Joint Replacement Surgery of the Hand

Joint replacement surgery involves replacing a destroyed joint with an artificial joint. In knee or hip replacement surgery, the artificial joint is made out of metal and plastic. In the case of joint replacement in the hand, the new joint is most commonly composed of silicone rubber or the patient's own tissues such as a portion of tendon.

Joint replacement surgery, also known as arthroplasty, is very common. Each year, orthopedic surgeons perform thousands of joint replacement surgeries in the U.S. (Most of these procedures are performed on the large weight-bearing joints such as the hips and knees.) Joint replacement surgery in the hand is typically used in treating severe arthritis that involves the small joints of the hand.

The hips and knees receive continuous stress from walking, running, sporting activity, or injury and are more commonly affected by the wearing of cartilage (degenerative arthritis) than the hand joints. However, the joints of the hand do experience stress in everyday use, and because the hand joints are smaller, these stresses are concentrated over a smaller surface area. The high ratio of stress to surface area can cause the smooth joint cartilage to wear over the years. As the cartilage degenerates, the underlying bone becomes exposed. When the deteriorated joint moves, bone rubs upon bone causing pain, swelling, limiting motion, and frequently causing a grinding or popping sensation. Furthermore, forms of arthritis that are caused by inflammation of the tissues lining the joint frequently affect the small joints of the hands and wrists to cause joint destruction. Examples include rheumatoid arthritis and psoriatic arthritis.

The most common symptoms of arthritis of the hands include pain, stiffness, and swelling over the joints. The pain is usually worsened when the joint is moved. Moreover, motion of the joint is frequently limited due to pain and joint contractures. Symptoms can lead to difficulty with daily living activities including tying shoes, buttoning buttons, opening jars, or turning a key in a lock.

Physical signs of arthritis of the hand include changes in the appearance of the joints. The joints most commonly affected by degenerative arthritis are those at the ends of the fingers. Swelling and bumps, or nodes, can occur at the small joints at the area of the base of the nail. These bumps are called Heberden nodes and can become extremely painful. The joint at the base of the thumb can also become swollen with bone spurs and cause pain and deformity. The joint destruction also leads to severe pain when pinching the fingers together and gripping forcefully. Joint motion limitation can also decrease the ability to grip.

Wrist arthritis can cause pain with motion of the wrist or grasping and lifting. Wrist range of motion is frequently limited by the arthritis. Patients typically experience relief when the wrist is stabilized by a splint.

Rheumatoid arthritis frequently causes swelling, pain, and stiffness in the wrists, as well as the small joints in the middle and at the base of the fingers. This disease frequently causes hand deformities. Tissue lumps called rheumatoid nodules can form over the joints of the hand and wrist. The joints of the fingers and thumb can become deformed and contracted by the destruction of the supporting ligaments, so that grasping and pinching movements are not possible.

The diagnosis of hand joint problems typically involves evaluating symptoms, physical examination, and the x-ray appearance of the joints. Blood testing is sometimes also helpful in the assessment process. Joint replacement surgery becomes a treatment option when significant joint destruction and/or deformity are present.

Surgical options include

1. cleaning of the abnormal cartilage and bone, including removal of bone spurs,
2. fusion of the joint, and
3. joint replacement surgery.

The optimal surgical treatment of arthritis of the hand and wrist varies from patient to patient and is based on many factors. These factors include the patient's age, hand dominance, employment, level of pain, functional goals, and underlying disease.

Surgical cleaning of the joint, or salvage procedure, is usually performed in cases of early "wear and tear" arthritis where there are painful bone spurs or, in cases of rheumatoid arthritis, where there is a large amount of inflamed tissue. Removal of bone spurs is especially helpful when the arthritis involves the joints at the ends of the fingers (distal interphalangeal or DIP joints).

Fusion of a joint involves removing the joint and surgically "fusing" the bone ends so that the two bones effectively become one solid bone. This procedure terminates all motion at that joint and thus eliminates the pain. The benefit of fusion is pain relief and the downside is elimination of motion at the fused joint, which can hinder function. This surgical option is reserved for patients with advanced arthritis.

Joint fusion is usually the best surgical option in patients who are younger and very active. Younger patients may not be candidates for joint replacement because of the increased stress demand on the joints which accompany higher activity levels. This increased stress demand can quickly wear out an artificial joint.

Joint replacement surgery in the hand is an excellent option for treating arthritis of the hand in older, low-activity patients and for those with rheumatoid arthritis. Joint replacement surgery can provide pain relief, increase finger range of motion, and improve hand function.

Hand joint replacement surgery options differ according to the specific joint(s) involved.

1. DIP joint (joint closest to the fingertip): This joint is not a good candidate for joint replacement. The bones are very small and do not hold the implant very well. The best treatment option for advanced arthritis at this joint is fusion. Hand function is only minimally compromised by lack of motion at this joint after a fusion procedure, while pain is relieved.

2. PIP joint (second joint from the fingertip): Joint replacement is commonly performed in the PIP joint. Hand function, especially power grasp, can be hindered by fusion of this joint. The small and ring fingers are the best candidates for joint replacement as they are the most important for power grasp. The index finger is not a good candidate for a PIP joint replacement, as it must withstand sideways forces which accompany movements such as key turning and fine manipulation of objects. These forces cause excess stress on the joint implant and can lead to early implant breakage.

There have been numerous false (prosthetic) joints designed for PIP joint replacement, but only one has stood the test of time. The only nonexperimental PIP joint replacement is the silicone interpositional arthroplasty. These joints are made of silicone rubber and have a flexible hinge in the middle and stems at the ends which insert into the shaft of the bone, providing stability. The most frequently used silicone joint implants are termed the Swanson implant and the Sutter implant.

The best results with PIP joint replacement are in patients with rheumatoid arthritis and in older, lower-activity patients.

3. MCP joint (third joint from the fingertip): Osteoarthritis rarely affects the MCP joints. The most common need for joint replacement in this joint is destruction from rheumatoid arthritis. Silicone joint replacement of the MCP joint has been used since the 1960s and has produced excellent long-term results.

4. Thumb basal joint (where the thumb meets the wrist): This joint is exposed to very high stresses with normal activities. Forces felt at the tip of the thumb are multiplied 12 times in their effect to the thumb base, thus predisposing this joint to wear. Arthritis of this joint is very common, especially in women, and frequently requires joint replacement. Attempts at silicone replacement of this joint have not been as successful as hoped due to implant failure and bone destruction. Thus, the most common joint replacement procedure for the thumb base is done with natural material. The procedure is termed the ligament reconstruction-tendon interposition procedure (LRTI). This procedure uses the patient's own tendon to stabilize the thumb and resurface the joint. LRTI provides stability and pain relief. Long-term results have been excellent. This has also been called the tendon roll or "anchovy" procedure because the tendon used is curled to form the new joint cushion.

5. Wrist joint: Most patients with wrist arthritis are best treated with surgical joint cleaning or fusion and not joint replacement. Most wrist-joint prostheses on the market are currently investigational and for use in extremely low activity patients with osteoarthritis or rheumatoid arthritis.

Summary

Arthritis of the hand and wrist is a very common and complex problem with many nonsurgical and surgical treatment options. Deciding which alternative is best can require the skills of the primary doctor, the arthritis specialist (rheumatologist), and/or an orthopedic surgeon.