The use of a specific implant is helping orthopaedic surgeons improve the success rate of total knee replacement procedures in patients less than 55 years old.
The orthopaedic surgeons use a posterior stabilized, posterior cruciate substituting design prosthesis. Patients receiving this prosthesis have had excellent results.
Patients' activity levels are improved following surgery. Many of the patients continued their sports schedules or began participating in recreational activities that originally we advised not to do.
Concerns about loosening, polyethylene wear, osteolysis, and the need for multiple revisions has prevented the widespread application of total knee replacement in young patients. Studies have confirmed that total knee replacement surgery for younger patients in non-rheumatoid populations should not necessarily be discouraged.
It should, however, be emphasized that findings are for a conforming prosthesis of a specific design and may not apply to all types of total knee replacements.
Ninety-four percent of the patients in one study had a survivor rate of 15 years with the prosthesis. Of particular interest was how the younger patients were doing with the prosthesis, and the study revealed no significant evidence of adverse problems in patients involved in high-level activities. These findings suggest a cautious re-evaluation of activity restrictions in younger patients.
The results were obtained from 84 patients who had a total of 108 total knee replacements. The average age of the patients at the time of surgery was 51 years old.
Tests developed by the Hospital for Special Surgery and the Knee Society were administered before and after surgery to help determine patients' pain, function, range of motion, and stability. Patients also were assigned a Tegner activity score to help determine their sports activity level before and after surgery.
The average Hospital for Special Surgery score was 55 prior to surgery and 92 after surgery. Following surgery, the average Knee Society score was 94.
The patients' Tegner activity score improved from 1.3 before surgery to 3.5 after surgery. Twenty-four percent of the patients received a Tegner activity score greater or equal to five. These patients were able to participate in tennis, skiing, biking, or heavy farm or construction work.