Surgical treatment of degenerative spondylolisthesis

The "20-minute Rule" in Lateral Lumbar Interbody Fusion. Fact or Fiction? A Multi-Center Analysis of 658 Patients

Study DesignRetrospective Cohort Study.ObjectiveLateral lumbar interbody fusion (LLIF) is a treatment option for correcting lumbar degenerative pathologies that uses a retroperitoneal, transpsoas corridor to the disc space. Conventional teaching of the LLIF technique has been to perform the procedure 'as efficiently as possible', with a goal of keeping the total retractor time to less than 20 minutes to prevent injuries. This study aims to examine the sensitivity of the "20-minute" rule for predicting postoperative femoral nerve palsy.MethodsA multicenter, retrospective cohort of patients who underwent an LLIF was established. Retractor time was recorded and compared to postoperative motor exams for its relationship to motor injury.Results658 total patients were included in the study. The most frequently operated level was L4-5 (71.7%). The average retractor time was 17.5 ± 8.0 minutes. The injury rate of the cohort was 1.8% (12/658). There was no difference in average retractor time for non-injured vs injured patients (17.5 ± 8.0 min vs 19.6 ± 11.2 min, P = 0.367). Analysis of the "20-minute" rule for LLIF revealed a sensitivity of 50%, a specificity of 73.8%, and a positive predictive value of 3.4%. There were 174 patients with retractor times >20 minutes and six injuries, yielding a false positive rate of 96.6%.ConclusionPost-operative quadriceps motor palsy after lateral lumbar interbody fusion does not appear to be caused by prolonged retractor time greater than 20 minutes. The authors recommend surgical efficiency without the need to rush through the procedure because the "20-Minute" threshold is approaching. Limiting retractor time to under 20 minutes was a poor predictor of post-operative quadriceps injury.

Surgical and non-surgical management of spondylolisthesis: a comprehensive review

Spondylolisthesis is a spinal condition characterized by the forward or backward displacement of a vertebral body, most commonly affecting the lower lumbar spine. It can be classified into different types, with isthmic and degenerative being the most prevalent. Early diagnosis is essential to initiate appropriate treatment based on symptom severity, degree of slippage, and neurological deficits. Non-surgical management is the first-line approach for low-grade spondylolisthesis (Grade I-II) and includes physical therapy, activity modification, pain management with nonsteroidal anti-inflammatory drugs or epidural steroid injections, and, in some cases, bracing. While most patients experience symptom relief with conservative treatment, those with progressive neurological deficits, severe pain, or significant instability may require surgery. Surgical options typically include decompression for nerve compression and fusion to stabilize the spine. The choice between decompression alone and decompression with fusion remains controversial, particularly in degenerative spondylolisthesis without initial instability. Posterior lumbar interbody fusion and transforaminal lumbar interbody fusion are the most performed techniques, with minimally invasive surgery gaining popularity due to its less aggressive impact on tissues and faster recovery. Long-term follow-up is necessary to monitor for complications such as adjacent segment disease, pseudarthrosis, or reoperation rate. Advances in imaging, surgical navigation, and regenerative medicine are important for the future of spondylolisthesis treatment, but current management remains centered on optimizing patient outcomes through individualized care and evidence-based treatment selection.

Prediction Model and Risk Factor Analysis of Adjacent Segment Disease After L4-5 Transforaminal Lumbar Interbody Fusion Through Preoperative Radiographic Features

STUDY DESIGN

A retrospective study.

OBJECTIVE

To investigate the risk of adjacent segment disease (ASD) after L4-5 transforaminal lumbar interbody fusion (TLIF) in patients diagnosed with lumbar spinal stenosis (LSS), a prediction model for ASD is established and validated.

METHODS

A retrospective study was carried out on a sample of 290 patients who underwent L4-5 TLIF at Zhongda Hospital, Southeast University, from January 2015 to January 2021. The study collected baseline data and preoperative radiographic features of L3-4 and L5-S1. The determination of the outcome variable was based on X-ray results spanning over 24 months and JOA scores. Multivariate logistic regression was used to identify the risk factors in constructing a nomogram.

RESULTS

Independent risk factors for L3-4 degeneration after TLIF included osteoarthritis of L3-4 facet joints, L3-4 foraminal stenosis, L4 upper endplate osteochondritis, L3-4 local lordosis angle, and L3-4 spinal stenosis. Independent risk factors for L5-S1 degeneration after TLIF included osteoarthritis of L5-S1 facet joints, L5-S1 intervertebral disc degeneration, L5-S1 spinal stenosis, L5-S1 coronal imbalance, and S1 upper endplate osteochondritis. A predictive model was developed. The AUC for the prediction models at L3-4 and L5-S1 were .945 and .956. The calibration curve demonstrated good consistency between the predicted and actual probabilities. The DCA curve indicated the clinical benefit and practical value of this predictive model.

CONCLUSION

This study established nomograms for postoperative degeneration at L3-4 and L5-S1 based on selected preoperative radiographic features. These models provide a valuable auxiliary decision-making system for clinicians and aid in early surgical decisions.

Patient outcomes: One-stage vs. two-stage lumbar surgery for symptomatic low-grade spondylolisthesis: A quality outcomes database study

OBJECTIVE

Controversy exists regarding treatment of symptomatic low-grade spondylolisthesis (LGS). Both one- and two-stage fusions are commonly performed, but it is unclear if one approach is superior. We aim to compare the satisfaction rates and patient-reported outcomes (PROs) in patients with LGS undergoing one- versus two-stage lumbar spine surgery.

METHODS

The Quality Outcomes Database was queried for patients with Grades I and II spondylolisthesis who underwent one- (n = 3223) or two-stage (n = 325), 1-2 level lumbar fusion. Demographics, comorbidities, symptom burden, and PROs were extracted and compared. Outcomes included Visual Analogue Scale (VAS) for back and leg pain, Oswestry Disability Index (ODI), Quality-Adjusted Life Year (QALY), and satisfaction index. Minimal clinically important difference (MCID) values for VAS back pain, VAS leg pain, ODI, and QALY were 1.6, 1.7, 14.3, and 0.2, respectively. Patients with pre-existing scoliosis or kyphosis, missing data, and revision procedures were excluded. Categorical variables were compared with a Chi-square test; continuous variables were assessed for normality with a Shapiro Wilk test and compared with a Mann-Whitney U or Student's t-test.

RESULTS

No significant differences were noted for baseline characteristics, except for a lower mean age, percentage of female patients, and prevalence of osteoporosis in the two-stage cohort (58 ± 12.4 vs 62 ± 11.6 years; 50 % vs 62 %; 3.0 % vs 7.1 %, respectively; p < 0.01). The average surgery length was longer in the two-stage cohort (p < 0.01). A significantly higher percentage of patients returned to baseline activities within 3 months postoperatively following one-stage procedures (43 % vs. 29 %, p < 0.01), irrespective of whether they had Grade 1 or Grade 2 spondylolisthesis. Comparable proportions of patients achieved the MCID for PROs, with no significant differences in satisfaction indices observed at 3, 12, and 24 months postoperatively, regardless of preoperative spondylolisthesis grade.

CONCLUSIONS

Patients receiving one and two-stage procedures for symptomatic LGS had similar rates of satisfaction and PROs. More research is necessary to define the benefits of two-stage approaches given their increased time, cost, and risk profile.

Biomechanical assessment of anterior plate system, bilateral pedicle screw and transdiscal screw system for high-grade spondylolisthesis: a finite element study

Introduction

Limited information regarding the biomechanical evaluation of various internal fixation techniques for high-grade L5-S1 spondylolisthesis is available. The stiffness of the operated segment and stress on the hardware can profoundly influence clinical outcomes and patient satisfaction. The objective of this study was to quantitatively investigate biomechanical profiles of various fusion methods used for high-grade spondylolisthesis by using finite element (FE) analysis.

Methods

An FE lumbar spine model of healthy spine was developed based on a patient's CT scan. High-grade (III-IV) spondylolisthesis (SP model) was created by sliding L5 anteriorly and modifying L5-S1 facet joints. Three treatment scenarios were created by adding various implants to the model. These scenarios included L5-S1 interbody cage in combination with three different fixation methods-the anterior plate system (APS), bilateral pedicle screw system (BPSS), and transdiscal screw system (TSS). Range of motion (ROM), von Mises stress on cage, internal fixation as well as on the adjacent annuli were obtained and compared. The resistance to slippage was investigated by applying shear force on L5 vertebra and measuring its displacement regarding to S1.

