Abstract
In a society dependent upon the motor car, impaired driving ability is a significant disability which may affect patients with total knee replacement during the postoperative rehabilitation. Recently, there has been much interest in minimally invasive surgery for total knee arthroplasty (TKA). This study evaluated the hypothesis that a minimally invasive technique using a small incision (7 to 10 cm), and a minimal quadriceps muscle splitting without eversion of the patella (MIS approach) would have a beneficial effect on driving reaction time.
15 patients undergoing a primary TKA with the MIS approach were compared with 15 TKAs using a standard approach. An experimental car was used to measure the force and timing of pressure by the foot on accelerator and break pedals. The mean reaction time for normal adults was 0.442 s to go from the accelerator to the brake pedal. This time falls well within the code guideline of 0.7 s. The driving reaction times of the patients with knee arthroplasty were measured at one, two and three months after the operation. The ability to perform an emergency stop was assessed as the time taken to achieve a brake pressure of 100 N after a visual stimulus.The patients have an actual follow-up of 2 years. A clinical and radiological evaluation was performed. Radiographic analysis included evaluation of postoperative alignment variables and progressive radioluciencies.
Over all 27 among the 30 knees have good and excellent objective knee Society Scores and patient satisfaction indices. The patients in the MIS group had a statistically shorter time until they could straight leg raise, used less epidural analgesia, used less overall analgesics and had a more rapid regaining of flexion. Patients with standard approach and technique for total knee replacement recovered sufficient knee function to return to driving at only three months after the operation according to the time and the force necessary to the brake pedal. Patients with mini invasive surgery approach have recovered sufficient knee function to return driving at one month after the operation. There was no significant difference in alignment of implants and in alignment of the knee between the two groups. Three knees had radioluciencies (two with a standard incision and one with a MIS approach).
Using a small incision without patellar eversion does not jeopardize the alignment of the implants and improves postoperative rehabilitation.
Theses abstracts were prepared by Professor Roger Lemaire. Correspondence should be addressed to EFORT Central Office, Freihofstrasse 22, CH-8700 Küsnacht, Switzerland.
