Digital radiographic measurement of tibial and femoral condylar articular surface asymmetry and knee joint space

Abstract

Introduction: Knee joint is a major weight bearing synovial joint. In frontal radiograph we can see asymmetrical joint spaces between femoral and tibial components due to asymmetric wear and tear. Articular surfaces of tibial and femoral condyles are also asymmetrical. In frontal radiograph, the tibial condylar articular surface can be seen projected outside laterally or medially with respect to lateral or medial femoral condyle. Objectives: To measure tibial and femoral articular surface asymmetry. Measurement of tibial and femoral joint space. Materials and Methods: This epidemiological study was conducted in Orthopaedic outpatient department (OPD) of Ramakrishna Mission Seva Pratishthan Kolkata. Total 350 patients were selected. Frontal standing radiograph of both knees with 100% magnification were obtained. Tibial condylar asymmetry and joint spaces were measured with calliper. Height and weight measurements were also done. Statistical analysis was done. Results: In right knee 96% patients lateral tibial condyle was projected outside with respect to femoral condyle. In 9.3% patients’ medial tibial condyle was outside. In left knee 92.6% patients lateral tibial condyle was outside and 15.7% patients’ medial tibial condyle was outside. In right knee lateral joint space was mean + sd= 4.45 + 1.06, medial joint space mean + sd= 1.70 + 94. In left knee lateral joint space was mean + sd= 4.59 + 1.00, medial joint space was mean + sd= 1.76 + 1.00. Conclusion: In this study, in most of the patients we found tibial and femoral articular surface asymmetry mainly in lateral side. In joint space measurement, we found that medial joint space was less than lateral joint space in both knees.