Patellar Height Assessment Methods: An Update.

Abstract

* Direct and indirect radiographic methods have been proposed for patellar height assessment. Direct methods relate the position of the patella to the femur, and indirect methods relate the position of the patella to the tibia.* Various knee flexion angles have been used for practicality or because obtaining a true lateral knee radiograph is difficult. Knee flexion angles and quadriceps contraction modify patellar height measurements because of proximal patellar displacement and influence patellar height ratios.* Over time, progression from a simple radiographic measurement to modern biomechanical and imaging technologies has added complexity to the techniques devised to measure patellar height. Currently, the definition of patellar height and its causal relationship to the conditions commonly associated with anterior knee pain remain controversial.