Lower Extremity Anatomy for NBPME Part 1 Exam PDF

LOWER EXTREMITY ANATOMY R FOR NBPME PART I EXAM BY DR. DANIEL BAREITHER PART 1 - OSTEOLOGY (BONY LANDMARKS AND ASSOCIA STRUCTURES AND OSSIFICATIO QUESTION AREAS FOOT LEG THIGH AND GLUTEAL  Part 1...

LOWER EXTREMITY ANATOMY R FOR NBPME PART I EXAM BY DR. DANIEL BAREITHER PART 1 - OSTEOLOGY (BONY LANDMARKS AND ASSOCIA STRUCTURES AND OSSIFICATIO QUESTION AREAS FOOT LEG THIGH AND GLUTEAL  Part 1 BONES OF THE FOOT ¥/ In the anatomical position: Ð/ The foot is at a right angle to the leg. ¥/ Anatomical division of the foot: Ð/ Tarsus: ¥/ Calcaneus, talus, cuboid, navicular and three cuneiforms. Ð/ Metatarsus: ¥/ Five metatarsal bones. Ð/ Phalanges: ¥/ Total of fourteen bones that make up the toes. Ð/ Sesamoids: ¥/ Two bones located in the tendons of flexor hallucis brevis.  BONES OF THE FOOT ¥/ Biomechanical division: Ð/ Medial portion or column: ¥/ Calcaneus; talus; navicular; three cuneiforms; first, second, and third metatarsals with their respective phalanges; and the constant sesamoids. Ð/ Lateral portion or column: ¥/ Calcaneus; cuboid; and fourth and fifth metatarsals with their respective phalanges.  BONES OF THE FOOT ¥/ Surgical division (forefoot, midfoot, and rearfoot): Ð/ Forefoot (anterior unit): ¥/ Metatarsals (five), phalanges (fourteen), and sesamoids (two). Ð/ Midfoot (middle unit or Forefoot lesser tarsus): ¥/ Navicular, cuboid, and the three cuneiforms. Tarsometatarsa Joint (Lisfrancʼs Ð/ Rearfoot (posterior Midfoot unit, hindfoot or Midtarsal Join greater tarsus): ¥/ Calcaneus and talus Rearfoot ¥/ Anatomical note: The joint between the rearfoot and midfoot is the midtarsal joint (transverse tarsal joint or Chopartʼs joint) and the joint between the forefoot and midfoot is Lisfrancʼs joint (tarsometatarsal joint). Sobotta:Anatomy © Elsevier  TALUS ¥/ Second largest tarsal bone. ¥/ Located at the superior and posterior aspect of the foot. ¥/ Only tarsal bone that does not have any muscular attachments. ¥/ Articulates with: Ð/ Tibia and fibula (ankle joint). Ð/ Calcaneus (subtalar joint). Ð/ Navicular (talonavicular portion of midtarsal joint). ¥/ Composed of: Ð/ Body Ð/ Neck Ð/ Head ¥/ Body of the talus: Ð/ Cuboid in shape. Ð/ Located at posterior aspect of talus. Ð/ Has five surfaces: ¥/ Superior ¥/ Inferior ¥/ Medial ¥/ Lateral ¥/ Posterior Sobotta:Anatomy © Elsevier GmbH Germany  TALUS ¥/ Superior surface of body: Ð/ Referred to as the trochlea. Ð/ Articular surface for the distal extremity of the tibia (tibial plafond). Ð/ Wider anteriorly than posteriorly. Ð/ Small triangular facet at posterolateral aspect for inferior transverse ligament of tibiofibular syndesmosis. ¥/ Clinical note: Shape of trochlea is important in ankle joint stability. ¥/ Inferior surface of body: Ð/ Posterior calcaneal articular surface for the posterior articular facet on the superior surface of the calcaneus.  TALUS ¥/ Medial surface of body: Ð/ Articular facet at superior aspect for the medial malleolus. ¥/ Lateral surface of body: Ð/ Articular facet for the lateral malleolus. Ð/ Roughened apex of this surface is called the lateral process of the talus. ¥/ Clinical note: Lateral process can be important in calcaneal fractures especially in the area of the neutral triangle.  TALUS ¥/ Posterior surface of body: Ð/ Ledge of bone that projects posteriorly called the posterior process. Ð/ Divided into a medial and lateral tubercle by a groove for the tendon of flexor hallucis longus. Ð/ Lateral tubercle is the larger of the two. ¥/ Clinical note: Accessory bone located posterior to the lateral tubercle is known as the os trigonum. ¥/ Clinical note: An enlarged lateral tubercle is called a Steidaʼs process or Trigonal process. ¥/ Neck of the talus: Ð/ Constricted and directed anteriorly and medially from the body. Ð/ Has numerous nutrient foramina for vascular supply to the talus. Ð/ Groove on inferior surface is the sulcus tali. Ð/ Sulcus tali courses in a anterolateral direction, opens into the sinus tarsi of the talus, and combines with the calcaneal sulcus to form the tarsal canal.  TALUS ¥/ Head of the talus: Ð/ Articular surface for the navicular. Ð/ Three facets on inferior surface of the head: ¥/ Middle calcaneal articular facet. ¥/ Anterior calcaneal articular facet. ¥/ Facet for spring ligament. Sobotta:Anatomy © Elsevier GmbH Germany  CALCANEUS ¥/ Largest bone of the foot. ¥/ Also referred to as the heel bone. ¥/ A portion of the calcaneus projects posteriorly from the ankle joint to create a lever. ¥/ Articulates with: Ð/ Talus (subtalar joint) Ð/ Cuboid (calcaneocuboid portion of midtarsal joint) ¥/ Has six surfaces: posterior, anterior, medial, lateral, superior, and inferior. Ð/ Clinical note: The neutral triangle of the calcaneus is an area of sparse bony trabeculae. Sobotta:Anatomy © Elsevier GmbH Germany  CALCANEUS ¥/ Superior surface: Ð/ Contains three facets: ¥/ Posterior ¥/ Middle ¥/ Anterior Ð/ Calcaneal sulcus is located between the posterior and middle facets. Ð/ Calcaneal sulcus courses anterolaterally, opens into the sinus tarsi of the calcaneus, and unites with the sulcus tali to form the tarsal canal. Ð/ The middle facet is on the superior surface of the sustentaculum tali.  CALCANEUS ¥/ Clinical note: Hokeʼs Tonsil is the tissue located in the sinus tarsi. ¥/ Clinical note: The anterior facet and the region below it are termed the anterior process of the calcaneus which may be fractured. ¥/ Clinical note: Bohlerʼs angle or tuberosity joint angle is an important measurement in calcaneal fractures. The angle is between a line connecting the superior aspect of the posterior facet with the most superior point of the posterior surface and a line connecting the superior aspect of the posterior facet and the most superior point of the anterior surface.  CALCANEUS ¥/ Inferior surface: Ð/ Calcaneal tuberosity composed of a medial and lateral tubercle with a groove between. Ð/ The medial process is much larger than the lateral. Ð/ At the anterior aspect is a tubercle with an transverse groove anterior to it. ¥/ Clinical note: A heel spur (infracalcaneal exostosis) is a bony projection from the anterior aspect of the medial process of the calcaneal tuberosity. ¥/ Clinical note: Plantar fascitis is an inflammation of the attachment of the central portion of the plantar aponeurosis to the medial process of the calcaneal tuberosity.  CALCANEUS ¥/ Medial surface: Ð/ Concave superior to inferior and anterior to posterior. Ð/ Sustentaculum tali located at the anterosuperior aspect. Ð/ Groove for tendon of flexor hallucis longus on inferior aspect of sustentaculum tali, and the middle articular facet is located on the superior aspect. ¥/ Lateral surface: Ð/ Retrotrochlear eminence located near the center. Ð/ Peroneal tubercle (trochlear process or peroneal trochlea) located anterior to the eminence. Ð/ Groove superior to peroneal tubercle for tendon of peroneus brevis and groove inferior for tendon of peroneus longus. Ð/ Peroneal spine located superior to retrotrochlear eminence for calcaneofibular ligament.  CALCANEUS ¥/ Anterior surface: Ð/ Articular surface (saddle-shaped) for the cuboid. ¥/ Posterior surface: Ð/ Upper one-third is smooth for a bursa (subtendinous or retrocalcaneal) for the tendo calcaneus. Ð/ Middle one-third is rough for attachment of tendo calcaneus and the tendon of plantaris. Ð/ Lower one-third is rough and part of the weight bearing portion of the calcaneus.  CUBOID ¥/ Pyramidal in shape. ¥/ Articulates with: Ð/ Calcaneus (calcaneocuboid portion of midtarsal joint). Ð/ Fourth and fifth metatarsal bases (tarsometatarsal joint or Lisfrancʼs joint). Ð/ Third cuneiform (cuneocuboid joint). Ð/ Occasionally with the navicular (cuboideonavicular joint). ¥/ Has six surfaces (posterior, anterior, medial, lateral, superior, and inferior). Sobotta:Anatomy © Elsevier GmbH  CUBOID ¥/ Superior surface ¥/ Inferior surface: Ð/ Peroneal sulcus or groove for tendon of peroneus longus at anterior aspect. Ð/ Peroneal ridge forms posterior boundary of the groove and the ridge ends laterally in a tuberosity. Ð/ Beak-like process formed at posteromedial aspect called the beak of the cuboid (coronoid process or calcaneal process of the cuboid).  CUBOID ¥/ Medial surface: Ð/ Articular facet near the center for the third cuneiform. Ð/ Occasional articular facet for the navicular located posterior to facet for third cuneiform. ¥/ Lateral surface: Ð/ Has peroneal notch which is the beginning of the peroneal sulcus. Ð/ Peroneal notch is bounded posteriorly by a tuberosity which sometimes has a facet if an accessory bone known as the os peroneum is present. ¥/ Clinical note: The os peroneum is an accessory sesamoid in the tendon of peroneus longus.  CUBOID ¥/ Anterior surface: Ð/ Articular surface divided by a ridge into two facets. Ð/ Medial facet is for the base of the fourth metatarsal. Ð/ Lateral facet is for base of the fifth metatarsal. ¥/ Posterior surface: Ð/ Articular surface (saddle-shaped) for the calcaneus. Ð/ The medial inferior angle of this surface supports the anterior aspect of the calcaneus.  