Use of mid-vastus approach in less invasive primary total knee arthroplasty

Abstract

Total knee arthroplasties (TKR) combined with the concept of reduced trauma to tissue has been performed by many doctors. The aim of this study was to retrospectively assess the early results of a group of TKR with a mid-vastus approach, which was characterized as no patellar eversion, no disruption of suprapatellar pouch and extensor mechanism, and to compare the outcome with conventional operative techniques. A total of 59 patients (67 knees) were followed. All patients received the same prosthesis of Genesis II posterior-stabilized total knees. Of them, 29 consecutive patients (34 knees) had a mid-vastus approach and were operated on with less invasive instruments and techniques. The mean follow-up duration was 11.6 months. Clinical evaluations were performed according to the Hospital for Special Surgery scores; radiographic assessment followed the guidelines of the Knee Society. Postoperative recovery of quadriceps strength and the extensor mechanism was also evaluated. No prosthetic loosening or anterior knee pain was found at the latest follow-up; 1 patient had a superficial infection and postoperative stiffness of the knee who undertook a debridement and manipulation several months later. The angulations of tibial osteotomy were within normal range. The average preoperative and postoperative Hospital for Special Surgery scores were 57.9 points and 86.1 points respectively. The mean postoperative range of motion was 113.5 degrees . Most patients regained their quadriceps strength at the third or fourth month postoperatively. The overall early results from using the mid-vastus approach were comparable with that of using a standard approach, and the exposure did not affect the accuracy of the tibial cut. The muscle maximal contraction strength recovered gradually after operation. The approach was safe and patients of this group obtained satisfactory outcomes.