Regional variation in fascicular architecture of the suprascapular nerve: implications for suprascapular nerve block techniques

Background The microanatomy of the suprascapular nerve is incompletely described, yet it may be relevant to the safety and performance of regional anesthetic techniques targeting this nerve. We characterized the macroanatomy and microanatomy of the suprascapular nerve across three clinically relevant regions: (1) the anterior cervical course towards the suprascapular notch, (2) the supraspinous fossa and (3) the infraspinous fossa. Methods Three intact suprascapular nerves were dissected along their entire course from three fresh human cadavers. Each nerve underwent gross anatomical assessment, followed by a bloc excision and histologic evaluation to define fascicular architecture, connective-tissue organization and regional structural relationships relevant to procedural targeting. Results Across specimens, the suprascapular nerve showed a proximal-to-distal increase in fascicular complexity. The cervical segment was predominantly monofascicular, with a transition to a more multifascicular organization within the supraspinous and infraspinous fossae. Regional branching patterns and relationships to adjacent vascular and connective tissues were documented and interpreted in the context of commonly performed suprascapular block techniques. Conclusions The suprascapular nerve shows clinically meaningful regional variation in fascicular architecture: a proximal-to-distal transition from predominantly monofascicular to increasingly multifascicular architecture. These findings expand the current anatomical understanding of the nerve and may inform technique selection and future comparative safety studies.