Quadriceps sparing (subvastus/midvastus) approach versus the conventional medial parapatellar approach in primary knee arthroplasty

Abstract

IntroductionQuadriceps-sparing (subvastus/midvastus) approach has emerged as an alternative to the classical medial parapatellar approach in total knee arthroplasty with the results claiming faster rehabilitation in the quadriceps sparing group. The present study was conducted to determine if the quadriceps sparing (subvastus/midvastus) approach offers any advantages over the classical medial parapatellar approach in primary knee replacements. Material and methods55 patients undergoing unilateral TKA were randomized into two groups: the subvastus/midvastus group and the medial parapatellar group. The patients were assessed preoperatively and postoperatively at 7 days, 1 month, 3 months and finally at 6 months. Knee Society Scoring was used to compare the groups. Perioperative blood loss, duration of surgery and need for lateral release were also compared. The patient was kept on same pain management and postoperative rehabilitation protocol. Statistical analyses tested the null hypotheses of no differences in patients treated with either group at 95% significance level (p<0.05). ResultsThe difference between the two groups in terms of duration of surgery and perioperative blood loss were statistically not significant. Lateral release was required in 13.8% of patients in the parapatellar group compared to 3.8% of patients in the quadriceps-sparing group. On comparing the postoperative Knee Society Scores of the two groups at each follow up the difference was statistically significant at 7 days and 4 weeks postoperatively (p value<0.05) but the difference between the two groups at 3 and 6 months was not significant statistically (p value>0.05). ConclusionQuadriceps sparing approach (subvastus/midvastus) offers advantages over the standard medial parapatellar approach in terms of better pain relief and faster rehabilitation in the early postoperative period.