No correlation between slip reduction in low-grade spondylolisthesis or change in neuroforaminal morphology and clinical outcome

What Preoperative Factors Are Associated With Achieving a Clinically Meaningful Improvement and Satisfaction After Single-Level Transforaminal Lumbar Interbody Fusion for Degenerative Spondylolisthesis?

STUDY DESIGN

Prospective cohort study.

OBJECTIVES

The purpose of this study was to identify preoperative factors associated with clinically meaningful improvement, patient satisfaction and expectation fulfilment at 2 years follow-up in patients undergoing single-level TLIF for degenerative spondylolisthesis.

METHODS

Patients who underwent a primary, single-level TLIF for degenerative spondylolisthesis between 2006 and 2015 were identified from a prospectively maintained institutional spine registry. Baseline characteristics and PROMs including the Oswestry Disability Index (ODI), 36-Item Short-Form Physical Component Score (SF-36 PCS), Mental Component Score (SF-36 MCS), Visual Analogue Scale (VAS) back pain, and VAS leg pain were collected preoperatively, at 1 month, 3 months, 6 months, and 2 years.

RESULTS

A total of 997 patients were included. Multivariate analyses showed that increasing age (OR 1.039, P < .001) and better preoperative ODI (OR .984, P = .018) were associated with achieving minimal clinically important difference (MCID) for VAS Back. Increasing age (OR 1.032, P = .007) and better preoperative VAS Back (OR .783, P < .001) were associated with achieving MCID for VAS Leg. Lower BMI (OR .952, P = .024) and better preoperative ODI (OR .976, P < .001) were associated with achieving MCID for SF-36 PCS. Importantly, a better preoperative SF-36 MCS was associated with MCID attainment for ODI (OR 1.038, P < .001), satisfaction (OR 1.034, P < .001) and expectation fulfilment (OR 1.024, P < .001).

CONCLUSION

Patients who were older, have less preoperative disability and better preoperative mental health were significantly more likely to attain clinically meaningful improvement in PROMs and postoperative satisfaction after single-level TLIF. Identification of these factors would aid surgeons in patient selection and surgical counselling for single-level TLIF.

Clinical effectiveness of reduction and fusion versus in situ fusion in the management of degenerative lumbar spondylolisthesis: a systematic review and meta-analysis

PURPOSE

To compare the clinical effectiveness of reduction and fusion with in situ fusion in the management of patients with degenerative lumbar spondylolisthesis (DLS).

METHODS

The systematic review was conducted following the PRISMA guidelines. Relevant studies were identified from PubMed, Embase, Scopus, Cochrane Library, ClinicalTrials.gov, and Google Scholar. The inclusion criteria were: (1) comparative studies of reduction and fusion versus in situ fusion for DLS patients, (2) outcomes reported as VAS/NRS, ODI, JOA score, operating time, blood loss, complication rate, fusion rate, or reoperation rate, (3) randomized controlled trials and observational studies published in English from the inception of the databases to January 2023. The exclusion criteria included: (1) reviews, case series, case reports, letters, and conference reports, (2) in vitro biomechanical studies and computational modeling studies, (3) no report on study outcomes. The risk of bias 2 (RoB2) tool and the Newcastle-Ottawa scale was conducted to assess the risk of bias of RCTs and observational studies, respectively.

RESULTS

Five studies with a total of 704 patients were included (375 reduction and fusion, 329 in situ fusion). Operating time was significantly longer in the reduction and fusion group compared to in situ fusion group (weighted mean difference 7.20; 95% confidence interval 0.19, 14.21; P = 0.04). No additional significant intergroup differences were noted in terms of other outcomes analyzed.

CONCLUSION

While the reduction and fusion group demonstrated a statistically longer operating time compared to the in situ fusion group, the clinical significance of this difference was minimal. The findings suggest no substantial superiority of lumbar fusion with reduction over without reduction for the management of DLS.

A New Technique for Lumbar Spondylolisthesis Reduction Using T-Shaped Tools

STUDY DESIGN

Retrospective study.

PURPOSE

To introduce a simple technique to facilitate lumbar spondylolisthesis reduction during posterior lumbar interbody fusion (PLIF).

OVERVIEW OF LITERATURE

Spondylolisthesis reduction has been conducted in various ways, but most of them require special complicated tools.

