1. Basedon the history and physical examination, what would be included in your [email protected]
diagnosis? Shin pain is a common problem in young athletes, accounting for up to 10% of all athletic complaints (Busch, 1990). The most common causes of shin pain are shin splints, sometimes referred to as medial tibial stress syndrome, stress fractures of the tibia or fibula, and compartment syndromes. Less commonly arterial and venous anomalies, tumors, or infections may cause lower leg pain (Reid, 1992). The American Medical Association defines the shin splint syndrome as “pain and discomfort in the leg from repetitive activity on hard surfaces, or due to forcible, excessive use of the foot flexors; and, it is Limited to musculoskeletal excluding stress inflammations, fractures or ischemic disorders” (Reid, 1992). On review of several articles and texts, however, there is some disagreement about definition. Some authors and orthopedists define the shin splint syndrome to include stress fractures and compartment syndromes. For the purposes of this column, however, shin splints will not include stress fractures or compartment syndromes.
In patients with shin splints the pain is bilateral in more than half of the cases, and both sexes are equally affected. Predisposing factors include muscle weakness, running shoes with a lack of heel cushion, inadequate arch support, and hard running surfaces. Training errors such as sudden increases in intensity or mileage are common factors. Contributing biomechanical abnormalities include varus hindfoot alignment, excessive forefoot pronation, genu valgum, excessive femoral anteversion, and external tibia1 torsion (Busch, 1990). The history should include intensity of sports participation, any recent change in regimen or footwear, and surface training conditions. The localization of pain, intensity, onset, duration, and any associated numbness are important in the differential diagnosis. The physical examination should include evaluation of gait, leg lengths, rotational abnormalities, muscle laxity or tightness, joint motion, and muscle strength. An attempt should be made to localize the pain (Busch, 1990).
j Pediatr Health Care. (I 997). Copyright
0 1997 by the National Association
Stress fractures are partial or incomplete disruptions of the bone caused by inability to withstand repetitive nonviolent loads. Normally, the bone remodels itself in response to microtrauma. However, with excessive use the mechanical fatigue and bone resorption can outpace the osteoblastic response. The proximal third of the tibia is the most commonly affected site. There is also equal distribution of incidence in this entity among male and female patients. Although most stress fractures in adolescents are associated with endurance running, the average training distance is typically not excessive (Busch, 1990). The history in stress fractures is one of insidious onset of pain in the area of the fracture that is initially relieved by rest. Eventually the pain increases, persists after activity and affects normal walking. On examination the tenderness can be localized to the site of the fracture in approximately two thirds of cases, and swelling is present in approximately one fourth. Approximately 10% of initial radiographs are ab-
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normal. Up to 50% of adolescents with stress fractures show multiple asymptomatic areas of stress response on bone scan (Busch, 1990). Chronic compartment syndromes can also be a cause of lower leg pain. In contrast to the acute compartment syndrome that results from trauma or arterial insufficiency and is generally a medical or surgical emergency, chronic compartment syndromes are a result of exertion, relieved by rest, and seldom result in tissue necrosis or residual disability. The elevated interstitial pressure of these syndromes is caused by inadequacy of the osseofacial compartments to accommodate exercise-induced volume and pressure changes. When compartment pressures exceed capillary filling pressure, the muscle becomes ischemic and produces pain. The anterior compartment is the most commonly involved, although any of the four compartments in the lower leg may be affected. The history includes aching pain, tightness, or a squeezing sensation brought on by and interfering with athletics. The pain usually lasts only a short time after exercise. There may be a transient foot drop, and there are often paresthesias across the dorsum of the foot with an anterior compartment involvement or plantar paresthesi.as with chronic posterior compartment syndrome (Busch, 1990). The pain is usually induced only by athletic activity, often arising at a specific point in the training session, and it is located along the specific muscle group involved. If the athlete persists with the activity despite the symptoms, muscle weakness and subsequent local tenderness may occur (Reid, 1992).
IOURNAL OF PEDIATRIC HEALTH CARE
2. What additional i$ormation would you obtain? Based on the information given previously, you might carefully review the history with regard to onset, duration, and severity of the pain and reconsider your physical findings. If stress fracture is suspected, radiographs or bone scan should be ordered if symptoms persist after a reasonable trial of rest and use of other treatment measures. The diagnosis of compartment syndromes is made by measuring compartment pressures. Various techniques are used for measuring compartment pressures, and the method used, the experience of the clinician, and the measurement at rest versus exercise have significant implications (Reid, 1992). In chronic compartment syndrome resting pressures are typically not elevated. With exercise the pressures rise to XI to 100 mm Hg, whereas normal compartments rise to less than 30 mm Hg. The degree of compartment pressure elevation correlates with the level of symptoms (Busch, 1990). Radiographs of Katie’s lower legs were reported as normal.
3. What is the diagnosis and treatment? Based on the history and physical examination of Katie, you suspect shin splints. Her pain began after she increased her activity to include jogging. The pain is most intense with activity and does subside with rest, and she has no pinpoint tenderness or edema on examination. She also has no paresthesias or obvious muscle weakness.
The first stage of treatment for any of the shin pain entities is to decrease inflammation by rest, nonsteroidal antiinflammatory medications, and regular use of ice applications, particularly after any activity. In addition, evaluation and discussion of other contributing factors include running mechanics, appropriate footwear, foot shape and biomechanics, lower limb structural abnormalities, muscle tightness and imbalance, inadequate or improper conditioning, overweight, inadequate warmup and training errors, terrain and training surfaces, environment, and nutrition (Reid, 1992). For stress fractures crutches or a cast can be used if there is risk of displacement or if the patient is not compliant with activity limitations. Healing takes 2 weeks to 3 months, and compliance is critical in ensuring that a complete fracture does not occur (Busch, 1990). Alternative training such as swimming or cycling can be suggested for aerobic conditioning in the serious athlete. In chronic compartment syndrome approximately one third of patients will find the previously described measures helpful, perhaps also with the addition of physical therapy. Definitive treatment, however, involves surgical intervention. At least 90% of surgical cases yield successful results (Busch, 1990).
4. What is the prognosis? The prognosis for Katie is excellent. She indeed was very compliant with the recommendations given to her. After 1 week of very limited activity she resumed field hockey practice. She has continued the use of ice applications after practice
and has been taking ibuprofen as needed. She has improved her warmup and stretching routine. She and her mother report that she will purchase appropriate running shoes before she resumes jogging. And when she does resume jogging, she will do so more slowly and will try to find a softer running surface. The prognosis for stress fractures is also very good if treatment measures are adhered to and if the original causative factors are eliminated or at least minimized. Most patients with chronic compartment syndrome will require surgery, but as mentioned previously, most of those patients will have successful results.
BROWN, H.J. (I 991). Life’s Lit& /r~stwction TN: Rutledge Hill Press.
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In R.T. Morrissy pediatric
I am certain that children always know more than they are able to tell, and that makes the big difference between them and adults, who, at best, know only a fraction of what they say. The reason is simple they know everything with their whole beings, while we know it only with our heads. JacquesLusseyran Cp.311