By Dr. Les Dutko, Ed.D, LAT, ATC
WHAT IS A STRESS FRACTURE?
As we exercise and through everyday living activity a certain amount of bone tissue is broken down according to the intensity and duration of the activity that we participate in. Conversely, our body balances the bone tissue with new bone tissue which was lost. Thus, the bone tissue stays in equilibrium as we stay healthy. However, as we increase our activity level beyond what our system can remodel or lay down new bone tissue, as result micro cracks, called “stress fractures” can occur in the bone.
The most common cause of stress fractures is a sudden increase in the duration, intensity and frequency of physical activity without adequate rest protocol. Conversely, stress fractures may be the result of hormonal imbalances, nutritional deficiencies, and sleep deprivation, to mention the most common.
Stress fractures are most often seen in athletes, especially runners. Stress fractures have been documented in every bone in the body; they are most common in the lower extremity weight-bearing bones. Stress fractures are associated with specific sports for examples, in the humerus in throwing sports, the ribs in golf and rowing, the spine in gymnastics, the lower extremity in running sports and the foot in gymnastics and basketball.
HOW WILL I KNOW IF I HAVE A STRESS FRACTURE?
You will undergo pain directly over the fractured area, which is exacerbated by activity and is relieved with rest. Bone point tenderness is the most obvious finding on physical evaluation. Jumping or hopping on affected leg with result in pain.
X-rays are usually not helpful unless the stress fracture is several weeks old and remodeling has occurred and a callus has formed. The diagnosis of an early stress fracture can usually be confirmed by a bone scan or a MRI. In a bone scan, a radioactive substance called a “tracer”, normally used by the bone for repair, is injected into the athlete’s bloodstream. All of the bones will absorb some of the tracer, but if a bone is repairing a stress fracture, it will absorb more of the tracer at the fracture site and will appear darker than healthy bones.
HOW IS A STRESS FRACTURE TREATED?
Stress fractures are broadly classified as either low-risk injuries and these are less likely to become more serious fractures or high-risk injuries which are more likely to become serious fractures. The majority of low-risk stress fractures very seldom require expensive imaging test since most can be diagnosed via of a through history, physical examination and radiographs. A rest period of one to six weeks of limited weight bearing progressing to full weight bearing may prove essential. Return to activity should be a gradual process. Once the pain subsides, activities such as swimming or biking can be performed in order to maintain cardiovascular conditioning. When the athlete can execute low-impact exercises without pain for extended period of time the athlete can perform high-impact activities, such as increasing jogging miles progressively than return to sport-specific activities.
High risk stress fractures require an X-ray, a bone scan or MRI. High risk stress fractures have a high complication rate, and must be treated like a traumatic fracture, most often with a cast and occasionally with surgery when required.
HOW ARE STRESS FRACTURES PREVENTED?
The best way to manage stress fractures is to prevent them from occurring in the first place. Biomechanical training errors and excessive increase in intensity and duration is the main culprit and must be corrected immediately. In addition, new protocol of hill running or running on hard surfaces can be contributing factors. Lastly, female athletes and their coaches need to be alerted to the adverse effects of eating disorders and hormonal abnormalities.
TREATING LOWER EXTREMITY STRESS FRACTURE!
- Non-weightbearing, non-impact activities such as swimming or biking.
- Weightbearing, non-impact activity such as a stair machine of a treadmill.
- Weightbearing, impact activities such as jogging.
- Low intensity, short duration.
- Low intensity, increased duration.
- Higher intensity, short duration.
- Higher intensity, increased duration.
- Advance to next activity level.
Stress fractures, Barry Boden, MD and Matthew Matava, MD: www.sportsmed.org