METHODS

T-shaped levering tool was newly designed. This study included 23 patients who underwent PLIF for lumbar spondylolisthesis treatment using newly designed T-shaped tools and followed up for >2 years. Demographic, clinical, and surgical data, which had been routinely collected in a database, were analyzed. The degree of listhesis was measured on lateral radiographs by the Taillard method.

RESULTS

The authors could achieve lumbar spondylolisthesis reduction without difficulty using newly designed T-shaped tools. Immediate postoperative lateral radiographs revealed a reduced preoperative slip of 36.9%±9.6% to 1.2%±1.9%, showing a correction rate of 96.7%. The final follow-up radiographs revealed the mean final slip of 2.6%±2.7%, showing a correction rate of 93.0%.

CONCLUSIONS

This technique allowed lumbar spondylolisthesis reduction without difficulty.

Correlation Between Postoperative Imaging Parameters and Clinical Outcomes of Percutaneous Endoscopic Transforaminal Decompression for Lumbar Spinal Foraminal and Lateral Recess Stenosis

Objective

To investigate the correlation between postoperative imaging parameters and clinical outcomes in patients with foraminal stenosis (FS) and lateral recess stenosis (LRS) who underwent percutaneous endoscopic transforaminal decompression (PETD).

Methods

The study included 104 eligible patients who underwent PETD, and the mean follow-up time was 2.4 years (range 2.2-3.6 years). Visual Analog Scale (VAS) scores, Oswestry Disability Index (ODI) scores, and the modified MacNab criteria were used to evaluate the clinical outcomes. The related parameters of the FS and LRS based on computed tomography and magnetic resonance imaging were measured before and after surgery. Correlations between the imaging parameters and clinical outcomes were investigated.

Results

The proportion of excellent and good results following MacNab evaluation was 82.6%. In the treatment of LRS, VAS-back, VAS-leg, and ODI at the 2-year follow-up were negatively correlated with postoperative facet joint length based on computed tomography. In the treatment of FS, the above clinical results were positively correlated with the variation of foraminal width and nerve root-facet distance before and after surgery based on magnetic resonance imaging.

Conclusion

PETD can achieve good clinical outcomes in the treatment of patients with LRS or FS. Postoperative facet joint length was negatively correlated with clinical outcomes of LRS patients. In FS patients, the variation in foraminal width and nerve root-facet distance before and after surgery were positively correlated with their clinical outcomes. These findings may help surgeons optimize treatment strategies and selection of surgical candidates.

Patient reported outcomes after navigated minimally invasive hybrid lumbar interbody fusion (nMIS-HLIF) using cortical bone trajectory screws

Prospective observational study. To evaluate patient-reported outcomes after navigation-guided minimally invasive hybrid lumbar interbody fusion (nMIS-HLIF) for decompression and fusion in degenerative spondylolisthesis (Meyerding grade I-II). Posterior lumbar interbody fusion (PLIF) and transforaminal lumbar interbody fusion (TLIF) are well-known standard procedures for lumbar spinal fusion. nMIS-HLIF is a navigation-guided combined percutaneous and open procedure that combines the advantages of PLIF and TLIF procedures for the preparation of a single-port endoscopic approach. 33 patients underwent nMIS-HLIF. Core outcome measure index (COMI), oswestry disability index (ODI), numeric rating scale (NRS) back, NRS leg, and short form health-36 (SF-36) were collected preoperatively and at follow-up of 6 weeks, 3 months, 6 months, and 1 year. The impact of body mass index (BMI) was also analyzed. Computed tomography reconstruction was used to assess realignment and verify fused facet joints and vertebral bodies at the 1-year follow-up. 28 (85%) completed the 1-year follow-up. The median BMI was 27.6 kg/m2, age 69 yrs. The mean reduction in listhesis was 8.4% (P < .01). BMI was negatively correlated with listhesis reduction (P = .032). The improvements in the NRS back, NRS leg, ODI, and COMI scores were significant at all times (P < .001-P < .01). The SF-36 parameters of bodily pain, physical functioning, physical component summary, role functioning/physical functioning, and social functioning improved (P < .003). The complication rate was 15.2% (n = 5), with durotomy (n = 3) being the most frequent. To reduce the complication rate and allow transitioning to a fully endoscopic approach, expandable devices have been developed. The outcomes of nMIS-HLIF are comparable to the current standard open and minimally invasive techniques. A high BMI hinders this reduction. The nMIS-HLIF procedure is appropriate for learning minimally invasive dorsal lumbar stabilization. The presented modifications will enable single-port endoscopic lumbar stabilization in the future.

