1. “Coxitis Simplex” Transient Synovitis
Hlynur Georgsson
24/11/2003

2. Etiology Remains obscure Inflammation of synovial lining
Post-traumatic, allergic, infectious
Inflammation of synovial lining
Often after URTI (32-50%) or virosis
4x increase in viral titers seen in 45%
Elevated interferon levels seen in 43%
No association shown with B-19 or HHSV6
History of Trauma in 17-30%

3. Epidemiology Bilateral 5%
Most common cause of non-traumatic hip pain in children
Annual incidence 0.2%
% of pediatric ER admissions
lifetime risk 3%
Typically children aged 3-8y
Boys>girls 2:1
Seasonal increase in Autumn?
Bilateral 5%
Symptomatically unilat. show bilat. effusions in 25%
Recurrence within 6 months in 4-15%

4. Presentation/History
6 year old non-febrile boy with a limp and uni- or bilateral hip-pain
Onset
Acute, typically less than one week at presentation
Pain
Partial flexion and external rotation to minimize intraarticular pressure
Internal rotation especially restricted during
Hip or groin region, occasionaly referred to ant. Thigh or medial knee
Typically no fever or low-grade

5. Workup Bloodstatus + WBC, ESR X-ray Ultrasonography Arthrocentesis
maybe unspecific soft-tissue changes
Ultrasonography
Can detect as little as 2-3ml of fluid
Arthrocentesis
Ddx. Septic arthritis
Three-phase bone scanning
Ddx. Osteomyelitis, osteoma, occult fracture

6. Treatment NSAID Aspiration therapeutic?
Ibuprofen, Celebrex
Aspiration therapeutic?
Full activity as tolerated vs. no weight-bearing?
? Traction ?
? Antihistamine, i.m. Steroids ?
Full recovery 1-4w
1-2% may go on to develop Perthes disease with avascular necrosis of femoral head, Higher risk if delayed bone age
Recurrence within 6m = 4-15%