Posterior surgery in high-grade spondylolisthesis

Influence of slippage reduction and correction of lumbosacral kyphosis by single-level posterior lumbar interbody fusion on spinal alignment in patients with dysplastic spondylolisthesis

PURPOSE

To investigate the influence of slippage reduction and correction of lumbosacral kyphosis by L5-S1 single-level posterior lumbar interbody fusion (PLIF) on spinal alignment and clinical outcomes including postoperative complications in patients with dysplastic spondylolisthesis (DS).

METHODS

Twenty consecutive patients with symptomatic and severe DS who underwent L5-S1 single-level PLIF with a minimum of 2 years of follow-up after surgery were included. Clinical outcomes were evaluated using the Japanese Orthopaedic Association (JOA) and visual analog scale (VAS) scores for low back and leg pain obtained on preoperative and postoperative examinations. Postoperative instrumentation failure and L5 radiculopathy were also evaluated. The preoperative and postoperative spinopelvic parameters were measured.

RESULTS

The JOA score significantly improved from 21.5 ± 4.8 (preoperative) to 27.0 ± 2.5 (postoperative), with a mean recovery rate of 75.0% ± 30.4%. The VAS score for low back pain significantly improved from 44.5 ± 30.1 (preoperative) to 11.5 ± 15.9 (postoperative), and that for leg pain significantly improved from 31.0 ± 33.2 (preoperative) to 5.0 ± 10.2 (postoperative). The slip percentage (% slip) significantly improved from 59.6% ± 13.5% (preoperative) to 25.2% ± 15.0% (postoperative). The lumbosacral angle (LSA) significantly improved from 12.3° ± 9.5° (preoperative) to 1.0° ± 4.9° (postoperative). L5-S1 PLIF led to significant improvement of lumbar lordosis (from 52.0° ± 15.9° to 59.7° ± 8.0°) and pelvic incidence - lumbar lordosis mismatch (from 23.9° ± 20.6° to 13.3° ± 10.0°). Correction of lumbosacral kyphosis had a significant positive correlation with postoperative pelvic tilt (PT) (r = 0.50, P = 0.02), while postoperative % slip did not have a significant correlation with postoperative PT.

CONCLUSIONS

L5-S1 PLIF for DS provided good clinical outcomes. Correction of lumbosacral kyphosis had a positive impact on regaining ideal spinopelvic balance and may be beneficial in the setting of treating DS.

LEVEL OF EVIDENCE IV

Restoration of Spinopelvic Alignment After Reduction of High-grade Spondylolisthesis: Myth or Reality? A Systematic Review of the literature and Meta-analysis

STUDY DESIGN

Systematic review and meta-analysis of literature.

OBJECTIVE

The aim of the presented study is to assess whether the reduction of high-grade spondylolisthesis (HGS) through the correction of lumbosacral kyphosis leads to a decrease in the sagittal spinopelvic compensatory mechanisms.

SUMMARY OF BACKGROUND DATA

HGS is as an anterior translation of a vertebra, >50%. It is also characterized by a kyphotic deformity of the affected level. This combination of translation and kyphosis leads to compensatory mechanisms on the sagittal plane [pelvic retroversion, increased lumbar lordosis (LL), reduction in thoracic kyphosis (TK)].

METHODS

A systematic search of electronic databases was conducted. Inclusion criteria were diagnosis of HGS (Meyerding >II, Slip% >50%), partial or complete reduction surgery (with a significant decrease in Slip%), and report of spinopelvic parameters (pelvic incidence, pelvic tilt, or sacral slope). Clinical and radiographic outcomes were extracted and summarized. Meta-analyses were performed to estimate the differences between preoperative and postoperative spinopelvic alignment measures. P<0.05 was considered significant.

RESULTS

Eighteen studies were included. PT showed a statistically significant decrease of -2.1217 (95% CI: -3.4803 to -0.7630), while SS showed a significant increase of 4.8349 (95% CI: 2.7462-6.9236). Conversely, both LL and TK showed nonsignificant changes, -4.7043 (95% CI: -10.4535 to 1.0449) and 6.3881 (95% CI: -0.8344 to 13.6106), respectively. VAS significantly decreased by -3.1950 (95% CI: -4.9462 to -1.4439).

