Pyogenic discitis following discectomy.

PURPOSE To assess the treatment outcome for disc infection in 35 patients. METHODS Records of 23 men and 12 women aged 36 to 62 (mean, 43) years who underwent treatment for pyogenic discitis after open discectomy were reviewed. All patients had single-level disc herniation of L4-5 (n=28) or L5-S1 (n=6), except for one who had 2-level disc herniation of L4-S1. Single antibiotic was given one day prior to discectomy and continued for 2 days. All excised discs were found to be sterile. Discitis was classified into acute (n=26), subacute (n=7), and chronic (n=2). Antibiotic therapy was started immediately when the clinical diagnosis was made. 31 patients were treated with antibiotics alone; the remaining 4 underwent surgery entailing simple posterior superficial wound drainage (n=1), anterior radical surgery (n=2), or posterior instrumentation and posterolateral fusion for post-discectomy syndrome (n=1). Six of the 12 patients who had percutaneous disc space aspiration underwent disc space irrigation. RESULTS The initial symptoms included mild-to-moderate fever (n=4), severe back pain (n=27), back muscle spasms (n=26), back pain radiating to the limb (n=2), Gower sign (n=11), and a draining wound (n=1). The wound aspirates of the 12 patients grew organisms, although blood cultures were negative in all. After antibiotic therapy, symptoms gradually subsided in parallel with normalisation of white blood cell count and inflammatory markers. Surgery was indicated only when symptoms worsened and the disease progressed. Spontaneous intercorporal fusion did not occur. CONCLUSION Early diagnosis and treatment with appropriate antibiotics is important for post-discectomy discitis.