summary Tibial stress syndrome (also known as shin splints) is an overuse injury or repetitive-load injury of the shin area that leads to persistent dull anterior leg pain. Diagnosis is made clinically with tenderness along the posteromedial distal tibia made worse with plantarflexion. Radiographs or bone scans may be obtained to rule out stress fractures. Treatment is generally nonoperative with NSAIDs, rest and activity modifications. Epidemiology Incidence 10-15% of running injuries 60% of leg pain syndromes Anatomic location medial (posteromedial) tibial stress syndrome most common anterior (anterolateral) tibial stress syndrome distal and posteromedial tibia Risk factors runners without enough shock absorption (running on cement or uneven surfaces, improper running shoes) training errors (sudden increase in training intensity and duration) running >20 miles/week hill training early in the season history of previous lower extremity injuries over-pronation or increase internal tibial rotation Etiology Pathophysiology caused by a traction periostitis anterolateral traction periostitis of tibialis anterior on tibia and interosseous membrane posteromedial traction periostitis of tibialis posterior and soleus Associated conditions female athlete triad critical to diagnose and treat tibial stress fractures females have 1.5-3.5 increased risk of progression to stress fractures Presentation Symptoms vague, diffuse pain along middle-distal tibia that decreases with running (early stage) differentiate from exertional compartment syndrome, for which pain increases with running earlier onset of pain with more frequent training (later stages) Physical exam tenderness along posteromedial border of tibia 4cm proximal to medial malleolus, extending proximally up to 12cm pes planus tight Achilles tendon weak core muscles provocative test pain on resisted plantar flexion Imaging Radiographs indications exclude stress fracture findings conventional radiographs are normal in first 2-3weeks long-term changes include periosteal exostoses differentiate from stress fracture, which shows "dreaded black line" 3-phase bone scan indications exclude stress fracture findings diffuse, longitudinal increased uptake along posteromedial border of tibia in delayed phase (Phase 3) normal findings on Phase 1 (flow phase) and blood pool phase (Phase 2) differentiate from stress fracture, which has focal, intense hyperperfusion and hyperemia in Phase 1 and 2, and focal, fusiform uptake in Phase 3 MRI indications identify other soft tissue injuries findings periosteal edema progressive marrow involvment Differential Differential Diagnosis for Exertional Leg Pain Condition Characteristics Tissue origin Anterior tibial stress syndrome Vague, diffuse pain along anterolateral tibia, worse at beginning of exercise that decreases during training Periosteum Medial tibial stress syndrome Vague, diffuse pain along middle-distal tibia, worse at beginning of exercise, that decreases during training Periosteum Tibial/fibular stress fracture Pain with running, point tenderness over fracture site, "dreaded black line" on lateral x-ray Bone Exertional compartment syndrome Symptoms begin 10min into exercise andresolve 30min after exercise, sensory or motor loss, elevated anterior compartment pressures Muscle and fascia Leg Tendinopathy May be Achilles tendon, peroneal tendon, or tibialis posterior Tendon Sural or SPN entrapment Dermatomal distribution of symptoms Nerve Lumbar radiculopathy Worse with lumbar tension position (sitting) Nerve Popliteal artery entrapment Diagnosed with vascular studies Blood vessel Treatment Nonoperative activity modification with nonoperative modalities indications first line of treatment and successful in vast majority techniques activity modification decreasing running distance, frequency and intensity by 50% use low-impact and cross-training exercises during rehab period regular stretching and strengthening run on synthetic track avoid running on hills, uneven or hard surfaces shoe modifications change running shoes every 250-500miles as shoes lose shock absorbing capacity at this distance orthotics may be helpful in patients with pes planus therapy focus on strengthening of invertors and evertors of the calf other local phonophoresis with corticosteroids may be effective Operative deep posterior compartment fasciotomy + release of painful portion of periosteum indications failed nonoperative treatment outcomes variable results, not likely to cause complete resolution of symptoms Complications Recurrence common after resumption of heavy activity