The effect of total knee arthroplasty on joint movement during functional activities and joint range of motion with particular regard to higher flexion users.

PURPOSE: To evaluate active and functional knee excursion of patients before and after total knee arthroplasty (TKA) and to determine whether TKA restores quality of life related to functional activities of daily living.
METHODS: Electrogoniometry was used to measure the functional movement of the knee during 11 activities of daily living in 50 patients who underwent TKA. These data were compared with the patient's active range of motion and quality-of-life scores.
RESULTS: A cut-off point existed between loss and gain in flexion at between 90 and 95 degrees of preoperative active flexion. Two thirds of patients had preoperative flexion of more than 90 degrees, 83% of them had reduced flexion postoperatively. The remaining one third had preoperative flexion of 90 degrees or less, 85% of them had improved flexion postoperatively. A similar pattern of loss and gain occurred for functional movement of the knee. Reduced functional range was associated with significantly reduced physical quality of life compared with age-matched healthy subjects.
CONCLUSION: Although TKA offers excellent pain relief and contributes to the overall well-being of the patient, these results suggest that it also leads to a reduced range of active and functional motion in the majority of patients. This is associated with a lower-than-normal physical quality of life. The design of implants and rehabilitation programmes should be reconsidered so that better range of motion and quality of life can be achieved for patients.