Bursal-Sided Rotator Cuff Tears: Simple Versus Everted Type.

Background: No studies have focused on the everted type of bursal-sided partial-thickness rotator cuff tears (PTRCTs).

Purpose: To evaluate the radiological characteristics, arthroscopic findings, and clinical and structural outcomes after arthroscopic repair of the everted type of bursal-sided PTRCTs.

Study Design: Cohort study; Level of evidence, 3.

Methods: Two groups of patients with bursal-sided PTRCTs (simple type, 25 shoulders; everted type, 25 shoulders) were enrolled. The mean age was 59.6 years (range, 47-73 years) and 60.8 years (range, 48-72 years) among patients with the simple and everted type, respectively. The mean follow-up period was 2.7 years (range, 2.0-5.1 years).

Results: The everted type always exhibited an acromial spur (hat-shaped, 52%; heel-shaped, 48%) and bony changes in the greater tuberosity (bony spur, 52%; sclerotic changes, 48%). Hat-shaped spurs of the acromion were not observed in the simple type. The everted type showed significantly thicker tendon on magnetic resonance imaging (MRI), as the stump was retracted superomedially (mean thickness: 8.1 ± 1.2 mm vs 5.5 ± 1.1 mm for the everted and simple type, respectively). During arthroscopic repair, additional sutures were needed more often for the everted type than for the simple type (64% vs 16%, respectively). After repair, the tendon margin was uneven and ragged in 16% of shoulders with the everted type. Preoperatively, the visual analog scale (VAS) score for pain during motion and range of motion (ROM) were significantly worse in patients with the everted type than in those with the simple type (VAS score, 7.2 vs 5.6, respectively; ROM for forward flexion, 146.8° vs 156.4°, respectively). Postoperatively, no significant differences in the VAS score, ROM, or clinical outcomes were observed between the 2 groups, with no retears on follow-up MRI in either group.

Conclusion: The everted type of bursal-sided PTRCTs showed a characteristic hat-shaped acromion, often with bony spurs of the greater tuberosity. On MRI, the tendon stump appeared thickened because of the everted flap. The everted type was more likely to require additional sutures because of an uneven or ragged tendon margin. However, satisfactory clinical and structural outcomes were observed for both the simple and everted types.