Maximising early recovery by modified surgical approach: Randomized control prospective series of 50 patients treated with the standard medial parapatellar and mid-vastus surgical approaches

Abstract

Background: The medial parapatellar approach is the workhorse of total knee replacement. Modified (mid-vastus and subvastus) approaches have been advocated to improve quadriceps power, improve knee flexion and provide better pain relief. However, detractors state difficulty in patella eversion and visualisation of the lateral tibial plateau as concerns. Does the mid-vastus approach really provide these purported advantages? We report an analysis of our prospective randomised controlled trial in 50 patients undergoing simultaneous bilateral total knee arthroplasty using a medial parapatellar approach in one knee and the mid-vastus approach in the other. Methods: 50 consecutive elderly patients with bilateral knee osteoarthritis underwent simultaneous bilateral total knee replacement (randomized to undergo standard medial parapatellar approach in one knee and mid-vastus approach in the other knee) from Dec 2012 to Mar 2013. Strict inclusion and exclusion criteria were followed and the two surgical approaches were randomised to the left or right knee. A blinded independent observer evaluated immediate and early post-operative clinical radiological criteria for each knee at 2 weeks, 6 weeks, 3 months and 12 months post-surgery. The collated results were then matched to the approach taken, and analysed for statistical differences. Results: The return of active straight leg raise, quadriceps power and function was statistically higher with the mid-vastus approach at 2 weeks, 3 months and 6 months, without any statistical difference at 12 months. Pain control was also better in the mid-vastus approached knee, though statistically not significant. All other intra-operative and post-operative parameters were the same at the points of evaluation. At 12 months, comparable criteria between the two groups were statistically insignificant. Discussion: The mid-vastus approach significantly reduces the immediate post-operative pain, and improves the quadriceps function and knee flexion. There is no difficulty in exposing the lateral tibial surface and/or implanting the tibial component. However, it needs to be reiterated that this benefit lasts for the first 3 months, and seems to provide no extra benefit in the mid- or long-term. This approach is recommended in patients with low BMI as one of the components for early recovery. It may significantly reduce the duration of hospital stay as well.