Hand & Wrist Anatomy

The hand and wrist are comprised of twenty seven bones. There are eight carpal (wrist) bones and nineteen metacarpal and phalanges (bones of the fingers) (Fig.1).

Hyaline Cartilage

As with all the synovial joints in the body, the carpal, metacarpal and phalanges are covered with hyaline cartilage (Fig.2). This material cushions and provides a smooth surface which permits movement with minimal friction.

Nerves

The hand and wrist are primarily innervated by two nerves; the Median and Ulnar nerves (Fig.3) run the length of the arm providing the electrical impulses which allow the fingers, wrist and hand to move.

Ligaments

Ligaments connect bone to bone. Wrist stability is the result of the orientation of the individual carpal bones and their ligament connections (Fig.4). Wrist instability typically results from an interference of the ligamentous support between the carpal bones and between the radius and the carpals.