What is Trapeziometacarpal (TMC) Arthritis?
Trapeziometacarapal (TMC) joint arthritis, also known as carpometacarpal (CMC) joint arthritis or basilar thumb arthritis or rhizarthrosis, is a common form of arthritis that affects the first carpometacarpal (trapeziometacarpal) joint of the thumb. It is an inflammatory condition characterised by gradual wearing away of the cartilaginous surface of the TMC joint and the bones rubbing against each other causing inflammation and pain. It occurs most commonly in middle-aged, elderly, and postmenopausal women.
The TMC joint or CMC joint is formed by the first metacarpal bone of the thumb and the trapezium (carpal) bone of the wrist. The joint is located at the base of the thumb and attaches the base of the thumb to the wrist and the base of the fingers to the hand. The TMC joint is crucial for hand dexterity and strength and allows the hand to grasp objects with a strong grip.
Causes of Trapeziometacarpal (TMC) Arthritis
Some of the causes of TMC arthritis include:
- Advanced age
- Genetic or congenital anomalies
- Family history
- Trauma or previous joint fractures
- Inflammatory arthritis, such as rheumatoid arthritis and lupus
Signs and Symptoms of Trapeziometacarpal (TMC) Arthritis
Some of the signs and symptoms of TMC arthritis include:
- Tenderness, stiffness, and swelling at the base of the thumb
- Pain that gets worse after prolonged use of the thumb
- Enlarged and bony ("out-of-joint") appearance at the base of the thumb
- Limited motion of the thumb and feeling of loss of strength
- Grinding sensation with a grating sound when moving the thumb
- Difficulty in gripping or grasping objects or in pinching
Diagnosis of Trapeziometacarpal (TMC) Arthritis
Your doctor will assess your symptoms, take your medical history, and perform a thorough physical examination of your thumb. During the examination, your physician will manoeuvre the thumb and check for range of motion and strength. Your physician may notice grinding when manoeuvring the thumb in a certain way. Imaging tests such as X-rays may also be ordered for detailed evaluation of the TMC joint to assess the severity of arthritis and to confirm the diagnosis. The imaging may exhibit bone spurs, joint space narrowing, or hyperextension of the metacarpophalangeal joint.
Treatment for Trapeziometacarapal (TMC) Arthritis
The treatment options for trapeziometacarpal (TMC) arthritis include both nonsurgical methods as well as surgical methods. Your doctor will determine the right option for you based on the severity of the condition.
- Activity Modification: Avoiding activities that trigger symptoms and changing one’s habits
- Ice: Application of ice packs on the joints to decrease swelling and pain
- Physiotherapy: Regular exercise regimen to improve range of motion and strengthen joint muscles
- Anti-inflammatory Medication: Medications like naproxen and ibuprofen to relieve inflammation and pain
- Orthotics: Use of assistive devices such as thumb spica bracing to avoid mechanical stresses to the TMC joint
- Cortisone Injection: Injection of corticosteroid medication directly into the affected joint to relieve pain and swelling. Cortisone is a very effective anti-inflammatory medicine and long-term pain reliever.
Some of the common surgeries employed in the treatment of TMC arthritis include:
- Total Joint Replacement (Arthroplasty): The procedure involves removing all or a section of the damaged thumb joint and replacing it with a prosthesis or artificial implant.
- Fusion (Arthrodesis): This procedure involves fusing together the trapezium bone and the first metacarpal bone thereby preventing movement of the joint and eliminating pain.
- Ligament Reconstruction: In this procedure, a portion of the damaged ligament is removed and replaced with a portion of the patient’s wrist flexor tendon to stabilise the TMC joint. The transposition of the tendon helps to restore and reconnect the mechanical function of the thumb with the rest of the hand.
- Trapeziectomy with Ligament Reconstruction and Tendon Interposition (LRTI): This is the most commonly employed surgery for the treatment of TMC arthritis. In this procedure, the damaged joint surfaces are removed and replaced with a cushion of tissue that keeps the bones separated. To achieve this objective, your surgeon removes part or all of the trapezium bone in the wrist and inserts a folded piece of tendon in the empty space previously occupied by the trapezium.