Osteology (Part 4): Midfoot Flashcards
Cuboid
- Name is derived from its “cubed” appearance
- Superior surface faces dorsolaterally
- Contributes to transverse arch
Cuboid articulates with
- Calcaneus
- 4th and 5th metatarsal
- 3rd cuneiform
- Navicular
Posterior surface of cuboid
- Facet for calcaneus (posterior surface that articulates with calcaneus)
- Saddled shaped (convex: S to I, concave: transversely)
- Calcaneocuboid portion of midtarsal joint
Cuboid medial surface structures
- Facet for lateral cuneiform (3rd)
- Facet for navicular
Facet for lateral cuneiform (3rd)
- Oval shaped
- Located superior aspect of medial surface
Facet for navicular
- Located on the inferior medial surface
- Proximal to facet for lateral cuneiform
Facet for navicular presence
- Present in ~ 50% of population
- If present it is a synovial joint
- If not present it is a fibrous joint
Cuboid anterior surface structures
- Facet for 4th metatarsal
- Facet for 5th metatarsal
- (Facets separated by a vertical ridge)
Facet for 4th metatarsal
- Distal anterior surface
- Medial
- Rectangular in shape
Facet for 5th metatarsal
- Distal anterior surface
- Lateral to facet for 4th metatarsal
- Triangular shaped with apex lateral
Cuboid inferior surface structures
- Fibular sulcus/groove
- Fibular ridge
- Beak of cuboid (coronoid process)
Fibular sulcus/groove
- Located on the inferior aspect
- Anterior to the fibular ridge
- Tendon of the fibularis longus passes in this groove
Fibular ridge
- Posterior boundary of fibular sulcus
- Long plantar attaches to ridge
- Short plantar ligament attaches posterior to ridge (extends onto beak)
Beak of cuboid (coronoid process)
- Beak-like process
- Posteriormedial aspect (some ligaments attach)
Cuboid lateral surface structures
- Fibular notch
- Tuberosity of cuboid
Fibular notch
- Found on lateral surface
- Beginning of fibular sulcus
- Passage of fibularis longus
- Os peroneum found within fibularis longus tendon lateral to notch
Tuberosity of cuboid
- Lateral end of fibular ridge
- Posterior to fibular notch
- Can contain a facet that the os peroneum can articulate with
Navicular (scaphoid)
- Concave posterior
- Convex anterior
- Articulates with talus, 3 cuneiforms, cuboid
Navicular posterior surface structures
- Facet for head of talus
Facet for head of talus
- Large, oval, concave facet
- Located posteriorly
- Articulates with talar head (talonavicular joint, part of midtarsal joint)
Navicular anterior surface structures
- 3 articular facets separated by 2 faint crests
- Facet for medial cuneiform
- Facet for intermediate cuneiform
- Facet for lateral cuneiform
Facet for medial cuneiform
- Largest cuneiform facet
- Triangle shaped medial facet on anterior surface
- Apex superior
Facet for intermediate cuneiform
- Triangle shaped middle facet on anterior surface
- Apex inferior
Facet for lateral cuneiform
- Triangle shaped lateral facet on anterior surface
- Apex inferomedial
Navicular lateral suface structures
- Facet for cuboid
Facet for cuboid
- Small facet on lateral surface
- Present in 50% of individuals
- Continuous with facet for lateral cuneiform
- If not present it is a fibrous joint
Navicular medial surface structures
- Navicular tuberosity
Navicular tuberosity
- Prominent projection on medial surface at top of medial arch
- Easily palpated
- Os tibiale externum (os navicular secundum)
Navicular tuberosity is an attachment point for
- Tibialis posterior
- Parts of spring and deltoid ligaments
Os tibiale externum (os navicular secundum)
- If present, located posterior to tuberosity
- Within tendon of tibialis posterior
Navicular inferior surface structures
- Groove for tibialis posterior tendon
- Tubercle for spring ligament (beak of navicular)
Groove for tibialis posterior tendon
- Groove on plantar surface of navicular
- Inferior to navicular tuberosity
- Allows for part of the tibialis posterior tendon to pass into foot
Tubercle for spring ligament (beak of navicular)
- Lateral to groove for tibialis posterior tendon
- Spring ligament attaches here
Cuneiforms (Latin for shaped like a wedge)
- Medial (1st)
- Intermediate (Middle or 2nd)
- Lateral (3rd)
- Part of the medial longitudinal arch and transverse arch
Medial cuneiform characteristics
- Largest
- Extends furthest distally
Intermediate cuneiform characteristics
- Smallest
- “Keyhole”
- Distal end is recessed most proximal of the 3
Medial (1st) cuneiform articulates with
- 1st & 2nd metatarsals
- Intermediate cuneiform
- Navicular
- Largest cuneiform
Posterior surface (medial cuneiform)
- Posterior facet
- Concave face that articulates with navicular
- Triangular in shape
- Apex superior
Lateral surface (medial cuneiform)
- Roughened and concave
- “Hockey stick and puck facets”
- L-shaped articular facet for intermediate cuneiform
- Oval shaped articular facet for medial base of second metatarsal
L-shaped articular facet (lateral surface of medial cuneiform) is located
- Superior and proximal (posterior)
Oval shaped articular facet (lateral surface of medial cuneiform) is located
- Superior and distal
- Can be continuous with the facet for intermediate cuneiform
Medial surface (medial cuneiform)
- Rough
- Smooth oval impression for tibialis anterior tendon
- Located antero-inferior aspect
Inferior/plantar surface (medial cuneiform)
- Roughened tuberosity
- Anterior: attachment for tibialis anterior (medial plantar) and fibularis longus (lateral plantar)
- Posterior: attachment for tibialis posterior
Anterior surface (medial cuneiform)
- Anterior facet for base of 1st metatarsal
- Large kidney-shaped (reniform) facet on anterior surface
Intermediate (2nd) cuneiform articulates with
- Medial/lateral cuneiforms
- Base of 2nd metatarsal
- Navicular
Intermediate (2nd) cuneiform characteristics
- Smallest cuneiform
- Apex of the transverse arch
Medial surface (intermediate cuneiform)
- Inverted L-shaped articular facet for medial cuneiform
- Posterior and superior border
Anterior surface (intermediate cuneiform)
- Convex
- Triangular shaped articular facet for 2nd metatarsal base
- Apex inferior
Lateral surface (intermediate cuneiform)
- Articular facet for lateral cuneiform
- Shaped like a B
- On lateral surface along the proximal (posterior) border
Posterior surface (intermediate cuneiform)
- Concave triangular facet
- Articulates with navicular
- Apex is inferior
Superior/dorsal surface (intermediate cuneiform)
- Rectangular
Lateral (3rd) cuneiform articulates with
- 2-4 metatarsals
- Intermediate cuneiform
- Cuboid
- Navicular
Posterior surface (lateral cuneiform)
- Triangle shaped articular facet for navicular
- Apex inferior
Medial surface (lateral cuneiform)
- B-shaped articular facet for intermediate cuneiform (along proximal border)
- Articular facet for 2nd metatarsal base (2 demi-facets on medial surface along distal border, inferior one is smaller and may be absent)
Anterior surface (lateral cuneiform)
- Triangular shaped articular facet for 3rd metatarsal base
- Apex inferior
Lateral surface (lateral cuneiform)
- Large oval shaped articular facet for cuboid (along the posterior superior aspect)
- Small articular facet for 4th metatarsal base (at the anterior/superior edge)
Superior/dorsal surface (lateral cuneiform)
- Rectangular shaped
