MR Imaging of the Posterosuperior Glenohumeral Ligament, a Newly Described Shoulder Ligament

Purpose or Learning Objective: A 2007 cadaveric study described thickening of the posterosuperior glenohumeral capsule in 90% of their specimens and called it the posterosuperior glenohumeral ligament (PSGHL). To date, literature is lacking to identify the PSGHL on magnetic resonance (MR) imaging. The purpose of this review was to determine if the PSGHL can be confidently identified on MR arthrography.

Methods or Background: Two radiology fellows retrospectively reviewed 271 shoulder MR arthrograms, of which 110 fit the inclusion criteria. Exclusion criteria included prior surgery, articular-side tearing of the superior cuff, superior labrum anterior and posterior (SLAP) tear, prior dislocation, or age > 49 years. The PSGHL was assessed using oblique-sagittal and coronal T2-weighted fat-saturated (FS) and oblique-coronal T1-weighted FS sequences. Two criteria were assessed: (1) Bandlike low-signal thickening of the capsule on at least one slice between the glenoid and rotator cable, and (2) focal inferior indentation of the supraspinatus just lateral to the glenoid.

Results or Findings: Of the 110 shoulders, the two fellows agreed on 58 cases. Of these, 3 were agreed to have indentation only, 15 were agreed to have band-like thickening only, and 12 were agreed that both criteria were positive. A total of 28 shoulders were agreed negative to both.

A musculoskeletal radiology staff with 29 years of clinical experience at our institution reviewed the 52 shoulders where there was disagreement to provide consensus. Of the 52 cases, 11 were decided to have indentation only, 8 were decided to have band-like thickening only, and 8 deemed both criteria as positive. Fifteen shoulders were decided to be negative to both. The remaining 10 shoulders were equivocal with no consensus.

Overall, 23 of 110 (21%) demonstrated bandlike low-signal thickening, 14 of 110 (13%) demonstrated focal indentation, 20 of 110 (18%) demonstrated both criteria, 43 of 110 (39%) demonstrated neither, and 53 of 110 (48%) demonstrated neither or were inconclusive.

Conclusion: Bandlike thickening of the posterosuperior joint capsule and/or focal indentation into the posterosuperior joint cavity was identified in 52% of MR arthrograms. Although this prevalence is lower than that seen in the cadaveric study, these results are promising and lay the groundwork for further surgical-radiologic correlation in future studies.

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Artikel online veröffentlicht:
02. Juni 2022