A 3-week-old neonate is irritable and feeding poorly with minimal fever. There is swelling near the wrist and reduced limb movement. Radiographs show involvement of the distal radius and, separately, the proximal humerus. Which feature of neonatal osteomyelitis explains the multifocal presentation?

• A Maternal antibodies suppress local immunity at single sites
• B Neonates have absent periosteum, so infection spreads freely along the shaft
• C Transphyseal blood vessels allow spread between metaphysis and epiphysis ✓
• D The neonatal immune response confines infection to one metaphysis

Explanation

In neonates the growth plate is not yet a barrier because nutrient artery branches cross the physis to reach the epiphysis, allowing infection to seed multiple metaphyses and epiphyses simultaneously, often with joint involvement. Systemic signs are subtle, so pseudoparalysis of a limb may be the only clue. After the age of about 1 year the physis closes to vessels and multifocal disease becomes rare.

Reference: Nelson Textbook of Pediatrics, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.