Dislocated Thumb Overview

Could you imagine writing, typing, or playing your favorite sport without the use of your thumb? Even if a dislocated thumb is less common than some other finger injuries, the potential challenges and complications are worth taking seriously. Learn everything you need to know with this detailed guide on dislocated thumb injuries and discover what treatment options may be best for you.

What is a Dislocated Thumb?

A dislocated thumb is an injury in which one of the joints of the thumb is over-extended beyond its limitations. Broken bones and strained connective tissues are among the most serious and difficult-to-treat hand injuries that can result from dislocation and severely impact your daily activities.

Thankfully, this type of injury rarely occurs unless you are an athlete or are in a high-impact accident. However, fingers (including the thumb and particularly the middle joint), are some of the most commonly dislocated joints. There are three different joints in the thumb that can be dislocated, depending on where and how impact occurs.

Dislocated Thumb IP Joint

The interphalangeal (IP) joint is the most distal joint in the thumb. This kind of thumb injury is rare when compared to an MCP joint injury (see below). A dislocated thumb IP joint is caused by excessive pressure on the end of the thumb (hyperextension or axial loading),  possibly caused by a fall.

This injury is typically associated with tendon ruptures, avulsion fractures, and damage to the connective tissue that stabilizes the thumb IP joint known as the volar plate. The dislocation requires immediate reduction and often needs surgery to repair damaged tissues or remove bone fragments.

Dislocated Thumb MCP Joint

The metacarpophalangeal (MCP) joint connects your palms to your fingers, except in the thumb where this joint is located in the web space. Dislocated thumb MCP joint injuries occur when excessive strain is placed on the metacarpophalangeal joint with hyperextension or a fall. It is more common than thumb IP joint injuries. Treatment and recovery require reduction and stabilization of the joint with an appropriate brace to allow connective tissue healing.

Dislocated CMC Joint

The carpo-metacarpal (CMC) joint is located near the wrist, acting as a bridge to the palm. A dislocated CMC joint injury most often results from overextension and high impact in this area, as pressure is applied to the carpometacarpal joint. However, it is a very rare injury and accounts for less than 1% of thumb injuries. Swelling and pain may be present, and some severe cases need surgery.

Causes of Thumb Dislocations

Typically, a thumb dislocation is caused by direct trauma due to a fall or high impact sports injuries. Many basketball players suffer a dislocated thumb knuckle after being hit by the ball at the distal phalanx (tip of the thumb) and hyperextending the joint. This injury can damage the stability and integrity of local connective tissues in the thumb and makes it difficult to retain full mobility of the thumb or keep a normal position of the hand for daily activities.

In some cases, rheumatoid arthritis can increase the likelihood of experiencing a dislocated thumb because of local joint damage and instability. Luckily, tools like arthritis gloves are available to ease pain and keep the hands moving more comfortably.

Dislocated Thumb Symptoms

What are the signs of a dislocated thumb and how can you determine the best type of treatment? Listed below are the several dislocated thumb symptoms to look out for:

• Sharp pain around one or more of the thumb joints
• Limited and painful thumb range of motion
• Severe swelling and bruising
• Tenderness around the damaged area
• Noticeable dorsal/palmar deformity
• Feeling of numbness and discomfort when moved
• Loss of finger, hand, wrist and/or grip strength
• Changes in color

Learn more about treating these symptoms here.

Diagnosing a Dislocated Thumb Joint

It is important to seek medical attention as soon as possible, especially if bones are out of place to get immediate reduction of the dislocation. If needed, your doctor can use local anesthetic before resetting the joint.

General practitioners may require a dislocated thumb X-ray to assess the severity of your injury and the presence of any fractures. Knowing what a dislocated thumb looks like means accurate treatment and medication.

Blood tests may be required if there is a possible infection connected to the dislocated joint. Your doctor may also order dislocated thumb imaging, such as an MRI, for further reference and assessment of connective tissue damage (particularly local ligaments and the volar plate that provides thumb stability).

Preventing a Dislocated Thumb

While hand injuries can’t always be avoided, knowing what to do for a dislocated thumb can make the recovery process much smoother. Most importantly, the integrity of the injured joint needs to be preserved while damaged tissues heal. This typically involves the use of braces, splints or taping, pain and swelling management (ice packs, massage, etc.), and eventual return exercises to promote optimal hand range of motion and strength. Remember, patience and appropriate medical advice is key--and if the right treatments are employed, healthy hands will be right around the corner in spite of a finger dislocation.

Sources:

https://www.epainassist.com/hands/dislocation-of-hand-thumb-fingers

https://emedicine.medscape.com/article/109187-overview#a1

https://orthoinfo.aaos.org/en/diseases--conditions/thumb-fractures