Spondylodiscitis after lumbar discectomy: Incidence and a proposal for prophylaxis

Study Design. An analysis of the incidence of spondylodiscitis after umber disc surgery in 1642 patients. In 508 patients no prophylactic antibiotics were given. In 1134 patients a collagenous sponge containing gentamicin was placed in the cleared disc space. Objectives. To report the incidence of postoperative spondylodiscitis in cases in which no antibiotic prophylaxis was used and to define the value of a collagenous sponge containing gentamicin in preventing disc space infections. Summary of Background Data. Spondylodiscitis is considered to be a rare complication of lumbar disc surgery. The retrospective design of most studies and the rare use of magnetic resonance imaging for early radiologic diagnosis suggest that the reported incidence rates may be underestimates. Postoperative spondylodiscitis is the result of intraoperative contamination and theoretically could be prevented by treating these patient with prophylactic antibiotics. Methods. In 1642 patients, 1712 discectomies were performed. In 608 of these patients not prophylactic antibiotics were given in 1134 of these patients a collagenous sponge containing gentamicin was placed in the cleared disc space. Clinical reexamination and in cases of unsatisfactory results, laboratory and radiologic investigations were performed 4-8 weeks after surgery. Results. In nineteen of the 508 patients who were not treated with antibiotic prophylaxis (3.7%), a postoperative spondylodiscitis developed, whereas none of the 1134 patients who received antibiotic prophylaxis became symptomatic (P = 0.00001). Conclusion. In the current study, a 3.7% incidence of postoperative spondylodiscitis, was found in the absence of prophylactic antibiotics. Gentamicin containing collagenous sponges placed in the cleared disc space were effective in preventing postoperative spondylodiscitis.