A case of infectious erector spinae myositis during treatment of lumbar disk herniation

Abstract

We recently treated a patient who developed unilateral erector spinae myositis during inpatient treatment with continuous epidural block. The patient was diagnosed with radicular sciatica. A catheter was inserted (3.5cm cephalad from L3/4) for continuous epidural block, and left L5 nerve root block was performed. The catheter site was disinfected and the dressing was changed every other day. Intradiscal pressurized injection was performed on day 8. Lower back and leg pain gradually improved, and then erythema and tenderness at the catheter insertion site was noted on day 13. Blood tests yielded severe inflammatory findings, so cefazolin sodium was started by infusion. Urgent contrast-enhanced MRI confirmed left erector spinae myositis. Erector spinae myositis was attributed to contamination of the catheter insertion site. In cases of suspected infection like this, early diagnosis by MRI and prompt treatment are considered to be necessary