Factors Affecting Slip Reduction in Oblique Lumbar Interbody Fusion With Posterior Fixation for Degenerative Spondylolisthesis

STUDY DESIGN

Retrospective case series.

OBJECTIVES

Reduction of translational/angular slip is a favorable radiological result in spinal fusion for degenerative spondylolisthesis, although its clinical significance remains controversial. Few studies have investigated slip reduction and associated factors in oblique lumbar interbody fusion (OLIF) for degenerative spondylolisthesis.

METHODS

This study involved a retrospective analysis of 56 operated levels of 52 consecutive patients who underwent OLIF for degenerative spondylolisthesis and had more than 1-year of regular follow-up. Translational/angular slip, anterior/posterior disc height, and spinopelvic parameters were measured preoperatively, postoperatively at 6-weeks, and at the last follow-up. Demographic, radiological, and surgical parameters were analyzed to determine factors associated with the amount of slip reduction.

RESULT

The mean follow-up duration was 30.4 ± 12.9 months (range, 12 to 61). The mean decrease in translational slip was 5.7 ± 2.1 mm (13.6 ± 5.5%) and the mean increase in angular slip was 7.9 ± 7.1° at the last follow-up (both P < 0.001). The amount of slip reduction was greater in female sex, age < 65 years, use of a 12° cage, cage position from the anterior disc margin of < 7 mm, and cases with posterior decompression (laminectomy with inferior facetectomy).

CONCLUSIONS

OLIF showed satisfactory translational/angular slip reduction in degenerative spondylolisthesis. Surgical techniques for optimal reduction include the use of a large angle cage, anterior cage placement, and resection of the inferior facet.

Long-term Radiological and Clinical Outcome after Lumbar Spinal Fusion Surgery in Patients with Degenerative Spondylolisthesis: A Prospective 6-Year Follow-up Study

Objective

To assess which radiological alignment parameters are associated with a satisfactory long‐term clinical outcome after performing lumbar spinal fusion for treating degenerative spondylolisthesis.

Methods

This single‐center prospective study assessed the relation between radiological alignment parameters measured on standing lateral lumbar spine radiographs and the patient‐reported outcome using four different questionnaires (COMI, EQ‐5D, ODI and VAS) as primary outcome measures (level of evidence: II). The following spinopelvic alignment parameters were used: gliding angle, sacral inclination, anterior displacement, sagittal rotation, lumbar lordosis, sacral slope, pelvic tilt and pelvic incidence. Furthermore, the length of stay and perioperative complications were documented. Only cases from 2013 to 2015 of low‐grade degenerative lumbar spondylolisthesis (Meyerding grades I and II) were considered. The patients underwent open posterior lumbar fusion surgery by pedicle screw instrumentation and cage insertion. The operative technique was either a posterior lumbar interbody fusion (PLIF) or a transforaminal lumbar interbody fusion (TLIF) performed by three different senior orthopedic surgeons. Exclusion criteria were spine fractures, minimally invasive techniques, underlying malignant diseases or acute infections, previous or multisegmental spine surgery as well as preoperative neurologic impairment. Of 89 initially contacted patients, 17 patients were included for data analysis (11 males, six females).

Results

The data of 17 patients after mono‐ or bisegmental lumbar fusion surgery to treat low‐grade lumbar spondylolisthesis and with a follow‐up time of least 72 months were analyzed. The mean age was 66.7 ± 11.3 years. In terms of complications two dural tears and one intraoperative bleeding occurred. The average body mass index (BMI) was 27.6 ± 4.4 kg/m² and the average inpatient length of stay was 12.9 ± 3.8 days (range: 8–21). The long‐term clinical outcome correlated significantly with the change of the pelvic tilt (r_s = −0.515, P < 0.05) and the sagittal rotation (r_s = −0.545, P < 0.05). The sacral slope was significantly associated with the sacral inclination (r_s = 0.637, P < 0.01) and the pelvic incidence (r_s = 0.500, P < 0.05). In addition, the pelvic incidence showed a significant correlation with the pelvic tilt (r_s = 0.709, P < 0.01). The change of the different clinical scores over time also correlated significantly between the different questionnaires.

