annular ligament

:  a ringlike ligament or band of fibrous tissue encircling a part:a:  any of the transverse bands holding in place the extensor and flexor tendons of the wrist and ankleb:  a strong band of fibers surrounding the head of the radius and retaining it in the radial notch of the ulna—called also orbicular ligamentc:  any of several strengthening bands of the tendon sheaths of the digitsd:  a ring attaching the base of the stapes to the oval window