NAVICULAR (SCAPHOID) ¥/ Located on the medial side of the foot. ¥/ Articulates with: Ð/ Head of the talus (talonavicular portion of midtarsal joint). Ð/ The three cuneiforms (cuneonavicular joints). Ð/ Occasionally with the cuboid (cuboideonavicular joint). Ð/ On rare occasion with the calcaneus (calcaneonavicular joint). ¥/ Has six surfaces (posterior, anterior, medial, lateral, superior, and inferior). Sobotta:Anatomy © Elsevier G  NAVICULAR ¥/ Superior surface: ¥/ Inferior surface: Ð/ Groove for the plantar component of the tendon of tibialis posterior separates this surface from the tuberosity of the navicular. ¥/ Medial surface: Ð/ Tuberosity of the navicular which is the insertion of the main component of the tendon of tibialis posterior ¥/ Clinical note: Os tibiale externum is an accessory ossicle located posterior to the tuberosity, and sesamoid in the tendon of tibialis posterior is an accessory sesamoid located in the tendon of tibialis posterior before it divides into main, plantar, and recurrent portions. ¥/ Clinical note: Some clinicians refer to the os tibiale externum as a prehallux.  NAVICULAR ¥/ Lateral surface: Ð/ Occasional facet for articulation with the cuboid. ¥/ Anterior surface: Ð/ Articular surface that is divided into three facets for articulation with the three cuneiforms. ¥/ Posterior surface: Ð/ Articular surface for the head of the talus.  CUNEIFORMS ¥/ Triangular (wedge) in shape. ¥/ Three in number. ¥/ First or medial cuneiform sets in the foot apex up and base down. ¥/ Second, middle or intermediate cuneiform sets in the foot base up and apex down. ¥/ Third or lateral cuneiform sets in the foot base up and apex down.  FIRST OR MEDIAL CUNEIFORM ¥/ Largest ¥/ Articulates with: Ð/ Navicular (cuneonavicular joint). Ð/ First metatarsal base (tarsometatarsal joint). Ð/ Second cuneiform (intercuneiform joint). Ð/ Second metatarsal base (tarsometatarsal joint). ¥/ Has six surfaces (posterior, anterior, medial, lateral, superior, and inferior). Ð/ Clinical note: The first cuneiform is part of the first ray. Sobotta:Anatomy © Elsevier G  FIRST OR MEDIAL CUNEIFORM ¥/ Superior surface: ¥/ Inferior surface: Ð/ Base of the bone. Ð/ Tuberosity at anterior aspect for attachment of tendons of tibialis anterior and peroneus longus. Ð/ Tuberosity at posterior aspect for attachment of main portion of tendon of tibialis posterior.  FIRST OR MEDIAL CUNEIFORM ¥/ Medial surface: Ð/ Smooth oval impression at anteroinferior aspect for the tendon of tibialis anterior which sometimes contains an accessory sesamoid. ¥/ Lateral surface: Ð/ L-shaped articular facet for the second cuneiform at posterior and superior borders. Ð/ Oval articular facet at anterosuperior aspect for the base of second metatarsal.  FIRST OR MEDIAL CUNEIFORM ¥/ Anterior surface: Ð/ Kidney-shaped articular surface with the notch located laterally for the base of the first metatarsal. ¥/ Posterior surface: Ð/ Triangular- shaped articular surface with the apex superior for the medial facet of the navicular.  SECOND OR INTERMEDIATE CUNEI ¥/ Smallest ¥/ Articulates with: Ð/ Navicular (cuneonavicular joint). Ð/ Second metatarsal base (tarsometatarsal joint). Ð/ First cuneiform (intercuneiform joint). Ð/ Third cuneiform (intercuneiform joint). ¥/ Has six surfaces (posterior, anterior, medial, lateral, superior, and inferior). Sobotta:Anatomy © Elsevier G  SECOND OR INTERMEDIATE CUNEI ¥/ Superior surface ¥/ Inferior surface ¥/ Medial surface: Ð/ L-shaped articular facet along the posterior and superior borders for the first cuneiform. ¥/ Lateral surface: Ð/ Elongated articular facet along the posterior border for the third cuneiform.  SECOND OR INTERMEDIATE CUNEI ¥/ Anterior surface: Ð/ Triangular- shaped articular surface with the apex inferior for the base of the second metatarsal. ¥/ Posterior surface: Ð/ Triangular- shaped articular surface with the apex inferior for the middle facet of the navicular.  THIRD OR LATERAL CUNEIFOR ¥/ Intermediate size. ¥/ Articulates with: Ð/ Navicular (cuneonavicular joint). Ð/ Third metatarsal base (tarsometatarsal joint). Ð/ Second cuneiform (intercuneiform joint). Ð/ Second metatarsal base (tarsometatarsal joint). Ð/ Cuboid (cuneocuboid joint). Ð/ Fourth metatarsal base (tarsometatarsal joint) ¥/ Has six surfaces (posterior, anterior, medial, lateral, superior, and inferior). Sobotta:Anatomy © Elsevier G  THIRD OR LATERAL CUNEIFOR ¥/ Superior surface ¥/ Inferior surface ¥/ Medial surface: Ð/ Elongated articular facet for the second cuneiform. Ð/ Two small facets separated by a rough area at the anterior border for the base of the second metatarsal. ¥/ Lateral surface: Ð/ Oval articular facet at the posterosuperior aspect for the cuboid. Ð/ Small articular facet at the anterosuperior aspect for the base of the fourth metatarsal.  THIRD OR LATERAL CUNEIFOR ¥/ Anterior surface: Ð/ Triangular- shaped articular surface with the apex inferior for the base of the third metatarsal. ¥/ Posterior surface: Ð/ Most of this surface is an articular facet that is oval- triangular in shape for the lateral facet of the navicular. Ð/ Small rough area below the facet for attachment of ligaments.  METATARSALS ¥/ Miniature long bones with a base, shaft and a head. ¥/ Numbered 1 to 5 from medial to lateral. ¥/ Disarticulated length is: 2>3>5>4>1 ¥/ Distal projection in the articulated foot: 2>3>1>4>5 (major variation is 2>1>3>4>5). ¥/ Common characteristics: Ð/ Shaft: ¥/ Tapers from base to head. ¥/ Concave plantarly. Ð/ Base: ¥/ Articulate with the tarsus, and the lesser metatarsals articulate with each other. ¥/ Have five surfaces Ð posterior, medial, lateral, superior, and inferior. Sobotta:Anatomy © Elsevier G  METATARSALS ¥/ Common characteristics: Ð/ Heads of lesser metatarsals: ¥/ Articulate with the base of a proximal phalanx and the plantar plate. ¥/ Have a convex articular surface that extends further plantarly than dorsally. ¥/ The medial and lateral extensions of the articular surface on the plantar aspect are the plantar condyles (lateral condyle is usually larger than the medial). ¥/ On superior surface proximal to the articular surface is a depressed region called the surgical neck (where capsule attaches). ¥/ Proximal to the surgical neck are two tubercles which serve for attachment of the collateral MTP ligaments. ¥/ Proximal to the tubercles is the anatomical neck. Ð/ Clinical note: The heads of the metatarsals are weightbearing. Ð/ Clinical note: The anatomical neck is a landmark for performing osteotomies. Sobotta:Anatomy © Elsevier GmbH Germany  METATARSALS ¥/ Differences of the metatarsal bones: Ð/ Base: ¥/ Shape of the articular surface on the posterior aspect, and presence or absence of articular facets ion the medial and lateral surfaces. Ð/ Head: ¥/ Plantar surface of the lesser metatarsal heads have a longitudinal groove for the tendons of FDL and FDB. ¥/ Plantar surface of the first metatarsal has two grooved facets for the sesamoids separated by a ridge (crista). A longitudinal groove is not present because one is created by the sesamoids (but plantar condyles are present).  FIRST METATARSAL ¥/ Shortest but strongest. ¥/ Articulates with: Ð/ First cuneiform (tarsometatarsal joint). Ð/ Base of proximal phalanx of hallux (first metatarsophalangeal joint). Ð/ Medial and lateral sesamoids (first metatarsophalangeal joint). Ð/ Occasionally with the second metatarsal base (intermetatarsal joint). Sobotta:Anatomy © Elsevier G  FIRST METATARSAL ¥/ Base: Ð/ Posterior surface: Kidney- shaped articular surface for first cuneiform. Ð/ Lateral surface: Occasional facet for the second metatarsal base. Ð/ Inferior surface: Tubercle at medial aspect for tendon of tibialis anterior, oval depression surrounded by a ridge at lateral aspect for tendon of peroneus longus. ¥/ Shaft: Nutrient foramen on lateral surface. ¥/ Head: Inferior surface has two grooved facets for the sesamoids separated by a ridge called the crista. Ð/ Clinical note: Vascular supply to the first metatarsal by nutrient and metaphyseal arteries is important in bunion surgeries.  SECOND METATARSAL ¥/ Longest. ¥/ Articulates with: Ð/ Second cuneiform (tarsometatarsal joint). Ð/ Base of proximal phalanx of second toe (second metatarsophalangeal joint). Ð/ First cuneiform (tarsometatarsal joint). Ð/ Third cuneiform (tarsometatarsal joint). Ð/ Third metatarsal base (intermetatarsal joint). Ð/ Occasionally with the first metatarsal base (intermetatarsal joint). ¥/ Clinical note: Second metatarsal base is firmly wedged into the tarsus. Sobotta:Anatomy © Elsevier G  SECOND METATARSAL ¥/ Base: Ð/ Posterior surface: Triangular-shaped articular surface for second cuneiform with the apex inferior. Ð/ Medial surface: Oval articular facet for the first cuneiform, occasionally a facet for the first metatarsal base. ¥/ Anatomical note: Facet may be absent. Ð/ Lateral surface: Two facets separated by a rough area and each is divided by a ridge into two anterior articular facets for the base of the third metatarsal and two posterior facets for the third cuneiform. ¥/ Anatomical note: Facets may be absent Ð/ Superior surface Ð/ Inferior surface ¥/ Shaft: Same as common characteristics. ¥/ Head: Same as common characteristics.  