Results

Under different loading conditions all treatment scenarios showed substantial reduction of ROM in comparison with SP model. No notable differences in ROM were observed between treatment models. There was no notable difference in cage stress among models. The von Mises stress on the internal fixation in the TSS model was less than in APS and BPSS. The TSS model demonstrated superior resistance to shear load compared to APS and BPSS. No discernible difference was observed between the SP, APS, BPSS, and TSS models when compared the ROM for adjacent level L4-L5. TSS's von Mises stress of the adjacent annulus was higher than in APS and BPSS.

Conclusions

The TSS model exhibited biomechanical superiority over the APS and BPSS models.

Patient-reported outcome of lumbar decompression with instrumented fusion for low-grade spondylolisthesis: influence of pathology and baseline symptoms

INTRODUCTION

Low-grade isthmic and degenerative spondylolisthesis (DS) of the lumbar spine are distinct pathologies but both can be treated with lumbar decompression with fusion. In a very large cohort, we compared patient-reported outcome in relation to the pathology and chief complaint at baseline.

METHODS

This was a retrospective analysis using the EUROSPINE Spine Tango Registry. We included 582 patients (age 60 ± 15 years; 65% female), divided into four groups based on two variables: type of spondylolisthesis and chief pain complaint (leg pain (LP) versus back pain). Patients completed the COMI preoperatively and up to 5 years follow-up (FU), and rated global treatment outcome (GTO). Regression models were used to predict COMI-scores at FU. Pain scores and satisfaction ratings were analysed.

RESULTS

All patients experienced pronounced reductions in COMI scores. Relative to the other groups, the DS-LP group showed between 5% and 11% greater COMI score reduction (p < 0.01 up to 2 years' FU). This group also performed best with respect to pain outcomes and satisfaction. Long-term GTO was 93% at the 5 year FU, compared with between 82% and 86% in the other groups.

CONCLUSION

Regardless of the type of spondylolisthesis, all groups experienced an improvement in COMI score after surgery. Patients with DS and LP as their chief complaint appear to benefit more than other patients. These results are the first to show that the type of the spondylolisthesis and its chief complaint have an impact on surgical outcome. They will be informative for the consent process prior to surgery and can be used to build predictive models for individual outcome.

Is unilateral-approach full-endoscopic lumbar fusion effective for single-level lumbar spondylolisthesis with bilateral symptoms? A preliminary report of 43 CT analysis

PURPOSE

To investigate the clinical results and radiological parameters changes after unilateral-approach endoscopic lumbar interbody fusion (Endo-LIF) for lumbar spondylolisthesis with bilateral symptoms.

METHODS

43 single-level lumbar spondylolisthesis patients with bilateral lower limb symptoms were included from June 2020 to May 2022. All patients underwent unilateral-approach Endo-LIF and postoperative computed tomography. Radiological parameters including disk height (DH), degree of upper vertebral slip (DUVS), and foramen intervertebral parameters including bilateral foraminal height (FH), contralateral foraminal areas (FA) were evaluated. The clinical outcomes including low back pain and bilateral leg pain were evaluated using Visual Analog Scale (VAS) and the Oswestry Disability Index (ODI) before and after surgery.

RESULTS

All cases were successfully completed surgery and followed for average 15.16 ± 5.2 months. DH (44% ± 11%) and DUVS were significantly improvement postoperatively compared with preoperatively (p < 0.05). Statistically significant increases in bilateral FH (25% ± 11% on the surgical side, 17% ± 8% on the contralateral side) and contralateral FA (26% ± 6%) were observed (p < 0.05). The VAS and the ODI scores were significantly decreased in comparison with the preoperative scores (p < 0.05).

CONCLUSION

Unilateral-approach with contralateral indirect decompression in Endo-LIF can acquire satisfactory clinical outcomes. Therefore, unilateral-approach Endo-LIF may be a promising option for lumbar spondylolisthesis with bilateral symptoms.

Preoperative Adjacent Facet Joint Osteoarthritis Is Associated with the Incidence of Adjacent Segment Degeneration and Low Back Pain after Lumbar Interbody Fusion

STUDY DESIGN

A retrospective cohort study.

PURPOSE

To analyze the association between preoperative adjacent facet joint osteoarthritis (FJOA) and outcomes of lumbar interbody fusion (LIF).

OVERVIEW OF LITERATURE

Whether preoperative adjacent FJOA is associated with the incidence of radiological adjacent segment degeneration (RASD) and low back pain (LBP) relief after lumbar fusion remains unknown.

METHODS

The study included patients who underwent LIF. The demographic characteristics and radiographic and surgical data were collected and evaluated. The included patients were divided into control group and FJOA group based on the preoperative adjacent facet joint Pathria grade. Preoperative and last follow-up LBP Visual Analog Scale (VAS) score, leg pain (LP) VAS, Oswestry Disability Index (ODI) and RASD were evaluated and compared. The improvement rates in VAS and ODI were calculated and compared between the two groups. Logistic regression was used to analyze the risk factors of LBP relief and incidence of RASD.

RESULTS

In total, 197 patients (control group, 86; FJOA group, 111) were included, and the median follow-up was 46 months. The VAS and ODI in both groups significantly improved after surgery. At the last follow-up, the FJOA group had higher VAS and lower VAS improvement rates of LBP than the control group (p<0.05). However, no significant difference in the LP VAS and ODI was found between the two groups. The incidence of RASD in the FJOA group was significantly higher than that in the control group (48.6% vs. 30.2%, p=0.034). Multivariate logistic regression analysis showed that preoperative adjacent FJOA was significantly associated with LBP relief (odds ratio [OR], 0.691; 95% confidence interval [CI], 0.498-0.958) and the postoperative incidence of RASD (OR, 1.406; 95% CI, 1.020-1.939).

CONCLUSIONS

The preoperative FJOA in the adjacent segments was significantly associated with LBP following LIF. Patients with preoperative FJOA were more likely to have RASD following lumbar fusion surgery.

Comparison of safety and efficacy of posterior lumbar interbody fusion (PLIF) and modified transforaminal lumbar interbody fusion (M-TLIF) in the treatment of single-segment lumbar degenerative diseases

OBJECTIVE

To compare modified transforaminal lumbar interbody fusion (M-TLIF) with posterior lumbar interbody fusion (PLIF) in the treatment of single-segment lumbar degenerative disorders in order to assess its safety and effectiveness.

METHODS

From January 2016 to January 2021, 74 patients who received single-segment M-TLIF were examined. A total of 74 patients having single-segment PLIF during the same time period were included in a retrospective controlled study using the same inclusion and exclusion criteria. The two groups were compared in terms of the fusion rate, the Oswestry disability index (ODI), the visual analogue scale of low back pain (VAS), the perioperative condition, the postoperative complications, and the postoperative neighbouring segment degeneration.

RESULTS

All patients had surgery satisfactorily and were monitored for at least a year afterwards. The baseline values for the two groups did not significantly differ. The interbody fusion rate between PLIF (98.65%) and M-TLIF (97.30%) was not significantly different. In the follow-up, the M-TLIF group's VAS score for low back and leg pain was lower than that of the PLIF group. The ODI score of the M-TLIF group was lower than that of the PLIF group at 7 days and 3 months following surgery. Both groups' post-op VAS and ODI scores for low back and leg pain were much lower than those from before the procedure. In M-TLIF group, the operation time, drainage tube extraction time, postoperative bed rest time and hospital stay time were shorter, and the amount of intraoperative blood loss was less. Compared with those before operation, the height of intervertebral space and intervertebral foramen were significantly increased in both groups during postoperative follow-up (P < 0.05). The postoperative complications and adjacent segment degeneration of M-TLIF were significantly lower than those of PLIF.

CONCLUSIONS

M-TLIF is a safe and effective treatment for lumbar degenerative disorders, with a high fusion rate and no significant difference between M-TLIF and PLIF. M-TLIF's efficacy and safety are comparable to that of PLIF, particularly in terms of early relief of low back pain and improvement in quality of life following surgery. Therefore, M-TLIF technology can be popularized and applied in clinic.

Differences in imaging and clinical characteristics are associated with higher rates of decompression-fusion versus decompression-alone in women compared to men for lumbar degenerative spondylolisthesis

PURPOSE

The goals were to ascertain if differences in imaging/clinical characteristics between women and men were associated with differences in fusion for lumbar degenerative spondylolisthesis.

METHODS

Patients had preoperative standing radiographs, CT scans, and intraoperative fluoroscopic images. Symptoms and comorbidity were obtained from patients; procedure (fusion-surgery or decompression-alone) was obtained from intraoperative records. With fusion surgery as the dependent variable, men and women were compared in multivariable logistic regression models with clinical/imaging characteristics as independent variables. The sample was dichotomized, and analyses were repeated with separate models for men and women.

