The diagnosis and treatment of septic hip with osteonecrosis of the femoral head

This article aims to provide clinical doctors with references for the diagnosis and treatment of osteonecrosis of the femoral head (ONFH) accompanied with septic hip by summarizing and analyzing clinical data and postoperative follow-up information of patients treated with two-stage arthroplasty. We retrospectively analyzed ten patients who underwent two-stage arthroplasty in our hospital due to ONFH accompanied with septic hip. The diagnosis of septic hip includes erythrocyte sedimentation rate (ESR) > 30 mm/h, C-reactive protein (CRP) > 10 mg/L, pus-like synovial fluid, positive microbiological culture, and the findings of septic arthritis on magnetic resonance imaging (MRI) scan. Patient's information was evaluated based on the review of medical records, including gender, age, symptoms, risk factor of ONFH and septic arthritis, blood test, radiograph, MRI scan, microbiological culture, treatment, follow-up period and outcome. A total of ten patients were diagnosed with ONFH accompanied with septic hip. The average follow-up period was 43.5 months. None of the patients experienced failure during the follow-up period. The risk factor of ONFH was alcohol-related (60%), steroid-related (20%) and idiopathic (20%). Nine patients (90%) have no risk factor of septic arthritis and one patient (10%) has nephrotic syndrome. All patients did not experience any fever symptoms before surgery, but all showed worsening symptoms of pain. There were three patients (30%) with abnormal WBC count > 10 × 109/L. All patients had elevated ESR and/or CPR. Nine patients (90%) had positive MRI findings, and seven patients (70%) had positive microbiological culture. When patients with ONFH experience worsening hip joint pain accompanied by unexplained elevated CRP and/or ESR, it should be suspected whether ONFH is accompanied with septic hip. In these cases, MRI scans should be performed to exclude septic hip. Patients with ONFH accompanied with septic hip showed satisfactory results after two-stage arthroplasty.