Characterizing the distinct structural changes associated with self‐reported knee injury among individuals with incident knee osteoarthritis: Data from the osteoarthritis initiative
We aimed to characterize the agreement between distinct structural changes on magnetic resonance (MR) imaging and self‐reported injury in the 12 months leading to incident common or accelerated knee osteoarthritis (KOA). We conducted a descriptive study using data from baseline and the first 4 annual visits of the Osteoarthritis Initiative. Knees had no radiographic KOA at baseline (Kellgren‐Lawrence [KL]<2). We classified two groups: (1) accelerated KOA: a knee developed advanced‐stage KOA (KL = 3 or 4) within 48 months and (2) common KOA: a knee increased in radiographic severity (excluding those with accelerated KOA). Adults were 1:1 matched based on sex. The index visit was when a person met the accelerated or common KOA criteria. We limited our sample to people with MR images and self‐reported injury data at index visit and year prior. Among 226 people, we found fair agreement between self‐reported injuries and distinct structural changes (kappa = 0.24 to 0.31). Most distinct structural changes were medial meniscal pathology. No distinct structural changes (e.g., root or radial tears) appeared to differ between adults who reported or did not report an injury; except, all subchondral fractures occurred in adults who developed accelerated KOA and reported an injury. While there is fair agreement between self‐reported knee injuries and distinct structural changes, there is some discordance. Self‐reported injury may represent a different construct from distinct structural changes that occur after joint trauma. Clin. Anat. 31:330–334, 2018. © 2018 Wiley Periodicals, Inc.