Assessment of Knee Angular Deformities: Correlation between Photogrammetric, Clinical, and Radiographic Methods

Background: Photogrammetry is a safe and non-invasive technique for evaluating posture in clinical settings. Body Vision is a novel system that employs photogrammetric principles to assess postural parameters. This study aimed to determine the relationship between clinical, photogrammetric, and radiological techniques in detecting knee angular deformities.Methods: This cross-sectional study was performed on 53 volunteers of both genders, encompassing a total of 106 lower limbs with complaints of knee pain or knee deformity. Sampling was conducted in a non-random and accessible manner based on predefined inclusion and exclusion criteria. All participants had previously obtained full-length radiographs of their lower limbs. The clinical evaluation included measurements of the anatomical axis, Q angle, and intermalleolar and intercondylar distances. These parameters were also assessed using the Body Vision photogrammetric system while the patient was in a standing position. Data from all three methods were compared using the measured angles and distances.Results: The evaluations indicated a strong correlation between the photogrammetric and radiological methods regarding the anatomical axis of the lower limb (r = 0.939, p < 0.001). A high correlation was also observed between the clinical and photogrammetric methods for the intermalleolar distance (r = 0.948, p < 0.001) and intercondylar distance (r = 0.927, p < 0.001). For the Q angle, a high but relatively lower correlation was found between the clinical and photogrammetric methods (r = 0.834, p < 0.001). However, a moderate correlation was detected between the clinical measurement of the anatomical axis and both the photogrammetric (r = 0.70) and radiological (r = 0.62) methods.Conclusion: This study demonstrated a strong correlation between the photogrammetric technique and the gold standard radiological method, indicating that photogrammetry can serve as a viable alternative for evaluating knee angular deviations.