What is a triquetrum fracture?
The triquetrum is a wedge-shaped carpal bone in the proximal row of the carpus (Guo et al., 2021). It contains three bones in the outer wrist, lying in two rows between the hand and forearm. It is an essential body part for the motion of the wrist in the radiocarpal and midcarpal joints (Nanduri et al., 2022).
A triquetral fracture is a break in the three-sided bone in the outer wrist; it is the second most common carpal fracture (Guo et al., 2021). The protection of the triquetrum from surrounding carpal bones means that carpal bone fractures are typically caused by the impact of adjacent bony structures or the avulsion of attached ligaments rather than direct force. Fractures due to impaction are the most common. However, those caused by avulsion are still significant (Guo et al., 2021).
The most common cause of a triquetral fracture is a fall onto an outstretched hand with the wrist in ulnar deviation or extension. The typical mechanisms are impaction by the hamate or ulnar styloid, and avulsion from the dorsal radiotriquetral or dorsal scaphotriquetral ligaments.
The dorsal cortical fracture is the most common within triquetral fractures, accounting for 93-95% of triquetral fractures (Nanduri et al., 2022). The second and third most common types are volar cortical and triquetral body fractures (Guo et al., 2021). It is also common for significant soft tissue injuries to occur due to the various ligaments that attach to the triquetrum, commonly the dorsal scaphotriquetral ligament (Becce et al., 2013).
The main symptoms of a triquetral fracture are tenderness and wrist pain. There also may be bruising and swelling, or you may notice your finger or hand hanging at an unusual angle. In addition, there may be pain when you attempt to grip something, bend your wrist, or make a fist.
