The trochlea. A study of the anatomy and physiology.

Trochleas obtained from fresh surgical specimens, autopsy material, and cadavers were studied by means of dissection, light microscopy, and electron microscopy (scanning and transmission). A bursa-like structure that has not previously been described lines the inner surface of the cartilagenous trochlea. A fibrillar, vascular sheath surrounds the intratrochlear superior oblique tendon. This portion of the superior oblique tendon consists of discrete fibers with few, interfibrillar connections. Each superior oblique tendon fiber is thought to move through the trochlea by means of a sliding action with the central fibers undergoing the maximum excursion.