There are two sides of the human wrist. The Dorsal part is the top of the wrist where you would normally look at your watch. The Volar part is the underside of the wrist where you would feel for your pulse. There are ligaments about the wrist that support the radiocarpal and midcarpal joints. These ligaments are located on both the dorsal and the volar surfaces of the wrist. The Dorsal ligaments are divided into two subgroups, Superficial and Deep. The Volar ligaments are divided into the same two subgroups.
1. Deep dorsal ligaments- These ligaments are located deep within the hand and wrist. They are primarily short structures connecting the carpals to each other and to the radius, ulna and metacarpals. There are the Dorsal Metacarpal Ligaments which join the bases of the metacarpals (finger bones) together. The Dorsal Carpometacarpal Ligaments stabilize and attach the metacarpal bases to the distal carpal bones. The Dorsal Intercarpal Ligaments connect the dorsal proximal to the distal row of carpals in order to further strengthen the joint capsule. The Dorsal Radiacarpal Ligaments are made up of four ligaments. These four ligaments maintain joint integrity and movement of joint surfaces. The Ulnar Collateral Ligament limits radial deviation. The last deep dorsal ligament of the wrist is the Radial Collateral Ligament which limits ulnar deviation of the wrist.
2. Superficial dorsal ligaments- The Extensor Retinaculum is the name given to the ligament that extends like a band across the carpal bones, making a bridge over the extensor tendons. The Extensor Tendons are encased in synovial sheaths and extend from the wrist to each metacarpal. The Synovial Sheaths reduce the friction of tendons within their tunnels.
1. Deep volar ligaments- There are short ligaments called Palmar Metacarpal Ligaments that attach the distal row of carpals to the bases of the metacarpal bones. The Palmar Intercarpal Ligaments connect individual carpals to each other. The Palmar Radiocarpal Ligaments are a broad band of ligaments that connect the volar edge of the distal radius to the proximal carpal row. These ligaments can be divided in four separate ligaments. The Palmar Ulnocarpal Ligament reinforces the underside of the wrist. The Pisometacarpal Ligament attaches the pisiform bone to the fifth metacarpal and reinforces articulation.
2. Superficial volar ligaments- The Palmar Aponeurosis is connected to the superficial palmar fascia and covers the palmar aspect of the metacarpals and interosseous muscles. The Flexor Retinaculum spans across the carpal bones forming a tunnel. The median nerve and flexor tendons pass through this tunnel. The Radial Collateral Ligament limits ulnar deviation of the wrist. The Triangular Fibrocartilage Complex contains three structures which help reinforce the ulnar side of the wrist.