Analysis of reoperations after surgical treatment of degenerative cervical spine disorders: a report on 900 cases.

UNLABELLED Surgery on the degenerative cervical spine disorders aims at decompression of the neural structures and restoring the physiological profile of the cervical spine. The aims of internal fixation are to gain primary stability, introduce a bony fusion and to correct the shape of the spine. The present study will give answers to the following questions: 1. What is the overall revision rate following an operative treatment of degenerative cervical disorders using common operative techniques? 2. Is there any influence of the fusion length to the overall revision rate and especially to the decompensation ratio of adjacent segments? 3. What is the rate of revisions due to instrumentation failures? 4. Are there any differences concerning the revision rate between posterior and anterior instrumentation? MATERIAL We reviewed 900 patients, who underwent a cervical spine surgery with an internal fixation between January 1994 and December 2000. METHODS Five different operative techniques were used: type I (mono-and bisegmental intersomatic decompression and fusion using anterior instrumentation), type II (multisegmental intersomatic decompression and fusion using anterior instrumentation), type III (multisegmental anterior intersomatic decompression and fusion with posterior instrumentation), type IV (one-level corpectomy with vertebral body replacement and anterior instrumentation) and type V (multi-level corpectomy with vertebral body replacement and posterior instrumentation). The minimum follow up period was 2.2 years (mean 4.2 years). RESULTS In total, 121 revisions (13.4%) were recorded. The main indication for revision was implant failure in 5.4%. Operations type I showed the lowest revision rate (11%), while type V operations showed the highest revision rate (32%). CONCLUSIONS The influence of the fusion length on the revision rate was unexpectedly high. Adjacent level decompensation was neither influenced by the length of the fusion nor the performed procedure. Compared to anterior instrumentation, posterior instrumentation showed a tendency for a lower revision rate without statistical significance. However, the posterior procedures showed a high revision rate regarding to wound healing problems.