engleski

Range of Motion after Knee Arthroplasty in Rheumatoid Arthritis Patients with severe Flexion Contracture

Full knee extension is necessary for bearing full body weight with minimum muscular action, while flexion of various degrees is needed for walking, climbing the stairs or rising from a chair. Flexion contracture of the knee can affect the functional performance of the knee joint for everyday activities, especially if it is combined with angular deformity in the frontal plane, which is usually seen in RA patients. The flexion deformity in RA is multifactorial and is a result of osseous, muscular, ligamentous and capsular changes, as well as of fibrous adhesion among these structures. We measured the range of motion after total knee arthroplasty in RA patients with preoperative flexion contracture of 30-40 degrees, associated with valgus deformity. Range of motion in 25 female RA patients with valgus deformity and flexion contracture was measured. The range of motion was measured by goniometer and plain radiography preoperatively, as well as on the 14th day and one year postoperatively. We analysed the patients in whom components of prosthesis were placed in the proper position as well as in whom proper soft tissue balance and full range of motion were achieved during operation. All patients were operated on by the same surgical team and the same type of cemented knee prosthesis with sacrifice of posterior cruciate ligament was implanted in all the patients. The patella was also replaced. All patients had the same postoperative rehabilitation protocol. On the 14th postoperative day 15 patients had full extension and 10 had flexion contracture of no more than 10 degrees. The result was statistically significant compared to preoperative flexion contracture. Further flexion was 70 degrees in 13 and 90 degrees in 12 patients. We could not find any dependence between preoperative and postoperative flexion degree in the same patient. One year postoperatively full extension was achieved in all patients, but average improvement of flexion ranged from 5 to15 (average 10) degrees in comparison with the 14th postoperative day. We observed that patients with better flexion early in the postoperative period exhibited better improvement of flexion one year postoperatively. The results of this study showed that severe flexion contracture in RA patients can successfully be corrected with knee arthroplasty. The higher the flexion in the early postoperative period, the better the improvement in flexion one year postoperatively. References: Chiu, K Y, Ng, T P, Tang, W M, Yau Review article: Knee flexion after total knee arthroplasty. J Orthop Surg (Hong Kong). 2002 Dec ; 10(2):194-202.

rheumatoid arthritis; flexion contracture; knee arthroplasty

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