Study of knee range of motion after soft tissue repair in both flexion and extension during total knee arthroplasty: a randomized clinical trial

The patient's position during the recovery time after arthroplasty surgery can be a factor in reducing complications and improving patients’ condition. Therefore, this study was performed to compare the knee range of motion after soft tissue repair in both flexion and extension positions of total knee arthroplasty.

This study is a double-blind clinical trial. The study population was all candidates for total knee arthroplasty surgery in Al-Zahra and Kashani hospitals in Isfahan from July 2011 to September 2012. The sample size was selected using the statistical formula of 88 patients and randomly divided into two groups of flexion and extension. In the first group during the knee soft tissue repair, the knee was in flexion and in the second group it was in extension and then it was repaired. Information such as age, sex, body mass index and surgical position were recorded in the checklist. The knee range of motion was measured at the end of the first, second, fourth, eighth and twelfth weeks and recorded in a checklist. In order to compare the pattern of changes in mean knee range of motion over time in the two groups, mixed linear models and conventional marginal models to generalized estimator equations were used by STATA software.

The results showed that there was no significant difference between the flexion and extension groups in knee range of motion. In both groups, the mean knee range of motion increased with time (P<0.001). The mean scores of knee function after the end of the twelfth week in the flexion and extension groups were 141.04±23.19 and 143.09±22.34, respectively, and this difference was not significant.

Soft tissue repair in a particular position is not so effective on the outcome that we want to institutionalize it by spending a considerable amount of budget for training surgeons.