Late and Vague Presentation of Septic Arthritis of Hip in a IVDrug Abuser

INTRODUCTION: Septic arthritis of the hip is a rare entity in acute presentation of hip pain in adults. Even though hip is the second most commonly affected joint, adult patients with septic arthritis not related to a surgical procedure represent <0.00001% of total acute admissions. CASE REPORT: We present a 32-year-old female intravenous drug abuser, positive for Hepatitis B and C who had started to inject her femoral veins 2 years ago. She presented with a 10 weeks history of radiating pain in the leg which was full, constant and diffuse in nature with hip stiffness. She was treated for sciatica by her GP. She had later visited A and E twice (5 and 8 weeks) and was again treated symptomatically. She started to have increasing pain, hip stiffness, reduced mobility, and developed swelling of both legs extending upto groin medially. The patient was apyrexial throughout these visits. She did not have back/buttock pain. X-ray showed loss of joint space with evidence of articular surface destruction. Ultrasound showed no fluid collection inside the joint and deep vein thrombosis was ruled out. Hip joint was aspirated, and cultures grew Staphylococcus aureus from the aspirate. Flucloxacillin and fucidin were started as per hospital protocol. Skin traction was applied for pain relief with active hip movements as possible. Magnetic resonance imaging demonstrated complete joint destruction post- infective septic arthritis. After 8 weeks of antibiotics, inflammatory markers improved. Follow up X-ray showed complete ankylosis of hip joint, severe restriction ofhip movements and was allowed weight bearing as possible. CONCLUSION: Risk of septic arthritis should always be considered in mind when dealing with these cohorts of patients. Threshold for septic arthritis should be much lower especially in patients with complicated history, current or ex-drug abuser and presenting with vague symptoms. Early diagnosis, detection of organisms, specific targeted antibiotics, and joint wash out with a future consideration of total hip arthroplasty when the infection has settled will help patients resume their normal function.