A randomised controlled trial comparing TruMatch Instrument and Conventional Instrument in Total Knee Arthroplasty

Abstract

Introduction: Surgeons may use conventional instruments (CON) or custom-made TruMatch instruments (TMT) to achieve accurate bone cuts in total knee arthroplasty (TKA). We performed a randomised controlled trial to compare the operation time, as well as postoperative lower limb alignments and individual components’ positioning. Methods: A total of 60 (27 left and 33 right) knees in 51 patients (6 men, 45 women) were recruited. Their mean (± standard deviation) age was 69 ± 8.3 years. The diagnosis was osteoarthritis in 56 knees and rheumatoid arthritis in 4 knees. They were randomised in 1:1 ratio into CON and TMT groups. The prosthesis and surgical routines were standardised. Postoperative standing long films of the entire lower limbs were taken. Results: The mean (± standard deviation) tourniquet time was 42.6 ± 14.7 minutes for CON group and 42.9 ± 9.6 minutes for TMT group (p = 0.92). The mean operation time was 68.4 ± 16.3 minutes for CON group and 69.8 ± 17.9 minutes for TMT group (p = 0.75). The TMT group had significantly less outliers in femoral component flexion in the sagittal plane (p = 0.002). There was no difference in the number of outliers in other parameters including femoral component varus, tibial component varus and posterior slope, and lower limb alignment between CON and TMT groups. Conclusion: TruMatch instrument is a new option in TKA. Our study showed that its tourniquet and operation time was similar to that of CON. It also improved the accuracy of sagittal positioning of the femoral component.