The bones of the hand are essential for providing support and flexibility to the soft tissues. Anatomically, they can be divided into three groups- carpals, metacarpals, and phalanges. The carpals are eight irregularly shaped bones located in two rows- proximally, which contains the scaphoid and lunate, and distally, which contains the trapezium, trapezoid, capitate, and hamate. The metacarpals are five bones located in the middle of the hand, and the phalanges are the 14 bones that form the fingers and thumbs. Clinically, the bones of the hand are closely related to the nerves and blood vessels that pass through it, making fractures or dislocations of the hand bones potentially significant.
Proximally, the radius articulates with the scaphoid and lunate to form the wrist joint, famously known as the radio-carpal joint. The distal row of carpal bones articulates with the metacarpals.
The scaphoid is one of the most commonly fractured carpal bones, typically from a fall onto an outstretched hand (FOOSH). Characteristically, a scaphoid fracture is indicated by pain and tenderness in the anatomical snuffbox. Since the scaphoid bone receives its blood supply at its distal end, a fracture to the ‘waist’ of the scaphoid can interrupt the blood supply, leading to avascular necrosis.
Patients with a missed scaphoid fracture carry a high risk for developing osteoarthritis of the wrist in later life.
Two of the most common fractures of the metacarpals are Boxer's fracture and Bennett's fracture. Boxer's fracture, which involves the neck of the 5th metacarpal, is usually caused by a clenched fist striking a hard object, resulting in the distal part of the fracture being displaced anteriorly, hence shortening the affected finger. Meanwhile, Bennett's fracture is caused by forced hyperabduction of the thumb and involves the base of the 1st metacarpal, extending into the first carpometacarpal joint, causing instability and subluxation of the joint and likely requiring surgical repair.
The phalanges, which are the bones of the fingers, consist of three phalanges for each digit except for the thumb, which has two- a proximal and distal phalanx.
The bones of the hand are essential for providing support and flexibility, playing a critical role in enabling us to perform daily tasks. Anatomically, they can be divided into three groups- carpals, metacarpals, and phalanges. Clinically, the bones of the hand are closely related to the nerves and blood vessels that pass through it, making fractures or dislocations of the hand bones potentially significant.
Common fractures of the metacarpals include Boxer's fracture, which involves the neck of the 5th metacarpal, and Bennett's fracture, which involves the base of the 1st metacarpal. The scaphoid bone is one of the most commonly fractured carpal bones, typically from a fall onto an outstretched hand (FOOSH). Patients with a missed scaphoid fracture carry a high risk for developing osteoarthritis of the wrist in later life.
Thus, maintaining the health of the bones of the hand is essential for a healthy, functional, and flexible hand. Regular hand exercises and prompt treatment of fractures, dislocations, and other injuries is key to keeping the bones of the hand healthy and able to carry out its important functions.
