Hamate bone
Encyclopedia
The hamate bone is a bone
in the human
hand
that may be readily distinguished by its wedge-shaped form, and the hook-like process which projects from its volar surface. It is situated at the medial
and lower angle of the carpus
, with its base downward, resting on the fourth and fifth metacarpal bones, and its apex directed upward and lateralward. The bone is also found in many other mammals, and is homologous
with the "fourth distal carpal" of reptiles and amphibians.
The etymology derives from the Latin hamatus "hooked," from hamus which means "hook."
.
The inferior surface articulates with the fourth and fifth metacarpal bones, by concave facets which are separated by a ridge.
The dorsal surface is triangular and rough for ligamentous attachment.
The volar surface presents, at its lower and ulnar side, a curved, hook-like process, the hamulus
, directed forward and lateralward.
The medial surface articulates with the triangular bone by an oblong facet, cut obliquely from above, downward and medialward.
The lateral surface articulates with the capitate by its upper and posterior part, the remaining portion being rough, for the attachment of ligaments.
er hits the ground hard with their golf club
on the downswing. The fracture is usually a hairline fracture, commonly missed on normal X-Ray
s. Symptoms are pain aggravated by gripping, tenderness over the hamate and symptoms of irritation of the ulnar nerve
. This is characterized by numbness and weakness of the pinky finger with partial involvement of the ring finger as well, the "ulnar 1½ fingers."
It is also a common injury in baseball
players. A number of professional baseball players have had the bone removed during the course of their careers. This injury also appears in amateur ice hockey
players as they drive their stick to the ice to flex the stick for accelerated speed on a slap shot. This condition has been called "Wilson's Wrist".
The calcification of the hammate bone is seen on radiographs during puberty and is sometimes used in orthodontics
to determine if the adolescent patient is suitable for orthognathic intervention (e.g. before or at their growth spurt).
Bone
Bones are rigid organs that constitute part of the endoskeleton of vertebrates. They support, and protect the various organs of the body, produce red and white blood cells and store minerals. Bone tissue is a type of dense connective tissue...
in the human
Human
Humans are the only living species in the Homo genus...
hand
Hand
A hand is a prehensile, multi-fingered extremity located at the end of an arm or forelimb of primates such as humans, chimpanzees, monkeys, and lemurs...
that may be readily distinguished by its wedge-shaped form, and the hook-like process which projects from its volar surface. It is situated at the medial
Medial
- Medial magmas :In abstract algebra, a medial magma is a set with a binary operation which satisfies the identity \cdot = \cdot , or more simply, xy\cdot uv = xu\cdot yv...
and lower angle of the carpus
Carpus
In tetrapods, the carpus is the sole cluster of bones in the wrist between the radius and ulna and the metacarpus. The bones of the carpus do not belong to individual fingers , whereas those of the metacarpus do. The corresponding part of the foot is the tarsus...
, with its base downward, resting on the fourth and fifth metacarpal bones, and its apex directed upward and lateralward. The bone is also found in many other mammals, and is homologous
Homology (biology)
Homology forms the basis of organization for comparative biology. In 1843, Richard Owen defined homology as "the same organ in different animals under every variety of form and function". Organs as different as a bat's wing, a seal's flipper, a cat's paw and a human hand have a common underlying...
with the "fourth distal carpal" of reptiles and amphibians.
The etymology derives from the Latin hamatus "hooked," from hamus which means "hook."
Surfaces
The superior surface, the apex of the wedge, is narrow, convex, smooth, and articulates with the lunateLunate
Lunate is a term meaning crescent or moon-shaped. In the specialized terminology of lithic reduction, a lunate flake is a small, crescent-shaped flake removed from a stone tool during the process of pressure flaking....
.
The inferior surface articulates with the fourth and fifth metacarpal bones, by concave facets which are separated by a ridge.
The dorsal surface is triangular and rough for ligamentous attachment.
The volar surface presents, at its lower and ulnar side, a curved, hook-like process, the hamulus
Hamulus of hamate bone
The volar surface of the hamate bone presents, at its lower and ulnar side, a curved, hook-like process, the hamulus, directed forward and lateralward....
, directed forward and lateralward.
The medial surface articulates with the triangular bone by an oblong facet, cut obliquely from above, downward and medialward.
The lateral surface articulates with the capitate by its upper and posterior part, the remaining portion being rough, for the attachment of ligaments.
