Diagnostic Approach to Chronic Leg Pain in Young Adults

Initial Evaluation and First-Line Imaging

The American College of Radiology recommends conventional radiography as the initial imaging examination for chronic lower limb pain, allowing for the identification of stress fractures, bone lesions, tumors, or other structural anomalies 1.
Radiographs have a sensitivity of 87% for tibial fractures and can identify most significant bone pathologies 2.
In young patients with persistent pain, stress fractures represent a common cause that may not be immediately visible on initial radiographs 3.

If radiographs are negative but pain persists beyond 2-3 weeks, magnetic resonance imaging (MRI) without contrast is the examination of choice 2, 4, 5.
MRI is indicated for occult fractures, with higher sensitivity for stress fractures not visible on radiography 2, 5.
Computed tomography (CT) without contrast is an alternative if MRI is contraindicated, particularly useful for complex bone anatomy 2, 4.

The initial treatment approach includes activity modification, reduction of aggravating factors, and the use of nonsteroidal anti-inflammatory drugs (NSAIDs) for pain control and inflammation reduction 4, 6.
Relative immobilization, such as using a walker, should be considered if symptoms are severe 4.

Urgent orthopedic referral is indicated for suspected unstable fractures or lesions requiring surgical fixation 5.
Elective orthopedic referral is recommended for persistence of symptoms beyond 6-8 weeks despite appropriate treatment 4, 5.

Do not underestimate the significance of initial negative radiographs, as up to 41% of stress fractures may not be visible 3.
Do not delay advanced imaging if symptoms persist beyond 2-3 weeks with negative radiographs; proceed with MRI 4, 5.