CONCLUSIONS

The meta-analysis showed mild, yet statistically significant, decrease of PT and an increase in SS after HGS reduction. Conversely, nonstatically significant decrease in LL and an increase in TK occurred. The clinical significance of these results remains questionable.

LEVEL OF EVIDENCE

Level IV.

Clinical and Radiological Outcomes after Reducing Adult Lytic High-Grade Spondylolisthesis Using a Hybrid Technique: Combination of Percutaneous Pedicle Screws with Midline Microscopic Transforaminal Decompression

STUDY DESIGN

Retrospective study.

PURPOSE

To analyze the results and effectiveness of percutaneous screws (PS) with midline microscopic transforaminal decompression (MTFD) technique in reducing adult stiff lytic high-grade spondylolisthesis (HGSL) and compare it with the conventional technique.

OVERVIEW OF LITERATURE

Pedicle screw cannulation and segmental kyphosis negotiation are surgical challenges in HGSL. Open reduction is the preferred approach. PS have the advantage of optimized trajectory and minimized soft tissue exposure. The role of minimally invasive surgery in HGSL remains unknown. We propose a hybrid technique combining PS with MTFD for lytic HGSL.

METHODS

This study included 25 patients with adult lytic HGSL (Meyerding grade III and IV) operated using a hybrid technique from 2012 to 2015. Data were compared with retrospective data on conventional open reduction (n=23) operated from 2000 to 2015. The minimum follow-up was 5 years. Clinical outcomes were assessed using the Visual Analog Scale (VAS) score and modified Oswestry Disability Index (m-ODI). The spinopelvic and perioperative parameters were recorded. The inter-body fusion and adjacent segment degeneration (ASD) were assessed on radiographs at the final follow-up.

RESULTS

The average age in the MTFD and open groups was 45.84±12.70 years (nine males and 16 females) and 49.26±13.33 years (eight males and 15 females), respectively. Further, 22 and three patients in the MTFD group and 19 and four in the open group had grade III and IV listhesis, respectively. The MTFD group demonstrated less operative time, blood loss, and hospital stays than the open group. Significant improvements were observed in VAS and m-ODI in subsequent follow-ups in both groups. The MTFD group fared better at 3 months but outcomes were comparable at the final follow-up. Both techniques were equally effective in restoring spinopelvic parameters. The incidence of ASD is comparable.

CONCLUSIONS

The technique was proven effective in reducing HGSL. The long-term clinical and radiological outcomes were favorable and comparable with the conventional approach.

Biomechanical analysis of reduction technique for lumbar spondylolisthesis: anterior lever versus posterior lever reduction method

BACKGROUND

Reduction of lumbar spondylolisthesis during spinal fusion surgery is important for improving the fusion rate and restoring the sagittal alignment. Despite the variety of reduction methods, the fundamental mechanics of lumbar spondylolisthesis reduction remain unclear. This study aimed to investigate the biomechanical behavior while performing spondylolisthesis reduction with the anterior and posterior lever reduction method.

METHODS

We developed an L4-L5 spondylolisthesis model using sawbones. Two spine surgeons performed the simulated reduction with a customized Cobb elevator. The following data were collected: the torque and angular motion of Cobb, displacement of vertebral bodies, change of lordotic angle between L4 and L5, total axial force and torque applied on the model, and force received by adjacent disc.

RESULTS

Less torque value (116 N-cm vs. 155 N-cm) and greater angular motion (53o vs. 38o) of Cobb elevator were observed in anterior lever reduction. Moreover, the total axial force received by the entire model was greater in the posterior lever method than that in the anterior lever method (40.8 N vs. 16.38 N). Besides, the displacement of both vertebral bodies was greater in the anterior lever method.

