Q: My 16 year old daughter runs for her high school cross country team and she is getting worsening shin pain. What do you think is causing this?
A: Your daughter may be developing a stress fracture. I see this mainly in female athletes in their teen years and not uncommonly they are long distance runners. There are multiple factors that can contribute to this condition, both intrinsic and extrinsic. Some intrinsic factors are bone metabolism, hormonal imbalances, fitness level, limb alignment and muscle endurance. Some extrinsic factors are dietary habits, footwear, a harder running surface, and training regimens. Stress fractures commonly occur in areas of bone where there is poor blood supply to begin with. In this way, the bone is unable to repair the micro damage that occurs, as there is insufficient blood flow and thus compromised healing ability in that area. The more common areas affected by stress fractures are the lower leg bones (tibias) and two different small bones in the foot.
Most patients who are suffering from a stress reaction or later a stress fracture in the bone do not recall a particular injury or incident. Instead, patients report that the pain has been slowly worsening over several weeks. Their symptoms may correspond with a significant increase in their training. In young people, it is important to determine if there is an underlying eating disorder. If so, there may be insufficient intake of calcium, Vitamin D, and total calories to allow the bone to heal. In addition, certain foods and beverages can be more acidic and in turn leach calcium and phosphate from the bone, thus compromising its microstructure. Stress fractures are common in young female athletes if they are suffering from the so-called female triad of an eating disorder, osteoporosis, and amenorrhea.
In the office, these young athletes will be point tender over the bone when I push on it. Hopping on one foot may worsen the pain. I obtain x-rays on these patients but not uncommonly they are normal. Only in chronic cases can you actually see a stress fracture in the bone on an x-ray. MRI’s are much more sensitive, and they will demonstrate the condition much earlier. On an MRI, one can see fluid in the affected bone. However, MRI’s are expensive and the findings on MRI probably won’t change the management of the condition, so getting an MRI is optional if the diagnosis is clear-cut.
As for treatment, it comes down primarily to rest. In addition, any metabolic or hormonal imbalances should be corrected. The recommended daily allowance of calcium and Vitamin D is 1000 mg and 800-1000 IU respectfully. For young female athletes, I recommend taking 50% more than this. There are medications such as bisphosphonates, which have been used to treat stress fractures, but I do not recommend these anti-osteoporosis medications in young athletes. Moreover, I do not recommend taking anti-inflammatory medications, as I want the athletes to feel the pain so it limits them accordingly. As for activities, athletes can try to maintain their cardiovascular fitness and strength by doing low impact activities such as swimming, biking and weight training. Physical therapy is helpful. Namely, pulsed ultrasound has been shown to accelerate healing. Some early studies have also shown promise with Extracorporeal Shock Wave Therapy. Unfortunately, however, stress fractures can take months to resolve and can cost an athlete their entire sports season.
Stress fractures of the foot occur in the midfoot, namely the navicular bone (the same bone in the middle of your foot that gets sore and swollen in a tight ski boot) or the base of the 5th metatarsal. Unfortunately, patients have to be placed in a nonweightbearing cast in order to give these difficult stress fractures the best chance of healing. Sometimes, navicular stress fractures require surgery to finally get them to heal.
Dr. Rick Cunningham is a Knee and Shoulder Sports Medicine Specialist with Vail-Summit Orthopaedics. He is a Physician for the US Ski Team and Chief of Surgery at Vail Valley Medical Center. Do you have a sports medicine question you’d like him to answer in this column? Visit his website at www.vailknee.com to submit your topic idea. For more information about Vail-Summit Orthopaedics, visit www.vsortho.com.