RESULTS

For 380 patients (mean age 67, 61% women), women had greater translation, listhesis angle, lordosis, and pelvic incidence, and less diastasis and disc height (all p ≤ 0.03). The rate of fusion was higher for women (78% vs. 65%; OR 1.9, p = 0.008). Clinical/imaging variables were associated with fusion in separate models for men and women. Among women, in the final multivariable model, less comorbidity (OR 0.5, p = 0.05), greater diastasis (OR 1.6, p = 0.03), and less anterior disc height (OR 0.8, p = 0.0007) were associated with fusion. Among men, in the final multivariable model, opioid use (OR 4.1, p = 0.02), greater translation (OR 1.4, p = 0.0003), and greater diastasis (OR 2.4, p = 0.0002) were associated with fusion.

CONCLUSIONS

There were differences in imaging characteristics between men and women, and women were more likely to undergo fusion. Differences in fusion within groups indicate that decisions for fusion were based on composite assessments of clinical and imaging characteristics that varied between men and women.

Surgical management of isthmic spondylolisthesis: A comparative study of postoperative outcomes between ALIF and TLIF

INTRODUCTION

Circumferential fusion by the anterior (ALIF) or transforaminal (TLIF) approach combined with posterior instrumentation is currently used for the surgical treatment of low-grade isthmic spondylolisthesis. But few studies have compared the clinical and radiological outcomes of various interbody fusion techniques. The objective of this study was to compare the clinical and radiological results at 2 years postoperative of two fusion techniques-TLIF versus ALIF plus posterior instrumentation-for low-grade isthmic spondylolisthesis in adults.

MATERIALS AND METHODS

This was an observational multicenter study done at nine French healthcare facilities specialized in spine surgery. The inclusion criteria were minimum age of 18 years, grade 1-3 isthmic spondylolisthesis, ALIF+posterior fixation (ALIF+PS) or TLIF, minimum follow-up of 2 years. Clinical and radiological evaluations were done preoperatively and at 2 years of follow-up. A lumbar CT scan was done at 1 year postoperative to evaluate fusion.

RESULTS

The cohort consisted of 89 patients (50 women, 39 men) with a mean age of 47.7±12.3 (18-79) years. The patients in the ALIF groups (n=71) had a significantly longer hospital stay than those in the TLIF group (n=18): 5.7 days versus 4.6 days (p=.04). However, their medical leave from work was significantly shorter: 31.0 weeks versus 40.7 (p=.003). Lumbar pain VAS diminished faster in the ALIF groups, with a significantly larger drop than the TLIF group in the first 3 months postoperative. Only the increase in lumbar disc lordosis was larger in the ALIF group: 11.7°±12.0° versus 6.0°±11.7° (p=.036). There was a significant correlation between the increase in global lordosis and reduction in lumbar VAS at 2 years postoperative (ρ=-0.3295; p=.021).

CONCLUSION

ALIF+PS provides a faster relief of postoperative low back pain than TLIF but there are no significant clinical differences between techniques at 2 years of follow-up. Despite better restoration of disc lordosis in the ALIF+PS group, there was no difference in the restoration of global lordosis.

LEVEL OF EVIDENCE

III; multicenter comparative study.

Surgical treatment of degenerative lumbar spondylolisthesis: Effect of TLIF and slip reduction on sagittal alignment

INTRODUCTION

The surgical treatment of lumbar degenerative spondylolisthesis (LDS) remains controversial. The aim of this study was to determine the effect of adding transforaminal lumbar interbody fusion (TLIF) to posterolateral fusion (PLF) on the local lordosis, sagittal alignment and potential complications. The second aim was to evaluate the effect of slip reduction on the same parameters.

HYPOTHESIS

The initial hypothesis was that TLIF provides better correction of the local lordosis and that reducing the slip improves the global sagittal balance.

METHODS

In this retrospective, single-center study, patients who had been operated on for LSD at one or two levels by laminectomy and PLF, with or without a TLIF cage, were included. Data collected consisted of age, sex, number of levels fused and whether or not a TLIF cage was used. Fusion was defined as the absence of indirect nonunion signs on radiographs at 2 years postoperative. The occurrence and time frame of any complications and the need for reoperation were documented. Lateral radiographs of the entire spine were analyzed preoperatively, in the early postoperative period (3 to 6 months) and at a minimum follow-up of 2 years. The following parameters were measured: pelvic parameters, C7 sagittal tilt (C7ST), spinosacral angle (SSA), maximum lumbar lordosis (LL), lordosis at slipped level (LS), slip percentage. The analysis compared patients treated by PLF and TLIF and determined the impact of slip reduction.

RESULTS

One hundred and three patients were included in the study (71% women). The mean follow-up was 38 months. The mean age was 69 years. Seventy-seven patients (75%) underwent PLF. Comparing the preoperative and early postoperative data identified 5.4% better spondylolisthesis reduction in the TLIF group than the PLF group (-8.9±9.5% vs -3.5±7.6%; p=0.04) that was not maintained at the final follow-up. The fusion rate was comparable between groups: 94% in APL and 89% in TLIF (p=0.7). The overall complication rate was 46% in the TLIF group versus 33% in the PLF group (p=0.35). A comparison based on whether or not the slip was reduced found significant improvement in the reduction group of the SSA by more than 6° (6.8°±6° vs 0.5°±7.4°; p=0.04). The fusion rate was 91% in the reduced group and 95% in the non-reduced group (p=0.81); the complication rate was 44% versus 28% in the non-reduced group (p=0.10).

CONCLUSION

This study shows that slip reduction helps to improve the sagittal alignment by increasing the SSA when treating LDS. Posterolateral fusion and TLIF produce comparable radiographic outcomes at 2 years postoperative in the segmental lordosis, slip reduction, global sagittal alignment and fusion rate.

LEVEL OF EVIDENCE

IV.

Analysis of Degenerative and Isthmic Lumbar Spondylolisthesis from the Difference of Pelvic Parameters and the Degree of Degeneration through Imaging Data

BACKGROUND

In previous studies, many imaging analyses have been conducted to explore the changes in the intervertebral disc degeneration (DD), facet joint osteoarthritis (FJOA), L4 inclination angle (L4IA), pelvis-related parameters, lumbar lordosis (LL), and paravertebral muscle (PVM) in the occurrence and development of degenerative spinal diseases via measuring the X-ray, CT, and MRI data of clinical patients. However, few studies have quantitatively investigated the pelvic parameters and the degree of spine degeneration in patients with degenerative lumbar spondylolisthesis (DLS) and isthmic lumbar spondylolisthesis (ILS). This study discusses the changes in the imaging parameters of DLS, ILS, and a control group; explores the correlation between different measurement parameters; and discusses their risk factors.

METHODS

We evaluated 164 patients with single L4-L5 grade 1 level degenerative lumbar spondylolisthesis (DLS group), 161 patients with single L4-L5 grade 1 level isthmic lumbar spondylolisthesis (ILS group), and 164 patients with non-specific back pain (control group). The grades of DD and FJOA as well as the percentage of the fat infiltration area (%FIA) of multifidus muscle (MM) at the L4-L5 level were measured via CT and MRI. Lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), the L4 inclination angle (L4IA), and sacral slope (SS) were measured via X-ray film, and the differences among the DLS group, ILS group, and control group were analyzed. Furthermore, the risk factors related to the incidences of the DLS and ILS groups were discussed.

RESULTS

First, the pelvis-related parameters of DLS and ILS patients were 51.91 ± 12.23 and 53.28 ± 11.12, respectively, while those of the control group were 40.13 ± 8.72 (p1 < 0.001, p2 < 0.001). Lumbar lordosis (LL) in DLS patients (39.34 ± 8.57) was significantly lower than in the control group (44.40 ± 11.79, p < 0.001). On the contrary, lumbar lordosis (LL) in the ILS group (55.16 ± 12.31) was significantly higher than in the control group (44.40 ± 11.79, p < 0.001). Secondly, the three groups of patients were characterized by significant variations in the L4 inclination angle (L4IA), disc degeneration (DD), facet joint osteoarthritis (FJOA), pelvis-related parameters, and paravertebral muscle (PVM) (p < 0.05). Finally, logistic regression suggests that the L4IA, FJOA, and PT may be risk factors for the occurrence of DLS, and the occurrence of ILS is correlated with the L4IA, FJOA, DD, PT, and LL.

CONCLUSIONS

Compared with the control group, there are changes in pelvic parameters, the L4IA, LL, DD, FJOA, and PVM in DLS and ILS patients, and the degree is different. The parameters within the same group are related to each other, and DLS and ILS have different risk factors. The mechanical stability of the spine is affected by the parameter and angle changes, which may be of great significance for explaining the cause of spondylolisthesis, evaluating the health of the lumbar spine, and guiding the lifestyles of patients.

