Overview
The metatarsal bones are composed of five long bones. The 1st metatarsal is the thickest and has less chance of fracture; the 2nd-4th metatarsals have the most chance of fracture. The fifth metatarsal base is a cancellous bone and is often fractured by violent contraction of the short fibularis muscle. The fracture of the metatarsal (fracture of the metatarsal) is mostly caused by direct violence. Clinically, there are fractures of the metatarsal stem, fractures of the base of the 5th metatarsal, and fatigue fractures of the metatarsal neck.
Etiology and pathogenesis
1. Metatarsal trunk fractures.
Mostly due to direct external force from heavy object crushing. The second metatarsal is the most common, followed by the second and fifth metatarsals. Often several fractures exist simultaneously. Due to the mutual support between the metatarsals, displacement after fracture is usually not obvious, and only a few of them are angled to the metatarsal side or the distal segment overlaps below the proximal side due to external forces.
2.Fracture of the base of the 5th metatarsal.
Mostly due to the avulsion fracture caused by the violent contraction of the peroneal short muscle attached to it during the foot inversion injury, the displacement will not be too large, pay attention to the differentiation from the metatarsal base epiphysis not closed and the seed bone of the peroneal longissimus tendon. The latter two bone edges are smooth, regular, and bilateral.
3. Metatarsal neck fracture.
After the fracture, the metatarsal head is plantarflexed and displaced to the metatarsal side. If the deformity is not corrected, the protruding metatarsal head may cause local pain when bearing weight after healing.
4. Fatigue fracture.
It is mostly seen in soldiers who march long distances, so it is also known as march fracture. Long-distance walking or marathon running, the foot muscles are overworked, the arch collapses, and the weight-bearing of the second and third metatarsals increases, exceeding the loading capacity of the bone cortex and trabeculae, which gradually results in fracture.
Clinical manifestations
Metatarsal fracture, post-injury local pain, swelling, pressure pain, subcutaneous bruising, foot shortening deformity can not walk. Examination may reveal limited pressure pain at the fracture site with longitudinal percussion pain. The initial symptom of fatigue fracture is forefoot pain, which is aggravated by exertion and relieved by rest, with local pressure pain. After a few weeks, bone scabs form and a hard mass can be locally felt. The diagnosis is often delayed due to the absence of an obvious history of trauma. x-ray examination, which can be negative in the early stage, reveals fracture lines and bone scabs after 2 to 3 weeks.
Laboratory and other tests
X-ray radiography; may show signs of fracture, but fatigue fracture, early X-ray film can be mostly negative, generally fracture less than complete break, while the periosteum produces new bone.
Diagnosis
1, metatarsal fracture, local pain, swelling, and pressure pain.
2.Before fatigue fracture, initially forefoot pain, intensified after labor, reduced after rest, 2-3 weeks later in the local can be felt with bump.
3.X-ray examination: it can show signs of fracture, early X-ray examination may be negative.
Treatment
1.Metatarsal trunk fracture.
If there is no displacement or mild displacement, it does not need to be repositioned and can be moved to the ground after 3-4 weeks of rest. In case of multiple open fractures with severe displacement, if the fracture cannot be repositioned manually, consider incision and internal fixation with steel pins to restore the longitudinal and transverse arches of the foot, and fixation with a short leg cast for 4-6 weeks after surgery.
2. Basal fracture of the 5th metatarsal.
Generally, it is rarely displaced and does not need to be repositioned, and can be treated by applying local blood-activating and pain-relieving herbs, wrapping with bandages, and resting appropriately for 2-3 weeks.
3. Metatarsal neck fracture.
If the fracture is displaced, the toe should be repositioned, and the fracture surface should be forced to be plantar-flexed, and the fracture surface should be held against each other. If the manual repositioning fails, an incision is made and the fracture is fixed internally with crossed steel pins, which are removed after 4-6 weeks. After the bone heals firmly, walk with weight.
4. Fatigue fracture of metatarsal neck.
Rest is the main focus, and the anterior part of the shoe can be appropriately padded to make the negative focus posteriorly.