RESUMEN
To understand the lesion of the terminal branches of posterior interosseous nerve (PIN), an anatomic study was carried out. Thirty adult cadaver arms were dissected and the anatomic pattern of the nerve was documented. The distance between the point at which the nerve divides into branches and the distal edge of the supinator were measured, as well as the length of each nerve branch to its muscle-entering sites. The number of branches innervating each muscle was recorded. It was found that the PIN was branching to multiple short branches and a single deep long branch after leaving the supinator muscle with great morphometric and schematic variances.
Asunto(s)
Brazo/inervación , Músculo Esquelético/inervación , Nervio Radial/anatomía & histología , Adulto , Antropometría , Cadáver , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
The spinoglenoid ligament has been implicated in compression of the suprascapular nerve in cases with isolated atrophy of the infraspinatus muscle. We dissected 32 shoulders of 16 embalmed cadavers. We could detect a spinoglenoid ligament in only 5 shoulders, and it was thin, loose, and weak. Instead of the spinoglenoid ligament, we observed a septum formed by the thickening of the fascial cover of the distal third of the supraspinatus and infraspinatus muscles. It originated from the spinoglenoid notch and extended into the posterior capsule. We named this structure the spinoglenoid septum. The suprascapular nerve passed between the bony margin of the spinoglenoid notch and the medial concave margin of the spinoglenoid septum. This septum may be a cause of dynamic compression of the suprascapular nerve.