Validity of combining history elements and physical examination tests to diagnose patellofemoral pain

Publication date: Available online 9 November 2017
Source:Archives of Physical Medicine and Rehabilitation
Author(s): Simon Décary, Pierre Frémont, Bruno Pelletier, Michel Fallaha, Belzile Sylvain, Johanne Martel-Pelletier, Pelletier Jean-Pierre, Debbie Feldman, Sylvestre Marie-Pierre, Pascal-André Vendittoli, François Desmeules
Objectiveto assess the validity of diagnostic clusters combining history elements and physical examination tests to diagnose or exclude patellofemoral pain (PFP).Designprospective diagnostic study.Settingsorthopaedic outpatients clinics (n=2), family medicine clinics (n=2) and community-dwelling.Participantsconsecutive patients (n=279) consulting one of the participating orthopaedic surgeons (n=3) or sport medicine physicians (n=2) for any knee complaint.Interventionsnot applicable.Main Outcome Measureshistory elements and physical examination tests were obtained by a trained physiotherapist blinded to the reference standard: a composite diagnosis including both physical tests and imaging results interpretation performed by an expert physician. Penalized logistic regression (LASSO) was used to identify history elements and physical examination tests associated with the diagnosis of PFP and recursive partitioning was used to develop diagnostic clusters. Diagnostic accuracy measures including sensitivity (Se), specificity (Sp), predictive values and positive and negative likelihood ratios (LR+/-) with associated 95% confidence intervals (CI) were calculated.Resultstwo hundred seventy-nine participants were evaluated and 75 had a diagnosis of PFP (26.9%). Different combinations of history elements and physical examination tests including the age of participants, knee pain location, difficulty descending stairs, patellar facets palpation, and passive knee extension range of motion were associated with a diagnosis of PFP and used in clusters to accurately discriminate between PFP and non-PFP individuals. Two diagnostic clusters to confirm the presence of PFP yielded a LR+ of 8.7 (95% CI: 5.2-14.6) and three clusters to exclude PFP yielded a LR-: of 0.12 (95% CI: 0.06-0.27).ConclusionDiagnostic clusters combining common history elements and physical examination tests that can accurately diagnose or exclude PFP compared to various knee disorders were developed. External validation is required before clinical use.



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