They have been classified into two types: homolateral and divergent. Lisfranc fracture-dislocation is characterized by traumatic disruption between the base of the second metatarsal and the medial cuneiform. Fifth metatarsal fractures have been described by Dameron and later on by Quill as Zone 1 (tuberosity avulsion fractures), Zone 2 (metaphyseal-diaphyseal junction fractures), and Zone 3 (proximal shaft stress fractures). Metatarsal fractures can be topographically classified into metatarsal head fractures, sub-capital fractures, midshaft fractures, and basal fractures. While interpreting roentgenograms, anatomical variants such as the os vesalianum (within the peroneus brevis tendon), the os peroneum (within the peroneus longus tendon), the os cuneometatarsale, and the os intermetatarseum have to be kept in mind along with the apophysis at the fifth metatarsal base which is visible between 11 and 14 years in boys and 9 and 11 years in girls. Stress X-rays which include passive adduction and abduction of the forefoot, can be performed under local anesthesia to reveal ligamentous instability at the Lisfranc joint. In scenarios of multiple fractures of the base of metatarsals, computed tomography is advised to rule out the possibility of Lisfranc fracture-dislocation. Īlternatively, MRI and Technetium scans can be ordered as they have a high sensitivity in detecting such fractures. A radiolucent resorption gap can be seen around the fracture, which confirms the diagnosis. To confirm the diagnosis of stress fractures, the x-rays can be repeated after 10 to 14 days of the onset of symptoms. Acute stress fractures are usually not detected with a standard X-ray. To diagnose metatarsal overload, additional weight-bearing roentgenograms, including the lateral view of the foot and tangential view of metatarsal heads, are helpful. The radiographic evaluation consists of standard views of the foot, including anteroposterior, 45 degrees oblique, and lateral projection. Such injuries are usually seen in osteoporosis patients and postmenopausal women. Insufficiency fractures can also be seen in metatarsal bones, which occur due to normal stress loading over a weakened bone. The other variety of fractures that are commonly seen in metatarsal bones is stress fractures which result from a small amount of repetitive force and are commonly associated with ballet dancers, athletes and soldiers, hence termed “march fracture.” Multiple risk factors associated with stress fractures include hyper load syndrome, Morton’s foot, anorexia nervosa, amenorrhea, and prolonged hypoestrogenism. In the former mechanism, the metatarsal head remains fixed while body weight lies over the hindfoot, especially against the base of metatarsals. The common mechanisms of injury are either longitudinal compression of the foot or rotation around a fixed forefoot. The Lisfranc fracture-dislocation can result due to falling from height or stairs. The Lisfranc joint complex consists of the tarsometatarsal joints. Supination injuries to the foot may result in avulsion fractures of the fifth metatarsal base because of the tension generated over the peroneus brevis tendon and the lateral cord of plantar aponeurosis. Indirect trauma occurs when there is a twisting movement of the hindfoot and leg while the forefoot is fixed. Direct trauma can occur due to the fall of heavy objects on the foot and is usually seen in industrial workers. Such injuries may vary from a simple isolated metatarsal fracture to crush injuries involving multiple fractures and drastic soft tissue compromise. The most common etiology for metatarsal fractures is either direct or indirect trauma.
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