THIRD METATARSAL ¥/ Articulates with: Ð/ Third cuneiform (tarsometatarsal joint). Ð/ Base of proximal phalanx of third toe (third metatarsophalange al joint). Ð/ Second metatarsal base (intermetatarsal joint). Ð/ Fourth metatarsal base (intermetatarsal joint). Sobotta:Anatomy © Elsevier G  THIRD METATARSAL ¥/ Base: Ð/ Posterior surface: Triangular-shaped articular surface for third cuneiform with the apex inferior. Ð/ Medial surface: Two facets separated by a rough area for the second metatarsal base. Ð/ Lateral surface: Oval facet at posterosuperior aspect for the fourth metatarsal base. ¥/ Shaft: Same as common characteristics. ¥/ Head: Same as common characteristics.  FOURTH METATARSAL ¥/ Articulates with: Ð/ Cuboid (tarsometatarsal joint). Ð/ Base of proximal phalanx of fourth toe (fourth metatarsophalangeal joint). Ð/ Third cuneiform (tarsometatarsal joint). Ð/ Third metatarsal base (intermetatarsal joint). Ð/ Fifth metatarsal base (intermetatarsal joint). Sobotta:Anatomy © Elsevier G  FOURTH METATARSAL ¥/ Base: Ð/ Posterior surface: Quadrate-shaped articular surface for cuboid. Ð/ Medial surface: Facet at posterosuperior aspect that is divided into an anterior facet for the third metatarsal base and a posterior facet for the third cuneiform. Ð/ Lateral surface: Facet for the fifth metatarsal base. ¥/ Shaft: Same as common characteristics. ¥/ Head: Same as common characteristics.  FIFTH METATARSAL ¥/ Articulates with: Ð/ Cuboid (tarsometatarsal joint). Ð/ Base of proximal phalanx of fifth toe (fifth metatarsophalangeal joint). Ð/ Fourth metatarsal base (intermetatarsal joint). Sobotta:Anatomy © Elsevier G  FIFTH METATARSAL ¥/ Base: Ð/ Posterior surface: Triangular-shaped articular surface with the apex lateral for the cuboid. Ð/ Medial surface: Facet for the fourth metatarsal base. Ð/ Lateral surface: Large roughened eminence called the tuberosity or styloid process. ¥/ Clinical note: Occasionally an accessory ossicle is found posterior to the tuberosity known as the os vesalianum. ¥/ Shaft: Same as common characteristics. ¥/ Head: Same as common characteristics.  PHALANGES ¥/ Bones that make up the toes. ¥/ The first toe or hallux has two phalanges while the remaining toes have three phalanges (fifth toe sometimes has two due to a fusion of the middle and distal phalanges) ¥/ All phalanges consist of: Ð/ Base, shaft and a head. ¥/ Phalanges are divided into rows: Ð/ Proximal, middle, and distal.  PROXIMAL PHALANGES ¥/ Base: Ð/ Concave articular surface for its respective metatarsal head. Ð/ Tubercles on the sides for attachment of collateral metatarsophalangeal ligaments. ¥/ Head: Ð/ Trochlear articular surface for base of distal phalanx on the hallux and for base of a middle phalanx on a lesser digit. Ð/ Tubercles on the sides for attachment of collateral interphalangeal ligaments.  MIDDLE PHALANGES ¥/ Base: Ð/ Articular surface composed of two concave facets separated by a ridge for the head of a proximal phalanx on a lesser digit. Ð/ Tubercles on the sides for attachment of collateral interphalangeal ligaments. ¥/ Head: Ð/ Trochlear articular surface for base of a distal phalanx on a lesser digit. Ð/ Tubercles on the sides for attachment of collateral interphalangeal ligaments.  DISTAL PHALANGES ¥/ Base: Ð/ Articular surface composed of two concave facets separated by a ridge for the head of a middle phalanx on a lesser digit and for the head of the proximal phalanx of the hallux. Ð/ Tubercles on the sides for attachment of collateral interphalangeal ligaments. ¥/ Head: Ð/ Has no articular surface but rather a flattened surface for support of the nail. Ð/ Distal roughened aspect of plantar surface is the ungual tuberosity.  CONSTANT SESAMOIDS ¥/ There is a medial or tibial sesamoid and a lateral or fibular sesamoid. ¥/ The sesamoids are embedded in the tendons of flexor hallucis brevis and the plantar plate. ¥/ The sesamoids articulate with the inferior surface of the first metatarsal head. ¥/ Medial sesamoid: Ð/ Is usually larger than the lateral. Ð/ Is bipartite or tripartite more often than the lateral. ¥/ Clinical note: Position of the sesamoids in hallux abducto valgus. Sobotta:Anatomy © Elsevier GmbH Germany  OSSIFICATION OF BONES OF THE ¥/ Ossification times are an average of several studies. ¥/ Females tend to ossify at a faster rate than males. ¥/ Not uncommon for one foot to ossify slightly different than the other. ¥/ Most primary centers of ossification appear in fetal development, although some appear after birth. ¥/ Some secondary centers of ossification appear in fetal development, although most appear after birth. OSSIFICATION OF BONES OF THE Note: The shafts of the metatarsal are the first ossification centers to appear in the foot.  ACCESSORY BONES ¥/ Accessory bones do not appear as part of the normal osteology of the foot, but do appear in a small percentage of the population. ¥/ They are not the result of a pathological condition or fracture. ¥/ There are two types of accessory bones: Ð/ Ossicles: ¥/ Are the result of anomalous development or anomalous ossification patterns. Ð/ Sesamoids: ¥/ Are found in tendons and joint capsules and usually present to reduce the friction of a tendon or alter the pull of a tendon.  ACCESSORY OSSICLES Ð DORSUM O ¥/ More common: Ð/ Os trigonum (talus secondarius or talus accessorius) - Located posterior to the lateral tubercle on the posterior surface of the body of the talus. Sometimes it may fuse forming a Stiedaʼs process or Trigonal process. A Shepardʼs fracture is a fracture of the lateral tubercle. Ð/ Os tibiale externum - It is located just posterior to the tuberosity of the navicular. Sometimes it may fuse. Some clinicians call the ostibiale externum a prehallux. Ð/ Os intermetatarseum - Commonly located between the first and second metatarsal base on the dorsal aspect but may also be found between the fourth and fifth metatarsal bases. Ð/ Os supranaviculare (os talonavicular dorsale) - Located on the dorsal aspect of the talonavicular joint.  ACCESSORY OSSICLES Ð DORSUM OF ¥/ More common: Ð/ Os calcaneum secundum (os calcaneus secondarius) - Commonly located on the dorsal aspect of calcaneocuboid joint but may be found on the plantar aspect. Ð/ Os supratalare (talus secondarius) - Located at the proximal aspect of the dorsal surface of the neck of the talus. Ð/ Os vesalianum - Located posterior to the tuberosity of the base of the fifth metatarsal. Ð/ Accessory ossicle of hallux - Located on the medial or lateral aspect of the base of the distal phalanx Ð/ Os subtibiale - Located just inferior to the anterior colliculus of the medial malleolus. Ð/ Os subfibulare - Located inferior to tip of lateral malleolus.  ACCESSORY OSSICLES Ð DORSUM O ¥/ Less common: Ð/ Os intercuneiform - Located on the dorsal surface of the first intercuneiform joint. Ð/ Calcaneus accessorius (os trochlea) - Located on the lateral surface of the calcaneus near the trochlear process. Ð/ Os sinus tarsi - Located in the sinus tarsi region. Ð/ Os paracuneiform - Located on the dorsomedial aspect of the first cuneonavicular joint. Ð/ Os supracalcaneus - It is located on the superior surface of the calcaneus between the posterior surface and the posterior facet.  ACCESSORY OSSICLES Ð PLANTAR O ¥/ More common: Ð/ Os sustentaculi - Located near the sustentaculum tali of the calcaneus. Ð/ Os calcaneum secundum (os calcaneus secondarius ) - Commonly located on the dorsal aspect of calcaneocuboid joint but may be found on the plantar aspect. ¥/ Less common: Ð/ Os cuboideum secondarium (secondary cuboid) - Located on the plantar aspect between the navicular and cuboid bones. Ð/ Os subcalcis - Located inferior to the tuberosity of the calcaneus. Ð/ Os uncinatum - Located at the distal aspect of the plantar surface of the lateral cuneiform. Sometimes it may fuse forming a processus uncinatus.  ACCESSORY SESAMOIDS Ð DORSUM O ¥/ More common: Ð/ Os peroneum - - Located in the tendon of peroneus longus near the peroneal notch. ¥/ Less common: Ð/ Os sesamoideum tibialis anterior (sesamoid in the tendon of tibialis anterior) - Located at the anteroinferior aspect of the medial surface of the first cuneiform. Ð/ Sesamoid in the tendon of tibialis posterior - Located in the tendon of tibialis posterior proximal to the tuberosity of the navicular. Some clinicians call the sesamoid in the tendon of tibialis posterior the os tibiale externum. Ð/ Os tendinis calcanei - Located in the Tendo Achilles near the posterior surface of the calcaneus.  ACCESSORY SESAMOIDS Ð PLANTAR ¥/ More common: Ð/ Os interphalangeus (IPJ sesamoid of the hallux ) - Located in the IPJ joint capsule of the hallux on the plantar aspect. Ð/ Capsular sesamoids of the lesser MPJʼs (MTPʼs) and IPJʼs - Located in the capsules and tendons of muscles at the metatarsophalangeal and interphalangeal joints. ¥/ Less common: Ð/ Os cuneometatarsal peronea or tibiale - Located in the tendons of tibialis anterior or peroneus longus at the first tarsometatarsal joint. Ð/ Os sesamoideum tibialis posterior - Located in the plantar portion of the tendon of tibialis posterior near the plantar aspect of the navicular.  TIBIA (SHIN BONE) ¥/ Second largest bone of the body. ¥/ Medial bone of the leg. ¥/ Long bone and consists of: Ð/ Proximal extremity. Ð/ Shaft. Ð/ Distal extremity. ¥/ Articulates with: Ð/ Femur (knee joint). Ð/ Talus (ankle joint). Ð/ Fibula ( tibiofibular articulation and tibiofibular syndesmosis).  