Bilateral Facet Joint Septic Arthritis Induced by Acupuncture: A Case Report Highlighting Diagnostic Challenges and the Importance of Early Intervention.

BACKGROUND Facet joint septic arthritis (SAFJ) is a rare clinical entity that is extremely challenging to diagnose, often presenting unilaterally and with nonspecific clinical symptoms. However, SAFJ has significant morbidity and mortality, especially with delayed diagnosis. It becomes all the more important for the clinician to recognize that SAFJ can present bilaterally and be associated with direct inoculation, such as in acupuncture. CASE REPORT A 53-year-old woman with chronic alcoholism and well-controlled type 2 diabetes mellitus was initially admitted for progressively worsening atraumatic lower back pain. Initial non-contrast magnetic resonance imaging (MRI) of the lumbar spine revealed bilateral L4-L5 and L5-S1 nonspecific facet joint effusions. Clinical examination was unremarkable. Biochemically, the patient had mildly elevated inflammatory markers. She was treated conservatively with close outpatient follow-up. However, her back pain progressively worsened, with new-onset lower limb weakness and numbness. Repeat MRI showed L4-L5 bilateral facet joint fluid collection with adjacent bony destruction, as well as posterior paraspinal and epidural fluid collections compatible with L4-L5 bilateral SAFJ with paraspinal and epidural abscesses. Urgent surgical drainage and bilateral lateral facet decompression was performed. Intraoperative cultures revealed methicillin-sensitive Staphylococcus aureus as the causative organism. Postoperatively, 6 weeks of intravenous and oral antibiotics were given with good recovery. CONCLUSIONS We describe a case of bilateral SAFJ following acupuncture that was initially missed. With the increasing prevalence of acupuncture treatment for lower back pain, bilateral SAFJ should be a diagnostic consideration. Detailed clinical history is key; this, as well as a high index of suspicion, early evaluation and treatment, are essential to obtain a favorable outcome.