Conclusions

The surgical modification of the pelvic tilt and the sagittal rotation are the two radiological alignment parameters that can most accurately predict the long‐term clinical outcome after lumbar interbody fusion surgery.

Clinical outcome after lumbar spinal fusion surgery in degenerative spondylolisthesis: a 3-year follow-up

INTRODUCTION

Lumbar spinal fusion surgery is a widely accepted surgical treatment in degenerative causes of lumbar spondylolisthesis. The benefit of reduction of anterior displacement and restoration of sagittal parameters is still controversially debated. Purpose of the underlying publication was to analyze the influence of radiographic sagittal parameters of the spine in aspects of changes in postoperative clinical outcome.

MATERIALS AND METHODS

By prospective analysis, we included patients with low-grade degenerative lumbar spondylolisthesis (Meyerding grades I and II) with mono- or bisegmental fusion surgery with a minimum follow-up data of 3 years. For clinical outcome measures, COMI, ODI and EQ-5D were used. Spinopelvic parameters (sacral inclination, pelvic tilt, sacral slope and pelvic incidence, lumbar lordosis and lumbar index as well as anterior displacement and sagittal rotation) were measured on plain radiographs.

RESULTS

We could observe a significant benefit in clinical outcome after lumbar fusion surgery in low-grade spondylolisthesis in our mid-term follow-up data including 32 patients. By surgical reduction, we could see significant restoration of anterior displacement and sagittal rotation. Interestingly, a significant correlation between restoration of both sagittal rotation and sacral inclination and clinical outcome score was observed in the 3-year follow-up.

CONCLUSION

In low-grade spondylolisthesis, spinal fusion surgery is a well-established surgical procedure; however, the impact of sagittal parameters and reduction of anterior displacement remains controversial. Within our findings, restoration of sagittal parameters showed significant correlation to improvement in clinical outcome in our mid-term follow-up data.

Lumbar spinal fusion of low-grade degenerative spondylolisthesis (Meyerding grade I and II): Do reduction and correction of the radiological sagittal parameters correlate with better clinical outcome?

INTRODUCTION

Lumbar and lumbosacral spinal fusion is an established procedure for the treatment of degenerative spondylolisthesis. However, the impact of reduction in the affected segment and of improvement in the radiological sagittal parameters on the clinical outcome remains unclear. Purpose of the study is to analyze the correlation between the radiological sagittal parameters and clinical outcome after lumbar spinal fusion in low-grade degenerative spondylolisthesis.

MATERIALS AND METHODS

In a monocentric prospective, clinical study, patients with low-grade degenerative spondylolisthesis of a single lumbar segment have been included. All patients received a lumbar spinal fusion according to the pathology of the treated segment. Patients attended clinical and radiological follow-up examination 1 and 2 years postoperatively. Clinical outcome was assessed using the Core Outcome Measurement Index (COMI), the Oswestry Disability Index (ODI) and the EuroQol 5D. The sagittal spinopelvic radiological parameters, sagittal rotation and anterior displacement of the affected segment and lumbar lordosis were assessed. The correlation between the sagittal radiological parameters and clinical outcome was analyzed using Spearman-Rho bi-serial test.

RESULTS

Sixty-two patients (35 female and 27 male) with an average age of 59.3 years were included in the study. All patients completed the follow-up examinations. Significant improvement in COMI, ODI and EuroQol 5D scores was shown in all follow-up examinations. Significant reduction in the anterior displacement was measured postoperatively, which was preserved during the follow-up. However, no correlation could be demonstrated between reduction in anterior displacement and improvement in clinical outcome. Nonetheless, correlation between correction of sagittal rotation and clinical outcome was shown.

CONCLUSIONS

Reduction in anterior displacement of the affected segment in the surgical treatment of low-grade degenerative spondylolisthesis does not have an impact on the clinical outcome.