Comparison of the results of open PLIF versus UBE PLIF in lumbar spinal stenosis: postoperative adjacent segment instability is lesser in UBE

OBJECTIVE

To compare the difference in efficacy between open PLIF and UBE for lumbar spinal stenosis and the effect on postoperative adjacent segment instability.

METHOD

The clinical data of 37 patients with PLIF and 32 patients with UBE for lumbar spinal stenosis were retrospectively analyzed to compare the differences in perioperative conditions and short- and medium-term outcomes.

RESULTS

All 69 patients completed the surgery successfully. The operating time, number of intraoperative fluoroscopies and hospital days were higher in the UBE group than in the open PLIF group. Intraoperative bleeding and postoperative drainage were lower than in the open PLIF group (P < 0.05). The visual analogue scale (VAS) of low back pain was lower in the UBE group than in the open PLIF group at 1 month and 3 months postoperatively (P < 0.05), and there were no statistically significant VAS scores for low back pain in the two groups at 1 day and 6 months postoperatively (P > 0.05). Leg pain VAS scores were lower in the UBE group than in the open PLIF group at 1 month, 3 months and 6 months postoperatively (P < 0.05), and leg pain VAS scores were not statistically significant in both groups at 1 day postoperatively (P > 0.05). The ODI index was lower in the UBE group than in the open PLIF group at 1 day and 1 month postoperatively (P < 0.05) and was not statistically significant in the two groups at 3 months and 6 months postoperatively (P > 0.05). There was no statistically significant difference between the two groups in postoperative interbody height, sagittal diameter of the spinal canal, efficacy of modified MacNab and interbody fusion (P > 0.05). The open PLIF group was more prone to postoperative adjacent vertebral instability than the UBE group, and the difference was statistically significant (P < 0.05).

CONCLUSION

With appropriate indications, the open PLIF group and the UBE group had similar short- and medium-term clinical outcomes for the treatment of lumbar spinal stenosis, but patients in the UBE group had better symptomatic improvement than the open PLIF group at 3 months postoperatively, and the effect on postoperative adjacent vertebral instability was smaller in the endoscopic group than in the open PLIF group.

Deep learning system assisted detection and localization of lumbar spondylolisthesis

Objective: Explore a new deep learning (DL) object detection algorithm for clinical auxiliary diagnosis of lumbar spondylolisthesis and compare it with doctors' evaluation to verify the effectiveness and feasibility of the DL algorithm in the diagnosis of lumbar spondylolisthesis. Methods: Lumbar lateral radiographs of 1,596 patients with lumbar spondylolisthesis from three medical institutions were collected, and senior orthopedic surgeons and radiologists jointly diagnosed and marked them to establish a database. These radiographs were randomly divided into a training set (n = 1,117), a validation set (n = 240), and a test set (n = 239) in a ratio of 0.7 : 0.15: 0.15. We trained two DL models for automatic detection of spondylolisthesis and evaluated their diagnostic performance by PR curves, areas under the curve, precision, recall, F1-score. Then we chose the model with better performance and compared its results with professionals' evaluation. Results: A total of 1,780 annotations were marked for training (1,242), validation (263), and test (275). The Faster Region-based Convolutional Neural Network (R-CNN) showed better precision (0.935), recall (0.935), and F1-score (0.935) in the detection of spondylolisthesis, which outperformed the doctor group with precision (0.927), recall (0.892), f1-score (0.910). In addition, with the assistance of the DL model, the precision of the doctor group increased by 4.8%, the recall by 8.2%, the F1-score by 6.4%, and the average diagnosis time per plain X-ray was shortened by 7.139 s. Conclusion: The DL detection algorithm is an effective method for clinical diagnosis of lumbar spondylolisthesis. It can be used as an assistant expert to improve the accuracy of lumbar spondylolisthesis diagnosis and reduce the clinical workloads.

Lateral Lumbar Interbody Fusion (Direct Lateral Interbody Fusion/Extreme Lateral Interbody Fusion) versus Posterior Lumbar Interbody Fusion Surgery in Spinal Degenerative Disease: A Systematic Review

BACKGROUND

Degenerative diseases of the lumbar spine are often treated with posterior interbody fusion surgery (posterior lumbar interbody fusion [PLIF]) for spinal instability or intractable back pain with neurologic impairment. Several lateral, less invasive procedures have recently been described (lateral lumbar interbody fusion [LLIF]/direct lateral interbody fusion/extreme lateral interbody fusion [XLIF]). The aim of this systematic review is to compare structural and functional outcomes of lateral surgical approaches to PLIF.

METHODS

We conducted a MEDLINE (PubMed), Web of Science, ScienceDirect, and Cochrane Library search for studies focusing on outcomes and complications comparing LLIF (direct lateral interbody fusion/XLIF) and PLIF. The systematic review was reported using the PRISMA criteria.

RESULTS

In total, 1000 research articles were identified, of which 5 studies were included comparing the outcomes and complications between the lateral and posterior approach. Three studies found significantly less perioperative blood loss with a lateral approach. Average hospital stay was shorter in populations who underwent the lateral approach compared with PLIF. Functional outcomes (visual analog scale score/Oswestry Disability Index) were similar or better with LLIF. In most of the included studies, complication rates did not differ between the posterior and lateral approach. Most of the neurologic deficits with XLIF/LLIF were temporary and healed completely within 1 year follow-up.

CONCLUSIONS

A lateral approach (XLIF/LLIF) is a good and safe alternative for PLIF in single-level degenerative lumbar diseases, with comparable functional outcomes, shorter hospital stays, and less blood loss. Future prospective studies are needed to establish the role of lateral minimally invasive approaches in spinal degenerative surgery.

High preoperative expectations and postoperative fulfillment of expectations two years after decompression alone and decompression plus fusion for lumbar degenerative spondylolisthesis

BACKGROUND CONTEXT

Fulfillment of expectations is a patient-centered outcome that has not been assessed based on fusion status for lumbar degenerative spondylolisthesis (LDS).

PURPOSE

To compare preoperatively cited expectations and 2-year postoperative fulfillment of expectations between patients undergoing decompression alone (no-fusion) vs. decompression plus fusion (fusion) for LDS.

STUDY DESIGN

Longitudinal cohort.

PATIENT SAMPLE

357 patients.

OUTCOME MEASURES

Postoperative version of Lumbar Spine Surgery Expectations Survey, Oswestry Disability Index (ODI), satisfaction with surgery.

METHODS

Preoperatively patients completed the 20-item Expectations Survey measuring amount of 'improvement expected' for symptoms, physical function, and psychosocial well-being (score range 0-100); two years postoperatively patients completed the follow-up Survey measuring 'improvement received'. The proportion of expectations fulfilled was calculated as 'improvement received' divided by 'improvement expected' (<1 some expectations fulfilled, >1 expectations surpassed). Patients also completed the ODI, SF-12 mental health subscale, satisfaction with surgery, and measures of comorbidity and psychosocial status, including social support (i.e. help at home) and prior orthopedic surgery (i.e. hip/knee arthroplasty).

RESULTS

Patients' mean age was 67 years, 61% were women, 82% had single-level LDS, 73% had fusion, and mean follow-up was 26.2 months. Compared to patients with no-fusion, patients with fusion had more pain, spinal instability, use of opioids, disability, and greater preoperative Expectations Survey scores (69 vs 74, p=.008). The proportion of expectations fulfilled postoperatively was high and similar for both groups (.82 vs. .79, p=.40), but more variable for fusion (IQR .32 vs. .40). In multivariable analysis with the proportion as the dependent variable, fulfilled expectations was associated with better mental well-being (coeff=1.1, 95% CI 0.6-1.7, p=.0001) and more social support (coeff=3.3, 95% CI 1.1-5.6, p=.004) and unfulfilled expectations was associated with prior arthroplasty (coeff=-8.6, 95% CI -15.4-(-1.9), p=.01) and subsequent lumbar surgery (coeff=-15.6, 95% CI -25.2-(-6.0), p=.002). Similar associations were found for change in ODI and satisfaction.

CONCLUSIONS

Patients had high preoperative expectations of surgery with greater expectations for decompression-fusion compared to decompression-alone. Although more variable for the fusion group, both groups had high proportions of expectations fulfilled. This study highlights the spectrum of clinical and psychosocial variables that impacts fulfillment of expectations for both decompression-alone and decompression-fusion for LDS surgery.

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.

Intermodal Detection of Lumbar Instability in Degenerative Spondylolisthesis is Superior to Functional Radiographs

Purpose

In this study, we compare different imaging modalities to find the most sensitive and efficient way of detecting instability in lumbar spondylolisthesis.

