The quadriceps angle and its relation to femoral torsion.

In 29 patients with patellofemoral complaints paired values of Q-angle and internal hip rotation were determined. In addition the patellar height index of Insall & Salvati (1971) was calculated from measurements on lateral radiographs of the knees. Both Q-angle and internal hip rotation were significantly higher in women than in men and there was a statistically significant correlation between these two measurements. There was no significant correlation between Q-angles and patellar height indexes. As external hip rotation can generally be taken as a measure of internal femoral torsion, these findings favour the hypothesis of a torsional malalignment syndrome of the patellofemoral joint.