What Is a Skier's Thumb?
A strain or sprain of the ligament that links the bones of the thumb is known as a skier's thumb. The ulnar collateral ligament, which is located at the base of the thumb on the side opposite the pointer finger, is the one that gets injured. When the thumb is used to pinch or grab an object, this ligament helps to keep it steady. Pain and restricted thumb movement are common symptoms of a skier's thumb, caused when a ligament in the thumb is ruptured or stretched.
What Is a Stener's Lesion?
The severe abduction of the thumb causes an avulsion of the distal ulnar collateral ligament from its attachment at the base of a proximal phalanx of the finger, which results in the unique lesion known as the skier's thumb. The forceful abduction of the hand induces this lesion.
What Are the Symptoms of This Condition?
The symptoms may appear shortly after the injury:
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Pain in the web area between the thumb and index finger at the base of the thumb.
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Inflammation of the thumb.
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Loss of the ability or weakness to grasp with the thumb and index finger.
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Sensitivity to touch along the side of the index finger and the thumb.
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Thumb discoloration in blue or black.
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Pain in the thumb increases with movement.
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Discomfort in the wrist.
What Is the Diagnostic Procedure?
Skier's thumb should be diagnosed with a comprehensive medical history, physical assessment, and additional imaging techniques.
Physical Examination: The examination of the malformation, as well as the inspection of the hand in both it is resting and bending positions. Test on hand performed at both active and passive ranges of motion; results have been analyzed. In addition, the stability of the MCP joint is determined using a stress test and the detection of the endpoint of the following:
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The metacarpals are strengthened to prevent any strain from being placed on the proximal phalanges of the thumb.
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When in the extended position, the radial flexion tension is applied to locate the firm endpoint.
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The degree of deviation between the damaged and opposite sides is used to determine the extent of the tear. This is done by comparing the two sides.
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When a stener lesion is observed, a ligamentous lump is also present.
Imaging Technique
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Plain Radiograph: The existence of a minor avulsion fracture can be seen on a plain radiograph. This fracture can be found at the ulnar corner of the base of the proximal phalanx or the ulnar first metacarpal head. The stress radiograph can detect minute changes. When the tear is in mid-substance, and there is no associated fracture, the ulnar side of the joint can appear to be expanded.
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Ultrasound: The use of ultrasound is helpful in recognizing the rip, stener lesion, and retraction. For example, a stener injury will prevent the adductor aponeurosis from sliding smoothly over the ulnar collateral ligament (UCL) during passive flexion of the thumb interphalangeal joint.
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MRI: Magnetic resonance imaging (MRI) is increasingly being utilized to evaluate occult X-ray injuries to the ulnar collateral or to attempt a stener lesion. It can even detect discontinuity of the ligament from the joint capsule, as well as bone marrow edema and fracture.
What Are the Grades of the Sprain?
The severity of the wound determines which grade the patient receives. The grades are as follows:
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Grade 1: A minor strain occurs when ligaments are strained but not torn due to an injury.
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Grade 2: The thumb has suffered some function reduction due to the moderate sprain, which partially ripped the ligaments.
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Grade 3: A severe sprain in which the ligament has either been entirely ruptured or removed from its attachment to the bone. This injury requires medical care. An avulsion fracture is a type of fracture that occurs when a ligament tears and pulls off a component of the bone with it.
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Grade 4: The failure of immobilization led to the need for surgery, as was the case with patients with stener lesions.
What Is the Treatment Method?
The major treatment objective is to restore stability to the joint that connects the thumb to the metacarpal bone (MCPJ). Due to this, making a differentiation between a stable and non-displaced bony avulsion and a partial UCL lesion is the most crucial task to perform. It has been recommended that conservative treatment be the primary treatment without administering radial stress to facilitate unaffected ligament or bone healing.
Open Reduction - It provides the sole method to successfully repair the ligament anatomy and joint morphology in the event of a displaced bone avulsion fracture. Whole rips of the UCL without bone avulsion may heal effectively with closed therapy if the torn ligament's ends are aligned; however, there is no reliable assessment to differentiate undisplaced from displaced complete tears in unstable ligament ruptures other than surgical inquiry.
