Cadaveric dissection of 113 shoulders redefining the precise humeral footprints of the supraspinatus and infraspinatus. Challenges the textbook claim that supraspinatus fills the highest impression and infraspinatus is confined to the middle impression. Addresses why infraspinatus atrophy appears even in apparently small, isolated supraspinatus tears.
Gray's Anatomy and most orthopedic textbooks taught that supraspinatus fills the highest impression and infraspinatus fills only the middle impression. This paper proves that is wrong: the infraspinatus curves anteriorly as it extends laterally, occupying roughly half the highest impression.
A tear exposing bone on the highest impression is not an isolated supraspinatus tear. When a patient has infraspinatus atrophy or external rotation weakness with an apparently small cuff tear on MRI, direct infraspinatus tendon involvement is the more likely explanation — not suprascapular neuropathy.
During repair, anchors placed only in the anteromedial highest impression restore the supraspinatus but leave the infraspinatus footprint entirely unaddressed. To restore anatomy, fixation must extend laterally and posteriorly across both the highest and middle impressions.
This paper is the anatomic foundation for why modern double-row constructs extend further laterally than older single-row techniques. The lateral row is largely restoring infraspinatus, not supraspinatus. Use the long thick superior tendinous band of the infraspinatus to identify it intraoperatively when the two tendons appear fused.
Cadaveric dissection of 113 shoulders redefining the precise humeral footprints of the supraspinatus and infraspinatus. Challenges the textbook claim that supraspinatus fills the highest impression and infraspinatus is confined to the middle impression. Addresses why infraspinatus atrophy appears even in apparently small, isolated supraspinatus tears.
Gray's Anatomy and most orthopedic textbooks taught that supraspinatus fills the highest impression and infraspinatus fills only the middle impression. This paper proves that is wrong: the infraspinatus curves anteriorly as it extends laterally, occupying roughly half the highest impression.
A tear exposing bone on the highest impression is not an isolated supraspinatus tear. When a patient has infraspinatus atrophy or external rotation weakness with an apparently small cuff tear on MRI, direct infraspinatus tendon involvement is the more likely explanation — not suprascapular neuropathy.
During repair, anchors placed only in the anteromedial highest impression restore the supraspinatus but leave the infraspinatus footprint entirely unaddressed. To restore anatomy, fixation must extend laterally and posteriorly across both the highest and middle impressions.
This paper is the anatomic foundation for why modern double-row constructs extend further laterally than older single-row techniques. The lateral row is largely restoring infraspinatus, not supraspinatus. Use the long thick superior tendinous band of the infraspinatus to identify it intraoperatively when the two tendons appear fused.