Supraspinatus tendon and subacromial space parameters measured on ultrasonographic imaging in subacromial impingement syndrome

Abstract

The supraspinatus tendon was thicker and occupied a greater percentage of AHD, supporting an intrinsic mechanism. An extrinsic mechanism of tendon compression is theoretically supported, but future imaging studies need to confirm direct compression with elevation. Treatment to reduce tendon thickness may reduce symptoms, and surgical intervention to increase subacromial space may be considered if tendon compression can be verified.

Distribution of bone and tissue morphological properties related to subacromial space geometry in a young, healthy male population

“…The measurement of the minimum distance on anteriorposterior radiographs seldom occurred at the lateral-most point of the acromion where ultrasound measures are captured. Additionally, the undersurface of the acromion may be outside the ultrasound imaging area resulting in the subsequent underestimation of the true occupation ratio [23]. The occupation ratio calculated exclusively using ultrasound with the anterior transducer measurement was nearly identical to that reported by Michener et al [23].…”

“…Additionally, the undersurface of the acromion may be outside the ultrasound imaging area resulting in the subsequent underestimation of the true occupation ratio [23]. The occupation ratio calculated exclusively using ultrasound with the anterior transducer measurement was nearly identical to that reported by Michener et al [23]. Despite the previous use of the anterior measurement of the subacromial space, the mid-lateral location elicited a slightly closer magnitude to the radiographic measurement, likely due to higher visibility and thus more robust identification of the inferior acromion on the mid-lateral measurement.…”

“…The supraspinatus tendon was measured with the transducer positioned in a transverse (short axis) orientation, perpendicular to the tendon long axis. Participants extended their right arm, resting their hand on the ipsilateral hip during measurement [23]. Both the subacromial bursa thickness and the minimum subacromial space width were measured with the participant's arm resting at neutral and the transducer oriented in a longitudinal (long axis) ultrasonic view with its medial margin placed upon the lateral margin of the acromion and spanning over the greater tuberosity.…”

“…In particular, the occupation ratio, which describes the relative dimensions of the subacromial tissue thickness to the minimum subacromial space width, serves as an estimate of SAIS risk. Michener et al [23] recently calculated the occupation ratio in participants with SAIS and matched controls and determined that while the ratio was significantly higher in those with SAIS, even within the healthy population with the arm at neutral, the tissues can occupy more than half of the space. This fraction is expected to be greater in elevated arm postures as the space is markedly reduced [4,14].…”

Comparison of Upper Extremity Physical Characteristics Between Adolescent Competitive Swimmers and Nonoverhead Athletes

“…Sub- acromial-space distance was defined as the shortest distance between the anterior-inferior tip of the acromion and the superior humeral head ( Figure 2B). 17 A 3-trial mean was calculated for each side. Average subacromial-space distance was normalized to height and presented as a percentage.…”