Methods

Patients presenting with spondylolisthesis from June 01, 2018 to May 31, 2020 with functional radiographs and either CT scans or MRI images were included in our single-center retrospective cohort study. The amount of translation, in millimeters, was measured on supine MRI images, CT scans, and radiographs of inclination while sitting, standing, or prone and reclination while standing using the Meyerding technique. The amount of translation was compared among the different modalities.

Results

A total of 113 patients with spondylolisthesis on 125 vertebral levels were included in this study. The mean patient age was 73.52 ± 12.59 years; 69 (60.5%) patients were females. The most affected level was L4/5 (62.4%), followed by L3/4 (16%) and L5/S1 (13.6%). The average translations measured on supine CT were 4.13 ± 5.93 mm and 4.42 ± 3.49 mm on MRI (p = 0.3 for the difference between MRI and CT). The difference of inclination while sitting radiograph to slice imaging was 3.37 ± 3.64 mm (p < 0.0001), inclination while standing to slice imaging was 2.67 ± 3.03 mm (p < 0.0001), reclination while standing to slice imaging was 1.6 ± 3.15 mm (p = 0.03), and prone to slice imaging was 2.19 ± 3.02 mm (p = 0.03).

Conclusion

We found that a single radiograph in either inclination, reclination, or prone position compared to a CT scan or an MRI image in supine position can detect instability in spondylolisthesis more efficiently than comparison of functional radiographs in any position.

Comparison of 90-day complications and two-year reoperation rates between anterior and posterior interbody fusion for single-level degenerative spondylolisthesis

Background

For the surgical treatment of single-level degenerative spondylolisthesis (DS), patients can be treated with either an anterior or posterior interbody fusion. Prior studies have shown that patients with symptomatic degenerative spondylolisthesis treated surgically maintain substantially greater pain relief and improvement in function when compared to those treated non-operatively, but no consensus has emerged between which approach results in the best outcomes.

Methods

The PearlDiver MARINER database was queried for patients with single-level DS who underwent either an anterior or posterior lumbar interbody fusion. Both populations were compared on multiple outcomes, including reoperation, post-operative complications, and readmission rates at 90 days, as well as rates of reoperation and cauda equina syndrome two-years postoperatively.

Results

At 90 days patients who underwent anterior interbody were found to have higher rates of DVT (OR 2.53, 95% CI 1.74 – 3.70, p<0.001), ileus (OR 1.43, 95% CI 1.25 – 1.64, p<0.001), and readmission (OR 1.28, 95% CI 1.19 – 1.38, p<0.001). Patients who underwent posterior interbody fusion were found to have higher rates of revision procedures (OR 0.63, 95% CI 0.59 – 0.66, p<0.001), transfusion (OR 0.68, 95% CI 0.58 – 0.78, p<0.001), acute kidney injury (OR 0.84, 95% CI 0.75 – 0.95, p=0.0046), and cauda equina syndrome (OR 0.53, 95% CI 0.40 – 0.69, p<0.001). At 2 years, patients who underwent posterior fusion required revision procedures (OR 0.70, 95% CI 0.67 – 0.74, p<0.001) and developed cauda equina syndrome (OR 0.62, 95% CI 0.50 – 0.77, p<0.001) at a higher rate than those who underwent anterior fusion.

Conclusions

Patients who underwent anterior interbody fusion for treatment of degenerative spondylolisthesis were found to have increased rates of DVT, ileus, and were more likely to be readmitted to the hospital within 90 days, while patients who underwent posterior interbody fusion were found to have higher rates of reoperation, transfusion, AKI, and cauda equina syndrome. Increased rates of reoperation and development of cauda equina in the posterior fusion group persisted at 2 years post-operatively.

Clinical Evaluation of Paraspinal Mini-Tubular Lumbar Decompression and Minimally Invasive Transforaminal Lumbar Interbody Fusion for Lumbar Spondylolisthesis Grade I with Lumbar Spinal Stenosis: A Cohort Study

Objective

To investigate the clinical outcome data and difference in efficacy between paraspinal mini-tubular lumbar decompression (PMTD) and minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) in the treatment of degenerative lumbar spondylolisthesis grade I with lumbar spinal stenosis (DLS-I-LSS).

Methods

Patients with DLS-I-LSS, who underwent PMTD or MIS TLIF from September 2017 to March 2020, were included retrospectively. The follow-up period was 24 months after surgery. Outcome measurements included the Oswestry disability index (ODI) score, visual analog scale (VAS) low back pain score, VAS leg pain score, surgical data, and adverse events.

Results

A total of 104 patients with DLS-I-LSS were included in this study. The average improvement in ODI at 12 months (2.0%, 95% CI, −5.7% to 1.8%; p = 0.30) and 24 months (1.7%, 95% CI, −2.7% to 6.1%; p = 0.45) after surgery between the two groups were not statistically significant. The improvement in VAS low back pain score after 24 months and improvement in VAS leg pain score were not significantly different between the two groups. Compared with the PMTD group, the MIS TLIF group had more estimated blood loss and longer hospital stays. The cumulative reoperation rates were 5.66% and 1.96% in the MIS TLIF and PMTD groups, respectively (p = 0.68). The results of multivariate analysis showed that BMI, diabetes, and baseline ODI score were the main factors influencing the improvement in ODI in patients with DLS-I-LSS after minimally invasive surgery, accounting for 50.5% of the total variance.

Conclusions

The clinical effectiveness of PMTD was non-inferior to that of MIS TLIF for DLS-I-LSS; however, there was a reduced duration of hospital stay, operation time, blood loss, and hospitalization costs in the PMTD group. BMI, presence or absence of diabetes and baseline ODI score were influencing factors for the improvement of ODI (Trial Registration: ChiCTR2000040025).

Oblique versus Transforaminal Lumbar Interbody Fusion in Degenerative Spondylolisthesis: A Systematic Review and Meta-analysis

BACKGROUND: This meta-analysis compared transforaminal interbody fusion (TLIF) and oblique lumbar interbody fusion (OLIF) techniques for degenerative lumbar spondylolisthesis. AIM: The aim is to evaluate Oswestry Disability Index (ODI), Japanese Orthopedic Association Back Pain Evaluation Questionnaire, visual analog scale improvement for back and leg pain, disc height, slipped percentage, blood loss, surgical time, and complication rates in both groups. METHODS: A systematic literature search was carried out to obtain a study that compared OLIF and TLIF for degenerative lumbar spondylolisthesis. A literature search was performed using PubMed, Scopus, EuropePMC, and EBSCOHost. While the intervention was the OLIF technique, the control was the TLIF technique. The primary outcome was clinical outcome (ODI, Japanese Orthopaedic Association Back Pain Evaluation Questionnaire [JOABPEQ], visual analog scale [VAS] improvement for back, and leg pain). The Newcastle-Ottawa Scale was used to assess the quality of the studies. RESULTS: Total of 384 patients from four studies were included in this study. OLIF group was better than TLIF group in terms of disc height, slipped percentage, and blood loss. ODI, JOABPEQ, VAS improvement for back pain (standardized mean difference [SMD] 0.06 [−0.18, 0.29], p = 0.63, I2 = 0%, p = 0.87) and leg pain (SMD 0.12 [−0.36, 0.60], p = 0.63, I2 = 74%, p = 0.02), surgical time, and complication rates were similar in both groups. CONCLUSION: OLIF technique was better than TLIF technique in terms of radiologic outcome and surgical blood loss. Both techniques showed similar outcomes in clinical outcome, complication, and surgical time.

Posterior Oblique Square Decompression with a Three-Step Wanding Technique in Tubular Minimally Invasive Transforaminal Lumbar Interbody Fusion: Technical Report and Mid-Long-Term Clinical Outcomes

Although minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) is the most common procedure in minimally invasive spine stabilization (MISt), details of the technique remain unclear. This technical report shows the mid-long-term clinical outcomes in patients who underwent posterior oblique square decompression (POSDe) with the three-step wanding technique of tubular MIS-TLIF for degenerative lumbar disease. Tubular MIS-TLIF (POSDe) was performed on 50 patients (males, 19; age, 69.2 ± 9.6 years), and traditional open surgery was performed (OS) on 27 (males, 4; age, 67.9 ± 6.6 years). We evaluated the clinical outcomes using the Visual Analog Scale for back pain, Japanese Orthopedic Association (JOA) scores, and JOA Back Pain Evaluation Questionnaire. We also assessed the fusion rate using the Bridwell grading system with computed tomography or plain radiography for at least 2 years postoperatively. Although there was no significant difference in the improvement rate of JOA scores between the two groups, the mean operation time and blood loss were significantly lower with MIS-TLIF than with OS. In the tubular MIS-TLIF group, there were no cases of deep wound infection; four cases had a pseudarthrosis, two had dural injury, and three had cage retropulsion. We revealed good clinical outcomes in patients who underwent POSDe.