A new lever reduction technique for the surgical treatment of elderly patients with lumbar degenerative Spondylolisthesis

BACKGROUND

Proper reduction method for Lumbar degenerative spondylolisthesis (LDS) is still controversial. The aim of this study was to determine the safety and effectiveness of lever reduction combined with traditional elevating-pull reduction technique for the treatment of elderly patients with LDS.

METHODS

From May 2015 to December 2017, 142 elderly patients (≥65 years) diagnosed with LDS were enrolled in this study with a mean follow-up of 25.42 ± 8.31 months. All patients were operated using lever reduction combined with traditional elevating-pull reduction technique. Patient age, sex, body mass index, bone mineral density, preoperative comorbidities, surgical duration, blood loss, and surgical complications were collected form patient charts. Clinical data as visual analog scale (VAS), Oswestry Disability Index (ODI), and 36-Item Short Form Health Survey (SF-36) were collected preoperatively, 1 month postoperatively, and at the final follow-up. Radiographic evaluation included slip percentage, slip angle (SA), lumbar lordosis (LL), and fusion status.

RESULTS

The clinical parameters of VAS_back, VAS_leg, ODI, and SF-36 had significantly improved at both follow-ups after surgery. A significant improvement was indicated for slippage reduction at both follow-ups, showing no significant correction loss after surgery. SA significantly increased after surgery and was well maintained at the final follow-up. LL was not affected by the surgery. At the final follow-up, complete fusion was obtained in 121 patients (85.2%) and partial fusion in 21 (14.8%). Revision surgery was performed for one patient. Screw loosening was observed in 3 (2.11%) cases. No nerve root injury or adjacent segment disease was observed.

CONCLUSIONS

This new lever reduction combined with traditional elevating-pull reduction technique for the surgical treatment of elderly patients with LDS is both safe and effective. Satisfactory correction and fusion rates were achieved with acceptable correction loss and reduction-related complications.

Outcome of transforaminal lumbar interbody fusion in spondylolisthesis-A clinico-radiological correlation

Introduction

Lumbar spondylolisthesis is a common cause of morbidity in middle aged individuals. Spinal fusion with instrumentation has become the gold standard for lumbar segmental instability. Studies which correlate the improvement in radiology postoperatively with functional outcome show contrasting reports. This study is aimed at finding the correlation between clinical and radiological outcomes after surgery with transforaminal lumbar interbody fusion.

Methods

A retrospective study in 35 patients who underwent transforaminal lumbar interbody fusion in a period of 1 year was done. Preoperative pain (VAS Score), functional ability (ODI), radiological parameters (slip angle, slip grade, disc height, foraminal height, lumbar lordosis) were compared with postoperative recordings at the last followup. Functional improvement (Macnab's criteria) and fusion (Lee's fusion criteria) were assessed. Statistical analysis was done with student's paired t-test and Pearson's correlation coefficient.

Results

VAS score, ODI improved from 8 to 2 and 70 to 15 respectively. Slip angle improved from 23°to 5° on an average. 80% patients showed fusion and 85% showed good clinical outcome at 1 year followup. Analyzing with Pearson correlation coefficient showed no significant relation between pain scores and radiological parameters. But there was statistically significant relation between radiological fusion and the final clinical outcome.

Conclusion

TLIF produces spinal fusion in most individuals. Strong spinal fusion is essential for good clinical outcome in spondylolisthesis patients who undergo TLIF. Reduction in slip is not necessary for all patients with listhesis.

Effects of Preoperative Simulation on Minimally Invasive Hybrid Lumbar Interbody Fusion

OBJECTIVE

The main focus of this study was to evaluate how preoperative simulation affects the surgical work flow, radiation exposure, and outcome of minimally invasive hybrid lumbar interbody fusion (MIS-HLIF).

METHODS

A total of 132 patients who underwent single-level MIS-HLIF were enrolled in a cohort study design. Dose area product was analyzed in addition to surgical data. Once preoperative simulation was established, 66 cases (SIM cohort) were compared with 66 patients who had previously undergone MIS-HLIF without preoperative simulation (NO-SIM cohort).

RESULTS

Dose area product was reduced considerably in the SIM cohort (320 cGy·cm² NO-SIM cohort: 470 cGy·cm²; P < 0.01). Surgical time was shorter for the SIM cohort (155 minutes; NO-SIM cohort, 182 minutes; P < 0.05). SIM cohort had a better outcome in Numeric Rating Scale back at 6 months follow-up compared with the NO-SIM cohort (P < 0.05).

