Preliminary outcomes of kinematically aligned robot-assisted total knee arthroplasty with patient-specific cartilage thickness measurement

Abstract

This study aimed to assess the preliminary outcomes of kinematically aligned robot-assisted total knee arthroplasty (TKA) with patient-specific cartilage thickness measurement. Patients who underwent kinematically aligned robot-assisted TKA were included in this study. Robot-assisted total knee arthroplasties were performed by NAVIO Surgical System (Smith & Nephew, Memphis, USA), an image-free handheld robotic system. The kinematic alignment technique was performed according to our intraoperative cartilage thickness measurement technique. Hip-knee-ankle angle (HKA), mechanical lateral distal femoral angle (mLDFA), mechanical medial proximal tibial angle (mMPTA), joint-line orientation angle (JLOA), and joint-line convergence angle (JLCA) were measured through standing full-length anteroposterior radiographs. Knee Injury and Osteoarthritis Outcome Score, Oxford score, VAS pain and satisfaction score, and Forgotten Joint Score were used to assess clinical outcomes. A total of 142 knees of 109 patients (92 females and 17 males) were evaluated in this study. There was a significant correction in HKA, JLCA, and mMPTA postoperatively (p ≤0.001, < 0.001, and 0.029, respectively). We observed no significant change in mLDFA and JLOA measurements. All clinical scores significantly increased at the latest follow-up. Our results demonstrated that kinematically aligned robot-assisted TKA with patient-specific cartilage thickness measurement demonstrated no significant change in mLDFA and JLOA, as expected; however, significantly corrected the deformity in HKA, mMPTA, and JLCA measurements.

Keywords: Cartilage thickness; Kinematic alignment; Robot-assisted; Total knee arthroplasty.