Metatarsal Stress Fractures

What are metatarsals?

Your feet have to bear the weight of your whole body. They enable you to walk, jump, land and run. There are many bones in your foot, typically 26 in fact. Each foot can be divided into the tarsal bones, which are the larger bones that form the back section (rearfoot) of your foot, with the calcaneus (heel) being the largest. The five metatarsal bones (midfoot), they are relatively long bones, and are given names 1-5 from the first (big toe) largest to the smallest fifth (little toe). The metatarsals join to your toes, each toe has three phalanges, except the big toe, which only has two. This means that there are three joints in the toes (two joints in the big toe) and 14 phalanges bones in the toes altogether.  There are also many muscles, tendons and ligaments within your foot. Functionally, the ankle and foot have two principle functions: propulsion and support. The metatarsal bones play a major role in these functions. For propulsion they act like a rigid lever and for support they act like a flexible structure that aids balance, thus holding up the entire body.

What is a metatarsal stress fracture?

A stress fracture is a type of incomplete fracture in a bone. Stress fractures tend to occur as a result of overuse and are known as 'overuse injuries', due to the repetitive stress placed upon the bone, as opposed to trauma. It begins when a small crack appears in the cortex (outer shell) of the bone, which if left untreated may progress to a ‘through and through’ or overt fracture of the bone. Stress Fractures can occur in any bone, but are quite common in the metatarsal bones of the foot, particularly when excessive stress is placed upon the ball of the foot, there a hairline break (fracture) of a long metatarsal bone may occur. This occurs most frequently to the second, third, or fourth metatarsals. Historically, a metatarsal stress fracture has been called a "March fracture" because it was seen in soldiers who were marching for long periods of time. However, metatarsal stress fractures are not only seen in military recruits. They are commonly seen in athletes (especially runners), ballet dancers, gymnasts and other sports activities. Metatarsal stress fractures can affect anyone, not just athletes.

What causes a metatarsal stress fracture?

Metatarsal stress fractures generally occur due to overuse. They most commonly affect the second and third or fourth metatarsal bones as these bones have the most amount of stress placed on them when you are moving. They tend to occur in people who have recently increased the intensity, duration or frequency of their exercise. They can occur after new footwear, or insufficient rest, or continuing to exercise despite the presence of foot pain. Sometimes metatarsal stress fractures can occur in someone who has an underlying problem affecting the bones such as rheumatoid arthritis or osteoporosis. They can also occur in people who have lost sensation in their feet due to neurological problems, for example diabetes that has affected the nerves in the feet. Decreased density of the bones (e.g. osteoporosis) 
Unusual stress on a metatarsal due to mal position or another forefoot deformity (e.g. bunion).
Abnormal foot structure or mechanics (e.g. flatfoot, over pronation), or an increase in hill running or speed work.

What are the symptoms of a metatarsal stress fracture?

At the beginning, there may just be pain in the foot during exercise that is relieved by rest. After a while, the pain may not be relieved on resting and may be continuous. Pain tends to be more widespread in the foot when it starts. As the stress fracture progresses,pain tends to become sharp and more localised to the area of the fracture. Typically this means along the line of the metatarsal bone in the foot. Your foot may be tender to touch and pressure around the area of the fracture. You may also have some diffuse swelling of your skin over your forefoot. The second, third and fourth metatarsals are the most commonly affected, but the first and fifth metatarsals can also be affected. While a stress fracture of the second, third and fourth metatarsals usually heal well, the healing of a stress fracture to either the first or fifth metatarsal can be more problematic.

Symptoms of a metatarsal stress fracture include:

  • Pain can be dull or sharp, constant or intermittent in the forefoot, aggravated by walking or weight bearing activities.
  • Tenderness to pressure on the top surface of the foot over the affected metatarsal bone.
  • Diffuse swelling over the top of the stress fracture.
  • Aching pain may persist at rest and may even be severe enough to prevent sleep.

Frequently, the injury is so subtle that you may not recall any specific occurrence of injury, and you may simply develop a painful forefoot after some activity, such as walking, running, frequency sports or high impact sports. Activities like running can make the pain from a metatarsal stress fracture worse. Hopping or jumping can be particularly painful. If a metatarsal stress fracture progresses to a complete fracture there may be crepitus (a crunching noise) over the fracture site. At this point pain usually prevents weight bearing. A metatarsal stress fracture may not become apparent on x-rays until a few weeks after the injury.