CONCLUSIONS

The anterior lever reduction is a more effort-saving method than the posterior lever reduction method. The existing evidence supports the biomechanical advantage of the anterior reduction method, which might be one of the contributing factors to successfully treating high-grade lumbar spondylolisthesis with short-segment instrumentation.

Direct reduction of high-grade lumbosacral spondylolisthesis with anterior cantilever technique - surgical technique note and preliminary results

Backgrounds

Surgical reduction for high-grade spondylolisthesis is beneficial for restoring sagittal balance and improving the biomechanical environment for arthrodesis. Compared to posterior total laminectomy and long instrumentation, anterior lumbar inter-body fusion (ALIF) is less invasive and has the biomechanical advantage of restoring the original disk height and increasing lumbar lordosis, thus improving sagittal balance. However, the application of ALIF is still limited in treating low-grade spondylolisthesis. In this study, we developed a new technique termed anterior cantilever procedure to directly reduce the slippage of high-grade lumbosacral spondylolisthesis. The purpose of our study was to investigate the surgical outcomes of the anterior cantilever procedure followed by ALIF and posterior mono-segment instrumented fixation in high-grade spondylolisthesis.

Methods

All patients with high-grade spondylolisthesis who underwent anterior cantilever procedure followed by anterior lumbar inter-body fusion (ALIF) and posterior mono-segment instrumented fixation between November 2006 and July 2017 were enrolled in our study. The slip percentage, Dubousset’s lumbosacral angle, pelvic tilt, sacral slope, pelvic incidence, and sagittal alignment were measured pre-operatively and postoperatively at the last follow-up. Surgery time, blood loss, complications, and hospital stay were also collected and analysed.

Results

A total of 11 consecutive patients with high-grade spondylolisthesis patients were included and analysed. All of the high-grade spondylolisthesis in our series occurred at the L5-S1 level. The median age was 37 years, and the median follow-up duration was 36 months. The average slip reduction was 30% (60 to 30%, P < 0.01), and the average correction of Dubousset’s lumbosacral angle was 13.8° (84.1° to 97.9°, P < 0.01). The median intra-operative blood loss was 300 mL. All patients attained improved sagittal balance after the operation and achieved solid fusion within 9 months after surgery. No incidences of implant failure, permanent neurological deficit, or pseudarthrosis were recorded at the last follow-up.

Conclusions

Anterior cantilever procedure followed by ALIF and posterior mono-segment instrumented fixation is a valid procedure for treating high-grade spondylolisthesis. It achieved a high fusion rate, partially reduced slippage, and significantly improved lumbosacral angle, while minimizing common complications, such as pseudarthrosis, nerve traction injury, excessive soft tissue dissection, and blood loss in posterior reduction procedures. However, posterior instrumentation is still required to the structural stability in the ALIF procedure.

Level of evidence

IV

Health-Related Quality of Life Outcomes of Instrumented Circumferential Spinal Fusion for Pediatric Spondylolisthesis: A Comparison With Age and Sex Matched Healthy Controls

STUDY DESIGN

A prospective study on the clinical, radiographic, and the health-related quality of life (HRQOL) outcomes in adolescents with spondylolisthesis undergoing instrumented circumferential spinal fusion compared with age and sex matched controls.

OBJECTIVE

To determine the outcomes of pediatric spondylolisthesis patients minimum 2 years after surgery and to compare their HRQOL with age and sex matched controls.

SUMMARY OF BACKGROUND DATA

There is limited evidence of the HRQOL of adolescent spondylolisthesis patients after surgery and no studies comparing it with healthy controls.

METHODS

Twenty-six consecutive adolescents (mean age 14.7 yr, range 10-18 yr) undergoing instrumented reduction with intercorporeal spinal fusion for spondylolisthesis (11 low-grade, 15 high-grade) by a single orthopedic surgeon were included to this study cohort and matched by age and sex with two controls. The HRQOL was measured with Scoliosis Research Society-24 (SRS-24) questionnaire before surgery, 6 months and 2 years after the surgery.

