Cartilage health in high tibial osteotomy using dGEMRIC: Relationships with joint kinematics

Abstract

PurposeThe aims of this study are to determine how opening-wedge high tibial osteotomy (HTO) affects cartilage health in the tibiofemoral (TF) joint and patella, and to explore relationships between TF and patellofemoral (PF) joint kinematics and cartilage health in HTO. Methods14 knees (13 subjects) with medial TF osteoarthritis (OA) were examined before HTO and 6 and 12months after HTO using delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) to evaluate cartilage health at the TF joint and patella. They were also examined using a validated 3D MR knee kinematics measurement to obtain 11 rotations and translations at both TF and PF joints. ResultsNo statistically significant differences in overall TF or patellar dGEMRIC score were found at 6 or 12months after HTO. However three subjects had large decreases (mean 105ms) in TF dGEMRIC at 6months that recovered at 12months. Kinematics for these subjects were compared to subjects who did not have decreases in TF dGEMRIC at 6months (n=5). Differences were observed between groups with HTO in anterior and proximal tibial translation (mean differences 3.05mm and 1.35mm), and patellar flexion (mean difference 3.65°). These changes were consistent between 6 and 12months, despite recovery of TF dGEMRIC values. ConclusionsWe did not find significant differences in TF or patellar dGEMRIC before and after HTO with all subjects, however there were differences in kinematics between subjects who had a decrease in TF dGEMRIC at 6months and those who did not. This suggests a link between joint kinematics and cartilage health in HTO. Clinical relevanceThe effect of opening-wedge high tibial osteotomy on cartilage GAG concentration may be linked to specific changes in knee kinematics following surgery