Carpo-Metacarpal (CMC) Joint Arthritis

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Definition

 

CMC joint arthritis is a chronic cartilage wear of the joint located at the base of the thumb, between the first metacarpal bone and the trapezium (fig.2). It is the most common of all hand and wrist arthrites. 

 

Most often, it affects women over 50 and starts with the dominant hand (the right hand for a right-handed person). Both hands are commonly affected. 

 

The progression of CMC joint arthritis,with episodes of intense pain followed by temporary relief, progressively brings about stiffening and deformity of the thumb in a Z shape, with a narrowing of the first web. The destruction of this joint leads to the loss of the pollici-digital pinch, i.e. the possibility of grasping an object between the thumb and index finger.  

 

Genetic factors, menopause and repetitive movements all increase the probability of its occurrence. 

 

Treatment 

 

The treatment of arthritis is primarily conservative. Its goals are to reduce pain and to prevent deformity and loss of motion. 

 

1 - Medical Treatment

 

• - Analgesics are the first choice in the treatment of arthritis. They may relieve pain but do not decrease the inflammation. 
• - Nonsteroidal anti-inflammatory drugs (NSAIDs) ease pain, and treat both swelling and stiffness but do not prevent joint damage from worsening. They are prescribed by a physician. NSAIDs cause digestive problems such as stomach pain or diarrhea and usually require additional gastric protective drugs. 
• - Corticosteroid injections performed by trained physicians allow for relief of inflammation as well as a decrease of the swelling. Cortisone is a hormone which is naturally present in the body. Corticosteroids are a type of synthetic drugs very similar to cortisone. The injection itself may cause pain for 24 to 48 hours, but they most often provide a durable pain relief. It is advised not to perform too many injections (three injections is usually considered as the maximum number). 
• - COX-2 inhibitors are a specific type of NSAID drugs which can be prescribed for long term treatments. They require specific monitoring by specialized physicians. One must remember that all drugs have side effects. It is therefore critical to discuss with one’s physician the benefits and potential side effects of each drug one is considering to use.

2 - Immobilization

 

Whether it is done with a splint, a standard brace, or a costume-made orthosis, the goal of immobilization is to decrease muscle tension, to immobilize the joints and therefore to ease the pain. A night splint immobilizing the thumb ray is systematically prescribed at the initial stage of treatment of CMC joint arthritis. Such a splint maintains the thumb in an extended position at night which preserves the joint’s range of motion in order to avoid an adductus deformity. This treatment usually allows for normal use of the thumb during the day time. 

 

Rules To Follow

(Valid for all types of arthritis of the human body)

 

A physical therapy program established with a physiotherapist may improve use of the joints. Muscle strength can be reinforced in order to stabilize and protect the affected joints, consequently decreasing pain. Range of motion exercises help maintain or reestablish normal joint movement in order to decrease stiffness. However, the affected limb shouldn’t be used in excess. 

 

Surgical Treatment

 

When a joint is too damaged or when the pain becomes unbearable and the medical treatment has reached its limits, surgical options can be considered. There are many types of available procedures, ranging from arthroscopy, including removal of cartilage debris (fig.3 arthroscopic shaving of the joint arthritis; fig.4 arthroscopic removal of foreign bodies) to total arthrodesis of the joint, or joint replacement. 

 

Surgical Treatment of CMC joint arthritis

 

The surgical treatment of CMC joint arthritis addresses two different goals: complete immobilization of the joint by blocking it (arthrodesis), or preservation of motion. 

Arthrodesis is limited to specific cases of CMC joint arthritis in young manual workers, usually secondary to fractures or fracture-dislocations

Preserving motion may require an implant or trapeziectomy with or without ligamentoplasty. If implants allow for faster results, their life span is limited and they present a risk of loosening or dislocation in patients with highly demanding and forceful use of their hands. Trapeziectomy is usually combined with a suspension ligamentoplasty (fig.5 X-ray after trapeziectomy and ligamentoplasty), a procedure which presents the benefit of stable results over time. However, reaching such results may require a longer period of time.