Diagnosis

A typical presentation for someone with a metatarsal stress fracture would be pain and swelling in the ball of the foot, which is most severe in the push off phase of walking. Pressing on the bones in this area of the foot will reproduce the pain. Your podiatrist and G.P may suggest an X-ray of your foot if they suspect a metatarsal stress fracture. However, not all stress fractures show up on X-rays initially taken during the first two to three weeks after the injury often will not show any fracture In fact, about half of them never show up on a normal X-ray. A bone scan at this stage will be much more sensitive in diagnosing the early stress fracture. The decision to order a bone scan will be up to your podiatrist and G.P. A diagnostic bone scan involves an injection of a very small amount of radioactive material, usually into your arm. A gamma camera is then used that can detect the radiation emitted by the injected material. This can show up a stress fracture. MRI scanning is also sometimes used. Often times the diagnosis can be made based upon clinical findings, thus making the bone scan unnecessary. After several weeks, an x-ray will show the signs of new bone healing in the area of the stress fracture.

There are many factors that contribute to the development of a metatarsal stress fracture, including:

  • Medical conditions, such as osteoporosis and diabetes, which may result in decreased bone density.
  • Unusual stress on the metatarsal bone due to another forefoot deformity, such as a bunion.
  • Abnormal foot structure or function, such as a flat foot or a high-arched foot.
  • Increased levels of activity, especially without proper conditioning and insufficient rest between activity
  • (too much, too soon).
  • Inadequate footwear for your exercise activity, such as inadequate shock absorption on a hard surface.

If you suspect you have a stress fracture, it is important that you seek professional assessment and treatment, as there are many other causes of foot pain and swelling related to exercise. Your Podiatrist may require x-rays and diagnostic bone scans in order to determine the exact nature of your injury.

Treatment of Metatarsal Stress Fracture

Seek professional help as soon as possible.

Depending on the nature of your injury, treatment for a metatarsal stress fracture usually consists of;

  • Rest-the most important treatment is to rest your foot. This means avoiding any exercise or activity that may have caused your stress fracture.
  • Ice-initially applying ice to the top surface of the forefoot for about 20 minutes every hour to reduce swelling. Do not apply ice direct to skin.
  • Compression-wrap the foot in a tensor bandage with moderate compression may be applied to help reduce the swelling.
  • Elevation-elevating your foot can help to relieve pain.
  • Simple painkillers such as paracetamol and non-steroidal anti-inflammatory drugs such as ibuprofen may help to relieve pain.

Frequently, special walking boots are used to immobilise the stress fracture and support your foot so you are able to walk, but prevent you from pushing off the ball of your foot, thus eliminating any additional stress while the bone is healing. A podiatrist may also apply orthopaedic taping and padding to relieve stress from the metatarsals; Occasionally if pain is severe, you may need to have a below-the-knee plaster cast until the fracture is healed, or if pain is mild wear a running or walking shoe with a stiffer sole to reduce any flexion. However the removable walking boot is better than a plaster cast, because the boot can be removed for physiotherapy treatment, which is aimed at preventing stiffness in the ankle joint. In addition, cardiovascular fitness can be maintained by performing non-weight bearing exercises in a swimming pool. Surgery for metatarsal stress fractures is rarely needed.

Metatarsal stress fractures generally take around six to eight weeks to heal. However, it may be longer than this before a sports-person is fully back in action. After the fracture is healed, special attention should be applied to footwear assessment and advice on more appropriate footwear for your feet and your activities, in conjunction with; Prescription custom orthotics to avoid future recurrence of the injury. And a gradual return to exercise activities once the injury has healed. For those who may have osteoporosis, bone densitometry testing should be done, and appropriate treatment initiated to prevent further weakening of the bones. Nutritional and hormonal deficiencies or irregularities must also be addressed. Your podiatrist will advise which treatments are most suitable for your metatarsal stress fracture.

When can I return to activity?

Stress fractures normally heal without any complications and, in time, people are able to fully return to their previous activities. You can return to your activities when you can perform them without pain. This may take up to six to twelve weeks, occasionally longer. When you do start exercising again, you should gradually build up your activity levels after a stress fracture.

Can stress fractures be prevented?

There are a number of things that you can do to help prevent stress fractures. Exercise intensity and duration should be built up slowly and gradually. Rest and recovery time needs to be built in to any training or activity schedule. You should be aware of the symptoms of stress fractures. If they are treated quickly, this can reduce the amount of time that you need to stay away from activities. You should make sure that your equipment is of good quality and is properly fitted, particularly footwear and a biomechanical assessment to determine whether custom orthotics may be required.

If you suspect you may have a stress fracture, or are suffering from any exercise-related foot pain and swelling, contact Podiatry North on 02 9906 2544.

WARNING : This information is for educational purposes only and is not intended to replace professional podiatric advice. Treatment will vary between individuals depending upon your diagnosis and presenting complaint. An accurate diagnosis can only be made following a personal consultation with a Podiatrist.