Abstract
Introduction: We have previously demonstrated significantly elevated IgG titres (ELISA) to a glycolipid antigen found in the cell wall of most gram positive bacteria in patients with discogenic radiculitis (sciatica).
This raised the possibility that the inflammation associated with disc protrusion might be initiated or accelerated by the presence of bacteria.
Aim of the Study: To confirm whether bacteria were present in disc material harvested at the time of discectomy. To determine whether the presence of bacteria correlated with elevation of Anti Lipid S antibody levels. To compare these results with Antibody levels and disc specimens from patients undergoing surgery for indications other than radiculitis.
Methods: This was a prospective study. Recognising the frequency of contamination in clean wound culture, stringent aseptic precautions were taken. Disc material was harvested from 62 microdiscectomy patients with sciatica. Disc material was also obtained from three patients undergoing decompression but without radiculitis and from three patients undergoing anterior correction of scoliosis. Serology was obtained for all these patients.
Results: In the Microdiscectomy group, 27/62 (43%) had positive cultures after seven days incubation, of which nine (33%) had positive serology. 22 patients had Propionibacteria, three Coagulase negative Staphylococci, one Corynebacterium and one mixed growth. Thirty five (56.4%) patients had negative cultures and all except one had negative serology. There was a significant difference between patients with positive serology and culture compared with those with negative serology and culture (Fischer exact test P< 0.001). In some patients organisms were visible on microscopy prior to culture.
Ten of those with positive cultures and fourteen of those with negative cultures had had one or more epidural injections prior to surgery. Epidural injection was not found to be significantly associated with positive culture.
None of the patients undergoing surgery for other indications had positive serology or positive cultures.
Conclusion: A significant proportion of patients with discogenic radiculitis have positive cultures with low virulence Gram positive organisms (predominantly Propionibacteria) and in a proportion, a corresponding appropriate antibody response.
The abstracts were prepared by Dr P Dolan. Correspondence should be addressed to him at the British Orthopaedic Association, Royal College of Surgeons, 35-43 Lincoln’s Inn Fields, London WC2A 3PN.
