Thumb mobility is essential for countless daily tasks—gripping a pen, turning a key, holding a mug, or texting on your phone. At the base of the thumb lies the carpometacarpal (CMC) joint, a small but vitally important joint that enables the thumb’s remarkable range of motion. When arthritis or injury affects the CMC joint, pain and loss of function can make even the simplest activities a challenge. CMC joint replacement surgery offers a proven solution for those whose lives are disrupted by persistent thumb pain.
What Is the CMC Joint?
The CMC joint is located where the base of the thumb (first metacarpal bone) meets the trapezium bone in the wrist. This unique saddle-shaped joint allows you to move your thumb in multiple directions, giving the hand its remarkable dexterity.
Why Does CMC Joint Arthritis Occur?
CMC joint arthritis, also known as basal thumb arthritis, is among the most common forms of osteoarthritis affecting the hand. It typically results from:
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Wear and tear: The CMC joint is used in almost every gripping or pinching action, experiencing significant stress over time.
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Ageing: Cartilage covering the joint surfaces becomes worn, leading to bone-on-bone contact.
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Previous injuries: Damage from fractures or sprains can increase the risk.
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Genetics and gender: Women over 50 are especially susceptible.
Symptoms include pain at the base of the thumb, swelling, weakness, loss of grip strength, and visible joint deformity in advanced cases. Everyday tasks such as opening jars, writing, or fastening buttons may become unbearable.
When Is CMC Joint Replacement Surgery Recommended?
While early thumb arthritis may respond to conservative measures such as splints, physiotherapy, anti-inflammatory medications, or corticosteroid injections, these treatments may only provide temporary relief. Surgery is considered when:
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Pain persists despite non-surgical treatments
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Daily activities become increasingly difficult
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Deformity and loss of function worsen
Joint replacement surgery is designed to relieve pain, restore movement, and correct deformity, offering long-lasting results for suitable candidates.
Understanding CMC Joint Replacement Surgery
The Procedure
CMC joint replacement surgery (also referred to as thumb base arthroplasty or prosthetic arthroplasty) involves removing the arthritic bone surfaces at the base of the thumb and replacing them with an artificial joint. There are several surgical techniques:
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Implant arthroplasty: Involves replacing the joint with a prosthetic implant, made from materials such as metal, ceramic, or medical-grade plastic.
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Resection arthroplasty: In some cases, a portion of bone (usually the trapezium) is removed and replaced with a soft tissue spacer, often fashioned out of a tendon.
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Suspensionplasty: Sometimes the thumb’s ligaments are reconstructed or supported with sutures or tendon tissue to maintain joint stability.
The choice of technique depends on patient age, activity level, degree of arthritis, and surgeon preference.
Anaesthesia and Incision
The operation is typically performed under regional anaesthesia (numbing the arm) or a general anaesthetic. A small incision is made at the base of the thumb, allowing precise access to the affected joint.
Duration
Most procedures last 60–90 minutes and are performed as day cases, allowing patients to return home the same day.
Benefits of CMC Joint Replacement
Patients often experience dramatic improvement after CMC joint replacement:
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Significant pain relief: Most notice reduced discomfort within weeks.
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Restored grip and pinch strength: Enables return to normal activities and hobbies.
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Improved mobility: Greater thumb range of motion and dexterity.
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Cosmetic correction: Reduces “Z” deformity sometimes seen with advanced arthritis.
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Durability: Modern implants are engineered for longevity.
Recovery and Rehabilitation
Immediate Post-Op Care
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The thumb and wrist are immobilised in a bandage or splint for 2–4 weeks.
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Elevating the hand and using ice help minimise swelling and pain.
Physiotherapy
Gentle movements begin early to maintain flexibility, guided by a hand therapist. Strengthening exercises are gradually introduced as healing progresses.
Timeline
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2–6 weeks: Splinting and gentle range-of-motion exercises.
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6–12 weeks: Progressive strengthening and normal use resume.
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3–6 months: Most patients achieve their best function, with ongoing improvement in comfort and grip.
Risks and Complications
Like any surgery, CMC joint replacement carries some risks, including:
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Infection
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Nerve or blood vessel injury
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Implant loosening or failure over time
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Stiffness or instability in rare cases
However, careful surgical technique and expert post-operative care minimise these risks significantly.
Choosing the Right Surgeon
Selecting a surgeon who specialises in hand and upper limb procedures is crucial for optimal outcomes. An experienced orthopaedic surgeon—such as Mr Jagwant Singh, a leading London-based upper limb specialist—offers the knowledge, skill, and patient-centred approach vital for successful joint replacement and recovery.
Is CMC Joint Replacement Right for You?
If thumb arthritis is diminishing your quality of life, limiting independence, or interfering with work and hobbies, specialist consultation can clarify your options. After a thorough assessment, your surgeon will recommend the treatment plan best suited to your needs—whether further conservative care or CMC joint replacement surgery.
Conclusion
CMC joint replacement surgery offers hope and restored ability for those suffering from thumb base arthritis. With pain relief, improved movement, and better quality of life, this advanced procedure has helped countless patients reclaim the use of their hands—enabling them to live, work, and enjoy everyday life free from persistent thumb pain.
If you’re struggling with thumb discomfort or limited mobility, don’t wait. Seek advice from an upper limb orthopaedic specialist to begin your journey towards recovery and restored function.