A Comparison of Minimally Invasive and Open Transforaminal Lumbar Interbody Fusion for Grade 1 Degenerative Lumbar Spondylolisthesis: An Analysis of the Prospective Quality Outcomes Database

Long-Term Incidence of Adjacent Segmental Pathology After Minimally Invasive vs. Open Transforaminal Lumbar Interbody Fusion

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To compare the incidence of adjacent segmental pathology (ASP) following minimally invasive (MI) vs open transforaminal lumbar interbody fusion (TLIF) and to identify factors linked to ASP requiring reoperation.

METHODS

This retrospective study reviewed the outcomes of patients who underwent MI-TLIF or open TLIF. Radiographic ASP (RASP) was evaluated using X-ray imaging to distinguish between degenerative changes, spondylolisthesis, and instability in the adjacent spinal segment. Clinical ASP (CASP) was assessed with the visual analog scale score for leg and back pain and the Oswestry disability index. Patient data were collected 1, 2, 5, and 10 years postoperatively. The timing and frequency of ASP reoperation were analyzed.

RESULTS

Five years postoperatively, the RASP rate was 35.23% and 45.95% in the MI-TLIF and open TLIF groups. The frequency of CASP differed significantly between the MI-TLIF and open TLIF groups at 1 year postoperatively. The rates of RASP, CASP, and ASP necessitating reoperation were not significantly different 10 years postoperatively. Cranial facet violation significantly affected ASP in both groups. In the open TLIF group, preoperative adjacent segment disc degeneration significantly influenced ASP.

CONCLUSION

The RASP rate at 5 years postoperatively and the CASP rate at 1 year postoperatively differed significantly between groups. There was no difference in the rate of ASP requiring reoperation. Cranial facet violation is a crucial driving factor for ASP after both surgical procedures.

Comparison of minimally invasive transforaminal lumbar interbody fusion (Mis-TLIF) with bilateral decompression via unilateral approach and open-TLIF with bilateral decompression for degenerative lumbar diseases: a retrospective cohort study

OBJECTIVE

Presently, no study has compared the clinical outcomes of minimally invasive transforaminal lumbar interbody fusion (Mis-TLIF) with bilateral decompression via the unilateral approach (BDUA) and Open-TLIF with bilateral decompression for degenerative lumbar diseases (DLD). We aimed to compare the clinical outcomes of through Mis-TLIF combined with BDUA and Open-TLIF with bilateral decompression for the treatment of DLD, and reported the learning curve of the procedure of MIS-TLIF with BDUA.

METHODS

We retrospectively analyzed the prospectively collected data of consecutive DLD patients in the two groups from January 2016 to January 2020.

RESULTS

The operative time (OT) was significantly longer in the Mis-TLIF group (n = 113) than in the Open-TLIF group (n = 135). The postoperative drainage volume (PDV) and length of stay (LOS) were significantly higher in the Open-TLIF group than in the Mis-TLIF group. Additionally, the complication rate was significantly higher in the Open-TLIF group than in the Mis-TLIF group (14.8% vs. 6.2%, P = 0.030), while there was no significant difference in the reoperation and adjacent segment disease rates between the two groups. There were no significant differences in back pain and leg pain Numerical Rating Scale (NRS) scores and Oswestry Disability Index (ODI) between the two groups preoperatively, at discharge, and 2 years postoperatively. Patients in both groups showed significant improvements in NRS scores and ODI scores after surgery. OT was negatively correlated with the number of surgeries performed (P < 0.001, r =  -0.43). The learning curve of Mis-TLIF with BDUA was steep, with OT tapered to steady state in 43 cases.

CONCLUSION

Compared with Open-TLIF with bilateral decompression, Mis-TLIF with BDUA can achieve equivalent clinical outcomes, lower PDV and LOS, and lower complication rates. Although this procedure took longer, it could be a viable alternative for the treatment of DLD after a steep learning curve.

Is Full-Endoscopic Transforaminal Lumbar Interbody Fusion Superior to Open Transforaminal Lumbar Interbody Fusion for Single-Level Degenerative Lumbar Spondylolisthesis? A Retrospective Study

BACKGROUND

 In this study, we evaluate the clinical efficacy and safety of full-endoscopic transforaminal lumbar interbody fusion (TLIF) for treatment of single-level lumbar degenerative spondylolisthesis.

METHODS

 Fifty-three patients were divided into two groups according to the surgical techniques: Full endoscopic (Endo)-TLIF (n = 25) and TLIF (n = 28). Clinical efficacy was evaluated pre- and postoperatively. The operation time, operative blood loss, postoperative amount of serum creatine phosphokinase (CPK), postoperative drainage volume, postoperative hospital stay time, total cost, and operative complications were also recorded.

