Subvastus Versus Medial Parapatelar Approach in Primary Knee Arthroplasty: Postoperative Pain and Early Function

Abstract

Total knee arthroplasty causes significant postoperative pain that has always been negatively associated with recovery, satisfaction, length of hospital stay, and cost. Objective: To perform a comparison of postoperative pain and early function between the subvastus and medial parapatellar approaches used in primary knee arthroplasty. Material and methods: An observational, descriptive, cross-sectional, prospective study was carried out for 6 months; with an evaluation of postoperative pain on the second postoperative day, the third postoperative day, the first and second postoperative week, using the visual analog pain scale. In addition, walking ability with a walker-type support device and quadriceps response were evaluated with the Straight Leg Raise Test as a reference; evaluating the degrees of extension and extensor lag. Results: Significant differences were found between the groups when comparing pain and the SLRT test on the second and third postoperative day, as well as the first and second week after surgery (p <0.001). A significant correlation (p <0.001) was found on the first day evaluated; which predicts the evolution of VAS and SLRT levels until the second postoperative week. Conclusions: The subvastus approach has the advantage of reducing damage to the extensor mechanism and achieving recovery with less pain, better muscle response and a higher degree of satisfaction; more than the traditional medial parapatellar. The immediate postoperative period influences the clinical evolution of the patient in both groups.