Septic Arthritis in Children -

Written by

Dr Emily Kong
MBBS | Accredited Orthopaedic Registrar

Weekly Presentation 26th March 2010

Septic arthritis must be ruled out in the child with a painful joint
Delay in treatment or failure to diagnose problematic
Difficult patient group to obtain history and examination
Prognosis significantly improved:
- Mortality reduced from 50% in 1874 to <1% in 1974

Incidence

WCC
- Usually elevated in older children,
- sometimes elevated in younger children,
- rarely elevated in neonates
ESR
- alone sensitivity 79%
- with elevated temp, elevated WCC and NWB – 98%
CRP
- highest predictive value for septic arthritis

Plain XR
- Differential Diagnosis
  - osteomyelitis,
  - fracture,
  - neoplasia,
- increased joint space may indicate effusion
Ultrasound
- most sensitive tool for detection of hip effusion,
- false negative rate 5%,
- guided aspiration
  - can evacuate pus,
  - decrease damage to articular surfaces,
- DDx other arthridities
- direct ABx Rx,
- caution with –ve US with symptoms <24hrs or bilateral disease
MRI
- sensitive and specific, can differentiate from osteomyelitis and non-infective causes of hip pain,
- signal intensity alterations and contrast enhancement of bone marrow and adjacent soft tissue
Bone scan
- lacks sensitivity and specificity

Wide support for early administration and not withheld before diagnoseif clinical suspicion
Choice based on most likely organism
Initially administer i/v, then oral when clinical improvement evident
Debate on duration of i/v: 2-7wks
Growing evidence for short-course i/v therapy – 7 days

Arthrotomy best method of Rx
Doubt with adequacy of decompression achieved with U/S guided aspiration
Repeat aspirations may be required
Only significant difference in open Vs arthroscopic hip washout was shortened inpatient stay