Comparison of Patellofemoral Morphometric Parameters in Individuals with Patellofemoral Pain Syndrome versus Healthy Controls: A Cross-sectional Study

Introduction: Patellofemoral Pain Syndrome (PFPS) is one of the most common causes of anterior knee pain, yet its radiographic diagnostic indicators remain poorly defined. Aim: To evaluate morphometric parameters, including Q angle, sulcus angle, patellar tilt angle, and Insall-Salvati ratio, in individuals with PFPS compared to healthy controls. Materials and Methods: A cross-sectional study with 110 clinically confirmed PFPS patients and 110 age- and sexmatched controls was conducted at the Department of Anatomy, Saveetha Medical College and the Department of Radiology, HOSMAT Hospitals Bangalore Rural, Karnataka, India, between 01.02.2025 and 31.10.2025. Standardised lateral, and skyline (Merchant/ Tangential) view radiographs were analysed using INSTARISPACS® software to obtain morphometric parameters such as the Q angle (clinical parameter during patient assessment), sulcus angle, patellar tilt angle, and Insall–Salvati ratio. Group differences were assessed using the independent t-test. Correlation analysis and binary logistic regression were performed to identify predictors of PFPS. Results: A total of 220 participants (110 PFPS cases and 110 controls) were included. The mean age of cases was 38.9±8.2 years, while controls had a mean age of 37.9±9.1 years. In the PFPS group, 48 (43.64%) were male and 62 (56.36%) were female, whereas the control group included 57 (51.82%) males and 53 (48.18%) females. The mean Q angle in the PFPS group was significantly higher than the control values (21.55±2.76° vs. 15.8±2.5°, p-value <0.001). The Insall–Salvati index was slightly but significantly higher in PFPS patients than in controls (1.05±0.30 vs 1.00±0.12; p-value=0.021). Spearman’s correlation analysis demonstrated a moderate negative correlation between Q angle and sulcus angle (r=-0.292, p-value <0.001) and a moderate positive correlation between Q angle and patellar tilt angle (r=0.466, p-value <0.001). Conclusion: Radiographic measurements, particularly Q angle and patellar tilt angle, are reliable indicators of PFPS. Patellofemoral structural alignment has a greater impact on PFPS than anthropometric characteristics such as body composition. Further longitudinal studies are recommended to validate these markers for early detection and intervention.