PMN GRANULOCYTE ELASTASE - AN EARLY INDICATOR OF POSTOPERATIVE SPONDYLODISCITIS

The diagnosis of spondylodiscitis after lumbar disc surgery has been b ased so far on clinical abnormalities, non-specific changes in chemica l laboratory parameters [erythrocyte sedimentation rate (ESR), C-react ive protein (CRP)] and radiological examinations such as MRI. Such tec hniques do not enable any clear diagnosis to be made before the 3rd po stoperative week. The PMN elastase released from stimulated polymorpho nuclear granulocytes has been proved to be a good laboratory parameter by which it is possible to prognosticate bacterial and abacterial org an complications in surgical patients with a high degree of probabilit y. Under investigation were 12 patients with spondylodiscitis out of 1 162 operations on herniated lumbar discs. PMN elastase was determined on the 7th postoperative day. In patients with spondylodiscitis and a mean value of 110.5 mu g/l, the elastase was on average higher by a fa ctor of 2.6 as compared to 88 randomly selected control patients. Sinc e spondylodiscitis is a rare complication, this results in a positive value of only 7%, which does not allow a reliable diagnosis of spondyl odiscitis by the elastase assay. But because the negative predictive v alue is 100%, it is possible to exclude a postoperative spondylodiscit is already on the 7th postoperative day, if the elastase value is norm al.