RESULTS

 Compared with the TLIF group, the Endo-TLIF group had similar intraoperative blood loss, less postoperative increased CPK, less postoperative drainage volume, and shorter postoperative hospital stay, but longer operative time and higher total cost. The postoperative visual analog scale (VAS) scores of back and leg pain and Oswestry Disability Index (ODI) scores significantly improved compared with the preoperative scores in both two groups; more significant improvement of postoperative VAS scores of back pain and ODI scores were shown in the Endo-TLIF group at the 1-month follow-up (p < 0.05). No difference was found in the intervertebral fusion rate between the two groups.

CONCLUSION

 The Endo-TLIF has similar clinical effect compared with the TLIF for the treatment of lumbar degenerative spondylolisthesis. It also has many surgical advantages such as less muscle trauma, less postoperative back pain, and fast functional recovery of the patient. However, steep learning curve, longer operative time, and higher total cost may be the disadvantages that limit this technique. Also, the Endo-TLIF treatment of patients with bilateral lateral recess stenosis is considered a relative contraindication.

Endoscopic Lumbar Interbody Fusion, Minimally Invasive Transforaminal Lumbar Interbody Fusion, and Open Transforaminal Lumbar Interbody Fusion for the Treatment of Lumbar Degenerative Diseases: A Systematic Review and Network Meta-Analysis

STUDY DESIGN

network meta-analysis.

OBJECTIVE

To compare the clinical efficacy and safety of endoscopic lumbar interbody fusion (Endo-LIF), minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF), and open transforaminal lumbar interbody fusion (OTLIF) in the treatment of lumbar degenerative diseases (LDDs).

METHOD

A literature search was conducted in the PubMed, Embase, and Cochrane Library databases. Studies comparing Endo-LIF, MIS-TLIF and OTLIF published from September 2017 to September 2022 for the treatment of LDD were retrieved. Data were extracted from preset clinical outcome measures, including operation time, estimated intraoperative estimated blood loss (EBL), length of hospital stay (LOS), complications, visual analog scale (VAS) score, Oswestry disability index (ODI) score, etc.

RESULT

Thirty-one studies with 3467 patients were included in this study. Network meta-analysis showed that in the comparison of the 3 procedures, Endo-LIF was superior to MIS-TLIF and OTLIF in terms of reducing EBL, LOS, time to ambulation, and VAS score of back pain. MIS-TLIF was superior to Endo-LIF in terms of ODI improvement, and OTLIF required the shortest intraoperative fluoroscopy time. There was no significant difference in operative time, complication rate, fusion rate, VAS score of leg pain, or JOA score among the 3 procedures.

CONCLUSION

Endo-LIF, MIS-TLIF and OTLIF each have their own advantages and disadvantages and show similar results in many respects, except for better early outcomes achieved with the more minimally invasive procedure.

Monitored Anesthesia Care in Minimally Invasive Spine Surgery-A Retrospective Case Series Study

Background and Objectives: Minimally invasive spine surgery (MISS) under monitored anesthesia care (MAC) has emerged as a treatment modality for spinal radiculopathy. It is essential to secure the airway and guarantee spontaneous respiration without endotracheal intubation during MISS in a prone position. Materials and Methods: To evaluate the feasibility and safety of MAC with dexmedetomidine during MISS, we retrospectively reviewed clinical cases. A retrospective review of medical records was conducted between September 2015 and June 2016. A total of 17 patients undergoing MISS were included. Vital signs were analyzed every 15 min. The depth of sedation was assessed using the bispectral index (BIS) and the frequency of rescue sedatives. Adverse events during anesthesia, including bradycardia, hypotension, respiratory depression, postoperative nausea, and vomiting, were evaluated. Results: All cases were completed without the occurrence of airway-related complications. None of the patients needed conversion to general anesthesia. The median maintenance dosage of dexmedetomidine for adequate sedation was 0.40 (IQR 0.40-0.60) mcg/kg/hr with a median loading dose of 0.70 (IQR 0.67-0.82) mcg/kg. The mean BIS during the main procedure was 76.46 ± 10.75. Rescue sedatives were administered in four cases (23.6%) with a mean of 1.5 mg intravenous midazolam. After dexmedetomidine administration, hypotension and bradycardia developed in six (35.3%) and three (17.6%) of the seventeen patients, respectively. Conclusions: MAC using dexmedetomidine is a feasible anesthetic method for MISS in a prone position. Hypotension and bradycardia should be monitored carefully during dexmedetomidine administration.

Minimally invasive fusion surgery for patients with degenerative spondylolisthesis and severe lumbar spinal stenosis: a comparative study between MIDLIF and TLIF

PURPOSE

This study aims to compare midline lumbar interbody fusion (MIDLIF) and minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) for treatment of patients with severe stenosis and lumbar degenerative spondylolisthesis (DS), focusing on dural tears rates, other complications, clinical and radiological outcomes.

