Septic Arthritis of the Hip – Diagnosis and Management

Early diagnosis together with appropriate treatment is essential for the management of septic arthritis of the hip. Abnormal joint anatomy and intra-articular injections increase the risk of joint infection in adults. In children-young age, male gender, respiratory distress syndrome, umbilical artery catheterization, phagocytic deficiencies, haemoglobinopathies, joint interventions and instrumentation of the urinary or intestinal systems are risk factors. Staphylococcus aureus is the most commonly identified pathogen while a growing concern is the methicillin-resistant Staphylococcus aureus. Most adults present with one or two week history restricted motion and painful joint. At least two sets of blood cultures should be obtained before initiating antibiotic treatment. Blood samples for white blood cell count, erythrocyte sedimentation rate and C-reactive protein concentration should also be obtained. Synovial fluid white cell count of > 50,000 cells/mm3 is considered diagnostic for septic arthritis. Specimens for gram-stain and culture should be obtained before antibiotic therapy is started. Repeat aspiration is an available option in the paediatric age group, but open arthrotomy remains the gold-standard for surgical treatment. As opposed to arthrotomy, hip arthroscopy offers a minimally invasive approach, increased access to the hip joint and improved visualization, while eliminating risks such as avascular necrosis of the femoral head, joint instability, need for large surgical exposure, scarring, postoperative pain and prolonged hospital stay. The initial antibiotic choice is based on the patient’s clinical history and risk factors, local prevalence of drug-resistant pathogens and Gram-stain results. As Staphylococcus aureus is the most common pathogen empiric antibiotic treatment with b-lactamase-stable penicillins is recommended. UK guidelines recommend intravenous antimicrobial therapy for two weeks followed by four weeks oral therapy.