Septic Joint


A 7 year old boy presents to A+E with a 1 day history of a painful left hip. The boy has been spiking temperatures at home and off his food. His mother reports he has not been walking on the hip.

I would take a brief history from the patient including: Presenting complaint, history of presenting complaint, past medical history, obstetric history and social history. I would ask about other sources of infection. I would then assess this child according to ALS principles. Assessing the patients airway, breathing, circulation and disability in turn. I would then examine the hip in question and the joint above and below (Spine and knee). I would then perform a: urine dip, bloods, blood cultures, X-Ray (AP and frog leg lateral) and US hip.

Bedside tests

  • Urine dip
  • Observations


  • FBC
  • Blood cultures


  • US hip
  • X-Ray of joint above and below including a frog leg lateral view
  • Non weight bearing
  • ESR >40 (CRP >20)
  • Fever >38.5 (most sensitive)
  • WCC >12,000
  • Septic arthritis can lead to septic shock and death
  • It can also lead to irreversible damage to the patients joint (cartilage/bones) 8 hours
  • It can spread 
  • Femoral head osteonecrosis (capsular pressure)

The patient has a Kocher’s criteria of 4. I would therefore take the patient for an urgent washout in theatre.

In an appropriately marked and consented anaesthetised patient. I would complete a WHO checklist. 

Patient would be supine on the table.

Internervous plane: superior gluteal and femoral nerve

Incision: 6-8 cm. ASIS to lateral border of patella

Superficial dissection: Skin, subcut tissue and divide sartorius and Tensor fascia lata

Deep dissection: Rectus femoris and gluteus medius

Dangers: circumflex arteries, lateral femoral cutaneous nerve, femoral nerve, ascending branch of lateral femoral circumflex artery.

Pain is thought to radiate due to the femoral and obturator nerves which supply articular branches to the hip joint and cutaneous branches to the thigh and around the knee.

Anterior branch of obturator nerve thought to be particularly important.

  • Hip
  • Shoulder
  • Elbow
  • Ankle

Joint capsule of these joints extends to the metaphysis. The knee does not have a intracapsular metaphysis.