AANP Family Nurse Practitioner (FNP) Certification ExamDiagnosisMedium
A 6-year-old child presents with a 2-week history of worsening right hip pain, especially after activity, and an antalgic gait. Physical examination reveals limited internal rotation and abduction of the right hip, with some muscle atrophy in the right thigh. X-rays show flattening and fragmentation of the right femoral head. What is the most likely diagnosis?
- ATransient synovitis
- BLegg-Calvé-Perthes Disease (LCPD)
- CSlipped Capital Femoral Epiphysis (SCFE)
- DJuvenile Idiopathic Arthritis (JIA)
Show answer & explanationAnswer & explanation
Correct answer: B. Legg-Calvé-Perthes Disease (LCPD)
The clinical presentation of a 6-year-old with hip pain, antalgic gait, limited hip movement, and characteristic X-ray findings of femoral head flattening and fragmentation is classic for Legg-Calvé-Perthes Disease (LCPD). This condition involves avascular necrosis of the femoral head.
Why the other options are wrong
- A. Transient synovitis typically resolves within a week and does not show femoral head changes on X-ray.
- C. SCFE usually occurs in older, obese adolescents (10-16 years old) and involves a posterior and inferior displacement of the femoral head, not fragmentation.
- D. JIA would typically present with more generalized joint inflammation, morning stiffness, and systemic symptoms, and X-rays would show joint space narrowing and erosions, not specific femoral head changes.
Legg-Calvé-Perthes Disease (LCPD)
A childhood hip disorder characterized by avascular necrosis of the femoral head, leading to flattening and fragmentation, followed by reossification and remodeling.
- Typically affects children aged 4-8 years, more common in boys.
- Presents with hip or knee pain, limping (antalgic gait), and limited hip abduction/internal rotation.
- Diagnosis confirmed by X-rays showing characteristic changes in the femoral head.
Memory trick: Limping child, Perthes is a 'Pert'inent problem for the 'Head' of the femur.