Diagnosing the cause of limping in a child requires a careful and systematic approach, as limping can result from a wide range of conditions, including infections, trauma, congenital anomalies, neoplasms, and inflammatory diseases. The evaluation of a limping child involves taking a thorough history, performing a detailed physical examination, and, when necessary, ordering appropriate diagnostic tests.

History

A detailed history is crucial and should include questions about:

• The onset of the limp: When it started and whether it was sudden or gradual.

• Any associated symptoms: Pain, fever, recent illnesses, or injuries.

• The presence of pain: Location, severity, timing (e.g., worse in the morning or after activities), and whether it's relieved by rest.

• Any changes in activity level or participation in new sports.

• Previous episodes of limping or joint problems.

• Family history of musculoskeletal or systemic conditions.

Physical Examination

The physical examination should be comprehensive, including:

• Observation: Note the type of limp (antalgic, Trendelenburg, etc.), posture, and symmetry of the limbs.

• Gait analysis: Observe the child walking, running, and rising from a seated position.

• Joint examination: Assess for swelling, warmth, redness, range of motion, and pain in the joints.

• Neurological examination: Check for muscle strength, reflexes, and sensory abnormalities.

• Examination of the spine, pelvis, and lower limbs for deformities or asymmetries.

Diagnostic Tests

Depending on the findings from the history and physical examination, several diagnostic tests may be indicated:

• X-rays: To identify fractures, dislocations, bone infections, and some tumors.

• Blood tests: To look for signs of infection (e.g., elevated white blood cell count), inflammation (e.g., elevated ESR or CRP), or specific conditions (e.g., rheumatologic markers).

• Ultrasound: Useful for evaluating joint effusions, especially in the hip.

• MRI: Provides detailed images of soft tissues, including cartilage, ligaments, and tendons, and is useful for diagnosing conditions like osteomyelitis, septic arthritis, and tumors.

• Bone scan: Can detect areas of increased bone activity indicative of infection, fracture, or tumor.

Common Causes of Limping by Age Group

• Toddlers: Toddler's fracture (undisplaced spiral fracture of the tibia), transient synovitis.

• Preschool-aged children: Legg-Calvé-Perthes disease, transient synovitis.

• School-aged children: Osgood-Schlatter disease, Sever's disease, fractures.

• Adolescents: Slipped capital femoral epiphysis (SCFE), avulsion fractures, sports-related injuries.

Management

The management of a limping child depends on the underlying cause. It may range from conservative treatment, such as rest and anti-inflammatory medications for conditions like transient synovitis, to surgical intervention for more severe conditions like SCFE.

The approach to a limping child must be thorough and thoughtful to ensure an accurate diagnosis and appropriate treatment. If the initial evaluation does not lead to a diagnosis, or if the child's condition worsens, further evaluation and specialist referral may be necessary.