In a child between 18 months and 8 years of age, the femoral head epiphysis is supplied almost entirely by the lateral retinacular (ascending cervical) branches arising from which vessel?

• A Lateral circumflex femoral artery
• B Medial circumflex femoral artery ✓
• C Obturator artery via the ligamentum teres
• D Inferior gluteal artery

Explanation

From about 18 months to skeletal maturity, the posterior superior retinacular vessels from the medial circumflex femoral artery carry nearly the entire blood supply to the femoral head, while the ligamentum teres contribution is negligible until it reappears around puberty. Interruption of these lateral epiphyseal vessels by increased synovial pressure is considered central to Legg-Calve-Perthes disease. This vulnerable window explains why Perthes typically presents between 4 and 8 years.

Reference: Tachdjian's Pediatric Orthopaedics, 5th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.