Transient (toxic) synovitis
Background
- Self-limiting inflammatory process of the hip
- Most common cause of acute hip pain in children <10yr
- Peak incidence 3-8yrs, with a mean of 6 yrs
- Male:Female is 2:1
- Usually unilateral
- 32-50% present after recent viral URI
- Possible posttraumatic or allergic pathologies
Clinical Features
- Abrupt onset of unilateral hip pain, limp, and restricted hip motion
- Nontoxic appearance
- May have a low grade fever
Differential Diagnosis
Pediatric hip pain
- Acute rheumatic fever
- Developmental dysplasia of hip
- Femur fracture
- Juvenile idiopathic arthritis
- Legg-Calve-Perthes disease
- Septic arthritis of the hip (peds)
- Lyme disease arthritis
- Slipped capital femoral epiphysis
- Transient (toxic) synovitis
- Osteosarcoma
Evaluation
Work-up
- X-ray if suspicious for fracture
- Plain films or ultrasound can show effusion
- If effusion found consider arthrocentesis
- Presence of effusion does not rule in or out transient synovitis as bilateral effusions can occur in 25% of children
Evaluation
Must distinguish from septic arthritis
- Transient Synovitis favored by:
- Temperature <38.5
- ESR <20
- WBC <12,000
- CRP <2
- Septic arthritis favored by:
- Temperature >38.5
- ESR >40
- WBC >12,000
- CRP >2
- severe pain with ROM
Kocher Criteria for septic arthritis of the hip
- ESR > 40 mm/hr
- WBC > 12,000/microliter
- Refusal or inability to weight bear on affected joint
- Fever 38.5° C or greater
Number of Kocher Criteria | Chance of Septic Joint |
1 | 3% |
2 | 40% |
3 | 93% |
4 | 99% |
Management
- Return to full activity as tolerated
- NSAIDs
Disposition
- If diagnosis is certain, follow up with primary care provider within 1 week as needed