performing this exercise.
• Grip strengthening:  Strengthen your grip by continuing to squeeze a soft ball while counting for five seconds. Do two sets of fifteen reps.
• Wrist flexion: Raise your wrists. Perform two sets of fifteen. The load of the can or cargo you are keeping is added gradually and step by step.
• Wrist extension: Bend your wrist up slowly. Perform two sets of fifteen.

Post-surgical treatment:

After the procedure, the physical therapy’s substance is the same as that of the conservative management, anyway:

• The immobilization period is typically six weeks.
• Radiography control following immobilization A splint is often worn for four to six weeks after surgery. Faster and more precise functional results were obtained from the operated joint’s contiguous post-operative mobility. As a result, it is recommended to use a functional splint and to begin moving within the limits of pain as soon as possible. It usually takes three to four months for athletes whose injuries require surgery to return to competition.
• According to Derkash’s written report, less than 5% of patients experience stiffness and a weakened tweezer grip when taking into account pain, stability, muscular power (tweezer grip), and functionality in ADL. In 99 percent of the cases, the pain was either nonexistent or very little. Ninety-six percent of individuals who had treatment expressed satisfaction with the procedure’s results. The results were less successful when a secondary operation was necessary.

Complications of Skier’s thumb:

It is anticipated that the adductor aponeurosis, also known as a Stener lesion, may interrupt the distal end if there is injury to the UCL. Although difficult to identify, a Stener lesion results in poor healing and frequently requires surgery. A ruptured UCL can cause joint instability and pinch grip weakness if treatment is not received.

Prevention of Skier’s thumb:

Avoiding pole dragging and deep pole plants, teaching good pole technique for powder skiing, and reducing the size of baskets from the typical 4-inch diameter to 2.5 inches are all examples of preventive measures. The pole length should be two inches less than what the skier is advised to wear.

Wearing a correctly made ski glove, which not only inhibits excessive thumb movement but also has a mechanism for ejecting the ski pole, can further lower the chance of damage.

Prognosis:

Despite the lengthy period of immobilization, partial tears of the ulnar collateral ligament typically heal successfully when treated with splinting alone. In the case of full ulnar collateral ligament tears, surgery can usually be carried out without any difficulties, as was covered in the treatment and management section above.

Conclusion:

The preferred imaging technique for evaluating patients with unclear results and detecting ligament damage that needs to be repaired surgically, including the frequently seen Stener lesion, is magnetic resonance imaging (MRI).

FAQs:

References

• Mohseni, M., Sina, R. E., & Graham, C. (2024b, February 1). Ulnar collateral ligament injury (Gamekeeper’s thumb). StatPearls – NCBI Bookshelf. https://www.ncbi.nlm.nih.gov/books/NBK482383/
• Ulnar collateral ligament injuries of the thumb. (n.d.). https://www.advantagephysiotherapy.com/Injuries-Conditions/Hand/Hand-Issues/Ulnar-Collateral-Ligament-Injuries-of-the-Thumb/a~291/article.html