Accuracy in detecting knee effusion with clinical examination and the effect of effusion, the patient's body mass index, and the clinician's experience

Abstract

The purpose of this study was to determine the accuracy of detecting knee effusion with clinical examination and to evaluate whether the amount of effusion, patient obesity, and the clinicians' experience affect the clinicians' decisions in patients with knee osteoarthritis. Patients presenting with knee pain were examined by two residents with different levels of experience and underwent ultrasonographic examination, including measurement of effusion in the medial, mid, and lateral aspects of the suprapatellar bursa. One hundred seventy-two knees of 86 patients were examined. Of the knees investigated, 127 (73.8 %) had effusion. The consistency between ultrasonographic and resident examination were weak (κ = 0.193, p = 0.007 and κ = 0.349, p < 0.001), although the more experienced senior resident had a stronger agreement. The overall inter-rater agreement between the two residents was low (κ = 0.254). The senior resident had a significantly higher accuracy ratio (p = 0.036). In the knees without effusion, the two examiners had no agreement (κ = -0.028, p = 0.856); however, the ratios of the true decisions were similar (p = 1.0). The accuracy of the less experienced resident's decisions was affected by effusion depth (p = 0.005). Clinicians' decisions and their accuracy in detecting knee effusion during clinical examination were different, especially in the absence of effusion. The consistency between ultrasonography and residents was low. The accuracy of clinical examination was affected by effusion depth and experience, but not by patient obesity.

Association of Knee Effusion Detected by Physical Examination With Bone Marrow Lesions: Cross‐Sectional and Longitudinal Analyses of a Population‐Based Cohort

“…While a systematic review reported that some studies have poor inter-and intrarater reliability of clinical tests of effusion (10), other studies, including ours, have reported good-to-excellent interrater reliability of knee effusion on examination (11)(12)(13). Furthermore, the predictive utility of a combination of clinical examinations for bulge sign, ballottement, and patellar tap versus ultrasound effusion has been shown to have high sensitivity and moderate specificity in senior residents (14).…”

“…We have recently reported that physical examination effusion was highly correlated with MRI effusion, particularly moderate-to-large MRI effusion (9). Furthermore, the predictive utility of a combination of clinical examinations for bulge sign, ballottement, and patellar tap versus ultrasound effusion has been shown to have high sensitivity and moderate specificity in senior residents (14). Furthermore, the predictive utility of a combination of clinical examinations for bulge sign, ballottement, and patellar tap versus ultrasound effusion has been shown to have high sensitivity and moderate specificity in senior residents (14).…”

Anti-Inflammatory Effect of Cross-Linked Hyaluronic Acids in Osteoarthritic Knee, Detected by Ultrasonography

“…Compared to clinical examination, US is more sensitive and well correlated with the histological ndings. [6][7][8][9] Some studies reported equivalent sensitivity of synovitis detection by US compared to magnetic resonance imaging (MRI). 10,11 Moreover, this tool is non-invasive, relatively inexpensive, and involves a short examination time, as well as having no radiation burden and good patient acceptability.…”

Interobserver and Intraobserver Reliability of Clinical Assessments in Knee Osteoarthritis

“…As with any clinical test, clinical examination of the knee is subject to measurement error. There are, however, few studies which have formally assessed reliability in the assessment of common clinical signs for knee OA and in those studies that have reported reliability, findings have been somewhat inconsistent2–4,9–12. Some contributing factors to the inconsistency include lack of clarity and uniformity in the assessment procedures and also the grading criteria2–4,9–12.…”

“…There are, however, few studies which have formally assessed reliability in the assessment of common clinical signs for knee OA and in those studies that have reported reliability, findings have been somewhat inconsistent2–4,9–12. Some contributing factors to the inconsistency include lack of clarity and uniformity in the assessment procedures and also the grading criteria2–4,9–12. Reliable clinical assessment is important, as poor reliability may result in misclassification in clinical and research studies of knee OA and reduce the chance of finding clinically important biological associations between clinical features of the disease and outcome or response to therapy.…”