Characteristics of MR arthrography findings in traumatic posterosuperior rotator cuff tears

Abstract

Background

Few studies have investigated magnetic resonance (MR) characteristics of traumatic posterosuperior rotator cuff tears involving the supraspinatus and infraspinatus. We hypothesized that traumatic rotator cuff tears may have MR characteristics distinguishable from non-traumatic tears.

Methods

Preoperative MR arthrography and intraoperative tear size measurements were compared in 302 patients who received MR arthrography and underwent subsequent arthroscopic rotator cuff repairs for traumatic (61 patients, Group T) or non-traumatic (241 patients, Group NT) tears. The inclusion criteria for both groups were posterosuperior full-thickness rotator cuff tear and age between 40 and 60 years. For Group T, traumas were limited to accidental falls or slips, or sports injuries, motor vehicle accidents; injuries were associated with acute onset of pain followed by functional shoulder impairment; and time between injury and MRI was 6 weeks or less.

Results

In Group T, 72% of shoulders (44 patients) exhibited tendon tears with blunt edges while 28% shoulders (17 patients) showed tears with tapering edges. In contrast, 21% patients in Group NT (51 patients) had blunt-edge tears, while 79% (190 patients) of tears had tapering edges. These results were statistically significant (p < 0.001) and estimated odds ratio was 9.6. The size of tear did not vary significantly between groups.

Conclusions

We did not find an exclusive MR characteristic to define traumatic tears. However, oblique coronal MR images showed a significantly strong tendency for traumatic tears to have abrupt and rough torn tendon edges and relatively consistent tendon thicknesses (without lateral tapering) compared to non-traumatic cuff tears.