Thumb Base Joint Arthritis

The thumb base joint (carpometacarpal/CMC joint) is one of the most active and load-bearing joints of the hand. Due to age, repetitive use, and genetic predisposition, cartilage wear (arthritis) can develop. It is particularly common in women over 40. Daily activities like opening jars, turning keys, and gripping become painful, and grip strength decreases.

Symptoms

The most common complaints include:

• Localized pain at the thumb base, especially during gripping and pinching
• Difficulty opening jars, turning keys, holding pens
• Decreased grip strength
• Sometimes swelling and tenderness at the thumb base
• In advanced stages, thumb deformity (Z-deformity)

Diagnostic Methods

Diagnosis is largely made by clinical examination. Tenderness at the thumb base and a positive "grind test" (compressing and rotating the joint to provoke pain) suggest CMC arthritis. X-rays show joint space narrowing, osteophytes (bone spurs), and cartilage loss. The Eaton classification is used for staging (Stages 1-4).

Treatment Approach

Non-Surgical Treatments

Conservative treatment can succeed in early and middle stages. Approaches include: special thumb splint (worn at night or during daytime activity), joint-protective behavior changes, NSAIDs, physical therapy for muscle balance, and when needed, intra-articular cortisone injection. Surgery is considered if conservative treatment is insufficient after 6 months.

Surgical Treatment

For advanced arthritis, several surgical options exist: trapeziectomy (removal of the arthritic bone), LRTI (ligament reconstruction and tendon interposition), CMC arthroplasty, or in some cases arthrodesis. The technique chosen is determined by patient age, occupation, arthritis stage, and joint condition.

Surgical Process

Surgery is typically performed under regional or general anesthesia and takes about 1-1.5 hours. A small incision is made at the thumb base to address the arthritic joint structures.

Hospital Stay

Same-day discharge is usually possible; 1 overnight stay may be advised in some cases.

Recovery Process

• Weeks 1-4: Thumb cast/splint immobilization, swelling control
• Weeks 4-6: Splint removed, active range-of-motion exercises begin
• Weeks 6-12: Strengthening exercises, grip exercises
• Months 3-6: Return to full function, fine motor activities

Return to Work

Return to desk work in 4-6 weeks; return to hand-intensive work in 2-3 months. Some heavy hand work may require 4-6 months.

Potential Complications

Rare complications include nerve injury (temporary sensory loss in superficial branches of the radial sensory nerve), wound healing problems, and late-onset failure of grip strength to reach expected levels.