Leg Problems

12.1 Stress Fractures

Clin Sports Med 1997;l6:259; Med Sci Sports Exerc 2000;32:S15; Clin J Sp Med 1991;1:115; Clin Sports Med 2004;23:55

Cause: Most commonly due to overuse injuries in context of sporting activity with repetitive or high impact training; less commonly seen in overuse or normal activity in context of an athlete with poor bone quality. Increase in running mileage or intensity, change in training shoes or poor training shoes, change to a harder or different running surface; most commonly occur in the proximal 2/3 of the tibia (Am J Sports Med 1987;15:46)

Epidem: Runners, sports involving running, military recruits; incidence higher in women, especially in women with irregular menses.

Pathophys:

Risk factors: high impact activities, pes planus (flat foot), pes cavus (high-arched foot), low bone mineral density, limb length discrepancy, poor nutrition or eating disorders, menstrual irregularities.
Imbalance between bone resorption and bone deposition during host bone response to stress.
Microfractures progress to clinical stress fractures in the setting of continuing abusive activity and inadequate rest.

Sx: History of recent increase in duration, intensity or frequency of activity; dull or sharp pain, commonly in the proximal anterior
tibia. Initially present after activity, progressing to pain during activity, then pain preventing activity; if pain is in the distal lateral aspect of leg, a fibular stress fracture may be present, (see 13.11); swelling may accompany stress fractures.

Si: Exam may be normal if patient is asymptomatic during inactivity; tenderness over the tibia or fibula, localized to an area less than 5 cm in diameter, is very suggestive of a stress fracture. Pain may be elicited by percussion or vibration proximal or distal to site of injury.

Cmplc: Progression to complete fracture, nonunion of fracture, displacement of fracture, chronic disabling leg pain. Athletes with stress fracture in the anterior central third of the tibia are very slow to heal and have a high risk of progression to complete fracture.

Diff Dx: MTSS (see 12.4), tibialis posterior syndrome, exertional compartment syndrome (see 12.2), fascial hernia, bone tumors.

X-ray:

X-rays may appear normal in acute phase (as many as 50%).
AP and lateral radiographs may show stress fractures that have been symptomatic for more than 3 w.
Beware the anterior cortical tibial “dreaded black line” (“DBL,” horizontal radiolucent line in anterior tibial cortex denoting chronic injuries and/or high likelihood of progression; if + DBL, refer to orthopedic surgery).
Focal periosteal thickening or bony radiodensity may be seen in later phases; actual fracture line is rarely seen.
If plain films negative and suspicion is still high, consider bone scan, MRI or CT.
Bone scan will be positive 3-5 d after the onset of pain.

Rx: Stop pain-producing activities (including weight bearing if injury has progressed); modified weight bearing until no pain with ambulation; start RICE therapy; NSAIDs as needed; physical therapy for range of motion, strengthening and proprioceptive
rehab once pain free. If able to perform pain free, cycling or swimming may be done to maintain fitness; healing time is 4-6 w for noncomplicated stress fractures. Consider diagnostic workup for osteoporosis/osteopenia or eating disorder and treat as indicated. If fails conservative treatment or becomes a chronic problem, refer to orthopedic surgery for possible operative fixation.

Return to Activity: Should be gradual; use of pneumatic leg braces has been shown in a small study to reduce healing time by up to several w (Am J Sports Med 1987;15:86).

12.2 Exertional Compartment Syndrome (ECS)

Orthop Rev 1994; 23:219-226; Med Sci Sports Exerc 2000;32:S4; Clin Sport Med 2004;23:55

Cause: Overuse injury in runners from impact activities.

Epidem: Runners, endurance athletes in sports requiring running; 14% of patients with lower leg pain; most commonly in anterior compartment (45%).

Pathophys:

Exercise-induced soft tissue swelling in the limited volume of the fascial compartments produce ischemia.
The compartments most frequently affected by ECS are the anterior, followed by the deep posterior, lateral, posterior tibial, and superficial posterior (see Table 12.1).

Sx:

Exercise-induced aching, squeezing, or sharp pain in the anterior leg, exacerbated by increasing activity intensity or duration, and relieved by rest (may take several hr to resolve completely); symptoms that occur at rest more consistent with nerve entrapment syndromes (see Diff Dx).
May be bilateral (75-90%).
Pain often recurs at the same distance while running.
May have muscle or nerve dysfunction in the affected compartment (eg, numbness and tingling), most commonly the anterior or lateral compartments.
Anterior leg may be diffusely swollen and described as “tense” (Sports Injuries, Diagnosis and Management. Philadelphia: WB Saunders Company, 1999:350).

Table 12.1 Four Fascial Compartments of the Leg

Compartment	Muscles	Nerve	Sensory Area
Lateral	Peroneus brevis and longus	Superficial peroneal nerve	Dorsal foot
Anterior	Tibialis ant, Ext digitorum, and Hallucis	Deep peroneal nerve	Dorsal 1st and 2nd web space
Deep posterior	Flexor digit/hallux, posterior tibialis	Tibial nerve	Plantar foot
Superficial posterior	Soleus, gastrocnemius	Sural nerve	Lateral foot