Diagnostic Value of History Taking and Physical Examination to Assess Effusion of the Knee in Traumatic Knee Patients in General Practice
Abstract
Kastelein M, Luijsterburg PA, Wagemakers HP, Bansraj SC, Berger MY, Koes BW, Bierma-Zeinstra SM. Diagnostic value of history taking and physical examination to assess effusion of the knee in traumatic knee patients in general practice.
Objective
To assess the diagnostic value of history taking and physical examination for knee joint effusion in patients with a knee injury who consult their general practitioner (GP). In addition, to determine the association between effusion seen on magnetic resonance imaging (MRI) and internal derangement of the knee.
Design
Prospective, observational cohort study.
Setting
Primary care.
Participants
Patients (N=134) aged 18 to 65 years with a traumatic knee injury who consulted their GP.
Interventions
Not applicable.
Main Outcome Measures
Patients filled out a questionnaire, underwent a standardized physical examination and underwent an MRI scan to assess the presence of effusion. Multivariate logistic regression analysis was used to determine the diagnostic value of history taking and physical examination (P<0.10) as assessed by sensitivity, specificity, predictive values, and likelihood ratios. The relationship between effusion and internal derangement of the knee was assessed with a chi-square test.
Results
Of the 134 participating patients, 42 had knee joint effusion seen on MRI. Multivariate analysis showed an association with knee joint effusion for the symptom “self-noticed swelling” (history taking) and for the “ballottement test” (physical examination). The likelihood ratio positive (LR+) was 1.5 for self-noticed swelling and 1.6 for the ballottement test. These 2 combined improved the diagnostic value to an LR+ of 3.6. Effusion showed a positive association with internal derangement of the knee (chi-square 9.5); 31 of the 42 patients with knee joint effusion had internal derangement of the knee.
Conclusions
In patients with traumatic knee injury, knee joint effusion is frequently seen on MRI. The combination of self-noticed swelling and the ballottement test was of diagnostic value. Knee joint effusion was associated with internal derangement of the knee.
Department of General Practice, Erasmus University Medical Center, Rotterdam, The Netherlands
Correspondence to Marlous Kastelein, MD, Dept of General Practice, Erasmus Medical Center Rotterdam, PO Box 2040, 3000 CA Rotterdam, The Netherlands
Supported by TRIAS, Zilveren Kruis Achmea, and OZ.
No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit on the authors or on any organization with which the authors are associated.
ABSTRACT