CONCLUSIONS

Preoperative simulation reduced radiation exposure and resulted in less back pain at the 6 months follow-up time point. Preoperative simulation provided guidance in determining the correct cage height. Outcome controls enabled the surgeon to improve the procedure and the software algorithm.

Outcome of L5 radiculopathy after reduction and instrumented transforaminal lumbar interbody fusion of high-grade L5-S1 isthmic spondylolisthesis and the role of intraoperative neurophysiological monitoring

PURPOSE

To evaluate the incidence and course of iatrogenic L5 radiculopathy after reduction and instrumented fusion of high-grade L5-S1 isthmic spondylolisthesis and the role of intraoperative neurophysiological monitoring (IONM).

METHODS

Consecutive patients treated for high-grade spondylolisthesis with IONM from 2005 to 2013 were screened for eligibility. Prospectively collected clinical and surgical data as well as radiographic outcomes were analyzed retrospectively. Patients completed the multidimensional Core Outcome Measures Index (COMI) before and at 3, 12, and 24 months after surgery.

RESULTS

Seventeen patients were included, with a mean age of 26.3 (±9.5) years. Mean preoperative L5-S1 slip was 72% (±21%) and was reduced to 19% (±13%) postoperatively. Mean loss of reduction at last follow-up [mean 19 months (±14, range 3-48 months)] was 3% (±4.3%). Rate of new L5 radiculopathy with motor deficit (L5MD) after surgery was 29% (five patients). Four patients fully recovered after 3 months, one patient was lost to neurologic follow-up. IONM sensitivity and specificity for postoperative L5MD was 20 and 100%, respectively. COMI, back pain and leg pain scores showed significant (p < 0.001) improvements at 3 months postoperatively, which were retained up to 24 months postoperatively.

CONCLUSIONS

Transient L5 radiculopathy after reduction and instrumented fusion of high-grade spondylolisthesis is frequent. With IONM the risk of irreversible L5 radiculopathy is minimal. If IONM signal changes recover, full clinical recovery is expected within 3 months. Overall, patient-reported outcome of reduction and instrumented fusion of high-grade spondylolisthesis showed clinically important improvement.

Is reduction better than arthrodesis in situ in surgical management of low-grade spondylolisthesis? A system review and meta analysis

PURPOSE

To compare the clinical and radiographic outcomes of arthrodesis in situ with arthrodesis after reduction in low-grade spondylolisthesis.

METHODS

We performed a comprehensive search of both observational and randomized clinical trials published up to April 2016 in PubMed, MEDLINE, Cochrane Library, and Embase databases. The outcomes included age, sex, operative time, blood loss, and at least 2 years clinical results of Oswestry disability index (ODI), visual analogue scale (VAS), lumbar lordosis, slippage, fusion rate, the rate of good and excellent and the complication rate. Two authors independently extracted the articles and the predefined data.

RESULTS

Seven eligible studies, involving four RCTs and three cohort studies were included in this systematic review and meta-analysis. Patients who underwent reduction did achieved better slippage correction comparing with arthrodesis in situ (P < 0.00001). However, there was no significant difference in the case of operative time, blood loss, VAS (P = 0.36), ODI (P = 0.50), lumbar lordosis (P = 0.47), the rate of good and excellent (P = 0.84), fusion rate (P = 0.083) and complication rate (P = 0.33) between the arthrodesis in situ group and the reduction group.

CONCLUSIONS

On the basis on this review, arthrodesis after reduction of low-grade spondylolisthesis potentially reduced vertebral slippage. Reduction was neither associated with a longer operative time nor more blood loss. There was no significant difference in the outcomes between reduction and arthrodesis in situ group. Both procedures could be expected to achieve good clinical result.

LEVEL OF EVIDENCE

Therapeutic Level IIa.

Interbody Fusion in Low Grade Lumbar Spondylolsithesis: Clinical Outcome Does Not Correalte with Slip Reduction and Neural Foraminal Dimension

Study Design

Prospective nonrandomized study.

Purpose

To find a possible correlation between clinical outcome and extent of lumbar spondylolisthesis reduction.

