Ankle#Fractures

The ankle region is found at the junction of the leg and the foot. It extends downwards (distally) from the narrowest point of the lower leg and includes the parts of the foot closer to the body (proximal) to the heel and upper surface (dorsum) of the foot.{{rp|768}}

The talocrural joint is the only mortise and tenon joint in the human body,{{cite book|author=Susan Standring|title=Gray's Anatomy E-Book: The Anatomical Basis of Clinical Practice|url=https://books.google.com/books?id=b7FVCgAAQBAJ&pg=1418|date=7 August 2015|publisher=Elsevier Health Sciences|isbn=978-0-7020-6851-5}}{{rp|1418}} the term likening the skeletal structure to the woodworking joint of the same name. The bony architecture of the ankle consists of three bones: the tibia, the fibula, and the talus. The articular surface of the tibia may be referred to as the plafond (French for "ceiling").{{cite book|author=David P. Barei|editor=Robert W. Bucholz|title=Rockwood and Green's Fractures in Adults: Two Volumes Plus Integrated Content Website (Rockwood, Green, and Wilkins' Fractures)|chapter-url=https://books.google.com/books?id=OhVSFNEIanIC&pg=RA1-PA464|date=29 March 2012|publisher=Lippincott Williams & Wilkins|isbn=978-1-4511-6144-1|pages=1928–1971|chapter=56. Pilon Fractures}} The medial malleolus is a bony process extending distally off the medial tibia. The distal-most aspect of the fibula is called the lateral malleolus. Together, the malleoli, along with their supporting ligaments, stabilize the talus underneath the tibia.

Because the motion of the subtalar joint provides a significant contribution to positioning the foot, some authors will describe it as the lower ankle joint, and call the talocrural joint the upper ankle joint.{{cite book|author=Joseph E. Muscolino|title=Kinesiology - E-Book: The Skeletal System and Muscle Function|url=https://books.google.com/books?id=08fjDAAAQBAJ&pg=PA287|date=21 August 2016|publisher=Elsevier Health Sciences|isbn=978-0-323-39935-7|pages=284–292}} Dorsiflexion and Plantarflexion are the movements that take place in the ankle joint. When the foot is plantar flexed, the ankle joint also allows some movements of side to side gliding, rotation, adduction, and abduction.{{Cite web|url=https://www.earthslab.com/anatomy/ankle-joint-talocrural-joint/|title=Ankle Joint|last=Joseph H Volker|website=Earth's Lab|date=2018-08-08}}

The bony arch formed by the tibial plafond and the two malleoli is referred to as the ankle "mortise" (or talar mortise). The mortise is a rectangular socket. The ankle is composed of three joints: the talocrural joint (also called talotibial joint, tibiotalar joint, talar mortise, talar joint), the subtalar joint (also called talocalcaneal), and the Inferior tibiofibular joint. The joint surface of all bones in the ankle is covered with articular cartilage.

The distances between the bones in the ankle are as follows:{{cite journal|last1=Imai|first1=Kan|last2=Ikoma|first2=Kazuya|last3=Kido|first3=Masamitsu|last4=Maki|first4=Masahiro|last5=Fujiwara|first5=Hiroyoshi|last6=Arai|first6=Yuji|last7=Oda|first7=Ryo|last8=Tokunaga|first8=Daisaku|last9=Inoue|first9=Nozomu|last10=Kubo|first10=Toshikazu|title=Joint space width of the tibiotalar joint in the healthy foot|journal=Journal of Foot and Ankle Research|volume=8|issue=1|pages=26|year=2015|issn=1757-1146|doi=10.1186/s13047-015-0086-5|pmid=26146520|pmc=4490633 |doi-access=free }}

• Talus - medial malleolus : 1.70 ± 0.13 mm
• Talus - tibial plafond: 2.04 ± 0.29 mm
• Talus - lateral malleolus: 2.13 ± 0.20 mm

Decreased distances indicate osteoarthritis.

