Comparison of the surgical results in the patients with degenerative spondylolisthesis and isthmic spondylolisthesis

HUANG Wei-guo; HAI Yong

doi:10.3969/j.issn.2095-252X.2014.06.013

Abstract：Objective To compare the clinical results in the surgical treatment of degenerative spondylolisthesis and isthmic spondylolisthesis, regarding the safety, curative effects and fusion rate at 2 years after the operation.Methods A retrospective study was performed on 72 adult patients with grade II-III spondylolisthesis who underwent posterior lumbar interbody fusion ( PLIF ) from January 2005 to June 2011. All the patients were divided into 2 groups based on the pathological changes of lumbar spondylolisthesis, including the degenerative spondylolisthesis group (n=48 ) and the isthmic spondylolisthesis group (n=24 ). According to the Meyerding grading system for spondylolisthesis, there were 48 cases of grade II in the degenerative spondylolisthesis group and 10 cases of grade II and 14 cases of grade III in the isthmic spondylolisthesis group. All the patients underwent decompression, reduction, pedicle screw ifxation and spinal fusion. The differences in the preoperative general data between the 2 groups were not statistically significant (P>0.05 ). The operation time, intraoperative blood loss, postoperative ambulation time, postoperative average length of stay and average age were compared between the 2 groups. The curative outcomes were evaluated based on the Visual Analogue Scale ( VAS ) and Japanese Orthopedic Association ( JOA ) assessment criteria for back pain at 1 day before the surgery and 1 month and 2 years after the surgery. The lumbar fusion was observed by the X-ray and 3-dimensional reconstruction of CT scan at 1 year after the surgery.Results The average age of the isthmic spondylolisthesis group was ( 48.6±6.9 ) years old, who was younger than ( 59.5±9.9 ) years old of the degenerative spondylolisthesis group. The intraoperative blood loss, postoperative ambulation time and postoperative average length of stay were ( 343.3±62.4 ) ml, 5.3±2.7d and ( 8.6±2.4 ) d in the degenerative spondylolisthesis group, which were all less than ( 383.8±50.7 ) ml, ( 7.5±2.5 ) d and ( 10.2±3.8 ) d in the isthmic spondylolisthesis group. The differences between them were statistically signiifcant (P<0.01 ). The average operation time in the isthmic spondylolisthesis group was slightly longer than that in the degenerative spondylolisthesis group, with no statistically signiifcant differences between them (P>0.05 ). In each group there was 1 patient with dural laceration, and the results were not statistically different. The differences in the JOA score were not statistically signiifcant between the 2 groups at 1 day before the surgery (P>0.05 ). The JOA score was ( 24.19±1.21 ) points in the degenerative spondylolisthesis group at 1 month after the operation, which was larger than ( 22.83±1.68 ) points in the isthmic spondylolisthesis group, and the differences between them were statistically different (P<0.01 ). The JOA score was ( 25.33±1.06 ) points in the degenerative spondylolisthesis group at 2 years after the operation, which was larger than ( 24.04±1.99 ) points in the isthmic spondylolisthesis group, and the differences between them were statistically different (P<0.01 ). The differences in the VAS score were not statistically significant between the 2 groups at 1 day before the surgery (P>0.05 ). The VAS score was ( 1.77±0.78 ) points in the degenerative spondylolisthesis group at 1 month after the operation, which was larger than ( 3.00±1.02 ) points in the isthmic spondylolisthesis group, and the differences between them were statistically different (P<0.01 ). The VAS score was ( 1.79±0.87 ) points in the degenerative spondylolisthesis group at 2 years after the operation, which was larger than ( 2.96±0.91 ) points in the isthmic spondylolisthesis group, and the differences between them were statistically different (P<0.01 ). Complete reduction was achieved in 20 cases, partial reduction in 27 cases and no reduction in 1 case in the degenerative spondylolisthesis group. While in the degenerative spondylolisthesis group, complete reduction was obtained in 9 cases, partial reduction in 11 cases and no reduction in 4 cases. The differences in the fusion rate at 1 year after the surgery were not statistically signiifcant between the 2 groups (P>0.05 ). Based on the JOA score, there were 36 excellent cases, 9 good cases and 3 fair cases in the degenerative spondylolisthesis group and the excellent and good rate was 93.75%. While in the isthmic spondylolisthesis group, there were 14 excellent cases, 7 good cases and 3 fair cases and the excellent and good rate was 87.5%. The differences in the excellent and good rate between the 2 groups were statistically significant (P<0.05 ).Conclusions The safe and effective curative outcomes can be obtained in the isthmic spondylolisthesis group with the treatment of PLIF, which are just similar to that in the degenerative spondylolisthesis group with the treatment of PLIF. However, there will be less bleeding, faster recovery and more satisfactory clinical results in the degenerative spondylolisthesis group. No obvious differences exist in the operation time and postoperative fusion rate between the 2 groups.