Overview of Literature

There is no consensus in the literature concerning whether a beneficial effect of reduction on outcome can be expected following reduction and surgical fusion for low grade lumbar spondylolisthesis.

Methods

Forty six patients with a mean age of 37.5 years (age, 17–48 years) with isthmic spondylolisthesis underwent interbody fusion with cages with posterior instrumentation (TLIF). Clinical outcome was measured using visual analogue score (VAS) and Oswestry disability index (ODI). Foraminal dimensions and disc heights were measured in standard digital radiographs. These were analyzed at baseline and 1 year after surgery and changes were compared. Radiographic fusion was judged with computed tomography scans at 1 year.

Results

Ninety percent of the patients had good or very good clinical results with fusion and instrumentation. Baseline and one-year postoperative mean VAS score was 6.33 (range, 5–8) and 0.76 (range, 0–3), respectively (p=0.004). Baseline and one-year postoperative, mean ODI score was 48 (range, 32–62) and 10 (range, 6–16), respectively (p<0.001). A mean spondylolisthesis slip of 32.1% was reduced to 6.7% at 1 year. Average anterior disc height, posterior disc height, vertical foraminal dimension), and foraminal) diameter improved from 9.8 to 11.7 mm (p=0.005), 4.5 to 5.8 mm (p=0.004), 11.3 to 12.6 mm (p=0.002), and 18.6 to 20.0 mm (p<0.001), respectively. The fusion rate was 75% with TLIF. There is no significant correlation between the improvements of ODI scores and the extent of slip reduction.

Conclusions

Neural decompression and interbody fusion can significantly improve pain and disability but the clinical outcome does not correlate with radiological improvement in the neural foraminal dimension.

Intraoperative reduction does not result in better outcomes in low-grade lumbar spondylolisthesis with neurogenic symptoms after minimally invasive transforaminal lumbar interbody fusion-a 5-year follow-up study

BACKGROUND CONTEXT

Intraoperative reduction of low-grade lumbar spondylolisthesis (LGLS) remains disputed. There is currently no published data comparing midterm outcomes of reduction versus in situ fusion.

PURPOSE

This study aimed to compare mid-term clinical, radiological, and perioperative outcomes for reduction versus in situ fusion in LGLS with neurogenic symptoms.

STUDY DESIGN/SETTING

A retrospective review of prospectively collected spine registry data in a single institution was carried out.

PATIENT SAMPLE

All patients who underwent minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) for LGLS with neurogenic symptoms with a minimum 5-year follow-up comprised the patient sample.

OUTCOME MEASURES

Self-reported measures were Oswestry Disability Index, North American Spine Society Neurogenic Symptom Score, Health Outcomes Survey Short Form-36 score, and Numerical Pain Rating Scale (back and leg pain). Radiological outcomes were fusion grading, adjacent segment degeneration (ASD), and implant failure or loosening. Perioperative outcomes were fluoroscopic time, operative time, intraoperative blood loss, opioid analgesia usage, time to ambulation, duration of hospitalization, and complication rate. Functional outcomes were patient satisfaction rate and rate of return to full function.

METHODS

A retrospective review was performed on prospectively collected registry data of patients undergoing MIS TLIF for LGLS with neurogenic symptoms, from 2004 to 2009. The operative technique and postoperative protocol were standardized. Two groups were formed based on complete reduction of the spondylolisthesis (reduction group [RG]) or the lack thereof (non-reduction group [NRG]) in the immediate postoperative radiograph. Outcomes at baseline, 6 months, 2 years, and 5 years postsurgery were compared.

RESULTS

There were 56 patients included (RG=30, NRG=26). The two groups had comparable baseline characteristics: demographics, body mass index, spondylolisthesis etiology, spinal level involved, bone graft and bone morphogenetic protein used, and all self-reported outcome measures. Perioperative outcomes were not significantly different. The early complication rate (RG=3.3%, NRG=19.2%, p=.086) and late complication rate (RG=10%, NRG=23.1%, p=.184) were similar. All patients achieved Bridwell grade 1 fusion from 2 years onward. Adjacent segment degeneration rate at 5 years was similar (RG=10%, NRG=0%, p=NS). Both groups showed significant postoperative improvement in all self-reported measures with no significant differences between the two groups at all follow-up points. Functional outcomes were equivalent.