Conservative Treatment - Indications for nonoperative treatment include bone avulsion fractures that have stabilized and are not displaced and incomplete tears.
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Plaster Splint - It is essential to immobilize the metacarpophalangeal joint of the thumb (MCPJ) as soon as possible to prevent additional injury. After the swelling has subsided, the plaster splint, which protects the wrist, is replaced with a thermoplastic thumb splint, which may be easily removed from the hand. While shaping the splints, the MCPJ is slightly flexed, and the thumb is gently pressed into an ulnar deviation position. Throughout the healing phase, the interphalangeal joint will not be immobilized, and the patient will be instructed to maintain a complete active range of motion as much as possible. If an injury has been sustained, it is common practice to wait three to four weeks before beginning active flexion and extension activities of the thumb MCPJ. These exercises are performed as a means of helping to strengthen and extend the joint in question.
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Functional Splinting - The patient wore the functional splinting, designed to minimize radial deviation while permitting an active range of motion exercises of the thumb. MCP did not improve the patient's range of motion, increase the pinch grip strength, or reduce the time the patient needed to take sick leave. Therefore, until the sixth week following the injury, the individual must always wear the splint except when participating in therapy sessions. This requirement will remain in place until the sixth week after the injury. Following that point, the user is only required to wear the splint when involved in hard manual labor or in another high-risk condition. After eight weeks, the participants would begin a gradual muscular strengthening program, but their thumb motions would be restricted until twelve weeks. Taping can be used as a measure of protection during sporting activities for up to four months after an injury.
Surgical Intervention: Surgical intervention is required due to the presence of displaced bone avulsion fractures as well as extensive ligament tears. The surgery should be performed when the edema has reduced, occurring several days after the damage. Suppose the operation is pushed for longer than two to three weeks after the damage occurred.
The primary repair will be more difficult in that case, and the postoperative function may suffer. The dorsolateral incision will wrap around the medial collateral ligament of the thumb. The digital branches of the superficial radial nerve need to be located and preserved. Hence this is an essential step. If a Stener lesion is present, it is possible to identify the proximal stump of the UCL proximal to the adductor aponeurosis. After the ligament has been repaired, the aponeurosis is cut out in a direction parallel to the tendon of the extensor pollicis longus and then resutured. The reapproximation of a rare tear in the middle of the material requires interrupted mattress sutures.
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Osteosynthesis - Pull-out wires and sutures or intraosseous anchoring devices are employed in soft tissue fixation to bone fragments to repair purely ligamentous and tiny bony avulsions. This technique is also known as osteosynthesis. When this occurs, the UCL has to have its initial insertion at the volar base of the proximal phalanx reattached. When the reinsertion is performed too far to the dorsal side, the patient experiences instability and restricted MCPJ flexion.
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Anchoring Devices - K-wires or small lag screws could be used to anatomically connect significantly bigger fragments after separating them. Ruptures of the dorsal capsule between the accessory UCL and the volar plane can be seen in very unstable joints; additional sutures are required to restore these joints.
What Is the Preventive Method?
Trauma, which causes the thumb to be forced into a radial deviation, is the primary reason for the skier's thumb. Instruction on the proper pole technique for power skiing, including management to avoid dragging the pole and making deep pole plants, is one of the preventative strategies. Wearing-designed ski gloves can help lessen the likelihood of getting injured. It can prevent the user's thumb from making extreme movements and has the potential to add a mechanism for dislodging the ski pole. Taping may be advantageous after treating UCL lesions; however, it is not an effective strategy for preventing forced radial deviation of the thumb MCPJ.
Conclusion:
Skier's thumb is a metacarpal phalangeal joint disorder. Persistent instability can cause significant disability and functional deterioration, making this injury common in sports. Forced radial distortion of a ski pole can tear the knee-stabilizing ulnar collateral ligament (UCL). Clinical evaluation and imaging are needed to assess the lesion's impact on ulnar ligament capsular stability. Stability assessments should be done in all cases, including non-displaced avulsion fractures, to rule out further significant UCL tears. The patient should be referred to the specialist immediately as possible and have an early surgical evaluation if instability is suspected. Conservative and surgical patients follow the same protocols for returning to normal, unrestricted activities after the intervention.
