Collateral damage: rounding up the usual suspects: thumb injuries


Some would say that the main purpose of the thumb is to be lifted up like Arthur “Fonzie” Fonzarelli of Happy Days, but we’re more concerned about its role in gripping and grabbing objects in baseball. For this to happen, the thumb must be functioning properly. You can’t play baseball at a high level with your thumbs up like the Fonz, or if you just hit it with a hammer. One of the most common injuries of the thumb involves the ulnar collateral ligament of the metacarpophalangeal cut. In today’s episode, we’re going to look at some specific injuries to UCL the thumb, namely the gamekeeper’s thumb and Stener lesions.

The thumb, despite its appearance, is an extremely complex group of bones, tendons, and ligaments that work together in one way or another to enable gripping of objects and marathon play sessions. It is made up of five different bones (metacarpal, proximal phalanx, distal phalanx, radial metacarpophalangeal (MCP) sesamoid, and ulnar MCP sesamoid) and three main joints (carpometacarpal, MCP, and interphalangeal). The MCP and IP the joints also have ligaments on the ulnar side closest to the palm (UCL) and on the radial side on the outside of the thumb (RCL).


Again, despite the thumb’s small size, a number of muscles are involved in its movement and stability. The thumb, just like the shoulder, relies on its muscles and tendons for much of its overall stability, in part because it has such a great range of motion. Muscles that start in the forearm and travel up to the thumb include the abductor pollicis long (removes CMC joint), extensor pollicis brief (extend thumb MCP joint), extensor pollicis long (extend it IP joint) and flexor pollicis long (flex it IP cut).


The muscles that start in the hand are the abductors pollicis brief (removes CMC joint), adductor pollicis (adduct the CMC joint), first dorsal interosseous (adduct the CMC joint and flex, pronate and abduct the MCP joint), flexor pollicis brief (flexes MCP and joint CMC, assists in the opposition), and the opponents pollicis (opposition, flexion and pronation).

Injury and non-surgical treatment
The thumb is involved in several common injuries. Among the most common are sprains UCL of MCP cut. This occurs when a valgus force is exerted on the thumb, which pulls the thumb away from the hand, resulting in a sprain of the UCL to MCP cut.


The UCL is actually made up of two different bands of the ligament that resist the force of valgus in different ranges of motion. The appropriate collateral ligament resists the force of valgus in flexion, while the accessory collateral ligament and palmar plate resist this force in extension. Stress tests in each of these positions can tell you which band is injured. If laxity is present in both flexion and extension, then the entire LUC is ruptured, assuming no fracture is present. Valgus force can also cause a small piece of bone to be pulled from the UCL insertion point. X-rays can tell you if there is a bone injury, and MRI can also be used to assess this soft tissue injury.

When the ligament tears, it tears most often and separates at the insertion of the proximal phalanx. Often the torn part is compressed and gets stuck in the adductor fascia of the thumb as it passes over the UCL, limiting its ability to heal. This is called a Stener’s lesion, and since it hardly ever heals on its own, it usually requires surgery.

Unlike Stener’s injury, UCL sprains and even Gamekeeper’s thumb fractures heal well on their own with immobilization and physical therapy. If there is a large opening of the joint with a valgus stress test, usually due to the presence of a Stener lesion, then surgery is warranted.

Conservative treatment involves immobilization for a period of time depending on the degree of injury. In the event of a moderate partial tear (grade II out of III), a cast or rigid immobilization for four weeks is commonly prescribed. Physiotherapy begins almost immediately to decrease swelling and restore normal movement. Most UCL injuries that don’t require surgery can heal in one month to three months, again depending on the severity of the injury.

As discussed earlier, in most cases, surgery is not necessary. However, at other times, this is the only way for a player to return to the field. After re-examining the stability under anesthesia, an incision is made over the joint, taking care to avoid the extensor digitorum longus tendon and one of the nerve branches crossing the area. The incision is made through the tissue of the adductor fascia to the point where the repair will be made.

Most of the time, the ligament tears at the point of insertion, but it can tear and tear in the middle of the substance. If this is the case, the ligament is often sutured with nonabsorbable sutures. With the most common distal tear, the ligament is then prepared for reattachment and the bone is roughened to allow a better bite or grip when the ligament is reattached. The bone anchors are placed in the correct position for better anatomical reconstruction, and the ligament is reattached. A wire can be used to stabilize the associated fracture fragments.

Under chronic conditions, this repair may not be feasible. In these cases, the attachment is moved distally from the original insertion point to promote the necessary stability. If the tissue is frayed, ragged, and unusable, reconstruction similar to other ligament replacement surgeries can be used. The preferred tendon is the palmar longus, absent in about 25 percent of the population. (Quick note: this is also why other grafts should be used in place of the long palmar for Tommy Jean surgery).

In cases where the volar longus is absent, the surgeon may use one of several other tendons, including extensor digitorum brevis tendon, plantar of the foot, extensor digitorum longus, a small part of the abductor longus of the thumb or even part of the flexor. radial carpal tendon. The graft is passed through a tunnel from the metacarpal to the base of the proximal phalanx before being anchored. The skin is then closed and the patient is placed in a postoperative splint.

Surgical rehabilitation
When surgery is required, the patient should refrain from resuming full activities for at least three months. 10 days to two weeks after surgery, the patient will return to the clinic and have the stitches removed. A thumb spica plaster or custom molded hard splint is then used until the six week postoperative mark. After six weeks, the patient will stop using the cast / splint and begin formal physical therapy and / or occupational therapy to restore movement and strength. The athlete can usually return to full activity around the three month mark. When the player returns, a splint or duct tape is typically used for the remainder of the current season.

The prognosis for long-term recovery is generally very good, although some patients develop stiffness that takes a long time to resolve. There can also be associated arthritis, especially with chronic tears, so continued pain can also be a problem.

UCL tears have a huge impact on baseball performance due to the grip and grip demands of the game. Minor to moderate sprains heal well with relative rest and immobilization, but there are times when a surgical intervention is required. If the player ends up on the operating room table, he will be away for at least three months. Fortunately, the long-term prognosis for the surgery is excellent, and while the player may experience periods of stiffness and pain, they will still be able to mimic the Fonz. Ayyyy.

Thanks for the reading

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