TIBIA (SHIN BONE) ¥/ Clinical note: Ð/ Tibial torsion is a measurement of the external torquing of the distal extremity of the tibia with respect to the proximal extremity. Ð/ It is the angle between the bimalleolar line (line through the medial and lateral malleolus) and the bicondylar line (line between the medial and lateral condyles of the tibial plateau). Draves, D.J. Anatomy of the Lower Extremity  TIBIA (SHIN BONE) ¥/ Proximal extremity: Ð/ Expanded forming medial and lateral condyles: Ð/ Superior surface (Tibial Plateau): ¥/ Medial facet. ¥/ Lateral facet. ¥/ Intercondylar eminence. ¥/ Anterior intercondylar fossa and posterior intercondylar fossa. Sobotta:Anatomy © Elsevier GmbH G  TIBIA (SHIN BONE) ¥/ Proximal extremity: Ð/ Anterior surface: ¥/ Tibial tuberosity. ¥/ Tubercle on lateral condyle (Gerdyʼs tubercle). Ð/ Posterior surface: ¥/ Transverse groove on medial condyle for insertion of semimembranosus. Ð/ Medial surface Ð/ Lateral surface: ¥/ Articular facet for the head of the fibula. Sobotta:Anatomy © Elsevier GmbH Ger  TIBIA (SHIN BONE) ¥/ Shaft: Ð/ It is triangular in shape in cross section with three borders (anterior, medial, and lateral or interosseous) and three surfaces (medial, lateral, and posterior). Ð/ Medial surface: ¥/ No muscles originate from this surface but the sartorius, gracilis, and semitendinosus insert together as the pes anserinus in the superior portion. Ð/ Lateral surface: ¥/ Tibialis anterior originates from this surface. Ð/ Posterior surface: ¥/ The soleal or popliteal line. ¥/ The vertical ridge extends distally from the middle of the soleal line. ¥/ A nutrient foramen is distal to the popliteal line. Sobotta:Anatomy © Elsev  Part 2 TIBIA (SHIN BONE) ¥/ Distal extremity: Ð/ Anterior surface: Ð/ Posterior surface: ¥/ Groove for the tendon of flexor hallucis longus. Ð/ Inferior surface: ¥/ Continuous with the lateral surface of the medial malleolus. ¥/ Articulates with the trochlea. ¥/ Also known as the tibial plafond. ¥/ Part of the ankle mortice or malleolar fork. Sobotta:Anatomy © Elsevier GmbH Germany  TIBIA (SHIN BONE) ¥/ Distal extremity: Ð/ Lateral surface: ¥/ Fibular notch with anterior and posterior borders. ¥/ Tubercles located on inferior aspect of borders: Ð/ Tubercle of Tillaux or Chaput on anterior border. Ð/ Posterior or third malleolus on posterior border. Ð/ Medial surface: ¥/ Medial malleolus is a inferior projection. Sobotta:Anatomy © Elsevier GmbH  TIBIA (SHIN BONE) ¥/ Medial malleolus: Has two surfaces, two borders and an apex. Ð/ Medial surface Ð/ Lateral surface: ¥/ Articular surface for the medial surface of the body of the talus. ¥/ Continuous with the inferior surface of the distal extremity. Ð/ Anterior border Ð/ Posterior border: ¥/ Medial malleolar sulcus for the tendons of tibialis posterior and flexor digitorum longus. Ð/ Apex: ¥/ Composed of an anterior and posterior colliculus separated by an intercollicular groove. ¥/ Anterior colliculus is larger and extends further inferiorly. ¥/ Serve for attachment of the capsule and medial ligaments of the ankle joint. Sobotta:Anatomy ©  FIBULA (CALF BONE) ¥/ Lateral bone of the leg. ¥/ Not involved in the knee joint. ¥/ Carries no weight, but rather serves for muscular attachment. ¥/ Consists of: Ð/ Proximal extremity. Ð/ Shaft. Ð/ Distal extremity. ¥/ Articulates with: Ð/ Tibia (tibiofibular articulation ad tibiofibular syndesmosis). Ð/ Talus (ankle joint).  FIBULA (CALF BONE) ¥/ Proximal extremity or Head: Ð/ Articular facet for the lateral condyle of tibia. Ð/ Apex or styloid process. ¥/ Shaft: Ð/ Has three borders (anterior, interosseous, and posterior); and three surfaces (medial, lateral, and posterior). Ð/ The posterior surface is divided into two areas for muscular origin by the crista medialis. Ð/ The nutrient foramen is located on the posterior surface. Sobotta:Anatomy ©  FIBULA (CALF BONE) ¥/ Distal extremity or lateral malleolus: Ð/ Projects further inferiorly than the medial malleolus. Ð/ Composed of two surfaces, two borders, and an apex. ¥/ Lateral surface ¥/ Medial surface: Ð/ Articular facet for the body of the talus. Ð/ Malleolar fossa. ¥/ Anterior border ¥/ Posterior border: Ð/ Lateral malleolar sulcus. ¥/ Apex: Sobotta:A  PATELLA ¥/ Oval-triangular bone, with the base superior and the apex inferior. ¥/ Composed of two surfaces, (anterior and posterior); and three borders (superior, medial, and lateral). ¥/ Sesamoid bone located in the tendons of the quadriceps femoris muscle. ¥/ Articulates with: Ð/ Distal extremity of the femur (knee joint).  PATELLA ¥/ Anterior surface: Ð/ Covered by the quadriceps femoris tendon. Ð/ Subcutaneous and a prepatellar bursa separates it from the skin. ¥/ Posterior surface: Ð/ Large oval articular facet divided by a ridge into a medial and lateral facet. Ð/ Lateral facet is larger and has less of a slope. Ð/ Rough area below the facet for attachment of the ligamentum patellae. ¥/ Superior, medial, and lateral borders: Ð/ Rough for attachment of the portions of the quadriceps femoris. ¥/ Anatomical note: The patella commonly dislocates laterally due to the angle of pull of the quadriceps. Sobotta:Anatomy © Elsevier GmbH Germany OSSIFICATION  FEMUR ¥/ Longest and strongest bone of the body. ¥/ Consists of: Ð/ Proximal extremity. Ð/ Shaft. Ð/ Distal extremity. ¥/ Articulates with: Ð/ Os coxae (hip joint). Ð/ Patella (knee joint). Ð/ Tibia (knee joint).  FEMUR ¥/ Internal architecture: Ð/ Typical architecture of a long bone. Ð/ Central portion of the shaft is a hollow cylinder of compact bone. Ð/ Extremities consist of a thin shell of compact bone (cortical bone) and a central core of spongy bone (cancellous bone). Ð/ The trabeculae of the spongy bone in the extremities are arranged to transmit weight from the proximal extremity to the shaft. Ð/ In the proximal extremity they are arranged to transmit weight from the head to the neck, and from the neck to the shaft. Ð/ The calcar femorale is one of these trabeculae that is very large and passes from the neck to the shaft beneath the lesser trochanter.  FEMUR ¥/ Angle of inclination: Ð/ In the anatomical position the shaft of the femur is not vertical because the distal extremity moves towards the midline of the body. Ð/ It is the angle between the longitudinal axis of the shaft and the longitudinal axis of the neck. Ð/ The angle varies with age, sex, and boney development. ¥/ Note: Birth ~ 140¡, Adult ~ 90-130¡. ¥/ Angle of femoral torsion (angle of declination or antetorsion): Ð/ The angle represents the amount of medial (internal) rotation of the shaft of the femur. Ð/ It is the angle between the longitudinal axis of the neck and the bicondylar line. ¥/ Note: Birth ~ 30¡; Adult ~15- 20¡.  FEMUR ¥/ Angle of anteversion: Ð/ It is the angle between the longitudinal axis of the neck and the frontal plane. ¥/ Note: Birth ~ 60¡ external; Adult ~ 10¡ external.  FEMUR ¥/ Proximal extremity: Ð/ Head: ¥/ Fovea capitis femoris. Ð/ Neck: Ð/ Greater trochanter: ¥/ Trochanteric or digital fossa. Ð/ Lesser trochanter Ð/ Intertrochanteric crest: ¥/ Courses from the greater to the lesser trochanter on the posterior surface. Ð/ Intertrochanteric line: ¥/ Courses from the greater to the lesser trochanter on the anterior surface.  OSTEOLOGY OF THE FEMU ¥/ Shaft: Ð/ Narrowest in the middle and flares at the proximal and distal extremity. Ð/ Structures to note: ¥/ Linea aspera (medial, intermediate, and lateral lips). ¥/ Spiral line (superior continuation of medial lip of linea aspera). ¥/ Gluteal tuberosity (superior continuation of lateral lip of linea aspera). ¥/ Medial and lateral supracondylar lines (inferior continuation of medial and lateral lips of the linea aspera respectively). Sobotta:Anatomy © Elsevier G  FEMUR ¥/ Distal extremity: Ð/ Consists of the medial and lateral condyles. Ð/ The condyles are connected anteriorly by the patellar (trochlear) surface, and separated posteriorly by the intercondylar fossa or notch. ¥/ Medial condyle: Ð/ Extends further inferior than the lateral condyle. Ð/ Medial epicondyle. Ð/ Adductor tubercle. ¥/ Lateral condyle: Ð/ Lateral epicondyle. Sobotta:Anatomy © Elsevier GmbH Germany  OS COXAE ¥/ Irregular shaped bone. ¥/ Forms the bony pelvis with the sacrum. ¥/ Formed by the union of the ilium, ischium, and pubis. ¥/ Acetabulum marks the point of union of the three bones. ¥/ The acetabulum is a cup- shaped articular cavity located on the lateral side of the external surface. ¥/ Articulates with: Ð/ Opposite os coxae (pubic symphysis). Ð/ Sacrum (sacroiliac joint). Ð/ Femur (hip joint). Sobotta:Anatomy © Elsevier GmbH Germany  OS COXAE ¥/ Ilium: Ð/ Forms the superior potion of the os coxae. Ð/ Divided into a body and a ala by the arcuate line internally and the upper border of the acetabulum externally. Ð/ Body: ¥/ Forms part of the lunate surface and acetabular fossa of the acetabulum. ¥/ Iliopectineal eminence (iliopubic eminence). ¥/ Pelvic surface. Ð/ Ala: ¥/ Gluteal surface: Ð/ Posterior gluteal line. Ð/ Anterior gluteal line. Ð/ Inferior gluteal line. ¥/ Pelvic surface: Ð/ Iliac fossa. Ð/ Auricular surface. Ð/ Iliac tuberosity. Sobotta:Anatomy © Elsevier GmbH G  OS COXAE ¥/ Ilium: Ð/ Ala: ¥/ Crest of the ilium: ¥/ Anterior border: Ð/ Anterior superior iliac spine. Ð/ Anterior inferior iliac spine. ¥/ Posterior border: Ð/ Posterior superior iliac spine. Ð/ Posterior inferior iliac spine. Ð/ Beginning of the greater sciatic notch. ¥/ Clinical note: Use anterior superior iliac spine and tip of medial malleolus for rough limb length measurements. ¥/ Clinical note: Bruising of the crest of the ilium is a hip pointer. Sobotta:Anatomy © Elsevier GmbH  OS COXAE ¥/ Ischium: Ð/ Forms the inferior portion of the os coxae. Ð/ Divided into a body and a ramus. Ð/ Body: ¥/ Forms part of the lunate surface and acetabular fossa of the acetabulum, and most of the acetabular notch. ¥/ Ischial spine, part of the greater sciatic notch, and the lesser sciatic notch. ¥/ Ischial tuberosity. Ð/ Ramus Sobotta:Anatomy © Elsevier GmbH Ge  OS COXAE ¥/ Pubis: Ð/ Forms the anterior portion of the os coxae. Ð/ Divided into a body, superior ramus, and a inferior ramus. Ð/ Body: ¥/ Angle of the pubis. ¥/ Crest of the pubis. ¥/ Pubic tubercle. ¥/ Initial part of the pectineal line. ¥/ Forms part of the pubic symphysis. Sobotta:Anatomy ©  OS COXAE ¥/ Pubis : Ð/ Superior ramus: ¥/ Pectineal or superior surface: ¥/ Contains the obturator groove. Ð/ Anatomical note: The linea terminalis (formed by the crest of the pubis, pubic tubercle, pectineal line, iliopectineal line, and arcuate line) marks the boundary between the true and false pelvis ¥/ Forms part of the lunate surface and acetabular fossa of the acetabulum, and part of the acetabular notch. Ð/ Inferior ramus: Sobotta:Anatomy © OSSIFICATION  PART 2 Ð ARTHROLOGY (JOINT CLASSIFICATION, ARTICUL FACETS, LIGAMENTOUS SUPPORT, MOVEMENTS) QUESTION AREAS ANKLE AND FOOT KNEE AND TIBIOFIBULAR PELVIS AND HIP  ANKLE JOINT ¥/ Synovial joint formed by: Ð/ Malleolar fork or ankle mortice: ¥/ 1. Lateral surface of medial 3 2 1 malleolus. ¥/ 2. Inferior surface of the distal extremity of the tibia. ¥/ 3. Medial surface of the lateral malleolus. L S Ð/ Talar dome: M ¥/ Medial (M), superior (S), and lateral (L) surfaces of the body of the talus. Sobotta:Anatomy © Elsevier GmbH Germany  ANKLE JOINT ¥/ Lateral ankle ligaments: Ð/ Weaker than medial ankle ligaments. Ð/ Anterior talofibular ligament: ¥/ Capsular ligament. ¥/ Attaches to the anterior border of the lateral malleolus and the lateral surface of the body of the talus. Ð/ Calcaneofibular ligament: ¥/ Cord-like extracapsular ligament. ¥/ Attaches to the lateral malleolus at the anterior border and apex, and to the peroneal spine on the lateral surface of the calcaneus. ¥/ Crossed superficially by the tendons of peroneus longus and peroneus brevis. Ð/ Posterior talofibular ligament: ¥/ Capsular ligament. ¥/ Attaches to the inferior portion of the malleolar fossa and to the lateral tubercle on the posterior surface of the body of the talus.  ANKLE JOINT ¥/ Medial ankle ligaments (deltoid ligament): Ð/ All are capsular ligaments. Ð/ The deltoid ligament is divided into a superficial and deep portion. Ð/ The superficial deltoid is crossed by the tendons of tibialis posterior and flexor digitorum longus. Ð/ Superficial deltoid: ¥/ Tibionavicular ligament: Ð/ Attaches to the anterior colliculus and the dorsomedial aspect of the navicular. ¥/ Calcaneotibial ligament: Ð/ Attaches to the anterior colliculus and the sustentaculum tali. Ð/ Strongest component of the deltoid ligament. ¥/ Superficial posterior talotibial ligament: Ð/ Attaches to the anterior colliculus and the medial tubercle on the posterior surface of the body of the talus.  ANKLE JOINT ¥/ Medial ankle ligaments: Ð/ Deep deltoid: ¥/ Anterior talotibial ligament: Ð/ Attaches to the anterior colliculus and intercollicular groove and the medial surface of the body of the talus below the pear- shaped articular facet. ¥/ Deep posterior talotibial ligament: Ð/ Attaches to the posterior colliculus and intercollicular groove, and to the medial tubercle on the posterior surface of the body of the talus.  ANKLE JOINT ¥/ Ankle sprains: Ð/ Most common is an ankle sprain which involves twisting of the weightbearing foot usually in the inverted and plantarflexed position. Ð/ Damage usually consists of straining and/or tearing of the anterior talofibular and calcaneofibular ligaments. Ð/ In some inversion injuries there may be an avulsion fracture of the tuberosity of the fifth metatarsal base which may or may not also include ligament damage. ¥/ Ankle fractures: Ð/ Usually occur in weightbearing with the foot in a supinated or pronated position with a twisting motion of the ankle. Ð/ Fractures have been classified by: ¥/ Anatomic location: Ð/ Unimalleolar, bimalleolar, and trimalleolar. ¥/ Eponyms: Ð/ Pottʼs, Dupuytrenʼs, Maisonneuveʼs. ¥/ Foot position and talar movement at time of injury: Ð/ Lauge-Hansen.  JOINTS OF THE FOOT ¥/ Intertarsal joints: Interphalangeal of Hallux Ð/ All are synovial and permit gliding and rotational motion. Ð/ Within the intertarsal joints a functional joint is determined by motion about a joint axis, while an anatomical joint is Metatarsophalangeal determined by a joint capsule. ¥/ Clinical note: Tarsal Tarsometatarsal (black arrows) coalitions are when a syndesmosis, Intercuneiform synchondrosis, or synostosis develops instead of a synovial joint at an intertarsal articulation. A tarsal coalition reduces or Cuneonavicular eliminates motion at the X affected joint. The most common tarsal coalition Subtalar X (Anterior and occurs between the talus Posterior) X ans calcaneus. Sobotta:Anatomy © Elsevier  FUNCTIONAL SUBTALAR (TALOCALC JOINT ¥/ Formed by: Ð/ The three articular areas on the talus articulating with the corresponding areas on the calcaneus. ¥/ Axis: Ð/ Has a single fixed axis that allows triplanar motion (triplanar axis). Ð/ Triplane axis courses obliquely from the lateral, plantar and proximal aspect of the heel forward in a medial, dorsal, and distal direction. Ð/ Axis is angulated: ¥/ 42¡ from the transverse plane. ¥/ 48¡ from the frontal plane. ¥/ 16¡ from the sagittal plane. ¥/ Motion: Ð/ Occurs in the plane of supination and pronation.  FUNCTIONAL SUBTALAR (TALOCALC JOINT ¥/ Open kinetic chain motion (OKC) or non-weight bearing motion: Ð/ Pronation consists of simultaneous movement of the forefoot and midfoot in the direction of eversion (frontal plane motion), abduction (transverse plane motion), and dorsiflexion (sagittal plane motion). Ð/ Supination consists of simultaneous movement of the forefoot and midfoot in the direction of inversion (frontal plane motion), adduction (transverse plane motion), and plantarflexion (sagittal plane motion). ¥/ OKC supination and pronation result in the forefoot and midfoot moving in relation to OKC Supination the rearfoot. Root, M.L. Normal and Abnormal Function Of Th  FUNCTIONAL SUBTALAR (TALOCALC JOINT ¥/ Closed kinetic chain motion (CKC) or weightbearing motion: Ð/ Friction and ground reactive forces prevent the abduction/adduction (transverse plane motion) and dorsiflexion/plantarflexion (sagittal plane motion) components of OKC motion. Ð/ To counteract these forces, the talus functions to maintain the transverse and sagittal plane motion of supination and pronation and the calcaneus functions to maintain the frontal plane motion. ¥/ CKC Supination consists of: Ð/ Calcaneal inversion (varus). Ð/ Abduction and dorsiflexion of the talus. Ð/ External rotation of the tibia. ¥/ CKC Pronation consists of: Ð/ Calcaneal eversion (valgus). Ð/ Adduction and plantarflexion of the talus. Ð/ Internal rotation of the tibia. Ð/ In CKC supination and pronation the movement of the talus and calcaneus allows for the same relationship between the forefoot/midfoot complex to the rearfoot as in OKC motion. Root, M.L. Normal and Abnormal Function Of Th  FUNCTIONAL MIDTARSAL JOIN ¥/ Also known as the transverse tarsal joint, Chopartʼs joint, or Cyma line. ¥/ Formed by: Ð/ The calcaneocuboid and talonavicular joints. These two joints are anatomically separate however they function together because motion occurs simultaneously at both joints.  FUNCTIONAL MIDTARSAL JOIN ¥/ Axes: Their movement is more extensive than other intertarsal joints and movement occurs about two axes of motion: a longitudinal midtarsal joint axis and an oblique midtarsal joint axis. Ð/ Longitudinal: ¥/ Angulated 75¡ from the frontal plane, 15¡ from the transverse plane, and 9¡ from the sagittal plane. Ð/ Oblique: ¥/ Angulated 38¡ from the frontal plane, 52¡ from the transverse plane, and 57¡ from the sagittal plane. ¥/ Motion: Ð/ Longitudinal: ¥/ Allows primarily inversion and eversion to occur while supination and pronation occur. Ð/ Oblique: ¥/ Allows primarily adduction- abduction and plantarflexion- dorsiflexion to occur while supination and pronation occur. Root, M.L. Normal and Abnormal Function Of Th  POSTERIOR SUBTALAR JOINT ¥/ Anatomically the subtalar joint is divided into an anterior and posterior synovial cavity. ¥/ The posterior subtalar articular cavity involves only the posterior articular areas of the calcaneus and talus. ¥/ The anterior subtalar articulation involves the middle and anterior articular areas of the calcaneus and talus and is anatomically included with the talonavicular articulation as the talocalcaneonavicular articular cavity. Sobotta:Anatomy © Elsevier GmbH Germany  POSTERIOR SUBTALAR JOINT ¥/ Ligaments: Ð/ Anterior talocalcaneal ligament (cervical): ¥/ Attaches to the lateral surface of the neck of the talus and the sinus tarsi of the calcaneus. Ð/ Posterior talocalcaneal ligament Ð/ Lateral talocalcaneal ligament Ð/ Medial talocalcaneal ligament Ð/ Interosseous talocalcaneal ligament: ¥/ Attaches to the sulcus tali and the calcaneal sulcus (occupies the tarsal canal). ¥/ Limiting factor in subtalar joint motion. Sobotta:Anatomy © Elsevier GmbH Germany  TALOCALCANEONAVICULAR JOI ¥/ Anatomically includes the anterior subtalar joint, the talonavicular joint, and the articulation between the head of the talus and the fibrocartilaginous thickening of the plantar calcaneonavicular (spring) ligament. Ð/ Bifurcate ligament: ¥/ Attaches to the sinus tarsi of the calcaneus and divides into calcaneonavicular and calcaneocuboid portions as it courses anteriorly. Ð/ Spring or plantar calcaneonavicular ligament: ¥/ Attaches to the anterior margin of the sustentaculum tali and the plantar surface of the navicular. ¥/ Its superior surface contains fibrocartilage for articulation with the head of the talus. ¥/ Only ligament in the foot with elastic fibers.  