The relationship of stride characteristics to pain before and after total knee arthroplasty.

The relationship between the changes in stride characteristics and the changes in pain that occurred before and after total knee arthroplasty (TKA) were examined in 18 patients with a diagnosis of osteoarthritis. The patients were observed after either bilateral or unilateral TKA. Measurements of stride characteristics by footswitch analysis and assessments of pain by visual analog scale were performed preoperatively and at five months and at 13 months postoperatively. Stride characteristics improved and pain diminished after surgery. Improvements, from preoperative to five months postoperative, were noted in seven of eight stride characteristics. The improvements in velocity and stride length were related to the decreases in pain over that period. Improvements from five months to 13 months postoperative were independent of the decrease in pain over that period and independent of the increase in active knee flexion angle. When evaluating stride characteristics after TKA, it is necessary to consider the effect of pain relief and to monitor the patient's ambulatory progress after pain diminishes.