Dynamization-Posterior Lumbar Interbody Fusion for Hemodialysis-Related Spondyloarthropathy: Evaluation of the Radiographic Outcomes and Reoperation Rate within 2 Years Postoperatively

Study Design

Clinical case series.

Purpose

This study aimed to report dynamization-posterior lumbar interbody fusion (PLIF), our surgical treatment for hemodialysisrelated spondyloarthropathy (HSA), and investigate patients' postoperative course within 2 years.

Overview of Literature

HSA often requires lumbar fusion surgery. Conventional PLIF for HSA may cause progressive destructive changes in the vertebral endplate, leading to progressive cage subsidence, pedicle screw loosening, and pseudoarthrosis. A dynamic stabilization system might be effective in patients with a poor bone quality. Thus, we performed "dynamization-PLIF" in hemodialysis patients with destructive vertebral endplate changes.

Methods

We retrospectively examined patients with HSA who underwent dynamization-PLIF at our hospital between April 2010 and March 2018. The radiographic measurements included lumbar lordosis and local lordosis in the fused segment. The evaluation points were before surgery, immediately after surgery, 1 year after surgery, and 2 years after surgery. The preoperative and postoperative radiographic findings were compared using a paired t-test. A p-value of less than 0.05 was considered significant.

Results

We included 50 patients (28 males, 22 females). Lumbar lordosis and local lordosis were significantly improved through dynamization- PLIF (lumbar lordosis, 28.4°-35.5°; local lordosis, 2.7°-12.8°; p<0.01). The mean local lordosis was maintained throughout the postoperative course at 1- and 2-year follow-up (12.9°-12.8°, p=0.89 and 12.9°-11.8°, p=0.07, respectively). Solid fusion was achieved in 59 (89%) of 66 fused segments. Solid fusion of all fixed segments was achieved in 42 cases (84%). Within 2 years postoperatively, only six cases (12%) were reoperated (two, surgical debridement for surgical site infection; two, reoperation for pedicle screw loosening; one, laminectomy for epidural hematoma; one, additional fusion for adjacent segment disease).

Conclusions

Dynamization-PLIF showed local lordosis improvement, a high solid fusion rate, and a low reoperation rate within 2 years of follow-up.

Robotic-Assisted Lumbar Fusion: An Effective Technique for Pedicle Screw Placement

Degenerative lumbar disease is a common condition in which progressive deterioration of the structures in the spine causes severely incapacitating pain and disability. Conservative management, including passive or active physical therapy, activity modification, and medications (eg, anti-inflammatory medications, oral and injectable steroids, opioids), may provide relief. However, when conservative management is unsuccessful or patients experience symptoms for an extended period of time, they may require spine surgery. Surgeons use a variety of techniques to perform lumbar fusion procedures with instrumentation, including open, percutaneous, minimally invasive, and robotic-assisted with navigation. The accuracy of pedicle-screw placement varies according to the technique used, and accuracy rates are high after robotic-assisted with navigation procedures. In addition, robotic-assisted spine procedures result in fewer infections than non-robotic-assisted spine procedures (P = .04). Perioperative nurses should understand basic lumbar spine anatomy, steps completed during robotic-assisted lumbar spine surgery, and the nursing considerations for patients undergoing this type of procedure.

Static cage morphology in short-segment transforaminal lumbar interbody fusions is associated with alterations in foraminal height but not clinical outcomes

INTRODUCTION

Steerable "banana" cages have been posited to increase segmental lordosis in short-segment transforaminal lumbar interbody fusions (TLIF). The same is not necessarily true for straight "bullet" cages. While increased lordosis is generally thought to be advantageous, a potential complication is decreased foraminal height. Here we evaluate for any association between cage type and change in foraminal height and clinical outcomes following short-segment TLIFs.

METHODS

We retrospectively reviewed consecutive one- and two-level TLIFs with bilateral facetectomies with minimum one-year clinical and radiographic follow-up. Two cohorts were based on cage morphology: steerable "banana" cage or straight "bullet" cage. Patient reported outcome measures (PROMs), radiographic measurements, and revision rates were compared.

RESULTS

46 patients with 53 straight and 95 patients with 131 steerable cage levels were included. Steerable cages showed increased segmental lordosis (9.1 vs 13.5°, p<0.001) and decreased foraminal height (20.3 vs 18.5 mm, p<0.001) after surgery. Straight cages demonstrated similar segmental lordosis (8.7 vs 8.1°, p=0.30) and foraminal height (19.4 vs 20.0 mm, p=0.065). Both cohorts showed improved PROMs at last follow-up (p≤0.005). Sub-analysis comparing patients that had increased or decreased foraminal height revealed similarly improved PROMs between cohorts. Revision rates at one-year were similar between cohorts (4.3% for straight and 3.2% for steerable group, p=0.72).

CONCLUSION

Although the increased segmental lordosis afforded by placement of steerable cages may decrease foraminal height after short segment TLIF, clinical outcomes are not negatively affected by this association.

Decompression Using Minimally Invasive Surgery for Lumbar Spinal Stenosis Associated with Degenerative Spondylolisthesis: A Review

Lumbar spinal stenosis (LSS), which often occurs concurrently with degenerative spondylolisthesis (DS), is a common disease in the elderly population, affecting the quality of life of aged people significantly. Notwithstanding the frequently good effect of conservative therapy on LSS, a minority of the patients ultimately require surgery. Surgery for LSS aims to decompress the narrowed spinal canals with preservation of spinal stability. Traditional open surgery, either pure decompression or decompression with fusion, was considered effective for the treatment of LSS with or without DS. However, the long-term clinical outcomes of traditional open surgery are still unclear. Moreover, the disadvantages of conventional open surgery are extensive, examples including tissue injuries or secondary instability, with limited outcomes and significant reoperation rates. With the development and improvement of surgical tools, various minimally invasive spine surgery (MISS) methods, including indirect decompression techniques of interspinous process devices (IPDs) and direct decompression techniques such as microscopic spine surgery or endoscopic spine surgery (ESS), have been updated with enhancement. IPDs, such as Superion devices, were reported to behave with comparable physical function, disability, and symptoms outcomes to laminectomy decompression. As an emerging technique of MISS, ESS has beneficial hallmarks including minimal tissue injuries, reduced complication rates, and shortened recovery periods, thus gaining popularity in recent years. ESS can be classified in terms of endoscopic hallmarks and approaches. Predictably, with the continuous development and gradual maturity, MISS is expected to replace traditional open surgery widely in the surgical treatment of LSS associated with DS in the future.

Should Iliac Wing Screws Be Included in Long Segment Dynamic Stabilization?

Background

In this article, clinical satisfaction and radiological results are discussed in a series of patients where the iliac wings participate in dynamic stabilization. Dynamic stabilization is an effective alternative surgical treatment method, especially in clinical pictures that go with pain due to minor instabilities. Practically the unique surgical instrument used in multilevel instabilities is the Dynesys system. The most important drawback of the Dynesys system is that the S1 screws become loose in time. In this article, our aim is to find solution to S1 insufficiency by extension of the system to the iliac wings.

Methods

Nineteen patients (eight females, 11 males) with a mean age of 54.16 were included in the study. Patients had multilevel (level 2 and above) instability, iliac wings were included in the stabilized segments, and Visual Analog Scale (VAS) and Oswestry Disability Index (ODI) were used for patient follow-up.

Results

First year results showed a significant improvement in VAS and ODI. Regarding the complications, infection developed in one patient, loosening in the proximal iliac wing in one patient, and both S1 and iliac proximals in one patient, but no clinical findings were encountered.

Conclusion

When more than two levels of dynamic systems are used in chronic instability, especially in the elderly patients, S1 screws are loosened. In these patients, if the iliac bones are also included in stabilization, this problem is solved successfully. However unfortunately, Dynesys system does not have a screw suitable for the iliac bones.

Lateral lumbar interbody fusion after reduction using the percutaneous pedicle screw system in the lateral position for Meyerding grade II spondylolisthesis: a preliminary report of a new lumbar reconstruction strategy

BACKGROUND

Utilization of a cage with a large footprint in lateral lumbar interbody fusion (LLIF) for the treatment of spondylolisthesis leads to a high fusion rate and neurological improvement owing to the indirect decompression effect and excellent alignment correction. However, if an interbody space is too narrow for insertion of an LLIF cage for cases of spondylolisthesis of Meyerding grade II or higher, LLIF cannot be used. Therefore, we developed a novel strategy, LLIF after reduction by the percutaneous pedicle screw (PPS) insertion system in the lateral position (LIFARL), for surgeons to perform accurate and safe LLIF with PPS in patients with such pathology. This study aimed to introduce the new surgical strategy and to present preliminary clinical and radiological results of patients with spondylolisthesis of Meyerding grade II.