CALCANEOCUBOID JOINT ¥/ Ligaments: Ð/ Short plantar ligament (plantar calcaneocuboid): ¥/ Attaches to the tubercle and transverse groove on the plantar surface of the calcaneus and the plantar surface of the cuboid posterior to the peroneal ridge. Ð/ Long plantar ligament (long calcaneocuboid ligament): ¥/ Attaches to the plantar surface of the calcaneus between the tuberosity and the tubercle, and distally it divides into superficial and deep fibers: ¥/ Deep fibers: Ð/ Attach to the peroneal ridge and tuberosity of the cuboid. ¥/ Superficial fibers: Ð/ Attach to the plantar surface of the bases of the second, third, fourth, and fifth metatarsals. Sobotta:Anatomy © Elsevier GmbH Germany  CUNEONAVICULAR JOINTS ¥/ There are three cuneonavicular joints. ¥/ Each joint has these ligaments: Ð/ Dorsal cuneonavicular ligament Ð/ Plantar cuneonavicular ligament Sobotta:Anato INTERCUNEIFORM AND CUNEOCUBOID ¥/ Intercuneiform joints: Ð/ There are two. Ð/ Ligaments are: ¥/ Dorsal intercuneiform ligaments ¥/ Plantar intercuneiform ligaments ¥/ Interosseous intercuneiform ligaments ¥/ Cuneocuboid joint: Ð/ Ligaments are: ¥/ Dorsal cuneocuboid ligament ¥/ Plantar cuneocuboid ligament ¥/ Interosseous cuneocuboid ligament Sobotta:Anatomy © Elsevier GmbH Germa TARSOMETATARSAL JOINTS (LISFRANC ¥/ The tarsometatarsal joints are formed by the cuneiforms and cuboid articulating with the bases of the metatarsals. ¥/ The joint between the first cuneiform and first metatarsal base, and the joint between the cuboid and the fifth metatarsal base have more motion. ¥/ Ligaments: Ð/ Dorsal tarsometatarsal ligaments: ¥/ There is a dorsal tarsometatarsal ligament for each of the eight tarsometatarsal articulations. Sobotta:Anatomy © Elsevier GmbH Germany TARSOMETATARSAL JOINTS (LISFRANC ¥/ Ligaments: Ð/ Interosseous tarsometatarsal ligaments (3): ¥/ First attaches to the lateral surface of the first cuneiform and the medial surface of the second metatarsal base (Lisfrancʼs ligament). ¥/ Second attaches to the medial surface of the third cuneiform and the lateral surface of the second metatarsal base. ¥/ Third attaches to the lateral surface of the third cuneiform and the medial surface of the fourth metatarsal base (some fibers to the lateral surface of the third metatarsal base). Ð/ Plantar tarsometatarsal ligaments (9): ¥/ There is one ligament one for each of the eight tarsometatarsal articulations plus one from the first cuneiform to the third metatarsal base. Sobotta:Anatomy © Elsevier GmbH Germany  INTERMETATARSAL JOINTS ¥/ Metatarsal bases: Ð/ The lesser metatarsal bases articulate with each other to form the intermetatarsal joints. Ð/ Ligaments are: ¥/ Dorsal intermetatarsal ligaments ¥/ Plantar intermetatarsal ligaments ¥/ Interosseous intermetatarsal ligaments Sobotta:Anatomy © Elsevie  INTERMETATARSAL JOINTS ¥/ Metatarsal heads: Ð/ The heads of the metatarsals do not articulate with one another but are interconnected at the plantar plates by the deep transverse metatarsal ligament. Ð/ The deep transverse metatarsal ligament in the first interspace divides into a dorsal and plantar component which surround the conjoined tendon of adductor hallucis.  LESSER METATARSOPHALANGEAL J (MTPʼs OR MPJʼs) ¥/ Synovial joints (functional and anatomical) that permit dorsiflexion and plantarflexion about a transverse axis and abduction and adduction about a vertical axis (biaxial joint). ¥/ The Ligaments are: Ð/ Metatarsophalangeal capsular Ð/ Metatarsophalangeal plantar plate Ð/ Collateral metatarsophalangeal (2) Ð/ Metatarsophalangeal suspensory or metatarsoglenoid (2) Sobotta:Anatomy © Elsevier GmbH Ger  LESSER METATARSOPHALANGEAL J (MTPʼs OR MPJʼs) ¥/ Ligaments: Ð/ Metatarsophalangeal capsular ligament: ¥/ Attaches to the surgical neck of the metatarsal and the edges of the base of the proximal phalanx. ¥/ It has a loose attachment to the metatarsal head which allows for dorsiflexion and plantarflexion. Ð/ Metatarsophalangeal plantar plate: ¥/ Capsular ligament that is actually a fibrocartilaginous thickening of the plantar portion of the capsule. ¥/ The firm attachment to the base of a proximal phalanx allows the plantar plate to stay in contact with the ground as the metatarsal head undergoes movement. ¥/ The flexor sheaths and deep transverse metatarsal ligaments attach to the plantar plate.  LESSER METATARSOPHALANGEAL J (MTPʼs OR MPJʼs) ¥/ Ligaments: Ð/ Collateral metatarsophalangeal ligaments (2): ¥/ Cord-like capsular ligament that attach to the tubercles on either side of the head of the metatarsal and the tubercles on the base of a proximal phalanx. Ð/ Metatarsophalangeal suspensory ligaments or metatarsoglenoid ligaments (2): ¥/ Triangular- shaped capsular ligaments that attach to the tubercles on either side of the head of a metatarsal and the sides of the plantar plate. METATARSOPHALANGEAL JOINT OF TH (MTP or MPJ OF HALLUX ¥/ Synovial joint that permit dorsiflexion and plantarflexion about a transverse axis and abduction and adduction about a vertical axis. ¥/ Ligaments (same as lesser metatarsophalangeal joints): Ð/ Metatarsophalangeal capsular ligament Ð/ Metatarsophalangeal plantar plate Ð/ Collateral metatarsophalangeal ligaments(2) Ð/ Metatarsophalangeal suspensory ligaments or metatarsoglenoid ligaments (2) ¥/ Plantar plate is firmly attached to the base of the proximal phalanx of the hallux. METATARSOPHALANGEAL JOINT OF TH (MTP or MPJ OF HALLUX ¥/ The inferior surface of the first metatarsal head is grooved for articulation with the sesamoids which are embedded in the plantar plate. ¥/ Sesamoids divide the plantar plate into a number of ligamentous regions. Ð/ Metatarsosesamoid ligaments (medial and lateral) Ð/ Phalangeosesamoid ligaments (medial and lateral) Ð/ Intersesamoid ligament ¥/ Sesamoid apparatus formed by: Ð/ Tendon of flexor hallucis brevis. Ð/ Tendon of abductor hallucis. Ð/ Conjoined tendon of adductor hallucis. Ð/ Sesamoids. Ð/ Plantar plate (which includes sesamoid ligaments).  INTERPHALANGEAL JOINTS ¥/ There are nine interphalangeal joints, the hallux has one while each of the lesser digits has a proximal and distal. ¥/ They all are synovial joints that permit only dorsiflexion and plantarflexion about a transverse axis. ¥/ Major ligaments are: Ð/ Interphalangeal capsular ligament Ð/ Interphalangeal plantar plate Ð/ Collateral interphalangeal ligaments(2) Sobotta:Anatomy © Elsevier GmbH Germany  SYNOVIAL CAVITIES OF THE FO ¥/ There are twenty synovial cavities in the foot: Ð/ 9 interphalangeal. Ð/ 5 metatarsophalangeal. Ð/ 6 within the intertarsal, tarsometatarsal, and intermetatarsal articulations. Sobotta:Anatomy © Elsevier GmbH  SYNOVIAL CAVITIES OF THE FO ¥/ The six within the intertarsal, tarsometatarsal, and intermetatars are: Ð/ 1. Posterior subtalar synovial cavity: ¥/ Encloses the posterior articular surface of the talus and the posterior facet o Ð/ 2. Calcaneocuboid synovial cavity: ¥/ Encloses the articulation between the calcaneus and the cuboid. Ð/ 3. Talocalcaneonavicular synovial cavity: ¥/ Encloses the middle and anterior facets of the talus and calcaneus, talonavic the articulation between the head of the talus and the spring ligament. Ð/ 5. Lateral tarsometatarsal synovial cavity: ¥/ Encloses the tarsometatarsal articulations between the cuboid and the base fifth metatarsals, and the intermetatarsal articulation between the bases of metatarsals. Ð/ 6. Medial tarsometatarsal synovial cavity: ¥/ Encloses the tarsometatarsal articulation between the first cuneiform and th metatarsal. Schaefffer, J.P. Morris Human anatomy © Blakiston Comp.  SYNOVIAL CAVITIES OF THE FO 4. Greater tarsal synovial cavity (encloses the following): ¥/ Cuboideonavicular (if present) ¥/ Cuneonavicular ¥/ Intercuneiform ¥/ Cuneocuboid ¥/ Intermediate tarsometatarsal (articulations between the cuneiforms and the second, third, and fourth metatarsal bases). ¥/ Intermetatarsal (articulations between the bases of the second and third metatarsals, and the bases of the third and fourth metatarsals). Schaefffer, J.P. Morris Human anatomy © Blakis  ARCHES OF THE FOOT ¥/ The foot absorbs the impact of the body weight on its plantar surface and is used as a lever in propelling the body forward. ¥/ Strength and resiliency is imparted to the foot in the form of arches. ¥/ Arches are formed by bone and maintained by ligaments and muscles. ¥/ Longitudinal arch: Ð/ Posterior base is the tuberosity of the calcaneus, the anterior base is the metatarsal heads and sesamoids. Ð/ Body of the arch is formed by the metatarsal and tarsal bones with the talus being the keystone. Ð/ Lateral part or rigid component is flatter and composed of the calcaneus, cuboid, lateral two metatarsals and their phalanges. Ð/ Medial part or flexible component is more arched and composed of the calcaneus, talus, navicular, cuneiforms, medial three metatarsals with their phalanges and the sesamoids.  