Young Adult Hip: Reactivation of dormant, previously undiagnosed Mycobacterium Tuberculosis infection following intra-articular steroid injection

INTRODUCTION: Tuberculosis (TB) still remains a common problem in the UK and, with the increasing number of patients being offered arthroplasties; periprosthetic involvement is not uncommon anymore. However, the diagnosis of TB infected arthroplasties still remains difficult and misdiagnosis is common, therefore delaying treatment. CASE REPORT: We describe a 36-years old Caucasian female with no known history of TB who presented with hip pain thought to be due to femoro-acetabular impingement (FAI). In the course of 18 months, the patient had been investigated extensively; including steroid injection, hip arthroscopy (including synovial biopsies), and eventually a total hip arthroplasty. During arthroplasty, further extensive biopsies were performed which raised the suspicion of TB on histology. Further synovial biopsies obtained arthroscopically were microbiologically positive for TB (PCR). The patient was sent to an infectious disease specialist. It appeared that the patient had TB in the past, of which she was unaware. CONCLUSION: We hypothesise that the immunosuppressant effects of the steroid injections she received reactivated her TB.