2007

New Generation of Durable Implants for Severe Wrist Arthritis Conserves Mobility

Points to Remember

• Wrist joint replacement was first used in the 1970s, but the implant designs had unacceptably high loosening rates.
• In the 1980s, Mayo Clinic orthopedic hand surgery specialists began designing sturdier wrist implants to eliminate the problems of early implants while conserving wrist mobility.
• For selected arthritis patients, these polyethylene-metal wrist implants appear to be a safe and effective option to relieve arthritic pain while conserving wrist mobility.
  

The Challenge

Osteoarthritis and rheumatoid arthritis are major causes of adult disability in the United States. When affecting the wrist, these conditions are initially treated conservatively with splinting, activity modification, and cortisone injections and a range of medications, including various antiinflammatory agents and disease-modifying antirheumatic drugs.

If these measures fail to provide long-term relief, surgery may be indicated. Arthrodesis - surgical fusion of the bones - is performed on more than 10,000 patients per year in the United States. Although arthrodesis does relieve pain, it is a suboptimal treatment because fusion of the bones deprives the patient of wrist mobility and function. Preferable is a procedure for medically refractory arthritis that eliminates pain, yet conserves mobility and wrist function.

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A New Approach

Beginning in the 1970s, silicone implants were used in wrist joint replacement procedures. These were not desirable because of adverse effects that included bone erosion and osteolysis caused by foreign-body granulation. Because of poor early results with silicone, wrist implants have not been widely performed, and arthrodesis has remained the standard procedure, despite advances in wrist joint replacements at advanced hand surgery specialty centers.

During the past 20 years, Mayo Clinic orthopedic hand surgery researchers have devised new wrist implant designs. These new polyethylene-metal wrist implants are free of the adverse effects of silicone and are sturdier, thus offering greater implant longevity. A key innovation is the modified distal metacarpal fixation to improve survivorship.

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Promising Early Results

Mayo Clinic orthopedic surgeons who specialize in hand procedures have used a new generation of wrist implant for approximately 6 years in about 20 carefully selected patients older than 50 years who have low-activity lifestyles and place low demands on their hands and wrists. To date, none of the prostheses has failed. In addition, the new implant appears to be durable, well accepted by patients, and free of the adverse effects associated with silicone implants.

Indications for Implantation

Although results are preliminary, early data suggest that the new wrist implants may be the best option for wrist arthritis patients more than 50 years old who have fairly sedentary lifestyles and low demands on the hands and wrists. Patients younger than 50 years who lead active lives and have high-demand hand and wrist work, such as manual labor, are not suited for wrist implantation at this time.