Disproportionate fluid sign as an aid in diagnosing high-grade bursal-sided supraspinatus tendon tear

Abstract

Background Deep, high-grade bursal-sided supraspinatus tendon tears are sometimes preoperatively misinterpreted as full-thickness tears on shoulder magnetic resonance imaging (MRI). Purpose To determine the usefulness of disproportionate fluid sign for differentiating high-grade bursal-sided partial-thickness tears from full-thickness tears on conventional MRI. Material and Methods Preoperative MRIs of 198 patients with arthroscopically confirmed high-grade bursal-sided partial-thickness tears and full-thickness tears were independently reviewed by two readers on two occasions. The presence of high-grade bursal-sided partial-thickness tears with a confidence level using a five-point grading scale was assessed based on tear depth alone and also in combination with disproportionate fluid sign, defined as a prominent subdeltoid or subacromial-subdeltoid bursal fluid distension with a relative paucity of effusion in the glenohumeral joint. The sensitivity, specificity, accuracy, and area under the receiver operating characteristic curve (AUC) were calculated, as well as inter-observer reliability. Results The disproportionate fluid sign was identified in 60/74 (81.2%) bursal-sided partial-thickness tears and 9/124 (7.5%) full-thickness tears. The sensitivity and accuracy of the diagnosis of bursal-sided tear were higher when disproportionate fluid sign was used in conjunction with the tear depth, compared with tear depth alone ( P < 0.001). There was excellent inter-observer agreement for disproportionate fluid sign and deep bursal-sided tear. The AUCs were significantly higher in combination with disproportionate fluid sign. Conclusion The disproportionate fluid sign indicates the presence of a deep, high-grade bursal-sided partial-thickness tear, which can be misinterpreted as a full-thickness tear. Thus, it can provide greater diagnostic assistance to less-experienced radiologists and clinicians.

Partial-Thickness Tear of Supraspinatus and Infraspinatus Tendon Revisited: Based on MR Findings

“…이전 연구에 따르면, 점액낭 측 부분 파열의 주요 원인은 외인성 견봉하 충돌(subacromial impingement)이 흔하여서 직접적인 견봉하 물리적 충돌 및 자극에 의해 파열이 유발되고 subacromial-subdeltoid bursa의 염증과 관련이 있다고 알려져 있다( 39 ). 이 파열은 힘줄과 견봉(acromion)의 경계면(interface)에서 흔히 발생한다( 40 ).…”

Magnetic resonance imaging of the shoulder

“…Some high-grade partial-thickness bursal-sided tears may be mistaken for full-thickness tears. In these cases, searching for a prominent subdeltoid or SA-SD bursal fluid distension with a relative paucity of effusion in the glenohumeral joint (disproportionate fluid sign), can aid diagnosis because this finding is much more likely in bursal-sided tears [ 28 ] ( Figure 4 ). Partial-thickness articular-sided tears can also involve the rotator cable or crescent.…”

Reliability of Magnetic Resonance Imaging Criteria for the Preoperative Assessment of Rotator Cuff Tears: A Systematic Review

“… § References 1-7, 15, 18-20, 23, 25-27, 30, 31, 33, 34, 37, 39, 42, 44, 49, 55, 56, 58, 62, 69, 73, 77, 78, 82-84, 86-88, 90, 92. …”