[Function of the glenohumeral ligaments in active protection of shoulder stability]

We harvested the joint capsule, the glenohumeral ligaments, and the coracohumeral ligaments of 8 fresh formalin-preserved shoulder specimen. We made use of the van Gieson technique and a special silver impregnation for staining peripheral axons according to Nowotny. The ligaments were cut into slices with a thickness of 15 microns. In total we performed 10,000 cuts. We discovered axons in all ligaments. These axons had no relation to vessels or vessel walls. Besides these axonal structures we detected type II mechanoreceptors (Pacini receptor).

The neural structures discovered in the glenohumeral capsule are of clinical importance especially in consideration of the high account of recurrent shoulder dislocation and concomitant Bankart lesions. Receptors located in the glenohumeral ligaments might control the stabilizing shoulder musculature. On this premises, rupture or detachment of these ligaments will lead to a loss of the feedback mechanism.