Comparison of degenerative lumbar spondylolisthesis and isthmic lumbar spondylolisthesis: effect of pedicle screw placement on proximal facet invasion in surgical treatment

Background Pedicle screw invasion of the proximal articular process will cause local articular process degeneration and acceleration, which is an important factor affecting adjacent segment degeneration. Although lumbar spondylolisthesis is a risk factor for screw invasion of the proximal joint, there is no clear conclusion regarding the two different types of spondylolisthesis. Therefore, the purpose of this study was to explore the influence of pedicle screw placement on proximal facet invasion in the treatment of degenerative spondylolisthesis and isthmic spondylolisthesis. Methods In total, 468 cases of lumbar spondylolisthesis treated by decompression and fusion in our hospital from January 2017 to January 2020 were included in this retrospective study. Among them, 238 cases were degenerative spondylolisthesis (group A), and 230 cases were isthmic spondylolisthesis (group B). Sex, age, body mass index, bone mineral density, preoperative visual analog scale (VAS) and Oswestry Disability Index (ODI) scores, postoperative VAS and ODI scores at 1 month and 3 months, and angle of the proximal facet joint at the last follow-up were recorded and compared between the two groups. The degree of pedicle screw invasion of the proximal facet joint was graded and compared by the SEO grading method. Results There were no significant differences in sex, age, body mass index, bone mineral density, preoperative VAS and ODI scores, or proximal facet joint angle between the two groups (P > 0.05). There was no significant difference in VAS and ODI scores between the two groups at 1 month and 3 months after the operation (P > 0.05). The VAS score of group A at the last follow-up was 1 (1,2). The VAS score of group B at the last follow-up was 3 (1,3). The ODI score of group A at the last follow-up was 6(4,26). The ODI score of group B at the last follow-up was 15(8,36). The VAS and ODI scores of the two groups at the last follow-up were significantly different (P < 0.05). According to the SEO grading method, the invasion of the proximal articular process by pedicle screw placement in group A involved 320 cases in grade 0, 128 cases in grade I and 28 cases in grade II. In group B, there were 116 cases in grade 0, 248 cases in grade I and 96 cases in grade II, with a significant difference (P < 0.01). Conclusion In summary, a certain number of cases involving screws invading the proximal facet joint occurred in the two different types of lumbar spondylolisthesis, but the number in the isthmic spondylolisthesis group was significantly higher than that in the degenerative spondylolisthesis group, which caused more trauma to the proximal facet joint and significantly affected the patient prognosis.

Comparison of Pedicle Screw Fixation With or Without Cement Augmentation Combined With Single-segment Isthmic Spondylolisthesis in Osteoporotic Spine

PurposeThis study aims to investigate the necessity of cement-augmented pedicle screw fixation in single-segment isthmic spondylolisthesis with osteoporosis.MethodFifty-nine cases were reviewed retrospectively. Thirty-three cases were in the polymethylmethacrylate-augmented pedicle screw (PMMA-PS) group, and the other 26 cases were in the conventional pedicle screw (CPS) group. Evaluation data included operation time, intraoperative blood loss,hospitalization cost, hospitalization days, rates of fusion, screw loosening, bone cement leakage, visual analog scores (VAS) , Oswestry disability index (ODI) , Lumbar Lordosis（LL）, Pelvic Tilt（PT） and Sacral Slope（SS）. ResultsThe operation time and blood loss in the CPS group decreased significantly compared to the PMMA-PS group (P < 0.05). The average hospitalization cost of the PMMA group was significantly higher than that of the CPS group (P < 0.05). There was no significant difference for the average hospital stay between the 2 groups (P > 0.05). The initial and the last follow-up postoperative VAS and ODI improved significantly in the two groups (P < 0.05). There were no significant differences in VAS and ODI at each time point between the 2 groups (P > 0.05). The last postoperative spine-pelvic parameters were significantly improved compared with preoperation (P < 0.05). In the PMMA-PS group, the fusion rate was 100%. The fusion rate was 96.15% in the CPS group. No significant difference was found between the two groups for the fusion rate (P > 0.05). Nine cases in the PMMA-PS group had bone cement leakage (27.27%). There was not screw loosening in the PMMA-PS group. There were 2 cases of screw loosening in the CPS group. There were no significant differences in screw loosening, postoperative adjacent segment fractures, postoperative infection or postoperative revision between the 2 groups (P > 0.05). ConclusionsThe use of PMMA-PS on a regular basis is not recommended for posterior lumbar interbody fusion for the treatment of single-segment isthmic spondylolisthesis with osteoporosis.

