Carpal coalition

Lunotriquetral coalition 001

Carpal Coalition refers to a condition where two or more bones in the carpus (wrist) are fused together. This fusion can be congenital (present at birth) or acquired due to trauma, infection, or arthritis. The carpus is made up of eight small bones that are arranged in two rows between the radius and ulna of the forearm and the bones of the hand. Carpal coalition is relatively rare and can occur in any of the carpal bones but is most commonly seen between the lunate and triquetrum.

Causes

Carpal coalition is primarily congenital, meaning it is a developmental anomaly that occurs during the embryonic stage of growth. The exact cause of this anomaly is not well understood, but it is believed to involve genetic and environmental factors. Acquired causes of carpal coalition include arthritis, severe trauma, or infection that leads to the fusion of the carpal bones.

Symptoms

Many individuals with carpal coalition may not experience any symptoms, and the condition is often discovered incidentally during an X-ray for an unrelated issue. When symptoms do occur, they may include:

• Limited range of motion in the wrist
• Pain in the wrist, especially with movement
• Swelling and tenderness over the affected area

Diagnosis

Diagnosis of carpal coalition typically involves imaging studies. X-rays are the most common initial test and can show the fusion of the carpal bones. More detailed imaging, such as Computed Tomography (CT) scans or Magnetic Resonance Imaging (MRI), may be used to assess the extent of the coalition and its effect on surrounding structures.

Treatment

Treatment for carpal coalition depends on the severity of symptoms and the extent of the fusion. For individuals without symptoms, no treatment may be necessary. When symptoms are present, treatment options may include:

• Non-steroidal anti-inflammatory drugs (NSAIDs) to reduce pain and inflammation
• Physical therapy to improve range of motion and strength
• Splinting or casting to immobilize the wrist and allow for healing in cases of acute pain
• Surgery to separate the fused bones or to remove one of the bones to alleviate symptoms, although this is rare and typically reserved for severe cases

Prognosis

The prognosis for individuals with carpal coalition is generally good, especially for those who do not experience symptoms. For individuals with symptoms, conservative treatment often provides relief. Surgical intervention has a good success rate in alleviating symptoms for those with significant pain or functional limitations.

Epidemiology

Carpal coalition is a rare condition, and its exact prevalence is not well-documented. It can occur in isolation or as part of a syndrome, such as Holt-Oram syndrome or Ellis-van Creveld syndrome. There is no known racial or gender predilection.