Axial and Lateral Radiographs in Evaluating Patellofemoral Malalignment

Abstract

This is a prospective study of 431 patients (862 knees) with patellofemoral pain, patellar dislocation, or other abnormalities of the knee joint. There were 217 asymptomatic knees with no contralateral problems for comparison. All patients had a history and physical and radiographic examination of both knees. The radiographs included standard anteroposterior views, axial views at 30 degrees of knee flexion, and standing lateral views at 0 degree and 30 degrees of flexion. The presence of patellar tilt or subluxation was noted on the axial view. The lateral view of the patella, with precise overlap of the posterior femoral condyles, allowed determination of relationships between the patella's medial edge, median ridge, and lateral edge to assess patellar tilt. Sixty-two percent of patients with patellar dislocations demonstrated subluxation on the axial view, while 98% demonstrated an abnormal lateral view. Eighteen percent of the control knees revealed evidence of subluxation on the axial view while 35% demonstrated subluxation on the extended lateral view. The axial view demonstrated 62% sensitivity for dislocation, while the lateral view taken in full extension demonstrated 98% sensitivity. The specificity for previous dislocation was 82% for the axial view and 93% for the lateral flexed view. Given the high sensitivity of the lateral view for detecting prior patellar dislocation, a normal result on this view can virtually eliminate the question of previous dislocation. Also, with the high specificity of the axial view and lateral view with knee flexion, the two views combined can confirm a clinical impression of patellofemoral malalignment.

Observer Agreement on the Dejour Trochlear Dysplasia Classification

“…The lateral view was taken in the supine position and 0°of knee flexion with superimposed condyles. 24 During clinical assessment, a firm typing was made using Dejour's classification. This study compares the reliability and accuracy of 2 diagnostic studies in grading the severity of trochlear dysplasia.…”

Q-angle and J-sign: Indicative of Maltracking Subgroups in Patellofemoral Pain

“…Numerous studies have compared PF alignment [1,14,22,24,26,31] and PF displacements/rotations [5,29,39,44,48] in patients diagnosed with PF pain with asymptomatic controls. These studies typically reported variations in PF alignment, displacements, and/or rotations between the two populations, but the results are inconsistent across studies.…”

Reliability of clinical methods in evaluating patellofemoral pain syndrome with malalignment

“…Physical examination and radiology (X-ray and CT scan) play a pivotal role in the diagnosis of patellofemoral pain syndrome, yet the literature contains limited publications focused on the diagnostic value of these parameters. 4,8,11 Most of the studies have taken clinical presentation of anterior knee pain as a reference standard for suspecting PFPS and some have used knee arthroscopy as a reference standard. [4][5][6][7]12,13 We proposed that just a mere presentation of the anterior knee pain without other identifiable causes cannot label a patient as having PFPS.…”