File:919 Ankle Feet Joints.jpg

The ankle joint is bound by the strong deltoid ligament and three lateral ligaments: the anterior talofibular ligament, the posterior talofibular ligament, and the calcaneofibular ligament.

• The deltoid ligament supports the medial side of the joint, and is attached at the medial malleolus of the tibia and connect in four places to the talar shelf of the calcaneus, calcaneonavicular ligament, the navicular tuberosity, and to the medial surface of the talus.
• The anterior and posterior talofibular ligaments support the lateral side of the joint from the lateral malleolus of the fibula to the dorsal and ventral ends of the talus.
• The calcaneofibular ligament is attached at the lateral malleolus and to the lateral surface of the calcaneus.

Though it does not span the ankle joint itself, the syndesmotic ligament makes an important contribution to the stability of the ankle. This ligament spans the syndesmosis, i.e. the articulation between the medial aspect of the distal fibula and the lateral aspect of the distal tibia. An isolated injury to this ligament is often called a high ankle sprain.

The bony architecture of the ankle joint is most stable in dorsiflexion.Gatt, A. and Chockalingam, N., 2011. Clinical Assessment of Ankle Joint DorsiflexionA Review of Measurement Techniques. Journal of the American Podiatric Medical Association, 101(1), pp.59-69.https://doi.org/10.7547/1010059 Thus, a sprained ankle is more likely to occur when the ankle is plantar-flexed,{{Cite web |last=Wong |first=Kevin M. |date=August 2013 |title=Treating Sprained Ankles With Chiropractic Care |url=https://dynamicchiropractic.com/article/56624-treating-sprained-ankles-with-chiropractic-care |url-status=live |website=Dynamic Chiropractic}} as ligamentous support is more important in this position. The classic ankle sprain involves the anterior talofibular ligament (ATFL), which is also the most commonly injured ligament during inversion sprains. Another ligament that can be injured in a severe ankle sprain is the calcaneofibular ligament.

A number of tendons pass through the ankle region. Bands of connective tissue called retinacula (singular: retinaculum) allow the tendons to exert force across the angle between the leg and foot without lifting away from the angle, a process called bowstringing.

The superior extensor retinaculum of foot extends between the anterior (forward) surfaces of the tibia and fibula near their lower (distal) ends. It contains the anterior tibial artery and vein and the tendons of the tibialis anterior muscle within its tendon sheath and the unsheathed tendons of extensor hallucis longus and extensor digitorum longus muscles. The deep peroneal nerve passes under the retinaculum while the superficial peroneal nerve is outside of it. The inferior extensor retinaculum of foot is a Y-shaped structure. Its lateral attachment is on the calcaneus, and the band travels towards the anterior tibia where it is attached and blends with the superior extensor retinaculum. Along with that course, the band divides and another segment attaches to the plantar aponeurosis. The tendons which pass through the superior extensor retinaculum are all sheathed along their paths through the inferior extensor retinaculum and the tendon of the fibularis tertius muscle is also contained within the retinaculum.

The flexor retinaculum of foot extends from the medial malleolus to the medical process of the calcaneus, and the following structures in order from medial to lateral: the tendon of the tibialis posterior muscle, the tendon of the flexor digitorum longus muscle, the posterior tibial artery and vein, the tibial nerve, and the tendon of the flexor hallucis longus muscle.

The fibular retinacula hold the tendons of the fibularis longus and fibularis brevis along the lateral aspect of the ankle region. The superior fibular retinaculum extends from the deep transverse fascia of the leg and lateral malleolus to calcaneus. The inferior fibular retinaculum is a continuous extension from the inferior extensor retinaculum to the calcaneus.{{rp|1418–9}}