Clinical significance
This is the bone most commonly fractured when an amateur golfGolf
Golf is a precision club and ball sport, in which competing players use many types of clubs to hit balls into a series of holes on a golf course using the fewest number of strokes....
er hits the ground hard with their golf club
Golf club (equipment)
A golf club is used to hit a golf ball in a game of golf. Each club is composed of a shaft with a grip and a clubhead. Woods are mainly used for long-distance fairway or tee shots; irons, the most versatile class, are used for a variety of shots; Hybrids that combine design elements of woods and...
on the downswing. The fracture is usually a hairline fracture, commonly missed on normal X-Ray
X-ray
X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...
s. Symptoms are pain aggravated by gripping, tenderness over the hamate and symptoms of irritation of the ulnar nerve
Ulnar nerve
In human anatomy, the ulnar nerve is a nerve which runs near the ulna bone. The ulnar collateral ligament of elbow joint is in relation with the ulnar nerve. The nerve is the largest unprotected nerve in the human body , so injury is common...
. This is characterized by numbness and weakness of the pinky finger with partial involvement of the ring finger as well, the "ulnar 1½ fingers."
It is also a common injury in baseball
Baseball
Baseball is a bat-and-ball sport played between two teams of nine players each. The aim is to score runs by hitting a thrown ball with a bat and touching a series of four bases arranged at the corners of a ninety-foot diamond...
players. A number of professional baseball players have had the bone removed during the course of their careers. This injury also appears in amateur ice hockey
Ice hockey
Ice hockey, often referred to as hockey, is a team sport played on ice, in which skaters use wooden or composite sticks to shoot a hard rubber puck into their opponent's net. The game is played between two teams of six players each. Five members of each team skate up and down the ice trying to take...
players as they drive their stick to the ice to flex the stick for accelerated speed on a slap shot. This condition has been called "Wilson's Wrist".
The calcification of the hammate bone is seen on radiographs during puberty and is sometimes used in orthodontics
Orthodontics
Orthodontics, orthodontia, or orthodonture is the first specialty of dentistry that is concerned with the study and treatment of malocclusions , which may be a result of tooth irregularity, disproportionate jaw relationships, or both...
to determine if the adolescent patient is suitable for orthognathic intervention (e.g. before or at their growth spurt).
Notable cases
- Jose CansecoJosé CansecoJosé Canseco Capas, Jr. is a Cuban-American professional baseball manager, outfielder, and designated hitter for the Yuma Scorpions of the North American League and former Major League Baseball player. He is the identical twin brother of former major league player and current teammate Ozzie Canseco...
, Oakland Athletics outfielder (1989) - Ken Griffey, Jr.Ken Griffey, Jr.George Kenneth "Ken" Griffey, Jr. , nicknamed "Junior" and "The Kid", is a former Major League Baseball outfielder and during his final years, designated hitter...
, Seattle Mariners outfielder (1996) - Jim ThomeJim ThomeJames Howard "Jim" Thome is a Major League Baseball player for the Philadelphia Phillies. He is the eighth player to hit 600 home runs in the major leagues. He is widely considered a future Hall of Famer.-Cleveland Indians :...
, Cleveland Indians first baseman (1996) - Eric HinskeEric HinskeEric Scott Hinske is a Major League Baseball outfielder, first baseman, and third baseman currently an Atlanta Braves organization...
, Atlanta Braves first baseman (2003) - Ryan KalishRyan KalishRyan Michael Kalish is an American professional baseball outfielder in the Boston Red Sox organization.A standout high school baseball and football player, he was drafted by the Red Sox in 2006...
, Boston Red Sox outfielder (2007) - Dustin PedroiaDustin PedroiaDustin Luis Pedroia is an American professional baseball second baseman with the Boston Red Sox of Major League Baseball. Pedroia has won several awards in Major League Baseball, including the 2007 American League Rookie of the Year and the 2008 AL MVP award...
, Boston Red Sox second baseman (2007) - Troy TulowitzkiTroy TulowitzkiTroy Trevor Tulowitzki , nicknamed Tulo, is a Major League Baseball shortstop for the Colorado Rockies.Tulowitzki's arm, range and instincts at shortstop are highly regarded...
, Colorado Rockies shortstop (2010) - Domonic Brown, Philadelphia Phillies outfielder (2011)
- Pablo SandovalPablo SandovalPablo E. Sandoval , nicknamed Kung Fu Panda, is a Venezuelan professional baseball infielder for the San Francisco Giants of Major League Baseball. Sandoval is a 5'11", 237 pound switch hitter. He was born left handed, but did not want to have to play outfield all of his career. He therefore...
, San Francisco Giants third baseman (2011) - Chase Woofter, Kansas City Royals second baseman (2011)