METHODS

Six consecutive patients (four men and two women; mean age, 72.7 years-old; mean follow-up period, 15.3 months) with L4 spondylolisthesis of Meyerding grade II were included. Regarding the surgical procedure, first, PPSs were inserted into the L4 and L5 vertebrae fluoroscopically, and both rods were placed in the lateral position. The L5 set screws were fixed tightly, and the L4 side of the rod was floated. Second, the L4 vertebra was reduced by fastening the L4 set screws so that they expanded the anteroposterior width of the interbody space. At that time, the L4 set screws were not fully tightened to the rods to prevent the endplate injury. Finally, the LLIF procedure was started. After inserting the cage, a compression force was added to the PPSs, and the L4 set screws were completely fastened.

RESULTS

The mean operative time was 183 min, and the mean blood loss was 90.8 mL. All cages were positioned properly. Visual analog scale score and Oswestry disability index improved postoperatively. Bone union was observed using computed tomography 12 months after surgery.

CONCLUSION

For cases with difficulty in LLIF cage insertion for Meyerding grade II spondylolisthesis due to the narrow anteroposterior width of interbody space, LIFARL is an option to achieve LLIF combined with posterior PPS accurately and safely.

TRIAL REGISTRATION

UMIN-Clinical Trials Registry, UMIN000040268, Registered 29 April 2020, https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000045938.

Minimally Invasive Reconstruction of Vertebral Arch in Spondylolisthesis in Children and Adolescents

The aim of the study was to assess the effectiveness of the minimally invasive technique used to reconstruct the vertebral arch with a pedicle screw hook system in grade I isthmic spondylolisthesis in comparison with the traditional technique of segment stabilization with interbody fusion.

Real-time dynamic 3-T MRI assessment of spine kinematics: a feasibility study utilizing three different fast pulse sequences

BACKGROUND

Half-Fourier acquisition single-shot turbo spin-echo (HASTE), continuous radial gradient-echo (GRE), and True FISP allow real-time dynamic assessment of the spine.

PURPOSE

To evaluate the feasibility of adding dynamic sequences to routine spine magnetic resonance imaging (MRI) for assessment of spondylolisthesis.

MATERIAL AND METHODS

Retrospective review was performed of patients referred for dynamic MRI of the cervical or lumbar spine between January 2017 and 2018 who had flexion-extension radiographs within two months of MRI. Exclusion criteria were: incomplete imaging; spinal hardware; and inability to tolerate dynamic examination. Blinded, independent review by two board-certified musculoskeletal radiologists was performed to assess for spondylolisthesis (>3 mm translation); consensus review of dynamic radiographs served as the gold standard. Cervical spinal cord effacement was assessed. Inter-reader agreement and radiographic concordance was calculated for each sequence.

RESULTS

Twenty-one patients were included (8 men, 13 women; mean age 47.9 ± 16.5 years). Five had MRI of the cervical spine and 16 had MRI of the lumbar spine. Mean acquisition time was 18.4 ± 1.7 min with dynamic sequences in the range of 58-77 s. HASTE and True FISP had the highest inter-reader reproducibility (κ = 0.88). Reproducibility was better for the lumbar spine (κ = 0.94) than the cervical spine (κ = 0.28). Sensitivity of sequences for spondylolisthesis was in the range of 68.8%-78.6%. All three sequences had high accuracy levels: ≥90.5% averaged across the cervical and lumbar spine. Cervical cord effacement was observed during dynamic MRI in two cases (100% agreement).

CONCLUSION

Real-time dynamic MRI sequences added to spine MRI protocols provide reliable and accurate assessment of cervical and lumbar spine spondylolisthesis during flexion and extension.

Technique for Exposing Lumbar Discs in Anterior Approach Using Steinmann Wires: Arthroplasties or Arthrodesis

BACKGROUND

Due to increasing longevity, the incidence of degenerative lumbar disc diseases has increased, and surgical treatment is often necessary. In this context, the anterior approach becomes an important technique. However, one of the main limitations of this method is the need for dedicated retractors, which requires larger incisions for its positioning and increases the cost of the procedure. The objective of the present study was to describe a technique for retracting abdominal structures by anterior approaches to the lumbar spine using Steinmann wires.

METHODS

This manuscript consists of a technique description of anterior approach for lumbar spine.

RESULTS

Surgical treatment of degenerative lumbar spine disease is often necessary when the patients have symptoms refractory to conservative treatments. Many of them will be candidates for surgical treatment with anterior approach, either for arthrodesis/anterior lumbar interbody fusion or arthroplasty. Small incisions are performed for positioning the modified Langenbeck retractors and the Steinmann wires. These retractors are easily positioned and provide good exposure of the lumbar discs making it possible to implant appropriate cages for restoring the necessary height, lordosis, and sagittal balance.

CONCLUSIONS

The technique described is safe, inexpensive, and reproducible. Simple and easily accessible instruments are required in most hospital complexes.

Comparison of Preoperative Pedicle Screw Measurement Between Computed Tomography and Magnet Resonance Imaging

BACKGROUND

Pedicle screw fixation is commonly used in the treatment of spinal pathologies. While the biomechanical factors that affect bone fixation have been frequently described, questions remain as to which imaging modality is the ideal medium for preoperative planning. Due to its perceived superiority in assessing bony changes, computed tomography (CT) scan is assumed to be the gold standard for preparative planning, and we hypothesize that magnetic resonance imaging (MRI) is sufficiently accurate to predict screw length and diameter compared to CT.

METHODS

We retrospectively measured the length and diameter of vertebral bodies in the lumbar region in both MRI and CT and tested for differences between the modalities as well as for confounding effects of age, sex, and the presence of spondyloarthrosis.

RESULTS

We found a significant difference in pedicle screw length between CT and MRI measurements for both sides. For the left pedicle, the mean difference was 1.89 mm (95% confidence interval [CI] -3.03 to -0.75; P < .002), while for the right pedicle, the mean difference was 2.05 mm (95% CI -3.27 to -0.84; P = .001). We also found a significant difference in diameter measurements between CT and MRI for the left pedicle (0.53 mm; 95% CI 0.13 to 0.93; P = .011) but not for the right pedicle (0.36 mm; 95% CI -0.06 to 0.78; P = .094). We identified no significant effect of sex, age or spondyloarthrosis on the results (P > .05).

CONCLUSIONS

Pedicle screw planning measurements were more accurate using CT images compared to MRI images. CT scan remains the gold standard for pedicle screw planning in trauma surgery. When using MRI images, the surgeon should be aware of the differences in screw length and diameter compared to CT in order to avoid intra- and postoperative risks.

Surgical treatment of high-grade spondylolisthesis: Technique and results

Background

Surgical management of high-grade spondylolisthesis is not only challenging but also controversial, from in situ fusion to complete reduction. We report our results of a safe three-stage spinal procedure in a single surgical session with seven patients diagnosed high-grade spondylolisthesis.

Hypothesis

Posterior fixation combined with interbody fusion is effective on reduction, ossification and clinical outcomes in high-grade spondylolisthesis.

Patients and methods

This study is a retrospective review of patients who underwent surgery between 2016 and 2018. The surgical method involved specific installation for deformity reduction, pedicle screw fixation, correction of lumbosacral kyphosis with a specific distraction maneuver, wide decompression, gradual reduction of the deformity, and sometimes maintenance of the reduction with interbody fusion. Patients were checked out at 2, 6 and 12 months and yearly after the procedure. Clinical, radiological, Visual Analogic Scale (VAS) and Oswestry Disability Index (ODI) outcomes measures were collected.

Results

Seven patients with high-grade spondylolisthesis at L5-S1 (2 patients grade II, 4 patients grade IV and 1 patient grade V), with a median age of 37 years [17; 72] were included. Median follow-up was 24 months [12; 25 months]. All patients have a fused joint at 6 months except one. Median lumbosacral angle (LSA) improved from 76°[59; 85] to 94°[76; 104]. Meyerding grade of 2 cases was stable after surgery, 3 cases with loss of two ranks and 2 cases with loss of one rank. The radiological parameters showed statistically significant difference (p = 0.036) postoperatively. There was not deep infection. Medians VAS and ODI showed improved pain and disability scores.

Conclusion

This procedure allows correct reduction rate of high-grade spondylolisthesis with good clinic-radiologic outcomes. Though surgically demanding, it was safe and reproducible.

Level of evidence

IV, retrospective.