ARCHES OF THE FOOT ¥/ Longitudinal arch supports: Ð/ Ligaments and plantar aponeurosis: ¥/ Spring ligament ¥/ Short plantar ligament ¥/ Long plantar ligament ¥/ Central portion of plantar aponeurosis Ð/ Tendons of extrinsic muscles: ¥/ Tibialis posterior: Ð/ Medial side of the arch. ¥/ FHL: Ð/ Medial side of the arch. ¥/ FDL: Ð/ Medial and lateral sides of the arch.  KNEE JOINT ¥/ Most hinge joints allow only flexion and extension but there is slight medial and lateral rotation in the knee joint (biaxial joint). ¥/ Anatomically formed by the distal extremity of the femur articulating with the proximal extremity of the tibia, and the patella articulating with distal extremity of the femur. ¥/ Functionally a bicondylar joint between the condyles of the femur and tibia. ¥/ Two menisci distribute the force of the femur over the condyles of the tibia. ¥/ Menisci help to increase the concavity of the tibial condyles but there is still a poor fit for the femoral condyles. ¥/ The strength of the knee joint is derived from the ligaments and muscles that cross the joint. Sobotta:Anatomy © Elsevier GmbH Germany  KNEE JOINT ¥/ Synovial membrane: Ð/ Lines most of the fibrous capsule. Ð/ Projects around the cruciate ligaments such that they are intracapsula intrasynovial. Ð/ Superiorly the synovial cavity and the synovial membrane is continuou suprapatellar bursa. Inferiorly it is separated from the ligamentum pat infrapatellar fat pad. Ð/ It projects from the sides of the infrapatellar fat pad as the alar folds. Ð/ The alar folds join posteriorly to form the infrapatellar synovial fold (lig mucosum). Ð/ The infrapatellar synovial fold attaches to the intercondylar eminence intercondylar notch of the femur.  KNEE JOINT ¥/ Ligamentum patellae: Ð/ Capsular ligament. ¥/ Medial patellar retinaculum: Ð/ Capsular ligament formed from the expansion of the tendon of vastus medialis. ¥/ Lateral patellar retinaculum: Ð/ Capsular ligament formed from the expansion of the tendon of vastus lateralis. Ð/ Attaches to the tubercle on the anterior aspect of the lateral condyle of the tibia (Gerdyʼs tubercle). ¥/ Oblique popliteal ligament: Ð/ Capsular ligament which is an expansion from the tendon of semimembranosus. Ð/ Forms part of the floor of the popliteal fossa. Ð/ Has numerous apertures for vessels and nerves to the knee joint. ¥/ Arcuate popliteal ligament: Ð/ Capsular ligament.  KNEE JOINT ¥/ Tibial collateral ligament: Ð/ Capsular ligament. Ð/ Attaches proximally to the medial epicondyle of the femur, and distally to the medial condyle and medial surface of the shaft of the tibia. Ð/ It attaches to the medial meniscus. ¥/ Fibular collateral ligament: Ð/ extracapsular ligament. Ð/ Attaches proximally to the lateral epicondyle of the femur, and distally to the lateral side of the head of the fibula. Ð/ It is separated from the lateral meniscus by the tendon of popliteus.  KNEE JOINT ¥/ Cruciate ligaments: Ð/ The synovial membrane projects around them so that they are extrasynovial. Ð/ Anterior cruciate ligament (ACL or external cruciate): ¥/ Attaches distally to the anterior intercondylar fossa. ¥/ Attaches proximally to the medial surface of the lateral condyle of the femur. Ð/ Posterior cruciate ligament (PCL or internal cruciate): ¥/ Stronger and shorter than the anterior cruciate ligament. ¥/ Attaches distally to the posterior intercondylar fossa. ¥/ Attaches proximally to the lateral surface of the medial condyle of the femur.  KNEE JOINT ¥/ Posterior meniscofemoral ligament (ligament of Wrisberg): Ð/ Intracapsular ligament but extrasynovial. ¥/ Transverse genicular or intermeniscal ligament: Ð/ They are intracapsular and intrasynovial. ¥/ Coronary ligaments: Ð/ Capsular ligaments Ð/ Portion of the articular capsule that connects the menisci to the tibial condyles.  KNEE JOINT ¥/ Menisci: Ð/ Crescent-shaped articular fibrocartilage. Ð/ They are intracapsular and intrasynovial. ¥/ Clinical note: The menisci are important in the distribution of force across the tibial plateau (articular facets). ¥/ Medial meniscus: Ð/ Semicircular in shape. Ð/ Anterior horn attaches to the anterior intercondylar fossa. Ð/ Posterior horn attaches to the posterior intercondylar fossa. Ð/ Medially it is attached to the capsule and tibial collateral ligament. ¥/ Lateral meniscus: Ð/ Circular in shape. Ð/ Anterior horn attaches to the anterior intercondylar fossa. Ð/ Posterior horn attaches to the posterior intercondylar fossa. Ð/ Laterally it is attached to the capsule but separated from the fibular collateral ligament  KNEE JOINT ¥/ Clinical note: “Screw Home Mechanism” Ð/ Flexion and extension of the knee joint are accompanied by internal rotation of either the tibia (OKC) or the femur (CKC). Ð/ Internal and external rotation is due to: ¥/ Geometry of the articular surfaces. ¥/ Ligamentous arrangement. ¥/ Popliteus muscle. Ð/ In CKC: ¥/ With knee extension there is internal femoral rotation. The internal rotation associated with the later stages of extension (screw home mechanism) puts the knee joint in a position of maximum joint congruency and the ligaments are taught. This position is screw home position and it requires little muscular activity. ¥/ With knee flexion there is external femoral rotation (popliteus muscle).  KNEE JOINT ¥/ Injuries: Ð/ Usually occur during weightbearing (CKC) as the result of direct or indirect trauma. Ð/ One of the most common injuries is a blow to the lateral side of the knee, or a twisting motion which disrupts the medial side. Structures affected on the medial side would be: ¥/ Medial aspect of the joint capsule and medial meniscus. Ð/ May result in synovial fluid (water) on the knee and/or a torn medial meniscus (may be a bucket handle tear). Ð/ May require tapping the knee to remove fluid, and partial or complete meniscectomy. ¥/ Tibial collateral ligament. Ð/ May be strained, partially torn, or completely torn. Ð/ Surgery may be required to repair or reconstruct the ligament. Ð/ Test knee motion in the flexed position. ¥/ Anterior cruciate ligament. Ð/ May be strained, partially torn, or completely torn. Ð/ Anterior drawer sign (also positive Lachman Test) if anterior cruciate ligament involved. Ð/ Surgery may be required to repair or reconstruct the ligament. ¥/ Clinical note: “unhappy triad” Moore, K.L., Dalley, A.F. Clinically Oriented Ana  Part 3 KNEE JOINT ¥/ Bursae: Ð/ There are several bursae around the knee joint to reduce the friction of tendons exerting their action lengthwise across the joint (parallel to the plane of motion). Ð/ Some bursae communicate with the synovial cavity of the knee joint and others are completely separate. Ð/ Communicating bursae: ¥/ Suprapatellar bursa ¥/ Popliteus bursa ¥/ Gastrocnemius bursa Ð/ Separate bursae: ¥/ Prepatellar bursa ¥/ Superficial infrapatellar bursa ¥/ Deep infrapatellar bursa ¥/ Anserine bursa  KNEE JOINT ¥/ Popliteal or Bakerʼs cyst: Ð/ A fluid-filled herniation of the synovial membrane of the knee joint, or a distention of the gastrocnemius bursa (or semimembranosus bursa). ¥/ Prepatellar bursitis or housemaids knee: Ð/ Inflammation of the prepatellar bursa. ¥/ Genu varum and genu valgum: Ð/ Genu varum: ¥/ The distal end of the tibia is bent inward and the knee joint is bent outward (bowleg). Ð/ Genu valgum: ¥/ The distal end of the tibia is bent outward and the knee joint is bent inward (knock- knee). Moore, K.L., Dalley, A.F. Clinically Oriented Anatomy © Lippincott Williams & Wilkins  HIP JOINT ¥/ Ball and socket type of synovial joint. ¥/ Formed by the head of the femur and the acetabulum of the os coxae. ¥/ Articular cartilage on the head of the femur and lunate surface of acetabulum. ¥/ Acetabulum is deepened by the acetabular labrum (fibrocartilage). Ð/ Clinical note: Major cause for hip replacement is degenerative joint disease. Sobotta:Anatomy © Elsevier GmbH G  HIP JOINT ¥/ Articular capsule: ¥/ Iliofemoral or iliocapsular ligament: Ð/ Attaches proximally to the anterior inferior iliac spine. Ð/ Attaches distally to the intertrochanteric line. ¥/ Ischiofemoral or ischiocapsular ligament: Ð/ Attaches proximally to the superior portion of the body of the ischium. Ð/ Attaches distally to the capsular ligament. ¥/ Pubofemoral or pubocapsular ligament: Ð/ Attaches proximally to the lateral portion of the superior ramus of the pubis. Ð/ Attaches distally to the capsular ligament. Sobotta:Anatomy © Elsev  HIP JOINT ¥/ Ligamentum capitis femoris or ligament of the head of the femur: Ð/ Attaches to the fovea capitis femoris and to either side of the acetabular notch and acetabular fossa. ¥/ Transverses acetabular ligament: Ð/ Converts the acetabular notch into a foramen for vessels and nerves entering the hip joint. ¥/ Acetabular labrum: Ð/ It is fibrocartilage which attaches to the acetabular lip to deepen the articular cavity. ¥/ Anatomical note: The ligamentous structure of the hip joint is such that it becomes very tight during extension and relaxed during flexion. ¥/ Clinical note: Congenital dislocation is more common in the hip joint than any other articulation of the body.  