Summary
Second and Third Metatarsal Stress Fractures is associated with pain in the forefoot. They typically occur after prolonged, repetitive walking and are often call “march fractures”. Risk factors for the development of these stress fractures include: an increase in repetitive activities such as, walking; a foot shape that leads to loading over the involved metatarsal usually associated with a long second toe; or weak bones such that may occurs with osteoporosis. Treatment is rest and relative immobilization with a stiff soled shoe for a 6 to 8 week period to allow the fracture to heal. In addition, addressing the underling reason why the fracture occurred is important.
Clinical Presentation
Stress fractures involving the second or third metatarsal bones will often present with an aching pain associated with a swelling in the forefoot. They usually develop after a period of repetitive loading For example; there is usually a recent history of prolonged walking or running. In fact, these injuries are often called “march fractures” because they were commonly seen in army recruits who would go on long “marches” during basic training. There is likely to be localized tenderness in the involved bone although this discomfort will not be painful as an acute metatarsal fracture. Patients with second and third metatarsal stress fractures are often able to walk albeit with a noticeable limp. Second and third metatarsal stress fractures occur in a typical type of foot. A foot with an associated bunion and a longer second toe will predispose to a concentration of force in this area of the forefoot. Individuals with inherently weaker bones such as patients with osteoporosis or young women who do not have regular periods because they are too thin (amenorrhea) are at increased risk of developing stress fractures
Physical Examination
Physical examination will demonstrate localized tenderness at the site of the fracture. There may also be some associated forefoot swelling. The foot type in general may be flat, often with a long second and possible third toe. There may also be an associated callus over the forefoot, at the base of the second or third toe. It is the repetitive absorption of the loading force beyond the capacity of the bone to withstand this force that causes stress fracture.
Imaging Study
Plain x-rays of the foot may demonstrate subtle signs of a stress fracture. However, in acute stress fractures the actual fracture may not be immediately apparent on plain x-rays. The fracture may only be visualize on plain x-rays two to three weeks after the injury as it takes this time for enough new bone (callus) to form in response to the stress fracture to be seen on an x-ray. A bone scan or MRI will demonstrate a stress fracture or possibly a stress reaction (pre-stress fracture) earlier and one of these studies may be indicated if the diagnosis is in question. Metatarsal stress fractures typically occur at the neck region or in the mid-part (shaft) of the bone. Occasionally, high level ballet and modern dancers will generate stress fractures at the base of the metatarsal near the midfoot.
Treatment
Non-Surgical Treatment
Most stress fractures can be treated non-surgically. Similar to an undisplaced acute metatarsal fracture a metatarsal stress fracture needs to be protected for 6 to 8 weeks in order to facilitate bone healing. This is done with use of a stiff soled shoe or a stiff sole walker boat, with limited weight bearing through the heel. It’s often 3 to 5 months before a full recovery is made.
Surgical Treatment
Surgery is rarely indicated for a second or third metatarsal stress fracture. Occasionally, there may be an associated non-union that will need to be treated with surgery. In this case treatment would include open reduction and internal fixation (stabilizing with a plate and screws) as well as possibly a local bone graph.
Revised 01.09.2012
