Minimal-incision total knee arthroplasty: The early clinical experience

Minimal-incision total knee arthroplasty can be considered part of the continuum from traditional extensile exposures to the quadriceps-sparing approach. We did this study to identify preoperative variables that predict which patients are amenable to a mini-incision and mini-arthrotomy technique, and to compare early outcomes in these patients versus patients in whom a standard approach was required. A consecutive series of 118 primary total knee arthroplasties were evaluated. In each case, the incision and arthrotomy were kept as small as possible, while still allowing proper implantation of the prosthesis. Group 1 consisted of 69 patients (58%) with skin incisions smaller than 14 cm and limited medial parapatellar arthrotomies. Group 2 consisted of 49 patients (42%) with incisions greater than or equal to 14 cm and standard medial parapatellar arthrotomies. Patients in Group 1 averaged one size smaller femoral and tibial components, had narrower femurs, required fewer transfusions and had better postoperative flexion. There were no differences between the groups in length of hospital stay, ambulatory ability, stair-climbing, tourniquet time, radiographic alignment, or complications. Based on these results, the ideal patient for a minimal incision total knee arthroplasty and limited arthrotomy seems to be a thin woman with a low body mass index, a narrow femur, and good preoperative range of motion. Level of Evidence: Prognostic study, Level III-1 (retrospective cohort study).