Ortho Case of the Week – Peds Lower Extremity ANSWERS
Case 1: A 4-year-old male with a presents with left hip and thigh pain and refuses to bear weight on it. He holds his hip in flexion and external rotation.
1. What is on your differential for a child with hip pain?
Pediatric hip pain has a broad differential including fracture, dislocation, NAT, transient synovitis, septic arthritis, osteomyelitis, JRE, bone tumors, SCFE, Legg-Calve-Perthes disease, and referred pain from the abdomen or testicles.
2. You note that is temperature is 100.6 degrees F. His x-rays are normal. You obtain the ultrasound of his hip, shown below. What two diagnoses are you concerned about and how can you differentiate them?
This ultrasound shows a moderate effusion of the left hip, concerning for septic arthritis versus transient synovitis. The Kocher criteria can be used to differentiate between the two diagnoses (though maybe not as well as Kocher described).
An elevated CRP has also been suggested to differentiate these two diagnoses, with a CRP greater than or equal to 20 mg/L found to be the strongest independent predictor of septic arthritis.
3. His ESR comes back at 85 mm/hr and his WBC comes back at 17k. How would you manage this patient?
This patient meets 3/4 Kocher criteria, which based on the original study gives him a 93% chance of having septic arthritis. This patient needs an emergent orthopedics consult for drainage and IV antibiotics (usually started after synovial fluid is obtained).
Source: Orthobullets
This was aspirated from the patient above’s hip joint:
Case 2: A 15-year-old male presents with atraumatic left hip pain. You obtain the plain film below.
1. What is the diagnosis?
This patient has SCFE, with slippage of the left upper femoral epiphyses. The line of Klein fails to intersect the femoral epiphysis.
In 10 to 15% of patients, the diagnosis cannot be made on an AP view, so a frog leg or true lateral view should also be obtained.
AP and frog leg lateral of a 13-year-old female with SCFE.
Source: Radiopaedia
2. How would you manage this patient?
This patient requires an emergent orthopedics consult for ORIF and will likely require admission. The patient should be non-weight bearing in the interim.
