The Relationships Between the Geometrical Features of the Patellofemoral Joint and Patellar Mobility in Able-bodied Subjects

This study examined the correlations between patellar mobility and geometry of the patella and femoral condyle. Using a custom designed patellar gliding instrument, the lateral mobility of patella in 17 able-bodied subjects was measured and these measurements were compared with the relative patellar tendon length and the inclination of lateral femoral groove obtained from conventional MR imaging. The data showed that there was significant correlation between patellar mobility and inclination of lateral femoral groove (r= -0.671, P=0.01). Because hip rotation angle would alter the inclination of lateral femoral groove, clinicians who perform patellar gliding test should be mindful that the hip position is critical for the accuracy of the test.