The fifth metatarsal bone is a

long bone The long bones are those that are longer than they are wide. They are one of five types of bones: long, short, flat, irregular and sesamoid. Long bones, especially the femur and tibia, are subjected to most of the load during daily activities ...

in the foot, and is palpable along the

distal Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position provi ...

outer edges of the feet. It is the second smallest of the five

metatarsal bones The metatarsal bones or metatarsus (: metatarsi) are a group of five long bones in the midfoot, located between the tarsal bones (which form the heel and the ankle) and the phalanges ( toes). Lacking individual names, the metatarsal bones are ...

. The fifth metatarsal is analogous to the

fifth metacarpal bone The fifth metacarpal bone (metacarpal bone of the little finger or pinky finger) is the most medial and second-shortest of the metacarpal bones. Surfaces It presents on its base one facet on its superior surface, which is concavo-convex and artic ...

in the hand. As with the four other metatarsal bones it can be divided into three parts; a base, body and head. The base is the part closest to the

ankle The ankle, the talocrural region or the jumping bone (informal) is the area where the foot and the leg meet. The ankle includes three joints: the ankle joint proper or talocrural joint, the subtalar joint, and the inferior tibiofibular joint. The ...

and the head is closest to the toes. The narrowed part in the middle is referred to as the body (or shaft) of the bone. The bone is somewhat flat giving it two surfaces; the plantar (towards the sole of the foot) and the dorsal side (the area facing upwards while standing). These surfaces are rough for the attachment of

ligament A ligament is a type of fibrous connective tissue in the body that connects bones to other bones. It also connects flight feathers to bones, in dinosaurs and birds. All 30,000 species of amniotes (land animals with internal bones) have liga ...

s. The bone is curved longitudinally, so as to be concave below, slightly convex above. The base articulates behind, by a triangular surface cut obliquely in a transverse direction, with the

cuboid In geometry, a cuboid is a hexahedron with quadrilateral faces, meaning it is a polyhedron with six Face (geometry), faces; it has eight Vertex (geometry), vertices and twelve Edge (geometry), edges. A ''rectangular cuboid'' (sometimes also calle ...

; and medially, with the fourth metatarsal. The fifth metatarsal has a rough eminence on the lateral side of its base, known as the tuberosity or the styloid process. The plantar surface of the base is grooved for the tendon of the abductor digiti quinti. The head articulates with the fifth

proximal phalanx The phalanges (: phalanx ) are digital bones in the hands and feet of most vertebrates. In primates, the thumbs and big toes have two phalanges while the other digits have three phalanges. The phalanges are classed as long bones. Structu ...

, the first bone in the fifth toe. A strong band of the plantar aponeurosis connects the projecting part of the tuberosity with the lateral

process A process is a series or set of activities that interact to produce a result; it may occur once-only or be recurrent or periodic. Things called a process include: Business and management * Business process, activities that produce a specific s ...

of the tuberosity of the

calcaneus In humans and many other primates, the calcaneus (; from the Latin ''calcaneus'' or ''calcaneum'', meaning heel; : calcanei or calcanea) or heel bone is a bone of the Tarsus (skeleton), tarsus of the foot which constitutes the heel. In some other ...

Proximal fractures

$Proximal fractures of 5th metatarsal$ Proximal fractures of the fifth metatarsal are common, and are distinguished by their locations: *A ''proximal

diaphysis The diaphysis (: diaphyses) is the main or midsection (shaft) of a long bone. It is made up of cortical bone and usually contains bone marrow and adipose tissue (fat). It is a middle tubular part composed of compact bone which surrounds a centr ...

'' fracture is typically a stress fracture, commonly among athletes. *A ''

metaphysis The metaphysis (: metaphyses) is the neck portion of a long bone between the epiphysis and the diaphysis. It contains the growth plate, the part of the bone that grows during childhood, and as it grows it ossifies near the diaphysis and the ep ...

'' fracture is also called a

Jones fracture A Jones fracture is a broken bone in a specific part of the fifth metatarsal of the foot between the base and middle part that is known for its high rate of delayed healing or nonunion. It results in pain near the midportion of the foot on ...

. Due to poor blood supply in this area, such a fracture sometimes does not heal and surgery is required. *A '' tuberosity'' fracture is also called a pseudo-Jones fracture or a dancer's fracture. It is typically an

avulsion fracture An avulsion fracture is a bone fracture which occurs when a fragment of bone tears away from the main mass of bone as a result of physical trauma. This can occur at the ligament by the application of forces external to the body (such as a fall ...

. Normal anatomy that may simulate a fracture include mainly: *The "apophysis", which is the secondary

ossification center An ossification center is a point where ossification of the hyaline cartilage begins. The first step in ossification is that the chondrocytes at this point become hypertrophic and arrange themselves in rows. The matrix in which they are imbedd ...

of the bone, and is normally present at 10 – 16 years of age. * Os vesalianum, an

accessory bone An accessory bone or supernumerary bone is a bone that is not normally present in the body, but can be found as a anatomical variation, variant in a significant number of people. It poses a risk of being misdiagnosis, misdiagnosed as bone fracture ...

which is present in between 0.1 - 1% of the population.

Muscle attachments

The

tendon A tendon or sinew is a tough band of fibrous connective tissue, dense fibrous connective tissue that connects skeletal muscle, muscle to bone. It sends the mechanical forces of muscle contraction to the skeletal system, while withstanding tensi ...

of the fibularis tertius inserts on the medial part of the dorsal surface and the fibularis brevis on the dorsal surface of the tuberosity. The plantar surface of the base is grooved for the tendon of the abductor digiti quinti, and gives origin to the flexor digiti minimi brevis. The fourth dorsal interosseus muscle originates from the medial side of shaft. The function of the muscle is to spread the toes. The third Plantar interosseus muscle originates from the medial side of the base and shaft of the fifth metatarsal. The function of the muscle is to move the fourth toe medially and move the toes together. The horizontal head of the adductor hallucis from the deep transverse metatarsal ligament, a narrow band which runs across and connects together the heads of all the metatarsal bones.

Additional images

File:Gray290.png, Skeleton of foot. Medial aspect. File:Gray360.png, Oblique section of left intertarsal and tarsometatarsal articulations, showing the synovial cavities. File:Foot bones - tarsus, metatarsus.jpg, Foot bones – tarsus, metatarsus File:Foot bones - metatarsus and phalanges.jpg, Foot bones – metatarsus and phalanges File:Metatarsus.jpg, Metatarsus

References

{{Bones of lower extremity Bones of the lower limb Bones of the foot 5