Objective
There are some different classifications for lumbar spondylolisthesis. Common surgical methods for lumbar spondylolisthesis, such as, posterior lumbar interbody fusion(PLIF), posterolateral fusion(PLF), and circumferential fusion using transpedicular screw fixation(TPSF) system, depend on the propensity of surgeons. This study compares the results of the operation for degenerative type(DS) and isthmic type of lumbar spondylolisthesis(IS) using PLIF or PLF with the transpedicular screw fixation system.
Methods
The authors reviewed 623 patients of PLF or PLIF with transpedicular screw fixation system for lumbar spondy- lolisthesis from April 30th, 1994 to March 31st, 2001. The follow up period was more than 2 years. We interviewed patients by telephone. To avoid prejudice of surgeons, telephone interview was done via 3rd party person. The surgical result was analyzed using the score rating system according to the medication, ADL(ability of daily living), and the degree of improvement and satisfaction.
Results
Among 623 operated patients, 602 were interviewed(follow up rate 96.6%). There were 236 IS and 366 DS patients(IS: DS = 1:1.55). Among IS, there were 89 male and 147 female patients. Among DS, there were 73 male and 293 female patients. The age group of the patients were between 21 and 74.
Two hundred thirty six patients with IS underwent 95 PLF and 141 PLIF with TPSF system. Three hundred sixty six patients with DS underwent 143 PLF and 223 PLIF with TPSF system. The overall success rate was 79.0%. There were 126 patients of non-success out of 602 patients. The main causes of non-success are poor indication(24) and pseudoarthrosis associated with instrumentation failure(24). Other causes are personality disoder and psycosocial problem(15), co-existence with other disease(15), degenerative lesion of adjacent level(10) and subsidence(4) so on. The success rate for PLF with TPSF system was 78.6%, and PLIF with TPSF system was 79.4%.
Conclusion
There are some debates about the methods for lumbar spondylolisthesis surgery. According to our study, PLF and PLIF are both ethically good ways of lumbar spondylolisthesis surgery. Main causes of non-success are poor indication, pseudoarthrosis associated with instrumentation failure. Success rate was similar between PLF and PLIF.