Mechanoreceptors of the ankle send proprioceptive sensory input to the central nervous system (CNS).{{cite journal |pmid=7706334 |year=1995 |last1=Michelson |first1=J. D. |title=Mechanoreceptors in human ankle ligaments |journal=The Journal of Bone and Joint Surgery. British Volume |volume=77 |issue=2 |pages=219–24 |last2=Hutchins |first2=C |doi=10.1302/0301-620X.77B2.7706334 |doi-access=free }} Muscle spindles are thought to be the main type of mechanoreceptor responsible for proprioceptive attributes from the ankle.{{cite journal |pmid=9554026 |year=1998 |last1=Lephart |first1=S. M. |title=Proprioception of the ankle and knee |journal=Sports Medicine |volume=25 |issue=3 |pages=149–55 |last2=Pincivero |first2=D. M. |last3=Rozzi |first3=S. L. |doi=10.2165/00007256-199825030-00002|s2cid=13099542 }} The muscle spindle gives feedback to the CNS system on the current length of the muscle it innervates and to any change in length that occurs.

It was hypothesized that muscle spindle feedback from the ankle dorsiflexors played the most substantial role in proprioception relative to other muscular receptors that cross at the ankle joint. However, due to the multi-planar range of motion at the ankle joint there is not one group of muscles that is responsible for this.{{cite journal |pmid=12677332 |year=2003 |last1=Ribot-Ciscar |first1=E |title=Proprioceptive population coding of limb position in humans |journal=Experimental Brain Research |volume=149 |issue=4 |pages=512–9 |last2=Bergenheim |first2=M |last3=Albert |first3=F |last4=Roll |first4=J. P. |doi=10.1007/s00221-003-1384-x |s2cid=14626459 }} This helps to explain the relationship between the ankle and balance.

In 2011, a relationship between proprioception of the ankle and balance performance was seen in the CNS. This was done by using a fMRI machine in order to see the changes in brain activity when the receptors of the ankle are stimulated.{{cite journal |doi=10.1523/JNEUROSCI.4159-11.2011 |pmid=22072686 |pmc=6633212 |title=Brain Activity during Ankle Proprioceptive Stimulation Predicts Balance Performance in Young and Older Adults |journal=Journal of Neuroscience |volume=31 |issue=45 |pages=16344–52 |year=2011 |last1=Goble |first1=D. J. |last2=Coxon |first2=J. P. |last3=Van Impe |first3=A. |last4=Geurts |first4=M. |last5=Doumas |first5=M. |last6=Wenderoth |first6=N. |last7=Swinnen |first7=S. P. }} This implicates the ankle directly with the ability to balance. Further research is needed in order to see to what extent does the ankle affect balance.

Historically, the role of the ankle in locomotion has been discussed by Aristotle and Leonardo da Vinci. There is no question that ankle push-off is a significant force in human gait, but how much energy is used in leg swing as opposed to advancing the whole-body center of mass is not clear.{{cite journal|last1=Zelik|first1=Karl E.|last2=Adamczyk|first2=Peter G.|title=A unified perspective on ankle push-off in human walking|journal=The Journal of Experimental Biology|volume=219|issue=23|year=2016|pages=3676–3683|issn=0022-0949|doi=10.1242/jeb.140376|pmid=27903626|pmc=5201006|bibcode=2016JExpB.219.3676Z }}

File:Ankle sprain -- Smart-Servier (cropped).jpg

Of all major joints, the ankle is the most commonly injured. If the outside surface of the foot is twisted under the leg during weight bearing, the lateral ligament, especially the anterior talofibular portion, is subject to tearing (a sprain) as it is weaker than the medial ligament and it resists inward rotation of the talocrural joint.{{cite book | last=Moore | first=Keith | title=Clinically oriented anatomy | publisher=Wolters Kluwer | location=Philadelphia | year=2018 | isbn=978-1-4963-4721-3}}{{rp|825}}

{{Excerpt|Ankle fracture}}

The initial evaluation of suspected ankle pathology is usually by projectional radiography ("X-ray").