Lumbar interbody fusion rates with 3D-printed lamellar titanium cages using a silicate-substituted calcium phosphate bone graft

The synthetic bone graft material, silicate-substituted calcium phosphate (SiCaP), has been successfully used in spinal fusion surgery. The efficacy of SiCaP-packed 3D-printed lamellar titanium cages used in transforaminal lumbar interbody fusion (TLIF) and lateral lumbar interbody fusion (LLIF) requires investigation. This study evaluated the efficacy of this combination in TLIF and LLIF surgeries treating adult spinal deformities and degenerative disorders. We retrospectively analysed a consecutive case series of 93 adult patients with lumbar degenerative disease or deformity requiring interbody cages who underwent TLIF or LLIF surgery with SiCaP-packed 3D-printed lamellar titanium cages, performed by a single lead surgeon. The primary endpoint was solid fusion 12 months after surgery, assessed using computed tomography. Secondary endpoints were patient-reported outcomes; EuroQOL five dimensions (EQ-5D), visual analogue scale (VAS) for pain (EQ-5D VAS), VAS pain scores for leg and back, and Oswestry disability index (ODI). Complications were recorded. Computed tomography revealed solid fusion in 92/93 (98.9%) patients with good cage integration at the vertebral body interface and no evidence of screw loosening. Patient-reported outcomes significantly improved for all parameters 1 year post-operation. Mean VAS significantly declined 1 year following TLIF surgery (back: -5.5; leg: -6.7) and following LLIF surgery (back: -5.9; leg: -6.9). Mean ODI declined 1 year following TLIF surgery (-43.0) from crippled to minimal disability and following LLIF surgery (-41.2) from severe to minimal disability. SiCaP-packed 3D-printed lamellar titanium cages provided excellent rates of solid fusion in TLIF and LLIF surgeries with notable improvements in patient-reported outcomes.

Correction of Spondylolisthesis by Lateral Lumbar Interbody Fusion Compared with Transforaminal Lumbar Interbody Fusion at L4-5

Objective

In an aging society, the number of patients with symptomatic degenerative spondylolisthesis (DS) is increasing and there is an emerging need for fusion surgery. However, few studies have compared transforaminal lumbar interbody fusion (TLIF) and lateral lumbar interbody fusion (LLIF) for the treatment of patients with DS. The purpose of this study was to investigate the clinical and radiological outcomes between TLIF and LLIF in DS.

Methods

We enrolled patients with symptomatic DS at L4–5 who underwent TLIF with open pedicle screw fixation (TLIF group, n=41) or minimally invasive LLIF with percutaneous pedicle screw fixation (LLIF group, n=39) and were followed-up for more than one year. Clinical (visual analog scale and Oswestry disability index) and radiological outcomes (spondylolisthesis rate, segmental sagittal angle [SSA], mean disc height [MDH], intervertebral foramen height [FH], cage subsidence, and fusion rate) were assessed. And we assessed the changes in radiological parameters between the postoperative and the last follow-up periods.

Results

Preoperative radiological parameters were not significantly different between the two groups. LLIF was significantly superior to TLIF in immediate postoperative radiological results, including reduction of spondylolisthesis rate (3.8% and 7.2%), increase in MDH (13.9 mm and 10.3 mm) and FH (21.9 mm and 19.4 mm), and correction of SSA (18.9° and 15.6°) (p<0.01), and the changes were more stable from the postoperative period to the last follow-up (p<0.01). Cage subsidence was observed significantly less in LLIF (n=6) than TLIF (n=21). Fusion rate was not different between the two groups. The clinical outcomes did not differ significantly at any time point between the two groups. Complications were not statistically significant. However, TLIF showed chronic mechanical problems with screw loosening in four patients and LLIF showed temporary symptoms associated with the surgical approach, such as psoas and ileus muscle symptoms in three and two cases, respectively.

Conclusion

LLIF was more effective than TLIF for spondylolisthesis reduction, likely due to the higher profile cage and ligamentotactic effect. In addition, LLIF showed mechanical stability of the reduction level by using a cage with a larger footprint. Therefore, LLIF should be considered a surgical option before TLIF for patients with unstable DS.

Evaluation of an increased strut porosity silicate-substituted calcium phosphate, SiCaP EP, as a synthetic bone graft substitute in spinal fusion surgery: a prospective, open-label study

Purpose

Silicate-substituted calcium phosphate-enhanced porosity (SiCaP EP, Inductigraft™, Altapore) is a synthetic bone graft material with enhanced strut porosity of 31–47%. SiCaP EP remains to be fully clinically evaluated in patients undergoing instrumented posterolateral fusion (PLF) surgery. We conducted a prospective, open-label, non-randomised, multicentre clinical study to evaluate efficacy of SiCaP EP as bone grafting material in PLF surgery with instrumentation for treatment of spinal disorders.

Methods

Patients with degenerative disc disease, spondylolisthesis or spinal stenosis underwent PLF surgery with SiCaP EP. The primary endpoint was evaluated in the per protocol population (N = 102) as solid fusion at postoperative month 12 assessed using computed tomography scans, with motion assessed using flexion–extension radiographs. Clinical outcomes included the Oswestry Disability Index, 36-item short-form health survey for quality-of-life, visual analog scale for pain scores and neurological assessments. Adverse events were recorded.

Results

Successful fusion was achieved in 59/89 (66.3%) patients at month 6, 88/102 patients (86.3%) at month 12 (primary endpoint) and 87/96 (90.6%) patients at month 24. Disability and pain reduced following surgery. Quality-of-life improved and neurological function was maintained postoperatively. Forty-three (33.3%) of the 129 patients who underwent surgery experienced adverse events; back pain was most frequent (n = 10); nine and 14 patients experienced serious adverse events judged related to device and procedure, respectively.

Conclusions

Enhanced strut porosity SiCaP EP provided high (month 12: 86.3%) spinal fusion success rates in PLF surgery. Fusion success was associated with improved clinical outcomes in patients within 12 months, relative to baseline.

ClinicalTrials.gov identifier

NCT01452022

Graphical abstract

These slides can be retrieved under Electronic Supplementary Material.

Acute rib fracture caused by preoperative positioning for direct lateral interbody fusion: A case report

RATIONALE

Degenerative spondylolisthesis is defined as forward slippage of a vertebra with respect to the underlying vertebra and is associated with the induction of lumbar canal stenosis. The use of anterior column support for degenerative lumbar conditions has been well documented. Direct lateral interbody fusion (DLIF) gains access via a lateral approach through the retroperitoneal fat and psoas muscle. It avoids many of the access-related complications yet comes with its own risks and limitations. The location of the iliac wing precludes exposure of the L5-S1 disc space and may make L4-5 surgery difficult. Therefore, accurate preoperative patient positioning is essential.

PATIENT CONCERNS

A 71-year-old female with a body mass index (BMI) of 39.2 kg/m (height 155.9 cm, weight 79.5 kg) presented with lumbar pain radiating to the left lower limb. She complained of neurologic claudication with more than 100 m ambulation.

DIAGNOSIS

Plain standing view on spine radiography revealed L4-5 spondylolisthesis and disc-space narrowing. Magnetic resonance imaging (MRI) revealed severe L4-5 bilateral foraminal stenosis. After the first surgery, simple rib cage radiography was performed to examine the source of her right-sided flank pain and it revealed acute fracture of the right ninth and tenth ribs.

INTERVENTIONS

The patient was laterally positioned on the table in an extreme bending position. The intervertebral cage was inserted in the L4-5 disc space and disc height was restored. With respect to the rib fracture, treatment was conservative.

OUTCOMES

The patient's radiating pain was immediately relieved and her lower back pain disappeared at 3 months after surgery. The patient reported right-sided flank pain after the first surgery. Simple rib cage radiography was performed and revealed fracture of the right ninth and tenth ribs. Follow-up assessments conducted 2 months later revealed complete bony union.

LESSONS

DLIF avoids many access-related complications. However, it is associated with other intraoperative complications, including injury to the lumbar nerve root and plexus. In addition, there are preoperative complications associated with improper patient placement on the table. In this case, the patient's obesity and strict positional requirements resulted in rib fracture. We suggest that surgeons consider this complication and exercise care in preoperative positioning.

Management of symptomatic degenerative low-grade lumbar spondylolisthesis

Degenerative low-grade lumbar spondylolisthesis is the most common form of spondylolisthesis.

The majority of patients are asymptomatic and do not require surgical intervention.

Symptomatic patients present with a combination of lower back pain, radiculopathy and/or neurogenic claudication and may warrant surgery if non-operative measures fail.

There is widespread controversy regarding the indications for surgery and appropriate treatment strategies for patients with this type of spondylolisthesis.

This article provides a comprehensive evidence-based review of the available literature to support the management of degenerative low-grade spondylolisthesis.

Cite this article: EFORT Open Rev 2018;3:620-631. DOI: 10.1302/2058-5241.3.180020.