Reliability of the lateral pull test and tilt test to assess patellar alignment in subjects with symptomatic knees: Student raters

Study Design: Test-retest reliability with blinded testers. Objectives: To determine the inter- and intra-rater reliability of the late ral pull test and patellar tilt test. Background: if patellar malalignment can be detected by clinical examinatio n, then condition-specific treatment interventions may be implemented in pa tients with patellofemoral pain syndrome. However, several clinical tests u sed to assess patellar mobility have recently been shown to have poor to fa ir reliability, Because the lateral pull test and the patellar tilt test ar e widely used clinically as diagnostic tests for patellofemoral pain syndro me but have not been previously tested for reliability, we examined these t ests. Methods and Measures: Fifty-two subjects (age range, 21-48 years) provided 95 knees (19 symptomatic and 76 asymptomatic) for assessment of the lateral pull test, Two testers, blinded to the presence or absence of symptoms, in dependently performed the lateral pull test in random order. Fifty-five sub jects (age range, 22-42 years) provided 99 knees (73 asymptomatic and 26 sy mptomatic) for assessment of the patellar tilt test. Three blinded testers independently performed the patellar tilt test in random order. All subject s were tested and retested within 3-5 days. A kappa (K) statistic was used to assess the agreement of findings within each tester and between testers. Results: The kappa coefficients for intrarater reliability varied from 0.39 to 0.47 for the lateral pull test and from 0.44 to 0.50 for the patellar t ilt test, while the coefficients for interrater reliability were 0.31 for t he lateral pull test and varied from 0.20 to 0.35 for the tilt test. Conclusions: Repeated lateral pull tests and patellar tilt tests had fair i ntrarater and poor interrater reliability. Our results suggest that care mu st be taken in placing too much emphasis on these tests when making clinica l decisions.