File:X-ray of frontal tibiotalar surface angle (TTS).jpg

Varus or valgus deformity, if suspected, can be measured with the frontal tibiotalar surface angle (TTS), formed by the mid-longitudinal tibial axis (such as through a line bisecting the tibia at 8 and 13 cm above the tibial plafond) and the talar surface.{{cite journal|last1=Nosewicz|first1=Tomasz L.|last2=Knupp|first2=Markus|last3=Bolliger|first3=Lilianna|last4=Hintermann|first4=Beat|title=The reliability and validity of radiographic measurements for determining the three-dimensional position of the talus in varus and valgus osteoarthritic ankles|journal=Skeletal Radiology|volume=41|issue=12|year=2012|pages=1567–1573|issn=0364-2348|doi=10.1007/s00256-012-1421-6|pmid=22609967|pmc=3478506}} An angle of less than 84 degrees is regarded as talipes varus, and an angle of more than 94 degrees is regarded as talipes valgus.[https://pure.uva.nl/ws/files/28148791/Chapter_5.pdf Chapter 5 - Radiological morphology of peritalar instability in varus and valgus tilted ankles], in: {{cite book|author=T.L. Nosewicz|title=Acute and chronic aspects of hindfoot trauma|date=2018-09-25|isbn=9789463750479|publisher=University of Amsterdam, Faculty of Medicine (AMC-UvA)}}

For ligamentous injury, there are three main landmarks on X-rays: The first is the tibiofibular clear space, the horizontal distance from the lateral border of the posterior tibial malleolus to the medial border of the fibula, with greater than 5 mm being abnormal. The second is tibiofibular overlap, the horizontal distance between the medial border of the fibula and the lateral border of the anterior tibial prominence, with less than 10 mm being abnormal. The final measurement is the medial clear space, the distance between the lateral aspect of the medial malleolus and the medial border of the talus at the level of the talar dome, with a measurement greater than 4 mm being abnormal. Loss of any of these normal anatomic spaces can indirectly reflect ligamentous injury or occult fracture, and can be followed by MRI or CT.{{cite journal|last1=Evans|first1=JM|last2=Schucany|first2=WG|title=Radiological evaluation of a high ankle sprain.|journal=Proceedings (Baylor University. Medical Center)|date=October 2006|volume=19|issue=4|pages=402–5|pmid=17106502|pmc=1618742|doi=10.1080/08998280.2006.11928206}}

Clubfoot or talipes equinovarus, which occurs in one to two of every 1,000 live births, involves multiple abnormalities of the foot.{{cite journal| author=Gore AI, Spencer JP| title=The newborn foot. | journal=Am Fam Physician | year= 2004 | volume= 69 | issue= 4 | pages= 865–72 | pmid=14989573 | url=https://pubmed.ncbi.nlm.nih.gov/14989573}} Equinus refers to the downard deflection of the ankle, and is named for the walking on the toes in the manner of a horse.{{cite book|last1=Källén|first1=Bengt|title=Epidemiology of Human Congenital Malformations|chapter=Pes Equinovarus|year=2014|pages=111–113|doi=10.1007/978-3-319-01472-2_22|isbn=978-3-319-01471-5}} This does not occur because it is accompanied by an inward rotation of the foot (varus deformity), which untreated, results in walking on the sides of the feet. Treatment may involve manipulation and casting or surgery.

Ankle joint equinus, normally in adults, relates to restricted ankle joint range of motion(ROM).{{cite journal |last1=Gatt |first1=Alfred |last2=Chockalingam |first2=Nachiappan |title=Clinical Assessment of Ankle Joint Dorsiflexion |journal=Journal of the American Podiatric Medical Association |date=2011-01-01 |volume=101 |issue=1 |pages=59–69 |doi=10.7547/1010059|pmid=21242472 }} Calf muscle stretching exercises are normally helpful to increase the ankle joint dorsiflexion and used to manage clinical symptoms resulting from ankle equinus.{{cite journal |last1=Macklin |first1=Katriona |last2=Healy |first2=Aoife |last3=Chockalingam |first3=Nachiappan |title=The effect of calf muscle stretching exercises on ankle joint dorsiflexion and dynamic foot pressures, force and related temporal parameters |journal=The Foot |date=March 2012 |volume=22 |issue=1 |pages=10–17 |doi=10.1016/j.foot.2011.09.001|pmid=21944945 |url=http://eprints.staffs.ac.uk/436/1/Macklin_Final.docx }}