SACROILIAC JOINT ¥/ Synovial joint permitting little movement due to irregular shaped articular surfaces. ¥/ Formed by the auricular surfaces of the sacrum (covered by hyaline cartilage) and ilium (covered by fibrocartilage). ¥/ Joint cavity may be reduced or obliterated in older life (due to bony fusion). ¥/ Ligaments: Ð/ Anterior or ventral sacroiliac ligament Ð/ Posterior or dorsal sacroiliac ligament Ð/ Interosseous sacroiliac ligament: ¥/ Attaches to the tuberosity of the ilium and the tuberosity of the sacrum. ¥/ Accessory ligaments: Ð/ Sacrospinous ligament: Ð/ Sacrotuberous ligament: Sobotta:Anatomy © Elsevier GmbH G  MISCELLANEOUS LIGAMENTS OF THE ¥/ Inguinal ligament: Ð/ It is the lower border of the aponeurosis of the external abdominal oblique muscle. Ð/ It attaches to the anterior superior iliac spine and the pubic tubercle. ¥/ Compartments beneath the inguinal ligament: Ð/ Muscular or lateral compartment (lacuna musculorum): ¥/ Contains the psoas major and iliacus muscles, the femoral nerve, and the lateral femoral cutaneous nerve. Ð/ Vascular or medial compartment (lacuna vasorum): ¥/ Contains the femoral artery, the femoral vein, and the femoral canal. ¥/ Lacunar ligament: Ð/ Medial extension of the aponeurosis of the external abdominal oblique muscle. Ð/ It reinforces the medial attachment of the inguinal ligament and forms the medial boundary of the femoral ring. ¥/ Pectineal ligament: ¥/ It courses laterally from the lacunar ligament and attaches to the pectineal line of the pubis. ¥/ Obturator membrane: Ð/ It is a fibrous membrane that almost closes off the obturator foramen except for the obturator canal. Ð/ It serves for origin of the obturator muscles.  PART 3 Ð MYOLOGY (MUSCLE ORIGINS, INSERTIONS, ACTIONS; FASCIA AND RETINACU QUESTION AREAS FOOT LEG THIGH AND PELVIS  DORSUM OF THE FOOT ¥/ The foot contains intrinsic muscles (originate and insert in the foot) and the tendons of extrinsic muscles (originate outside the foot and insert in the foot). ¥/ Dorsum of the foot - There is one intrinsic muscle and the tendons of four extrinsic muscles. ¥/ Skin: Ð/ Thin hairy skin composed of an epidermis and a dermis. ¥/ Superficial Fascia: Ð/ Very thin fatty layer. Ð/ Contains superficial veins and cutaneous nerves.  DORSUM OF THE FOOT ¥/ Deep Fascia: Ð/ Completely surrounds the muscles. Ð/ Forms retinaculae around the ankle. Ð/ As the deep fascia encloses the structures on the dorsum of the foot it forms a dorsal subfascial space which is continuous into the dorsum of the digits, and into the anterior compartment of the leg. ¥/ Clinical note: Infections spread along fascial planes within compartments, and between compartments along tendons.  DORSUM OF THE FOOT ¥/ Superior extensor retinaculum (transverse crural ligament): Ð/ Binds down the tendons of tibialis anterior, extensor hallucis longus, extensor digitorum longus, and peroneus tertius. ¥/ Inferior extensor retinaculum (cruciate crural ligament): Ð/ Y-shaped band with the stem of the Y attaching laterally to the sinus tarsi of the calcaneus. Ð/ Band courses medially as a double layer enclosing the tendons of peroneus tertius and extensor digitorum longus. Ð/ At the medial border of EDL a superior and inferior limb is formed. Ð/ The superior limb encloses the tendons of extensor hallucis longus and tibialis anterior and then attaches to the medial malleolus. Ð/ The inferior limb encloses the tendons of extensor hallucis longus and tibialis.  DORSUM OF THE FOOT ¥/ Flexor retinaculum: Ð/ Attaches to the medial malleolus and the medial surface of the calcaneus. ¥/ Clinical note: Posterior to the medial malleolus the following are arranged medial to lateral just before they pass into tunnels that are formed deep to the flexor retinaculum: Ð/ Tendon of tibialis posterior Ð/ Tendon of flexor digitorum longus Ð/ Posterior tibial artery with a vein on either side Ð/ Tibial nerve Ð/ Tendon of flexor hallucis longus ¥/ Clinical note: Posterior to the medial malleolus is the common site for taking the posterior tibial pulse and for performing a tibial nerve block. Sobotta:Anatomy © Elsevier GmbH Germany  DORSUM OF THE FOOT ¥/ Clinical note: Beneath the flexor retinaculum there are individual tunnels for each of the following: Ð/ Tendon of tibialis posterior. Ð/ Tendon of flexor digitorum longus. Ð/ Tendon of flexor hallucis longus. Ð/ Medial plantar vessels and nerve. Ð/ Lateral plantar vessels and nerve. ¥/ Clinical note: Tarsal tunnel syndrome is entrapment of the tibial nerve (or its medial plantar or lateral plantar branch) in the tunnels beneath the flexor retinaculum. Sarrafian, S.K. Anatomy of the Foot and  DORSUM OF THE FOOT ¥/ Peroneal retinaculum: Ð/ Composed of a superior and inferior portion. Ð/ Both portions bind down the tendons of peroneus longus and peroneus brevis. Ð/ Superior peroneal retinaculum attaches to the lateral malleolus and the lateral surface of the calcaneus. Ð/ Inferior peroneal retinaculum attaches to the lateral surface of the calcaneus including the peroneal tubercle. Sarrafian, S.K. Anatomy of the Foot and Ankle © Lippincott  DORSUM OF THE FOOT ¥/ Extensor digitorum brevis: Ð/ Origin: ¥/ Sinus tarsi of the calcaneus. Ð/ Insertion: ¥/ Medial (first) tendon (also known as extensor hallucis brevis) inserts into the dorsum of the base of the proximal phalanx of the hallux. ¥/ Other three tendons (second, third, and fourth) insert into the lateral side of the EDL tendons to the second, third, and fourth toes. Ð/ Action: ¥/ First tendon: Dorsiflex the proximal phalanx of the hallux (first tendon). ¥/ Second, third , and fourth tendons: Dorsiflex the phalanges of the second, third, and fourth (second through fourth tendons). Sobotta:An  DORSUM OF THE FOOT ¥/ Tendons of extrinsic muscles: Ð/ The tendons of tibialis anterior, extensor hallucis longus, extensor digitorum longus, and peroneus tertius course below the superior and inferior extensor retinaculae enclosed in synovial sheaths. Ð/ The tendons of tibialis anterior, and extensor hallucis longus have their own synovial sheaths while the tendons of extensor digitorum longus and peroneus tertius are enclosed in a common synovial sheath.  DORSUM OF THE FOOT ¥/ Extensor hood (extensor sheath, extensor expansion, extensor retinaculum): Ð/ The tendons of EDL and EHL expand at the level of the MTP to form an extensor hood. Ð/ The hood extends from the head of a metatarsal to the distal aspect of a proximal phalanx. Ð/ The proximal component of the hood is the sling portion. It has fibers that encircle the capsule of the MTP and blend with the plantar plate, the deep transverse metatarsal ligaments and the flexor sheaths. Ð/ The distal component of the hood is the wing portion which has fibers arranged obliquely on the sides of the digit.  DORSUM OF THE FOOT ¥/ Extensor hood (extensor sheath, extensor expansion, extensor retinaculum): Ð/ On the lesser digits the tendons of the dorsal interossei; plantar interossei; lumbricals; and the second, third, and fourth tendons of EDB contribute to the extensor hood. Ð/ On the hallux the tendons of abductor hallucis, flexor hallucis brevis, and adductor hallucis contribute to the extensor hood. Ð/ The extensor hood helps maintain the central position of the EDL tendons and the tendon of EHL. ¥/ Anatomical note: The extensor hood aids in dorsiflexion of the proximal phalanx through the windlass effect.  PLANTAR SURFACE OF THE FOO ¥/ The muscles are commonly arranged in four layers from superficial to deep, or they can be arranged in compartments: medial, lateral, central, and interosseous. Ð/ Clinical note: Knowledge of the compartments is important in the spread of infections. ¥/ Skin: Ð/ A thick hairless skin. ¥/ Superficial fascia: Ð/ Very thick and forms distinct pads at calcaneal tuberosity, metatarsal heads and distal phalanges. Ð/ Fibers pass from the dermis through the superficial fascia to the deep fascia to limit the mobility of the skin, maintain the position of the fat pads, and prevent compression of vessels and nerves. ¥/ Clinical note: The fat pad over the calcaneal tuberosity may be compressed resulting in a heel bruise or stone bruise (periostitis).  PLANTAR SURFACE OF THE FOO ¥/ Deep fascia, plantar fascia, or plantar aponeurosis: Ð/ Completely surrounds the muscles. Ð/ Also called the plantar aponeurosis which is divided into a central, medial and lateral portion. Ð/ Forms intermuscular septa. Ð/ Forms flexor sheaths in the digits. Ð/ Central portion of plantar aponeurosis: ¥/ Triangular in shape with the apex attaching at the medial process of the calcaneal tuberosity. ¥/ The deep slips blend with the plantar plate and deep transverse metatarsal ligaments , and then distally form the flexor sheaths. Ð/ Clinical note: Plantar fascitis is an inflammation of the attachment of the central portion of the plantar aponeurosis to the medial process of the calcaneal tuberosity. Ð/ Clinical note: Dorsiflexion of the digits tenses the plantar aponeurosis and increases the height of the longitudinal arch (windlass effect). Ð/ Flexor sheaths: ¥/ Fibrous sheaths that enclose the tendons of FHL, FDL, and FDB in the digits. ¥/ They are continuous with the deep slips of the central portion of th