Bulletin of the NYU Hospital for Joint Diseases 2011;69(1):17-26
18
Anatomy
The ankle joint is the most congruent in the body. Stabil
-
ity of the ankle is due to bony configuration of the ankle
mortise and talar dome, ligamentous structures, capsule,
syndesmosis, and the crossing tendons. The lateral ankle
ligamentous complex comprises the anterior talofibular
ligament (ATFL), the calcaneofibular ligament (CFL) and
the posterior talofibular ligament (PTFL) (Fig. 1).
The ATFL is the weakest of the lateral ankle ligaments.
It originates 1 cm proximal to the distal tip of the fibula and
inserts on the lateral talar neck just beyond the articular
surface about 18 mm proximal to the tibiotalar joint. It is
contiguous to the ankle joint capsule and has been found to
be a discrete capsular thickening. It measures 6 to 10 mm
in width, 10 mm in length, and 2 mm in thickness.
12,13
The CFL is the only extra-articular ligament within the
lateral complex and originates on the distal tip of the fibula.
It travels in an oblique direction plantarly and posteriorly
towards its calcaneal insertion 13 mm distal to the subtalar
joint. The CFL measures 20 to 25 mm in length and 6 to 8
mm in diameter and crosses both the tibiotalar and subtalar
joints. The CFL also forms the floor of the peroneal tendon
sheath and is larger and stronger than the ATFL.
12,13
The PTFL is the strongest of the lateral ankle ligaments
and is rarely injured in ankle inversion sprains. It originates
10 mm proximal to the distal tip of the fibula and inserts
onto nearly the entire nonarticular portion of the posterior
talus up to the flexor hallucis longus groove. The PTFL is
usually not involved in chronic ankle instability