Occasionally a human ankle has a ball-and-socket ankle joint and fusion of the talo-navicular joint.{{Cite journal | title=Ball-and-socket ankle joint: Anatomical and kinematic analysis of the hindfoot| journal=Journal of Pediatric Orthopedics| volume=4| issue=5| pages=564–568| date=September 1984| last1=Ono| first1=K.| last2=Nakamura| first2=M.| last3=Kurata| first3=Y.| last4=Hiroshima| first4=K.| doi=10.1097/01241398-198409000-00007|pmid = 6490876}}

The word ankle or ancle is common, in various forms, to Germanic languages, probably connected in origin with the Latin {{lang|la|angulus}}, or Greek {{lang|el|αγκυλος}}, meaning bent.{{Cite EB1911|wstitle=Ankle|volume=2|page=58}}

{{anchor|Other animals}}

It has been suggested that dexterous control of toes has been lost in favour of a more precise voluntary control of the ankle joint.{{cite journal |doi=10.1007/bf00229889 |pmid=1644127 |title=Corticospinal projections to lower limb motoneurons in man |journal=Experimental Brain Research |volume=89 |issue=3 |pages=649–54 |year=1992 |last1=Brouwer |first1=B. |last2=Ashby |first2=P. |s2cid=24650165 }}

• Foot
• Leg

{{Reflist}}

{{Anatomy-terms}}

• {{cite book |author1=Anderson, Stephen A. |author2=Calais-Germain, Blandine |title=Anatomy of Movement |publisher=Eastland Press |location=Chicago |year=1993 |isbn=978-0-939616-17-6 }}
• {{cite book |author1=McKinley, Michael P. |author2=Martini, Frederic |author3=Timmons, Michael J. |title=Human Anatomy |publisher=Prentice Hall |location=Englewood Cliffs, N.J |year=2000 |isbn=978-0-13-010011-5 }}
• {{cite book |author =Marieb, Elaine Nicpon |title=Essentials of Human Anatomy and Physiology |publisher=Benjamin Cummings |location=San Francisco |year=2000 |isbn=978-0-8053-4940-5 }}

File:Slide3Bubu.JPG|Dorsum of Foot. Ankle joint. Deep dissection.

File:Slide2bubu.JPG|Dorsum of Foot. Ankle joint. Deep dissection.

File:Slide2tat.JPG|Ankle joint. Deep dissection. Anterior view.

File:Slide2coco.JPG|Dorsum of Foot. Ankle joint. Deep dissection.

{{Commons category|Ankles}}

{{Wiktionary}}

• {{cite web

|url = http://www.podiatrytoday.com/article/4627

|title = How To Diagnose Lateral Ankle Injuries

|first1 = Remy

|last1 = Ardizzone

|first2 = Ronald L.

|last2 = Valmassy

|publisher = Podiatry Today

|date = October 2005

|access-date = September 21, 2017

|archive-url = https://web.archive.org/web/20100104133833/http://podiatrytoday.com/article/4627

|archive-date = January 4, 2010

|url-status = dead

}}

• {{cite web

| url = http://orthoinfo.aaos.org/menus/foot.cfm

| title = Foot & Ankle

| editor-first = Steven L.| editor-last = Haddad

| publisher = Your orthopaedic connection (American Academy of Orthopaedic Surgeons)

| access-date = September 21, 2017

| archive-url = https://web.archive.org/web/20100323145859/http://orthoinfo.aaos.org/menus/foot.cfm| archive-date= 23 March 2010 | url-status= live}}

{{Human anatomical features}}

{{Joints of lower limbs}}

{{Authority control}}

Category:Foot

*Ankle

Category:Lower limb anatomy