Topographic anatomy of suprascapular artery branches in the supraspinatus fossa: surgical implications for rotator cuff and muscle advancement.

PURPOSE: The suprascapular artery (SSA) is the main vascular supply to the rotator cuff musculature, but its detailed branching pattern in the supraspinatus fossa and clinical relevance for surgery and radiological interpretation are incompletely characterized. We aimed to provide morphometric data on SSA branches in the supraspinatus fossa and clarify their surgical and radiological implications. METHODS: The SSA course was traced in 20 shoulders from the superior transverse scapular ligament (STSL) to the spinoglenoid notch. SSA branches with a diameter of ≥ 1.0 mm were categorized into anatomical areas based on their relationship to the STSL, coracoclavicular ligament, and acromioclavicular joint. Morphometric measurements were obtained, and distances between the SSA main trunk and surgical landmarks were recorded. RESULTS: The SSA passed superior to the STSL as a single main trunk (mean diameter at the suprascapular notch: 2.47 ± 0.53 mm). Ninety-five branches were identified (mean 4.75 per shoulder). Of these, 73.69% were in Areas A and B (medial-to-mid fossa). All branches coursed along the deep surface of the supraspinatus muscle, between the muscle belly and the bony fossa floor. No "encircled vessel" pattern was identified on the superficial surface of the supraspinatus muscle. CONCLUSION: SSA branches mainly supply the supraspinatus muscle from its deep surface and are concentrated in the medial-to-mid fossa (Areas A-B, 73.69%). No circumferential superficial vascular network was identified, suggesting that the magnetic resonance imaging "encircled vessel" pattern may reflect an imaging phenomenon rather than a distinct anatomical structure. These deep feeding vessels may be at risk during aggressive dissection along the undersurface of the supraspinatus, with potential implications for muscle viability and intraoperative hemostasis.