Decompression alone versus decompression and instrumented fusion for the treatment of isthmic spondylolisthesis: a randomized controlled trial

OBJECTIVE The most advocated surgical technique to treat symptoms of isthmic spondylolisthesis is decompression with instrumented fusion. A less-invasive classical approach has also been reported, which consists of decompression only. In this study the authors compared the clinical outcomes of decompression only with those of decompression with instrumented fusion in patients with isthmic spondylolisthesis. METHODS Eighty-four patients with lumbar radiculopathy or neurogenic claudication secondary to low-grade isthmic spondylolisthesis were randomly assigned to decompression only (n = 43) or decompression with instrumented fusion (n = 41). Primary outcome parameters were scores on the Roland Disability Questionnaire (RDQ), separate visual analog scales (VASs) for back pain and leg pain, and patient report of perceived recovery at 12-week and 2-year follow-ups. The proportion of reoperations was scored as a secondary outcome measure. Repeated measures ANOVA according to the intention-to-treat principle was performed. RESULTS Decompression alone did not show superiority in terms of disability scores at 12-week follow-up (p = 0.32, 95% CI −4.02 to 1.34), nor in any other outcome measure. At 2-year follow-up, RDQ disability scores improved more in the fusion group (10.3, 95% CI 3.9–8.2, vs 6.0, 95% CI 8.2–12.4; p = 0.006, 95% CI −7.3 to −1.3). Likewise, back pain decreased more in the fusion group (difference: −18.3 mm, CI −32.1 to −4.4, p = 0.01) on a 100-mm VAS scale, and a higher proportion of patients perceived recovery as showing “good results” (44% vs 74%, p = 0.01). Cumulative probabilities for reoperation were 47% in the decompression and 13% in the fusion group (p < 0.001) at the 2-year follow-up. CONCLUSIONS In patients with isthmic spondylolisthesis, decompression with instrumented fusion resulted in comparable short-term results, significantly better long-term outcomes, and fewer reoperations than decompression alone. Decompression with instrumented fusion is a superior surgical technique that should in general be offered as a first treatment option for isthmic spondylolisthesis, but not for degenerative spondylolisthesis, which has a different etiology.

What is the difference in pedicle morphology of the fifth lumbar vertebra between isthmic and degenerative L5-S1 spondylolisthesis? An anatomic study of 328 patients via multi-slice spiral computed tomography

Purpose The purpose of this study was to investigate and determine whether there are differences in L5 pedicles morphology between isthmic and degenerative L5-S1 spondylolisthesis. Methods One hundred and nineteen patients with isthmic spondylolisthesis and 45 patients with degenerative spondylolisthesis at L5-S1 were enrolled in the IS group and DS group, respectively, and 164 lumbar disc herniation patients without spondylolysis or spondylolisthesis were classified into the normal (NL) group. A series of pedicle parameters of the fifth lumbar vertebra, including pedicle length (PL), pedicle width (PW), pedicle screw trajectory length (PSTL), pedicle height (PH), and the pedicle camber angle (PCA) were measured using multi-slice spiral computed tomography (MSCT). The slip distance of the L5 vertebra was measured on radiography, and the percentage of slip was also recorded. Results The pedicles of the fifth lumbar vertebra were shorter and wider, and the PCA was larger in the IS group compared to the DS group and NL group. On the contrary, the pedicles in the DS group were elongated and thinner, and the PCA was smaller. The pedicle parameters of PL were significantly positively correlated with the percentage of slip in the DS group, but PW and PCA were negatively correlated with the percentage of slip. There was no correlation between the percentage of slip and L5 pedicle parameters in the IS group. Conclusions The L5 pedicles morphology in L5-S1 isthmic spondylolisthesis shows abduction, shortness, and width, while that in the degenerative spondylolisthesis shows adduction, lengthening, and thinning compared with the normal populations. The morphology changes may be the result of pedicle stress remodeling in the development of spondylolisthesis, which should be taken into consideration when placing at the insertion of pedicle screws.