Comparing clinical,radiographic and photogrammetric measurements of angular deformities of knee

Abstract

Full-length weight-bearing lower limb X-ray is the gold-standard method for evaluating static lower limb alignment. However, it is not widely used due to high cost and radiation exposure. Photogrammetry is safe and newly established technique for quantitative evaluation of postural parameters. This study aimed to identify correlation between clinical, photogrammetric and radiologic findings in knee angular deformities. Methods: This cross-sectional, descriptive and analytic study was performed on 53 patients of both genders with compliant of knee pain or deformity. Selection of patients were randomized and also inclusion& exclusion criteria had defined. All patients had full-length lower limb radiograph. Clinical assessment is done by measuring anatomic axis, Q angle, intermalleolar and intercondylar distance. The same parameters has been measured by Body Vision photogrammetric system which consisted of anterior view digital picture in standing position. Angles and distances obtained by these methods compared and correlations analyzed. Results: There was good correlation between anatomic axis photogrammetric and radiologic findings(r=0.939, P<0.001) and also IMD&ICD clinical and photogrammetric values(r=0.948, r=0.927 respectively). Moreover, good correlation was found between Q angle clinical and photogrammetric measurements, however it was weaker than previous values(r=0.834). Moderate correlation has been detected between anatomic axis clinical-photogrammetric and clinical-radiologic findings(r=0.703, r=0.625 respectively).