What is a stress fracture?
A stress fracture is a small fracture of the bone that is caused by repeated mechanical stress, rather than an acute injury. They are often so small that they cannot always be seen on X-ray. Clinical examination coupled with MRI or Bone Scan is the gold standard for diagnosis.
Initially, it can start as a ‘’stress response’’ and if left untreated, a stress fracture can occur. The majority of stress fractures occur in the lower limb, being particularly common in the hip, shins and foot at points where the most force passes through when weight bearing. Most stress fractures are overuse injuries and are common in long distance runners, military personnel and in people who have significantly increased their loading..
What are the symptoms?
As with many overuse injuries, the pain of a stress fracture starts gradually (stress response), beginning with pain during or after activity or sometimes the morning after. If activity continues without modification, the pain will gradually increase (stress fracture). Eventually most people are unable to maintain their usual activity level. A stress fracture will be more likely to occur in a person who has weaker bone density and is affected by many factors such as adequate calcium intake, vitamin D deficiency and a history of inactivity.
How are stress fractures treated and how long will it take to get better?
Stress fractures can easily be mistaken for other conditions such as shin splints (MTSS). As the fracture is often too small to show up on X-ray, definitive diagnosis can be made using MRI or bone scan.
After diagnosis, the most important part of treatment will be ‘’relative rest’’ of the area to allow the bone to heal before resuming higher levels of activity. In some cases, it can be important to maintain some load through the affected bone to aid with the healing process. Stress fractures usually take at least 6 weeks heal and then a further period of at least 6 weeks to re-load the injured bone..Some areas of the body have poor blood supply, which makes healing slower and more complicated. For example, stress fractures of the navicular bone of the foot may need to be placed in a boot for a period of time to heal properly.
Other aspects of treatment will involve correcting any factors that contributed to the original injury. There is some evidence that unsupportive footwear is a risk factor, along with poor biomechanics and weak muscles that provide inadequate support to the skeletal system during activity. A structured training/loading program is required to ensure that you have a gradual increase in load that your body can tolerate. Speak to your physiotherapist if you suspect you may have a stress fracture or simply want to know more.