I. Overview The carpal navicular is the most radial of the proximal carpal bones, and its unique anatomic morphology and biomechanical characteristics make it the one with the highest fracture incidence among all carpal bones. The irregular morphology of the navicular bone also makes it easy for the fracture line to be obscured in plain radiographs, resulting in a missed diagnosis, and its unique blood supply system results in a high rate of necrosis and non-union of the proximal fracture. Second, the etiology of carpal navicular fractures is mostly due to the dorsal extension of the wrist joint supported by the patient during a fall or fall injury. Only the fracture of the navicular tuberosity may be caused by direct violence. Clinical manifestations of carpal navicular fracture can be manifested as local swelling of the wrist joint, more obvious in the area of the nasal fossa, which is normally manifested as a soft tissue depression, and the disappearance of the soft tissue depression after the trauma is indicative of its swelling. In addition, pain in the wrist joint (especially radial pain) is also an important clinical manifestation, and some patients may have limited wrist movement. In clinical work, there are also some patients with less obvious manifestations of swelling, pain, and limitation of movement, but the pressure pain in the area of the nasal fossa during physical examination has certain diagnostic significance; in addition, most patients have a positive Watson test. The diagnosis of navicular fracture depends on reliable imaging. radiographs are the initial screening tool, and when a navicular fracture is suspected, radiographs should be taken in multiple positions (frontal, lateral, oblique, navicular, etc.). If the fracture shadow is not seen on the radiographs in the acute phase, further CT examinations may be performed to confirm the diagnosis. In places where conditions are limited, the wrist can also be fixed in a cast for about 2 weeks and then reviewed on a multiposition radiograph, when the fracture line becomes more obvious due to bone resorption at the fracture site. Magnetic resonance examination is not more sensitive than CT for the diagnosis of navicular fracture, so it is not generally used as the first choice of examination, but only in the case of possible combination with other ligament injuries. V. Diagnosis Usually, it should not be difficult to make a clear diagnosis based on the typical symptoms, signs and imaging examinations. However, while the diagnosis of navicular fracture is clear, the site of the fracture should also be clarified to distinguish whether it is a fresh fracture or an old fracture, whether the fracture is displaced, whether there is a bone defect, whether there is a palmar flexion deformity of the distal navicular fracture block, whether there is sclerosis of the proximal pole, whether there is osteoarthritic manifestation, and whether there are other combined injuries. Because all of these factors directly determine the choice of further treatment. VI. Treatment 1. Treatment of fresh navicular fracture Fresh navicular fracture should be confirmed by imaging whether it is a stable type of fracture without displacement, if it is this type of fracture, a tubular cast fixation can be considered and reviewed 2 weeks after surgery, if the cast is loosened due to swelling, the tubular cast needs to be replaced, and the postoperative review of the film should be done 6 weeks, if it is not healed, it can be reviewed every 3-4 weeks until it is healed, if There is no sign of healing for more than 4-6 months of cast fixation, the need for surgical intervention can be considered. For stable undisplaced fresh navicular fractures, if the patient cannot receive prolonged tubular cast fixation for various reasons, percutaneous hollow screw internal fixation is also feasible, with early functional exercise after surgery. For unstable or displaced fresh navicular fractures, surgical treatment is required. After repositioning the fracture, internal fixation with kerf pins or hollow screws is used, and the postoperative fixation with or without auxiliary plaster or brace is decided according to the firmness of fixation. For old navicular fractures, it is necessary to distinguish whether there is osteoarthritis around the navicular bone. If there is no osteoarthritis, incision and repositioning, bone grafting, and internal fixation are feasible. If osteoarthritis is already present, different surgical options need to be selected according to the extent of osteoarthritis. VII. Prevention For the prevention of carpal navicular fracture is mainly to strictly follow the workflow during high-risk work and sports, and to wear wrist brace.