Criterion-Related Validity of a Clinical Measurement To Determine the Medial/Lateral Component of Patellar Orientation

Abstract

Dawn Nishimoto, MPT3 Debra Simon, MPT4Study Design: Repeated measures design using a sample of convenience.Objective: To assess the criterion-related validity and intrarater reliability of a clinical measurement used for determining the medialAateral position of the patella. Background: Patellar taping is a common treatment for patellofemoral pain. Application of this intervention requires accurate assessment of patellar orientation; however, the validity of this clinical procedure has not been documented. Methods and Measures: Fourteen subjects (1 0 women, 4 men; average age, 41 2 16 years) were evaluated. Clinical assessment of mediallateral patellar orientation using the technique described by McConnell was compared with the actual position of the patella as determined through magnetic resonance imaging (MRI). Imaging was done on 7 knees of 4 subjects who were asymptomatic and 11 knees of 10 subjects who were symptomatic. Both clinical and MRI assessments were made with the subjects supine, the knee extended, and the quadriceps relaxed. Agreement between the 2 techniques and the intrarater reliability of each measurement were quantified by means of the intraclass correlation coefficient (ICC). Results: Both the clinical and MRI measures of medialflatera1 patellar displacement were found to demonstrate good intrarater reliability (KC = 0.91 and 0.85, respectively). The agreement between the clinical and MRI determinations of mediallateral patellar position was poor (ICC = 0.44). The average amount of lateral patellar displacement as determined by the clinical method was more than twice that established through MRI. The necessity of a medial glide correction is determined visually or by use of a sort tape measure, with the femoral epicondyles and the midpoint of the patella used as landmarks. The course notes to the McConnell treatment plan state that if the distance between the medial femoral epicondyle and the midpoint of the patella is greater than the dis tance from the lateral epicondyle and the midpoint of the patella, it is assumed that there is a lateral glide component that needs to be corrected by means of a specific taping procedure. Although this clinical procedure is commonly used to assess the medial/lateral position of the patella, whether it accurately measures the true medial/lateral position of the patella is not known. The purpose of this study was to determine the concurrent, criterion-related validity of the McConnell technique in assessing medial/lateral patellar position by comparing the results of this clinical assessment with results of an established criterion measure, namely, magnetic resonance imaging (MRI). In addition, the intrarater reliability of both procedures was assessed in nonimpaired individuals. METHODS SubjectsFourteen subjects (18 knees), consisting of 10 women and 4 men, participated in this study. Four subjects (7 knees) were asymptomatic and 10 subjects (11 knees) were symptomatic. Subjects recruited for this study were either referred to Centinella Hospital Medical C...

A Multicenter, Single-Masked Study of Medial, Neutral, and Lateral Patellar Taping in Individuals With Patellofemoral Pain Syndrome

“…However, the assessment procedures for patellar alignment used by physical therapists have been shown to be both unreliable 9,39,40 and invalid. 31 This has led Watson et al 40 to conclude that the McConnell system of assessment of patellar position should not be used as a measurement tool or a basis for treatment decisions. It is also acknowledged that this study did not attempt to examine or adjust patellar tilt or rotation.…”

Prevalence of VMO muscle insufficiency in PFPS patients

“…In orthopedics sports medicine, the most common reasons for anterior knee pain are, [4] -Overuse -Mal-alignment -Trauma Studies on the natural history of PFPS report that in general it is a benign condition that may improve or persist over time serious disability is uncommon. PFPS is a condition of both malalignment and muscular dysfunction.…”

The Difference in a Clinical Measure of Patella Lateral Position Between Individuals With Patellofemoral Pain and Matched Controls

“…It is also important to acknowledge that the position of the patella is likely related to other factors as well. 15 The strong reliability reported within this study and others 11,13,12,18 may, in part, be related to the examination being carried out by experienced manual therapists. Other studies in which the level of training and experience was not as high have failed to show the same levels of reliability.…”

“…15 While some authors have reported the intertester 7,22 and intratester 21 reliability of the method to be poor and have questioned its validity, 18 Herrington, 11 Herrington and Nester, 12 and McEwan et al 17 have reported the method to be both reliable and valid when used by experienced clinicians.…”

“…23 The studies of Herrington,11 McEwan et al, 17 and Powers 18 overestimated patella position by 25% to 50%, as compared to measurements of lateral patella position The clinical measure will be influenced by the degree of lateral displacement and lateral patella tilt, which further increases the medial distance measured (medial epicondyle to midpoint patella) without necessarily changing mediolateral (frontal plane) position. The inability of the clinical measure to distinguish between tilt and lateral displacement (frontal plane position) may give the measure less validity when comparing it to lateral patella displacement on MRI, but may increase its clinical utility, as it shows an increased predisposition for asymmetrical loading of the patellofemoral joint.…”