Quantitative value of medial femoro-tibial width (FTW) with weight-bearing technique. Our experience with a modified Lyon-Schuss view.

In the period between September 2008 and February 2009, we evaluated with knee radiography a group of 30 patients with known knee osteoarthritis (OA). For each patient, two weight-bearing views of the knee were acquired, the first with a standard antero-posterior (AP) technique, the latter with a posteroanterior (PA) technique with a 10° skull-caudal incidence. The radiographs obtained were evaluated blinded by two radiologist who assessed the medial femoro-tibial width (FTW). Statistical analysis of the results, carried out with the “t” Student test, showed a statistically significant difference about FTW values between the two radiographic views (t = 5.2331 for reader 1 and t=5.1970 for reader 2). In conclusion, we believe that the dedicated PA view of the knee is better than standard AP view for a correct assessment of medial FTW.