Ulnar collateral ligament injury of the thumb metacarpophalangeal joint

　　First, Etiology

　　It is mainly caused by the thumb's forceful abduction, rotation, and overextension.

　　Second, Pathogenesis

　　Injury to the ulnar collateral ligament of the thumb metacarpophalangeal joint can be caused by the thumb's forceful abduction, rotation, and overextension. In skiing injuries, it is often due to incorrect grip on the ski pole; when playing sports, especially when catching the ball, it may be caused by direct trauma from the ball; using a walking stick can also lead to chronic injury. When the hand touches the ground and falls, the thumb in an abducted position overloads the ulnar collateral ligament, and the ski pole handle between the thumb and index finger further increases this load. The degree of ligament injury mainly depends on the direction of the force, the position of the thumb at the moment of force application, and the pressure on the joint.

　　The lateral collateral ligament rupture caused by external force generally has three types:

　　1. Distal insertion near rupture.

　　2. Distal small bone fragment avulsion.

　　3. Middle ligament rupture.

　　Swelling After trauma, local swelling appears, reaching a peak after 72 hours, and then gradually subsides. After swelling occurs, the affected limb should be elevated, preferably above the heart level, and appropriate ice application should be given to promote the subsidence of swelling.

　　Muscle atrophy Once the limbs are immobilized or lack of movement, muscle atrophy will occur. Active muscle search can reduce the degree of muscle atrophy. The specific method is: if the joint can move, muscle isometric contractions (i.e., muscles are exerted but the limb does not produce movement) and isotonic contractions (muscles are exerted and produce movement) can be done. If the joint is immobilized, isometric contraction exercises can be performed.

　　With a typical history of trauma, the injured side of the thumb metacarpophalangeal joint is painful and swollen, mostly accompanied by local subcutaneous cyanosis, significant restriction of movement, and local tenderness, especially when the lateral movement of the metacarpophalangeal joint can cause severe pain.

　　Under normal circumstances, the thumb metacarpophalangeal joint is outwardly flipped about 25°, which is a reliable sign of collateral ligament rupture. If the joint can be flipped laterally in the extended position, it indicates that both the palmar plate and the collateral ligament have been ruptured; if the slightly flexed joint is outwardly flipped about 20°, it indicates that there is only a collateral ligament injury. For patients with old ligament injuries, the skin nerves in the scar area often cause radiation pain.

　　Taking anteroposterior and lateral X-ray films of the thumb metacarpophalangeal joint, and when there is bony ligament avulsion, the size and location of the bone fragments can be determined, which provides a reference for the selection of clinical treatment methods.

　　In daily life, the following points should be followed:

　　1. Warm-up exercises should be done before exercise to heat up the joints first;

　　2. Do not exercise when tired, as this can lead to slow reactions and difficult coordination of movements;

　　3. Strengthen the exercise of limb strength to ensure the stability and flexibility of the joints;

　　4. In sports, prevent rough actions from causing accidental injuries;

　　5. Pay attention to the warmth of the knee joint, and perform joint heat therapy and massage regularly every day;

　　6. Avoid overexertion of the joints;

　　7. For those who are overweight, weight loss should be considered;

　　8. Avoid overloading during physical exercise.

　　In addition to clinical manifestations, the diagnosis of thumb metacarpophalangeal joint ulnar collateral ligament injury also relies on the following related examinations: thumb metacarpophalangeal joint anteroposterior and lateral X-ray films, which can reveal fractured fragments with avulsion.

　　What foods are good for the body of a patient with a thumb metacarpophalangeal joint ulnar collateral ligament injury?

　　It is advisable to eat light and well-balanced meals. Consuming foods rich in high protein is beneficial for the recovery of wounds. Supplementing with a variety of vitamins and eating fresh vegetables and fruits is recommended. It is also possible to eat various lean meats, milk, eggs, and other protein-rich foods.

　　2. Foods to avoid for thumb metacarpophalangeal joint ulnar collateral ligament injury are not recommended to eat

　　Avoid smoking, alcohol. Avoid spicy and刺激性刺激性 foods such as scallions, garlic, ginger, Sichuan pepper, chili, cassia bark, etc., and avoid greasy foods.

　　I. Treatment

　　1. Non-surgical Treatment:In cases of simple contusions, sprains, partial ligament ruptures without excessive hyperextension and instability of the thumb metacarpophalangeal joint, the entire thumb can be fixed to the interphalangeal joint using a cast for 3 weeks.

　　2. Surgical Treatment:Fresh collateral ligament injuries should be repaired in a primary manner after injury, with different methods adopted depending on the condition of the injury.

　　Ligament rupture can be directly sutured immediately after injury or 4 to 7 days after local swelling subsides. Delayed primary suture can be performed within 2 weeks after injury. The surgery is performed under brachial plexus nerve block anesthesia and tourniquet, with an oblique incision made on the ulnar side of the back of the thumb metacarpophalangeal joint, cutting through the skin and subcutaneous tissue, and protecting the radial nerve branches running through the incision. The adductor pollicis tendon is longitudinally incised, and the ruptured collateral ligament is exposed in its deep surface, usually seen in the middle and distal parts of the ligament. It can be directly sutured or the avulsed collateral ligament can be fixed to the rough surface of the proximal phalanx base using钢丝 wire suture technique, and the adductor pollicis tendon and skin are sutured.

　　In cases where old lateral injuries cannot be directly repaired, autograft tendons can be transplanted, and an '8' shaped ligamentoplasty can be performed within the metacarpophalangeal joint of the thumb, or a fascial flap can be transplanted to repair the injury.

　　In cases of progressive painful deformity of the joint with instability during movement, joint fixation can be performed, fixing the metacarpophalangeal joint at a flexion of 20°.

　　During surgery, a Kirschner wire can be used to temporarily fix the metacarpophalangeal joint to facilitate the healing of the ligaments. Or, after surgery, the thumb can be fixed in an adducted position for 4 to 5 weeks using a forearm cast, and in cases where small bone fragments are avulsed and fixation is performed using absorbable sutures, Kirschner wires, or miniature screws, the fixation should last for 6 weeks. When the cast is removed, the wire is removed, and thumb function exercises begin.

　　II. Prognosis

　　Generally, the prognosis is good.