RESULTS

The mean (SD) vertebral slip in the low-grade patients was 25% (13%) and 67% (15%) in the high-grade patients and 6% (7%) and 21% (25%) postoperatively, respectively (P ≤ 0.041 for both comparisons). Three (12%) patients developed a non-union during follow-up. None of the patients developed a persistent neurologic deficit, but two (8%) patients presented with chronic postsurgical pain persisting 24 months. Seven (27%) of the patients had reoperations for any reason during the follow-up. Pain and activity domains of the SRS-24 improved significantly from preoperative to 2-year follow-up (P ≤ 0.007 for both). SRS pain, self-image, function domains, and total score were significantly worse as compared with the 52 controls (P ≤ 0.020 for all comparisons).

CONCLUSION

Risk of non-union is relatively low after instrumented spinal reduction in adolescents with spondylolisthesis. HRQOL improves significantly after instrumented reduction and circumferential spinal fusion in adolescents with spondylolisthesis, but remains at statistically lower level than in the controls.

LEVEL OF EVIDENCE

2.

High-Grade Lumbar Spondylolisthesis

Most high-grade spondylolistheses are resultant from isthmic spondylolisthesis, as complete discontinuity of the pars is typically necessary to allow for this degree of anterior vertebral translation, although can occur less commonly in other scenarios. Higher-grade slips can affect the global sagittal balance of the patient and often result in altered gait patterns and compensatory posturing. Management usually entails surgical decompression and fusion with instrumentation. The addition of anterior column support carries many advantages, including greater surface area for fusion, dynamic compression load sharing at the lumbosacral junction, and a powerful adjunct for deformity correction.

The Challenge of Creating Lordosis in High-Grade Dysplastic Spondylolisthesis

High-grade dysplastic spondylolisthesis (HGDS) is a subset of L5-S1 spondylolisthesis that occurs due to dysmorphic anatomy at the lumbosacral junction, often resulting in sagittal imbalance. Enhanced understanding of global sagittal alignment has led many to preferentially treat HGDS with reduction and fusion to restore sagittal balance. The purpose of this article is to review published surgical techniques for obtaining sagittal correction in HGDS and to evaluate the current evidence regarding the associated surgical complications.

Operative management of high-grade dysplastic L5 spondylolisthesis with the use of external transpedicular fixation: advantages and drawbacks

PURPOSE

The aim of our study was to analyze clinical and radiographic outcomes of operative management of L5 high-grade dysplastic spondylolisthesis with the apparatus for external transpedicular fixation (AETF), and to compare the results of its use for reduction and spondylodesis.

METHODS

There were 13 patients with L5 dysplastic spondylolisthesis of grade 4 (Meyerding grading) and having a mean age of 25.0 ± 3.6 years. The management included two stages: gradual reduction with the AETF, followed by either isolated anterior spondylodesis with the same AETF (group 1, n = 8), or by spondylodesis using a combined method (internal transpedicular instrumentation and posterior lumbar interbody fusion [PLIF]) (group 2, n = 5). Clinical evaluation included pain (VAS scale) and functional status (Oswestry questionnaire [ODI]). Reduction and fusion completeness were assessed radiographically after treatment and at a mean follow-up of 2.1 ± 0.4 years.

RESULTS

Initial slippage was reduced by 51.6 % with AETF and was of grade 1 or 2. Reduction made up 31.1 % at follow-ups (grade 2 or 3). Pain decreased by 57.6 % (p < 0.01). The functional status improved. ODI decreased by 37.7 % (p < 0.01) after treatment and by 41.7 % (p < 0.01) at follow-ups. Fusion at the level of the involved segment was poor in group 1. All the cases fused in group 2.

CONCLUSIONS

The use of AETF for L5 high-grade dysplastic spondylolisthesis provides gradual controlled reduction of the slipped vertebra, decompression of cauda equine roots, and recovery of the local sagittal spinal column balance. It creates conditions for achieving stability of lumbosacral segments with combined spondylodesis (internal transpedicular instrumentation and PLIF). AETF is not suitable for spondylodesis due to a high rate of pseudarthrosis.

