title: Correlation Between Sonographic and In Vivo Measurement of A1 Pulleys in Trigger Fingers.
abstract: The thickness of 210 A1 pulleys of 21 male and female healthy volunteers in two different age groups (20-35 y and 50-70 y) were measured by ultrasound. In a second group, the thickness of 15 diseased A1 pulleys and 15 A1 pulleys of the corresponding other hand of 10 patients with the clinical diagnosis of trigger finger were measured by ultrasound. During open trigger finger release, a strip of A1 pulley was excised and immediately measured using an electronic caliper. The average pulley thickness of healthy volunteers was 0.43-0.47 mm, compared to 0.77-0.79 mm in patients with trigger finger. Based on the receiver operating characteristic (ROC) curve, a diagnostic cut-off value of the pulley thickness at 0.62 mm was defined in order to differ a trigger finger from a healthy finger (sensitivity and specificity of 85%). The correlation between sonographic and effective intra-operative measurements of pulley thickness was linear and very strong (Pearson coefficient 0.86-0.90). In order to distinguish between healthy and diseased A1 pulleys, 0.62 mm is a simple value to use, which can be applied regardless of age, sex, body mass index (BMI) and height in adults.
authors.affiliation: Department of Plastic and Hand Surgery, University Hospital, Inselspital, University of Bern, Bern, Switzerland.
authors.forename: Andres
authors.initials: A
authors.lastname: Spirig
authors.affiliation: Department of Plastic and Hand Surgery, University Hospital, Inselspital, University of Bern, Bern, Switzerland.
authors.forename: Bettina
authors.initials: B
authors.lastname: Juon
authors.affiliation: Institute of Pathology, University Hospital, Inselspital, University of Bern, Bern, Switzerland.
authors.forename: Yara
authors.initials: Y
authors.lastname: Banz
authors.affiliation: Department of Clinical Research, University Hospital, Inselspital, University of Bern, Bern, Switzerland.
authors.forename: Robert
authors.initials: R
authors.lastname: Rieben
authors.affiliation: Department of Plastic and Hand Surgery, University Hospital, Inselspital, University of Bern, Bern, Switzerland. Electronic address: esther.voegelin@insel.ch.
authors.forename: Esther
authors.initials: E
authors.lastname: Vögelin
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D005385:Fingers / Q000000981:diagnostic imaging / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013710:Tendons / Q000000981:diagnostic imaging* / Q000601:surgery*; D052582:Trigger Finger Disorder / Q000000981:diagnostic imaging* / Q000601:surgery*; D014463:Ultrasonography / Q000379:methods*; D055815:Young Adult
keywords: A1 pulley; Sonographic measurement; Stenosing tenosynovitis; Trigger finger