[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Anatomy](https://durgical.com/en/anatomy/) › [Lower limb](https://durgical.com/en/anatomy/region/lower-limb/) › Spring ligament [Joints and ligaments](https://durgical.com/en/anatomy/system/joints-and-ligaments/) · [Lower limb](https://durgical.com/en/anatomy/region/lower-limb/) # Spring ligament The spring ligament holds up the head of the talus from below like a sling; it is a key support of the inner arch of the foot. Official name: Plantar calcaneonavicular ligament [See in 3D →](https://durgical.app/?from=durgipedia&lang=en#region=lower_limb&select=spring_lig&side=r) Opens in the Durgical app, no sign-up needed. ## What it is A thick ligament under the inner midfoot, from the heel bone to the navicular. It cradles the head of the talus like a sling. ## What it does Holds up the head of the talus and supports the inner arch together with the tibialis posterior tendon. ## Key points - A complex of three parts (superomedial, medioplantar oblique, inferoplantar); the large superomedial part cradles the talar head and joins the [deltoid ligament](https://durgical.com/en/anatomy/medial-collateral-ligament-of-ankle/) - Despite its name it has little elastic tissue; its upper surface is fibrocartilage that articulates with the talar head - Works as a team with the tibialis posterior tendon: when the tendon fails, the ligament stretches and the talar head sags (planovalgus foot) ## Key facts **Attaches** Sustentaculum tali to plantar surface of navicular (plantar calcaneonavicular ligament) **Function** Supports head of talus; key support of medial longitudinal arch; tibialis posterior tendon supports it **Tight in** Weight-bearing (arch loaded); eversion ## Relations **Above** Head of the [talus](https://durgical.com/en/anatomy/talus/), which rests on its fibrocartilage surface as part of the talocalcaneonavicular joint **Medial** [Tibialis posterior tendon](https://durgical.com/en/anatomy/tendon-of-tibialis-posterior/), which runs along its medial and plantar side on the way to the [navicular](https://durgical.com/en/anatomy/navicular-bone/) tuberosity **Lateral** Calcaneonavicular limb of the [bifurcate ligament](https://durgical.com/en/anatomy/bifurcate-ligament/); together they complete the socket for the talar head (acetabulum pedis) **Below** [Flexor hallucis longus](https://durgical.com/en/anatomy/flexor-hallucis-longus/) tendon under the sustentaculum tali and, more superficially, the [abductor hallucis](https://durgical.com/en/anatomy/abductor-hallucis/) and [medial plantar nerve](https://durgical.com/en/anatomy/medial-plantar-nerve/) ## How to find it Not palpable directly: it lies in the gap between the sustentaculum tali (a finger's breadth below the tip of the medial malleolus) and the navicular tuberosity, under the tibialis posterior tendon. ## Examination - Single-limb heel rise: inability to rise, or a heel that fails to swing into varus, suggests [tibialis posterior](https://durgical.com/en/anatomy/tibialis-posterior-muscle/) and spring ligament failure - 'Too many toes' sign: seen from behind, more lateral toes show on the affected side because the forefoot has drifted into abduction ## On imaging Standing lateral X-ray: the line through the talus and [first metatarsal](https://durgical.com/en/anatomy/first/) (Meary's angle), normally straight, sags toward the sole; standing AP: the talar head is uncovered by the navicular. MRI or ultrasound shows thinning, thickening or tears of the superomedial band. ## Common problems - Adult-acquired flatfoot: when the tibialis posterior tendon weakens, this ligament stretches or tears and the arch slowly collapses. - Symptoms: pain and swelling on the inner ankle and arch, and the foot rolling inward. ## How it is diagnosed A physical exam, including standing on tiptoe on one foot (single heel rise). Standing X-rays; MRI or ultrasound. ## Treatment - Early stages: a brace or arch supports, and physical therapy to strengthen the tibialis posterior. - Surgery: repair or reconstruction of the ligament, often with a tendon transfer and bone cuts to realign the foot. A graft from the patient or a donor may be used. - Advanced, stiff flatfoot: fusion of the joints of the back of the foot. ## Clinical notes - As the support fails, the talus plantarflexes and turns inward, the heel drifts into valgus and the forefoot into abduction - Spring ligament repair or reconstruction is often added to tendon transfer and calcaneal osteotomy in flexible flatfoot surgery ## Related conditions - [Flatfoot (pes planus)](https://durgical.com/en/conditions/flatfoot/) ## Test yourself Think of the answer, then tap the question to see it. ## What are the attachments of the spring (plantar calcaneonavicular) ligament? From the sustentaculum tali to the plantar surface of the navicular. ## What does the spring ligament support? The head of the talus, which rests on its fibrocartilage surface; it is a key support of the medial longitudinal arch. ## Which tendon works with the spring ligament, and what happens when that tendon fails? The tibialis posterior; the ligament stretches, the talar head sags and a planovalgus (adult-acquired flat) foot develops. ## What is the 'too many toes' sign? Seen from behind, more lateral toes show on the affected side because the forefoot has drifted into abduction. [Add to my cards (4)](https://durgical.app/estudiar/?add=/en/anatomy/plantar-calcaneonavicular-ligament/) Educational information, not medical advice. For any symptom, see a health professional. ## Its names **Official Latin (TA2)** ligamentum calcaneonaviculare plantare TA2 1937 **Official Spanish (DeCS)** Ligamento calcaneonavicular plantar **English (TA2)** Plantar calcaneonavicular ligament **Also called** ligamentum calcaneonaviculare ## Related - [Deltoid ligament](https://durgical.com/en/anatomy/medial-collateral-ligament-of-ankle/) - [Tibialis posterior tendon](https://durgical.com/en/anatomy/tendon-of-tibialis-posterior/) - [Navicular](https://durgical.com/en/anatomy/navicular-bone/) - [Calcaneus](https://durgical.com/en/anatomy/calcaneus/) - [Talus](https://durgical.com/en/anatomy/talus/) Sources: Terminologia Anatomica (TA2); [Anatomy, Bony Pelvis and Lower Limb: Medial Longitudinal Arch of the Foot](https://www.ncbi.nlm.nih.gov/books/NBK562289/); [Anatomy, Bony Pelvis and Lower Limb, Foot Joints](https://www.ncbi.nlm.nih.gov/books/NBK536941/). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/anatomy/plantar-calcaneonavicular-ligament/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/anatomy/plantar-calcaneonavicular-ligament/