CONCLUSIONS

Intraoperative reduction does not improve outcomes in LGLS with neurogenic symptoms after MIS TLIF. Adequate decompression and solid fusion are likely the keys to good mid-term outcomes.

A novel minimally invasive technique for lumbar decompression, realignment, and navigated interbody fusion

We present a novel, minimally invasive, navigation-guided approach for surgical treatment of degenerative spondylolisthesis (DS) that is a hybrid of the two most common techniques, posterior interbody fusion (PLIF) and transforaminal interbody fusion (TLIF). DS is an acquired condition with intersegmental instability of one or more lumbar motion segments. Seven patients with single level lumbar DS underwent lumbar arthrodesis utilizing the hybrid technique (HLIF) in our center. Using a standard unilateral midline approach a decompression and partial facetectomy on one side was performed, allowing for implantation of a specially designed interbody cage. Pedicle screws were placed using neuronavigation in a vertical vector on the side of the partial facetectomy and dorsolaterally (percutaneous) on the contralateral side. Patient and operative data, numeric rating scale (NRS) pain scores, core outcome measures index (COMI) and Oswestry disability index (ODI) were recorded preoperatively as well as 6 weeks, 3 months, 6 months and 1 year after surgery. All patients completed the 1 year follow-up. There was significant postoperative improvement of NRS, COMI and ODI scores at all postoperative follow-up time points (p<0.05). The radiological assessments of realignment showed a reduction of listhesis from an average of 21.04% (standard deviation [SD] 5.1) preoperatively to 9.14% (SD 4.0) postoperatively (p<0.001). The average blood loss was 492 ml. Post-procedure CT scans demonstrated correct implant placement in all but one patient who required a revision of a single pedicle screw. HLIF allows thorough decompression as well as realignment and interbody fusion for patients with DS and may help reduce tissue trauma in comparison to other minimally invasive lumbar fusion techniques.

Lever reduction using polyaxial screw and rod fixation system for the treatment of degenerative lumbar spondylolisthesis with spinal stenosis: technique and clinical outcome

Background

The management for degenerative lumbar spondylolisthesis with spinal stenosis remains controversial. Reduction of lumbar spondylolisthesis has been performed via numerous techniques. Most of them need extra reduction assembly.

Methods

In this retrospective analysis, 27 patients of degenerative lumbar spondylolisthesis with spinal stenosis underwent reduction using polyaxial screw and rod constructs and posterolateral fusion. The average age at the time of surgery was 53 ± 3.23 years. The outcome measures consisted of a radiographic assessment of deformity and fusion rate and a clinical assessment of perioperative improvement in low back pain and function. Preoperative and postoperative radiographic evaluation included the percent slip, slip angle, and the lumbar lordosis between L1 and the sacrum measured using the Cobb method. Before surgery and at the final follow-up, the Oswestry Disability Index (ODI) and the visual pain analog scale (VPAS) between 0 (no pain) and 10 (maximal pain) were quantified.

Results

The average follow-up period more than 5 years was available. The mean operative time was 90.19 ± 14.51 min, and the mean blood loss during surgery was 152.59 ± 45.71 ml. The mean length of incision was 4.83 ± 0.63 cm. The average percent slippage and the mean slip angle were, respectively, 19.8 ± 4.49% and 9.69 ± 3.79° before surgery, 5.09 ± 3.40% and 6.39 ± 3.16° after surgery, and 5.67 ± 3.92% and 7.21 ± 3.05° at the last follow-up. The average lumbar lordosis was 36.88 ± 2.64° before surgery, 41.96 ± 1.64° after surgery, and 40.27 ± 1.19° at the final follow-up. No neurologic deficit occurred. Solid fusion was achieved for all cases. Compared with the outcome preoperation, the data improved from 6.56 ± 1.40 to 2.48 ± 1.16 for VPAS pain scores and from 32.22 ± 3.57 to 10.93 ± 4.93 for the ODI at the final follow-up.

Conclusions

Lever slip reduction maneuver techniques using polyaxial screw and rod fixation system was simple and practicable. The treatment outcomes showed satisfactory radiographic characteristics and clinical results. The length of the incision was relatively small with a low intraoperative blood loss and short operation time.