Background: Dysfunction of the distal branch of the suprascapular
nerve has been reported in athletes involved in throwing or overhead sports.
The consistent presence of a dynamic anatomic structure, the spinoglenoid
ligament, overlying the nerve in the spinoglenoid notch may be a contributing
factor to the dysfunction of this nerve. The purpose of this study was to
report the anatomy, morphology, and histological characteristics of the
Methods: The spinoglenoid ligaments of fifty-eight fresh-frozen
cadaver shoulders were dissected to evaluate their anatomic dimensions,
histological characteristics, and relationship to the suprascapular nerve, the
posterior part of the capsule, and the glenoid rim. The spinoglenoid ligament
was harvested, with its insertions on the scapular spine and on the capsule
and glenoid left intact, for the histological analysis.
Results: Dissection revealed that a spinoglenoid ligament was
present in all specimens. The ligament was found to form an irregular
quadrangular shape. On gross examination, the deep fibers of the ligament
extended from the lateral aspect of the scapular spine to the posterior part
of the glenoid and the superficial fibers blended with the posterior aspect of
the shoulder capsule. Histological sections demonstrated Sharpey fibers
inserting into bone at the scapular spine and blending with the posterior
aspect of the shoulder capsule to insert into the posterior surface of the
glenoid, findings that confirmed the ligamentous nature of this structure.
Conclusions: This study revealed the presence of the spinoglenoid
ligament in all of the shoulders that were examined, with some variation in
the size of the ligament.
Clinical Relevance: In this study, we identified a complex,
multilayer, distinct spinoglenoid ligament with superficial and deep
attachments to the glenoid. These findings support a possible relationship
between this ligament and entrapment neuropathy of the distal suprascapular