Lunate fractures are a carpal injury that if left untreated, can result in significant carpal instability.
Lunate fractures account for around 4% of all carpal fractures 1.
Lunate fractures are often secondary to axial loading of the head capitate bone, this is seen in forceful hyperextension with ulnar deviation 2.
The lunate is made up of the volar pole, body, and dorsal pole. Volar pole fractures are more commonly observed as the lunate is compressed by the capitate. Given the lunate's position in the wrist, there is significant overlap from other carpal bones and hence these fractures can be subtle.
The lunate is an important stabilizer of the wrist, fractures can lead to ligamentous injury and overall volar intercalated segment instability. There may be other associated injuries that require further investigation via cross-sectional imaging 1,2.
Treatment and prognosis
Isolated fractures without displacement or subluxation can be managed conservatively, however fractures that possess joint subluxation are unstable and require surgical intervention 2.
Around 20% of patients possess a single-vessel supply to their lunate hence there is an increased possibility of avascular necrosis, the remaining cohort typically has a two-vessel supply and intraosseous anastomosis 2.
- 1. Rathachai Kaewlai, Laura L. Avery, Ashwin V. Asrani, Hani H. Abujudeh, Richard Sacknoff, Robert A. Novelline. Multidetector CT of Carpal Injuries: Anatomy, Fractures, and Fracture-Dislocations1. (2008) RadioGraphics. 28 (6): 1771-84. doi:10.1148/rg.286085511 - Pubmed
- 2.Meenalochani Shunmugam, Joideep Phadnis, Amy Watts, Gregory I. Bain. Lunate fractures and associated radiocarpal and midcarpal instabilities: a systematic review:. (2017) Journal of Hand Surgery (European Volume). 43 (1): 84-92. doi:10.1177/1753193417740850 - Pubmed
Related Radiopaedia articles
- wrist fractures and dislocations
- distal radial fracture
- carpal bones
- carpal instability
- triangular fibrocartilaginous complex (TFCC) injuries
- ulnar-sided wrist impaction and impingement syndromes
- soft tissue and tendons