Anatomy of the spring ligament.
BACKGROUND
The spring ligament has been reported to be composed of the inferior calcaneonavicular and superomedial calcaneonavicular ligaments. We investigated the lower layer of the spring ligament fibrocartilage complex under the fibrocartilaginous surface, identified three distinct structures, and examined the morphology and running patterns of their fiber bundles.


METHODS
Forty-eight cadaveric feet were examined. After ablation of the ankle joint and extirpation of the talus, the surface cartilage of the spring ligament fibrocartilage complex was carefully removed with forceps, and the length, width, and thickness of the three components of the complex were measured with calipers.


RESULTS
The three components of the spring ligament complex are the superomedial calcaneonavicular ligament, the inferior calcaneonavicular ligament, and a structure that we termed the third ligament, which comprises fibers running from the notch between the calcaneal facets to the navicular tuberosity.


CONCLUSIONS
We demonstrated a third component of the spring ligament; this component runs from the notch between the anterior and middle calcaneal facets to the tubercle of the navicular in the lower layer of the spring ligament complex, lying beneath the cartilaginous surface of the complex.
Taniguchi
Akira
A
Department of Orthopaedic Surgery, Nara Medical University, 840 Shijyocho, Kashihara, Nara 634-8522, Japan. a-tani@naramed-u.ac.jp
Tanaka
Yasuhito
Y
Takakura
Yoshinori
Y
Kadono
Kunihiko
K
Maeda
Manabu
M
Yamamoto
Hiroshi
H
D005528:Foot / Q000033:anatomy & histology*; D006801:Humans; D008023:Ligaments, Articular / Q000033:anatomy & histology*