Reduction and fusion in high-grade L5-S1 spondylolisthesis by a single posterior approach. Results in 50 patients

INTRODUCTION

Treatment strategies in high-grade L5-S1 spondylolisthesis are controversial. Reduction of slippage, correction of lumbosacral kyphosis and the necessity of a complementary anterior approach are debated in the literature. The present study reports clinical and radiological outcome for reduction and instrumented fusion on a single posterior approach.

MATERIAL AND METHOD

A retrospective study included all consecutive adolescent and young adult patients operated on by a single surgeon (D.C.) for high-grade (Meyerding 3-4-5) L5-S1 spondylolisthesis. The technique consisted in reduction of lumbosacral kyphosis and posterolateral fusion on a single posterior approach without resection of the sacral dome or complementary anterior approach. Only cases of adult ptosis required impacted tibial interbody graft. Clinical complications, radiologic lumbopelvic results and sagittal balance were analyzed at last follow-up.

RESULTS

Fifty patients, with a mean age at surgery of 21±11 years, were followed up for a mean 5.5±4.6 years. Mean lumbosacral angle was reduced by 25° (from 76° to 101°; P<0.05), and mean listhesis grade by >50% (from 75% to 23%; P<0.0001), without correction loss at last follow-up. C7 sagittal offset was corrected (from 8° to 4°; P<0.05), with harmonization of lumbar (from 57° to 64°; P<0.001) and thoracic curvature (from 37° to 44°; P=0.1). Seventeen patients (34%) showed postoperative radicular deficit, without sequelae at last follow-up. There were no cauda equina lesions. Bone fusion was achieved in 42 patients (84%), in the same surgical step. After revision by complementary interbody graft, there was no residual non-union.

CONCLUSION

Surgery on a single posterior approach gave reliable results in high-grade spondylolisthesis in adolescents and young adults. The technique is not however, free of risk (transient neurologic deficit and non-union), and patients should be forewarned. Complementary interbody graft can be reserved to adult ptosis with incomplete reduction of lumbosacral kyphosis and to revision surgery for non-union.

LEVEL OF EVIDENCE

IV, retrospective study.

Radiologic and clinical outcomes of surgery in high grade spondylolisthesis treated with temporary distraction rod

Background

Surgical techniques used in the treatment of patients with high grade lumbar spondylolisthesis (> 50% slippage) are usually associated with a great deal of controversies. We aim to evaluate the surgical outcomes of high grade spondylolisthesis treated with an intraoperative temporary distraction rod.

Methods

We retrospectively studied 21 patients (14 females and 7 males), aged 50.4 ± 9.2 years, who had high grade lumbar spondylolisthesis that was treated with intraoperative temporary distraction rods, neural decompression, pedicular screw fixation, and posterolateral fusion involving one more intact upper vertebra. The mean follow-up period was 39.2 months. Radiologic and clinical outcomes were measured by slip angle, slip percentage, correction rate, Oswestry Disability Index (ODI), visual analogue scale (VAS), patient's satisfaction rate in the pre- and postoperative period. Data were analyzed by SPSS ver. 11.5.

Results

Analysis of the preoperative visits and final follow-up visits indicated that surgery could improve ODI, lumbar VAS, and leg VAS from 60.5% to 8.2%, from 6.7 to 2.2, and from 6.9 to 1.3, respectively. Slip angle and slip percentage were also changed from -8° to -15° and from 59.2% to 21.4%, respectively. Mean correction rate at the final follow-up visit was 64.1%. Loss of correction was insignificant and a neurologic complication occurred in one patient due to misplacement of one screw. Excellent and good levels of satisfaction were observed in 90.5% of the patients.

Conclusions

In the surgical treatment of refractory high grade spondylolisthesis, the use of a temporary distraction rod to reduce the slipped vertebra in combination with neural decompression, posterolateral fusion, and longer instrumentation is associated with satisfactory clinical and radiologic outcomes.