CMC Joint Replacement Surgery of Thumb

CMC or Carpo-Metacarpal Joint Arthritis is a common condition seen in people in the 6th and 7th decade of life. It's seen more commonly in women than men. The usage of the thumb for grip, grasp and pinch actions would become painful affecting the overall functioning of the hand. Clinical examination to assess site of pain, tenderness, shape of the base of the thumb gives enough pointers to diagnose.

Diagnosis

X-ray: X-ray is performed and is useful to understand the extent of the arthritis of the 1st CMC joint of the thumb. 

Treatment

Under-warm water exercises for 4-6 weeks can be of help. If poor improvement a steroid injection to the thumb base joint would help. If none of the simple treatments are of help, then CMC joint surgery is the appropriate treatment. 

Non-surgical Treatment

Using thumb spica splint at night and during times of rest can be of some help. Under warm water exercises do help in improving the pain and functionality of the hand and thumb. A small dose of steroid injection can help relieve the pain for a period of 4 to 6 months. 

Surgical Treatment

The advanced CMC joint arthritis needs to be treated surgically. There would be typically 3 cuts. One incision of around 4 cm would be on the side of the thumb base. Second and third cuts would be small 1cm cuts at the level of the wrist and one at the mid-forearm. The bone called trapezium at the base of the thumb is removed. Post that one half of the FCR tendon is released and retrieved from forearm to the base of the thumb area. A small bone tunnel is drilled through the base of the thumb (metacarpal bone). The tendon is passed through the tunnel and brought back to the joint space. The remaining tendon is rolled in to work as a spacer between the bones. The ligaments are then repaired on the side. Skin and soft tissue closure is done. 

Rehabilitation

Post-surgery, you can expect to be in a thumb splint for 4 weeks. However, the passive movements of the thumb are started early with the help of physiotherapists. We expect full movements to be achieved by 6 weeks. Further to this, strengthening exercises in the form of concentrics and eccentrics are started for the muscles controlling the thumb. By 3 months, resumption of full activities can be expected.