Hands Skeleton Three main Groups of Bones constitute

Hand’s Skeleton Three main “Groups” of Bones constitute the Skeleton of the Hand. From proximal to distal, these include: Carpal Bones Metacarpal Bones Phalanges Additionally, the hand also contains sesamoid bones. 1/5/2022 1

Hand’s Skeleton Carpal Bones: The hand contains 8 carpals in two rows: Proximal Row consists of: Scaphoid, Lunate, Triquetrum, & Pisiform. Distal Row consists of: Trapezium, Trapezoid, Capitate, & Hamate. 1/5/2022 2

Hand’s Skeleton The anterolateral margins of the scaphoid and trapezium elevate to make an attachment site for the flexor retinaculum. Hamate bone has a bony hook volarly, and pisiform stands on triquetrum; thus, these 2 protrusions provide the medial attachment side for the flexor retinaculum 1/5/2022 3

Applied Anatomy The carpus is cartilaginous at birth. Order of ossification is as follows: Capitate, Hamate, Triquetrum, Lunate, Scaphoid, Trapezium Trapezoid, Pisiform. Age: 2 nd. 3 rd. months; 3 rd. year, LSTT 4 th. Year, P 12 th. Year. 1/5/2022 4

Applied Anatomy: Fractured scaphoid versus blood supply (ischemic necrosis – proximal portion / in 13% of individuals), Lunate dislocation / fractured scaphoid / median nerve compression. 1/5/2022 5

Metacarpals: There are five metacarpal bones, all are long bones; thus each has base, shaft & head. The first metacarpal is the shortest, strongest & most mobile. It articulates with the trapezium proximally in a saddle joint. 1/5/2022 6

Metacarpals The other 4 metacarpals contact with the trapezoid, capitate & hamate, & lateral-medial surfaces of metacarpal bases. Heads of the metacarpals form the knuckles, 1/5/2022 7

Metacarpals The shaft of each metacarpal bone is slightly concave forward Triangular in transverse section, with medial, lateral, and posterior surfaces. 1/5/2022 8

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