Reliability of patellotrochlear index in patellar height assessment on MRI —correction for variation due to change in knee flexion

ConclusionsThis study demonstrates high inter-observer correlation of PTI on MRI and high test –retest reliability indicating unconscious quadriceps contraction does not change the index sufficiently. Knee flexion significantly alters PTI, increased patellotrochlear engagement with flexion increases the index. We propose use of the formula cPTI = PTI -1.3a to correct the index to 0 degr ee knee flexion in clinical practice.
Source: Skeletal Radiology - Category: Radiology Source Type: research