[Long-term results of diskectomy and primary spondylodesis in treatment of lumbar disk hernia].

The indication for spine fusion in combination with diskectomy it neither clearly defined nor widely accepted. It largely depends on the specialist to whom the patient is referred. While orthopedists often perform primary fusions, neurosurgeons hardly ever do so, no matter what the nature of the complaint is. Therefore, the selection of the procedure seems to be a rather random choice. The question is not whether the combined operation or the simple disc excision is superior in itself, but which of the two should be chosen in a given case. For patients with disc displacement and radicular pain as the predominant symptom, undercutting hemilaminectomy and disc excision will generally yield satisfying results. The main indication for a combined operation is a history of instability complaints long before radicular pain caused by the disc displacement appears. Since the number of patients (of all age groups) that require a disc operation is ever increasing, the selection of patients suited for a combined operation is becoming more and more important, so as to bring down the number of secondary fusions for the treatment of invalidating low back pain after disc excision. The aim of our clinical research is to test the criteria for the selection of patients for the combined operation by taking into account both patients who underwent a combined operation and others whose postoperative condition was such as to require a secondary fusion within one year after diskectomy. In the majority of these cases, one can presume that the fusion should have been carried out on the occasion of the first operation. 26 (90%) out of 29 patients showed a good result three months after the combined operation; 25 (86%) were still satisfied four years later. This confirms that patients with a long history of low back pain as a symptom of instability--in addition to the recent symptoms of the herniation--and those with a significant dislocation of one vertebral body (retrolisthesis, spondylolisthesis and pseudospondylolisthesis), too, should be examined in view of a possible combined operation. However, the combined operation is needed in no more than about three to four per cent of all diskectomies.