Module 37, General Orthopaedist Level

1,2

A 9 month old male child with history of normal pregnancy, delivery and growth presented to the emergency room. The mother reported a 2 day fever of unknown origin with vague abdominal pain and diarrhea. Initial work up revealed: temperature of 40.1, WBC 16,800 with left shift, X-rays of Chest Abdomen, Pelvis, and Hips were normal. A bone scan was negative, spinal tap was normal. The child was admitted with a diagnosis of viral infection vs. mycoplasma pneumonia. He was started on erythromycin.(images 1 & 2) On hospital Day 2 the Right hip was noted to be flexed and the child appeared to have pain with any movement of the hip. The hip was aspirated and the Gram stain identified gram positive cocci and the child was started on Nafcillin 150mg IV q4. Daily hip aspirations were performed for decompression. Final culture: coag (+) Staph aureus resistant to penicillin. On hospital Day 6 the child's temperature spiked to 103.4. The Right hip Xray showed a defect in proximal medial metaphysis.

Question 37A

This now suggests that this was osteomyelitis of the proximal femur and not a septic hip as previous thought.

Question 37B

Osteomyelitis of the proximal femur often drains into the hip joint mimicking a septic hip.

Question 37C

The correct treatment for this child is a posterior drainage of the hip joint so the fluid can run out of the hip when the child lies supine.

Question 37D

This child has definite risk for hip dislocation.

Question 37E

If a child develops avascular necrosis from a hip sepsis it is usually segmental and heals quickly especially in such a young child.