The navicular bone forms a joint with the distal radius, lunar bone, skull, and large and small polygonal bones through many ligaments, and it plays an extremely important role in maintaining the stability and power transmission of the wrist joint. A navicular fracture can lead to dysfunction of the entire wrist joint, and the best outcome can only be achieved through timely diagnosis, effective treatment, and appropriate functional exercises. The incidence of navicular fracture is second only to radius fracture in upper limb fractures, accounting for 2% of all fractures in the body and occurring mostly in men aged 15-40. The ratio of male to female is 6:1. Navicular fractures are rare in people under 15 years of age and occur mostly in the proximal end of the navicular bone, which is an incomplete fracture. The mechanism of a typical navicular fracture is dorsal extension of the wrist joint, which occurs in sports activities and motorcycle accidents. There are more than 10 different X-ray positions to diagnose navicular fractures. The most commonly used positions are the frontal and lateral wrist joint and two special positions (45º anterior rotation and 45º posterior rotation). At present, the secher position is increasingly used. The film is taken with the affected hand in the fisted ruler position, with the wrist and forearm flat on the negative box. This is because the navicular bone is not in the same plane as the wrist joint, but is tilted 45º to the palmar side. stecher position allows dorsal extension of the wrist joint so that the navicular bone is parallel to the radiograph; ulnar deviation of the wrist allows the navicular bone to extend completely from the wrist joint fossa, increasing the distance from the radial tuberosity and widening the fracture gap so that the fracture line is clearly visible on the radiograph. The navicular bone overlaps with other carpal bones on lateral radiographs, and it is difficult to diagnose a navicular fracture with lateral radiographs alone, but it is helpful to understand changes in the wrist joint axis. Diagnosis The diagnosis of a navicular fracture should be accompanied by exclusion of other fractures and ligamentous injuries, most commonly distal radius and radial tuberosity fractures. The incidence of navicular fractures combined with distal radius fractures ranges from 0.7% to 6.5%, while the incidence of combined radial tuberosity fractures is 6%. With the widespread use of arthroscopic techniques in the wrist joint, the incidence of navicular fractures with intertrochanteric ligament injuries was found to be as high as 35%, and the incidence of displaced navicular fractures with ligament injuries was even higher. Some scholars suggest that the navicular fracture should be routinely examined for damage to the intertrochanteric ligament while the navicular fracture is being fixed by incision. The navicular bone has a complex three-dimensional structure, and the diagnosis of navicular fracture by X-ray alone has some limitations. Up to 25% of navicular fractures cannot be diagnosed on initial wrist radiographs, and in addition, it is difficult to accurately determine the severity of the fracture (e.g., displaced, comminuted fracture, etc.) on radiographic plain films, and the conclusions reached vary widely between observers. In the past, patients with a high clinical suspicion of navicular fracture who initially had negative radiographic findings were managed with 10-14 d of external fixation in a plaster brace followed by radiographs. The rationale was that during external fixation the bone around the fracture would resorb and the fracture line would widen, making the fracture line clearly visible when the film was taken again. However, some studies have shown that this treatment does not significantly improve the diagnosis rate of navicular fracture; moreover, people who do not have navicular fracture also need to be fixed in plaster, and they cannot work normally during plaster fixation. Currently, CT, MRI or nuclear medicine examinations are performed in patients with suspected navicular fractures that cannot be diagnosed by X-ray to confirm or exclude navicular fractures. CT has a significant advantage over x-ray in that even the smallest fracture fracture can be visualized on CT films and the degree of fracture displacement can be determined. The most commonly used CT examination position is oblique sagittal, with the tomographic plane parallel to the long axis of the navicular bone and a scan thickness of 1-1.5 mm. preoperative CT examinations have been increasingly used routinely to accurately understand the degree of displacement of the fracture mass, fracture staging, and to determine the appropriate treatment plan. MRI has a sensitivity of 100% and a specificity of 92%, and can provide information on the blood supply to the proximal fracture and whether there is ligamentous injury. However, MRI is not the preferred method for diagnosing navicular fractures because it is more expensive than CT and is less accurate than CT in diagnosing avulsion injuries of the navicular bone cortex. Nuclear medicine examination has high sensitivity but low specificity in diagnosing navicular fractures and is mainly It is used to exclude navicular fractures. Nuclear medicine examination is positive 7-24 h after fracture and lasts for more than a year. It is best to perform nuclear medicine examination 48 h after the injury. A negative result can rule out a navicular fracture; a positive result cannot directly determine the location of the navicular fracture, and a false-positive result can occur in soft tissue injuries of the wrist. Ultrasonography has been reported to have high specificity and sensitivity for confirming navicular fractures, but most studies have shown that ultrasonography is not valuable for confirming navicular fractures. In conclusion, the imaging of navicular fracture is most important in frontal and lateral wrist x-ray and CT examination. Typing The purpose of typing of navicular fractures is to guide treatment, mainly according to the location of the fracture, the direction of the fracture line and stability. The most commonly used staging methods are the Herbert staging, Russe staging, and AO staging. The Russe typing classifies the navicular fracture into horizontal, transverse and vertical types, which makes it easy to determine the stability of the fracture. The horizontal type is the most stable, the horizontal type is the second most stable, and the vertical type is the least stable.