title: The anterior tilt of the acromion: radiographic evaluation and correlation with shoulder diseases.
abstract: The aim of this study was to test whether the anterior tilt of the acromion can be objectively evaluated on lateral radiographs, and whether there is a relation between this anatomical feature and the most common shoulder diseases. Lateral radiographs of 15 dried scapulas were performed in neutral position and with 5 degrees of caudal, cranial, anterior and posterior angulations. Two hundred and forty-three shoulders, both asymptomatic and affected by chronic and post-traumatic impingement, calcific tendinitis and instability, were examined by conventional radiography. The presence of rotator-cuff tears was investigated by sonography. A method was elaborated to obtain reproducible lateral radiographs and to determine the acromial tilt angle. Inter- and intraobserver and inter- and intraoperator variations in measurements were evaluated. Variations in tube angulation produced changes in tilt-angle values on dried scapulas. The average tilt angle for the chronic impingement and the instability groups were significantly different from the post-traumatic, calcific tendinitis and control groups. Rotator-cuff tears were significantly more frequent in the chronic impingement group and related to a more acute tilt angle. The inter- and intraobserver variability coefficients were 0.95 and 0.98, whereas the inter- and intraoperator variability coefficients were 0.94 and 0.96, respectively. Conventional radiography using fluoroscopy for positioning is a well-reproducible method for the evaluation of acromial tilt. There is a significant difference in tilt-angle values between some groups of subjects examined, but the lack of specificity limits the clinical importance of such measurement.
authors.affiliation: Department of Radiology, San Carlo Hospital, Genoa, Italy.
authors.forename: N
authors.initials: N
authors.lastname: Prato
authors.forename: D
authors.initials: D
authors.lastname: Peloso
authors.forename: A
authors.initials: A
authors.lastname: Franconeri
authors.forename: G
authors.initials: G
authors.lastname: Tegaldo
authors.forename: G B
authors.initials: GB
authors.lastname: Ravera
authors.forename: E
authors.initials: E
authors.lastname: Silvestri
authors.forename: L E
authors.initials: LE
authors.lastname: Derchi
mesh_terms: D000174:Acromion / Q000000981:diagnostic imaging* / Q000473:pathology; D000328:Adult; D002114:Calcinosis / Q000000981:diagnostic imaging; D002908:Chronic Disease; D005260:Female; D005471:Fluoroscopy; D006801:Humans; D006811:Humerus / Q000000981:diagnostic imaging; D007592:Joint Diseases / Q000000981:diagnostic imaging* / Q000473:pathology; D007593:Joint Instability / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results; D017006:Rotator Cuff / Q000000981:diagnostic imaging; D000070636:Rotator Cuff Injuries; D012421:Rupture; D012680:Sensitivity and Specificity; D019534:Shoulder Impingement Syndrome / Q000000981:diagnostic imaging; D000070599:Shoulder Injuries; D012785:Shoulder Joint / Q000000981:diagnostic imaging* / Q000473:pathology; D052256:Tendinopathy / Q000000981:diagnostic imaging; D014463:Ultrasonography