Associations Between Coronal Alignment, Patellar Height, Chondrocalcinosis and Radiographic Severity of Knee...

Background and Objectives: Knee osteoarthritis (OA) is a leading cause of pain and disability, with radiographic severity influenced by age, biomechanical alignment, and structural joint features. Data describing the association between common radiographic parameters and OA severity in Eastern European clinical populations remain limited. This study aimed to evaluate the associations between radiographic OA severity and coronal alignment, patellar height, and chondrocalcinosis in a Romanian clinical cohort. Materials and Methods: This single-center cross-sectional study included adult patients undergoing knee radiography for knee-related symptoms and/or functional assessment at a rehabilitation hospital between 2023 and 2025. Radiographs were obtained in the supine, non-weight-bearing position and included anteroposterior and lateral views. OA severity was graded using the Kellgren-Lawrence (KL) classification. Coronal alignment was assessed using the femorotibial angle, patellar height using the Insall-Salvati ratio (ISR), and chondrocalcinosis was recorded as present or absent. Associations between radiographic parameters and KL grade were analyzed using non-parametric statistics. Receiver operating characteristic (ROC) analyses were performed for exploratory assessment of limited separation between distributions. Results: Moderate to severe OA (KL ≥ 3) was present in 49% of patients. KL grade showed a moderate positive correlation with age (r = 0.50, p < 0.001) and differed significantly across coronal alignment categories (p < 0.001). Varus/valgus and pathological alignment classifications demonstrated moderate sensitivity (0.69-0.85) and variable specificity (0.52-0.85) for higher KL grades. ROC analyses of continuous alignment and ISR measures yielded area under the curve values ranging from approximately 0.65 to 0.68, indicating limited separation between distributions. Radiographically detected chondrocalcinosis was present in 5.3% of patients and showed no significant association with OA severity, and neither did patellar height. Conclusions: In this single-center Romanian clinical cohort, radiographic OA severity was associated with coronal plane alignment but not with patellar height or chondrocalcinosis. Alignment measures demonstrated limited discriminative ability and should be interpreted as complementary rather than diagnostic indicators of OA severity. These findings provide descriptive radiographic data from an Eastern European clinical population and highlight the need for longitudinal and population-based studies incorporating mechanical axis assessment and functional outcomes.