Adhesive capsulitis and ultrasound diagnosis, an inseparable pair: a novel review

Abstract

Purpose: Adhesive Capsulitis (AC) is a musculoskeletal disorder initially described by Codman in 1934. The disease is characterized by pain-limited restriction in active and passive glenohumeral range of motion (ROM) despite the lack of a structural deficit. In the last decades, arthroscopy and magnetic resonance imaging (MRI) has been the only diagnostic tools able to highlight the characteristic alterations of the glenohumeral capsular-ligament apparatus in AC; nevertheless, both arthroscopy and MRI are burdened by intrinsic limitations. The aim of this narrative review is to summarize the most significant evidence supporting the use of ultrasound (US) for the diagnosis of AC.

Methods: We extensively searched via PubMed library the terms "frozen-shoulder" and "adhesive capsulitis" each combined with "ultrasound".

Results: We found 3723 papers on PubMed and selected those inherent to AC diagnosis, US imaging, correlation with arthroscopic and MRI findings. Forty papers which were strictly related to the topic of this narrative review were initially chosen, then 20 studies which described and exploited US for AC diagnosis were finally included. Coracohumeral ligament (2.65 ± 0.4 mm) and axillary pouch thickening (3.34 ± 0.8 mm), as well as an increase in vascularity at rotator interval (78/214, 36.44%), represented the commonest US signs useful for AC diagnosis and for which the most significant cut-off values were reported.

Conclusions: The evidence collected in this review testify that musculoskeletal US is as reliable as MRI for AC diagnosis, therefore we believe that in this context US should be considered a first-line imaging technique.

Keywords: Adhesive capsulitis; Frozen shoulder; Painful shoulder; Ultrasound.

Fig. 1

Right humerus. GT great tuberosity; LT lesser tuberosity; CHL coracohumeral ligament; SGHL superior glenohumeral ligament; LHBT long head biceps tendon; SN surgical neck. In the small box, pulley axial section of RI. SST supraspinatus tendon; SUBT subscapularis tendon; BT biceps tendon

Fig. 2

Left humeral head: the bicipital groove (white arrows and dashed white line) begins just below the surgical neck (SN, green arrows)

Fig. 3

Coronal view of the axillary pouch in neutral rotation and slight abduction. SAB subacromial bursa; A-C acromioclavicular joint

Fig. 4

Left shoulder: axial section of the RI showing conspicuous coracohumeral ligament biceps tendon thickening (with double arrow). LHBT long head of the biceps tendon

Fig. 5

Oblique axial section: calipers shows the thickness of the axillary pouch in a patient with AC; the lest image is the contralateral side. HH humeral head

Fig. 6

Coronal section: the calipers show the thickness of the AP in patient with AC. HH, humeral head, SN, surgical neck

Fig. 7

Directional PD US shows hypervascularity in the RI: axial section of the rotator interval of a right shoulder in a patient with AC. CHL, Coracohumeral ligament; LHBT, Long Head Beceps Tendon; GT, greater tuberosity; LT, lesser tubercle

Fig. 8

US dynamic study of the infraspinatus tendon (green above and white arrows below) sliding backwards during passive external rotation from neural rotation (above) to external passive rotation (below). Note the change from a flat to a concave profile (yellow arrowhead) of the tendon. The sliding of the tendon folds towards the joint capsule because of the close contiguity