Basal Joint Osteoarthritis

Overview

This condition is a degeneration of cartilage in the joints at the base of the thumb, collectively called the basal joint. The main component of the basal joint is the thumb carpometacarpal (CMC), joint. This joint, which allows the thumb to pivot and swivel, can wear out even early in life.

Causes

This condition is caused by aging, repetitive motions, and wear and tear that occurs during normal use of the hand. It typically results from weakness of the volar beak ligament, which normally helps maintain joint stability. When this ligament weakens, the thumb can begin to move abnormally and the joint becomes irritated and inflamed. Gradually, the cartilage that lines the joint degenerates, allowing bone to rub directly against bone. As the CMC joint degenerates, other articulations of the basal joint can become affected.

Symptoms

The most common symptom is pain at the base of the thumb, especially when gripping or pinching. A grinding sensation may be felt when the thumb is moved. The thumb may also become weak and stiff. As the condition worsens, the joint may become deformed, and a bump may form where the thumb meets the wrist.

Diagnosis

The doctor will order x-rays of the wrist and hand to diagnose this condition. MRI or CT scans are usually not required.

Treatment

Treatment options include cortisone injections, non-steroidal anti-inflammatory medications, use of a splint or brace, exercise, and modification of daily activities. Surgery may be needed.

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.