Diagnostic accuracy of preoperative magnetic resonance imaging for detecting subscapularis tendon tears: a diagnostic test study

Abstract

Although the biomechanical importance of the subscapularis tendon has been recognized in biomechanical 1 and clinical studies, 2 it has long received little attention in the medical literature, 3 and has been called the "forgotten tendon". 4 Only 1% of rotator cuff tears affect only the subscapularis, 5,6 but more than half of all patients with supraspinatus tears present an associated tear of this tendon. 7,8 The accuracy of magnetic resonance imaging (MRI) is usually lower for detection of subscapularis tears than for rotator cuff tears overall, 9,10 with sensitivity ranging from 25% to 94% 5,11 and specificity from 67% to 100%. [12][13][14] Studies evaluating the diagnosis of subscapularis tears are important for clinical practice, with implications for prognosis and surgical planning. Among the published studies, some have included low magnetic field MRI, 7,13,15,16 small samples, 15,17 diagnosis not restricted to rotator cuff disorders, 7,12,14-16,18-21 and use of intra-articular 11,14,19 or intravenous 15,20 contrast. These factors can generate bias in data interpretation. OBJECTIVEThe objective of the present study was to evaluate the accuracy of preoperative high magnetic field MRI without the use of contrast, compared with arthroscopic inspection, for identifying subscapularis tears, in cases undergoing rotator cuff repair. METHODSThis was a diagnostic test study comparing the findings from preoperative MRI (index test) with those from shoulder arthroscopy (reference standard) for diagnosing subscapularis tears.Operative data were collected in a standardized manner from consecutive patients between January 2013 and August 2017, by three surgeons at the same institution.

Identifying key factors associated with subscapularis tendon tears and developing a risk prediction model to assist diagnosis

“…Clinicians often evaluated the severity of SSC tendon injuries on MRI according to changes in tendon morphology and signal, but there were still some limitations [ 7 , 12 , 23 ]. A reliable risk estimation tool is helpful for the screening and early identification of patients with SSC tendon tears.…”

Utilization of MRI in surgical decision making in the shoulder

“…MR-images are routinely used and read separately by the ordering orthopaedic surgeons and radiologists, the latter specialty generating an MRI report [ 3 , 4 ]. An additional cause for increased MRI utilization can be the patient generated request or the result of medical legal considerations, often encountered in the Canadian tort system.…”

“…They receive the referral often in order to prevent a legal action and for the sake of enhancing the patient-doctor relationship [ 5 , 6 ]. Despite increase in MR-imaging quality, signals detected may represent false positive pathologies particularly in cases of rotator cuff tears [ 4 , 7 , 8 ]. Changes in signal sensitivity, pixels and the width of the generated slice can lead to a discrepancy between pathologic and non-pathologic images [ 9 , 10 ].…”

Development and Validation of a Web-Based Dynamic Nomogram to Improve the Diagnostic Performance of Subscapularis Tendon Tear

“…Although the diagnostic performance of magnetic resonance imaging (MRI) in supraspinatus and infraspinatus tendon tears is excellent, it has been challenging to find MRI as an effective diagnostic tool for SSC tendon tears ( 4 – 6 ). Especially, the smaller and partial-thickness tears could directly decrease the diagnostic accuracy of MRI ( 7 – 9 ). Considering the SSC tendon tear usually begins at the upper part of the tendon insertion, most of which occurred in the superior one-third of the tendon insertion ( 10 ), the presence of a partial volume effect will also make it difficult to visualize the lesions in the anterosuperior region ( 11 ).…”