September 2010 Newsletter

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Leg Pain and Shin Splints
By Dr. Stephen A. Hunt

Shin pain in athletes, particularly field athletes and runners, is a common problem seen in our office during preseason training. Athletes will often be referred to us for evaluation of shin and leg pain that prevents them from running or competing. “I’ve been told I have shin splints” is a common phrase from patients in our practice. However, leg pain during running and exercise may be a result of several different problems. Below is a list of a few of the potential causes of leg pain.

Medial Tibial Stress Syndrome
Also know as Shin splints, this is an irritation/inflammation of the lining (called periosteum) of the shin bone (Tibia). It occurs from excessive pronation of the foot – the arch collapses-, overuse, or change in activity. Pain is usually present in the inside of the leg about 1/3 of the way up from the ankle towards the knee. Imaging studies usually are normal, although MRI may show some inflammation. MRI is generally indicated is ruling out a stress fracture and is not indicated if the clinical suspicion for shin splints is high. The treatment of shin splints is always nonoperative, with activity modification, non-steroidal anti-inflammatories, ankle stretching exercises, and arch supports are universally curative.

Stress Fractures
Stress fractures are a result of overuse and repetitive loading. Essentially, the bone turnover that naturally occurs in our bodies is unable to keep up with the demands being placed on it. This occurs in any athlete that changes intensity in training, but runners and early season athletes are more prone to this problem. Often, muscle fatigue will contribute to increased bone load because the muscles fail to absorb the impact from running. Additional risk factors include athletes who are malnourished or who have hormone imbalances. Stress reactions, a precursor to stress fractures, often present as a pain during the activity that gets better with rest. As the problem persists, pain may occur at rest. X-rays are often normal in the early stages of this injury and may need to be repeated at several week intervals. If clinical suspicion is high, an MRI or bone scan may be ordered to confirm the diagnosis. Most stress fractures of the leg will resolve without any surgical intervention. Rest, protected weight bearing, and orthotics will often resolve this problem.

Exertional Compartment Syndrome
Exertional Compartment syndrome (ECS) is a less common cause of leg pain in athletes. ECS is caused by swelling of the muscles of the leg that prevents blood from flowing to the muscles and nerves – causing “ischemia” (think heart attack) to the leg muscles. The pain is always activity related initially as the muscle swelling subsides when not in use. As this problem gets worse, athletes may experience pain with walking or even numbness and tingling in their foot or ankle. Sometimes the calf will feel very tight when the athlete exerts himself or herself. Often the physical exam by a physician does not demonstrate many findings. Imaging studies are often normal. Once more common problems like shin splints and stress fractures have been ruled out, measuring compartment pressures will test for ECS. Compartment pressure measurements involve placing a needle into the four leg compartments to measure the pressure before, right after, and five minutes after exercise. There are certain parameters that establish whether the pressures are too high. Once the diagnosis of ECS is confirmed, athletes may choose to modify their activities by cross training to resolve their symptoms. If this does not work, surgery may be performed to release the pressure in the compartments by a fasciotomy.

Other
Other, rare causes of leg pain in athletes such as nerve and artery entrapment syndromes also cause leg pain. These are very uncommon problems.

In summary, there are several causes of leg pain in athletes. The overwhelming majority can be treated with stretching, orthotics, and activity modification. If these do not work, further investigation may be warranted.

REFERENCES:

1. 1. Pell RF et al. Leg pain in the running athlete. J Am Acad Orthop Surg 2004;12:396-404.
2. 2. Subcommittee on Classification of Sports Injuries Committee on the Medical Aspects of Sports: Standard Nomenclature of Athletic Injuries. Chicago, IL: AMA, 1966.