Abstract
Introduction Range of motion (ROM) is an important measure of outcome. A better understanding of the factors influencing ROM is important when counselling patients undergoing TKA.
Aim The aim of the study was to prospectively evaluate the influence of a number of selected variables on knee flexion at one year using the same prosthesis in a single surgeon series.
Patients and Methods 170 patients (57 males; 113 females) undergoing TKA were prospectively evaluated. The following data was recorded for each patient: age, gender, primary diagnosis, direction and magnitude of the preoperative axial deformity, BMI, cement use, preoperative and one year Oxford Knee Scores (OKS), the active and passive range of motion (ROM) preoperatively, at the end of surgery and at three month and one year review.
Results Average flexion values at each stage were as follows: preoperative (1110), end of surgery (1200), three months (1030) and one year (1070). There was a significant loss of flexion following TKA. The improvement between three months and one year however proved significant. Multiple regression analysis revealed that preoperative flexion was the strongest predictor of one-year flexion. Increasing age was also found to have a significant influence on final flexion. Gender, BMI, pre-operative OKS and cement use had no significant influence on final flexion. Patients tend to migrate towards a middle range of flexion i.e. those with poor flexion gain movement whilst those with good flexion tend to lose motion.
Conclusions Preoperative flexion is the strongest predictor of final flexion following TKA.
Correspondence should be addressed to Roger Smith, Honorary Secretary, BASK c/o Royal College of Surgeons, 35 – 43 Lincoln’s Inn Fields, London WC2A 3PN
