Septic arthritis of the hip (peds)

Background

• hematogenous spread or local inf.
• wt. bearing joints most common
• knee (40-50%)
• hip (20- 25%)
• staph, S. Pneumo, group A strep
• in neonates also Groub B strep % gram neg.

Differential Diagnosis

Hip pain

Acute Trauma

• Femur fracture
  • Proximal
    • Intracapsular
      • Femoral head fracture
      • Femoral neck fracture
    • Extracapsular
      • Intertrochanteric femur fracture
      • Trochanteric femur fracture
  • Shaft
    • Mid-shaft femur fracture (all subtrochanteric)
• Hip dislocation
• Pelvic fractures
  • Acetabular pelvic fractures
  • Open book pelvic fracture
  • Straddle pelvic fracture
  • Pelvic avulsion fracture

Chronic/Atraumatic

• Hip bursitis
• Psoas abscess
• Piriformis syndrome
• Meralgia paresthetica
• Septic arthritis
  • Septic arthritis of the hip (peds)
• Obturator nerve entrapment
• Avascular necrosis of hip

Workup

1. Labs - ESR > 20 after 1-2 d, WBC >
2. Bld Cxs (40-50% grow out)
3. Xrays
   1. useful to exclude other cause of joint pain (AP & Frog leg)
   2. possible effusion
4. CT
   1. may be useful to look for abscess, UTZ for effusion

Diagnosis

• Age - 6 mo to 8 yrs
• Pres - Pain, Pseudoparalysis
• may present w/ referred knee or thigh pain
• usually hold jt in flexion, ext rotat & slt abduction.

Kocher Criteria

1. ESR > 40
2. WBC > 12
3. Refusal or inability to weight bear on affected joint
4. Fever

• 1/4 criteria met --> 3% have septic joint
• 2/4 --> 40%
• 3/4 --> 93%
• 4/4 --> 99%

Treatment

1. OR drainage
2. Oxacillin, Nafcillin or Clinda in pen all
3. cover H. inf as needed w/ 3rd gen ceph.
4. IV abx for 10-14 days before po

External Links

• MDCalc - Kocher Criteria for Septic Arthritis

See Also

• Hip Pain
• Septic Arthritis (Peds)
• Septic Arthritis (General)