METHODS

This cohort study included patients with severe lumbar spinal stenosis (Shizas C or D) and lumbar DS who underwent MIDLIF or MIS-TLIF. Propensity score matching was done and the groups were compared regarding surgery time, length of stay, perioperative complications, clinical results and radiological outcomes, at 1 year of follow-up.

RESULTS

The study included initially 80 patients, and 72 patients after matching, 36 in each group. Six patients had dural tears, four in the MIDLIF group and two in the MIS-TLIF group (p = 0.67). General complication rates and reoperations were not significantly different between the groups. Good or excellent clinical was achieved in 75% of the MIDLIF patients and 72% of the MIS-TLIF patients (p = 0.91). Radiological parameters showed small but statistically significant (p < 0.01) improvements after surgery, particularly in segmental lordosis and lumbar lordosis (2.0° and 1.7°), while pelvic tilt and global tilt decreased (1.6° and 2.6°). These findings were similar for both groups.

CONCLUSION

Our study confirms that MIDLIF is a safe and reliable minimally invasive alternative for lumbar interbody fusion in DS, even in patients with severe stenosis and previous spine surgery. It seems to offer similar results to MIS-TLIF regarding clinical results, radiological outcomes and complications.

A systematic review and meta-analysis of risk factors for reoperation after degenerative lumbar spondylolisthesis surgery

BACKGROUND

Considering the high reoperation rate in degenerative lumbar spondylolisthesis (DLS) patients undergoing lumbar surgeries and controversial results on the risk factors for the reoperation, we performed a systematic review and meta-analysis to explore the reoperation rate and risk factors for the reoperation in DLS patients undergoing lumbar surgeries.

METHODS

Literature search was conducted from inception to October 28, 2022 in Pubmed, Embase, Cochrane Library, and Web of Science. Odds ratio (OR) was used as the effect index for the categorical data, and effect size was expressed as 95% confidence interval (CI). Heterogeneity test was performed for each outcome effect size, and subgroup analysis was performed based on study design, patients, surgery types, follow-up time, and quality of studies to explore the source of heterogeneity. Results of all outcomes were examined by sensitivity analysis. Publication bias was assessed using Begg test, and adjusted using trim-and-fill analysis.

RESULTS

A total of 39 cohort studies (27 retrospective cohort studies and 12 prospective cohort studies) were finally included in this systematic review and meta-analysis. The overall results showed a 10% (95%CI: 8%-12%) of reoperation rate in DLS patients undergoing lumbar surgeries. In surgery types subgroup, the reoperation rate was 11% (95%CI: 9%-13%) for decompression, 10% (95%CI: 7%-12%) for fusion, and 9% (95%CI: 5%-13%) for decompression and fusion. An increased risk of reoperation was found in patients with obesity (OR = 1.91, 95%CI: 1.04-3.51), diabetes (OR = 2.01, 95%CI: 1.43-2.82), and smoking (OR = 1.51, 95%CI: 1.23-1.84).

CONCLUSIONS

We found a 10% of reoperation rate in DLS patients after lumbar surgeries. Obesity, diabetes, and smoking were risk factors for the reoperation.

Comparison of 270-degree percutaneous transforaminal endoscopic decompression under local anesthesia and minimally invasive transforaminal lumbar interbody fusion in the treatment of geriatric lateral recess stenosis associated with degenerative lumbar spondylolisthesis

PURPOSE

Various lumbar decompression techniques have been used for the treatment of degenerative lumbar spondylolisthesis (DLS). Few studies have compared the clinical efficacy of percutaneous transforaminal endoscopic decompression (PTED) and minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) in the treatment of lateral recess stenosis associated with DLS (LRS-DLS) in geriatric patients. The objective of the study was to compare the safety and short-term clinical efficacy of 270-degree PTED under local anesthesia and MIS-TLIF in the treatment of LRS-DLS in Chinese geriatric patients over 60 years old.

MATERIALS AND METHODS

From January 2017 to August 2019, the data of 90 consecutive geriatric patients with single-level L4-5 LRS-DLS were retrospectively reviewed, including those in the PTED group (n = 44) and MIS-TLIF group (n = 46). The patients were followed up for at least 1 year. Patient demographics and perioperative outcomes were reviewed before and after surgery. The Oswestry Disability Index (ODI), visual analog scale (VAS) for leg pain, and modified MacNab criteria were used to evaluate the clinical outcomes. X-ray examinations were performed 1 year after surgery to assess the progression of spondylolisthesis in the PTED group and bone fusion in the MIS-TLIF group.

RESULTS

The mean patient ages in the PTED and MIS-TLIF groups were 70.3 years and 68.6 years, respectively. Both the PTED and MIS-TLIF groups demonstrated significant improvements in the VAS score for leg pain and ODI score, and no significant differences were found between the groups at any time point (P > 0.05). Although the good-to-excellent rate of the modified MacNab criteria in the PTED group was similar to that in the MIS-TLIF group (90.9% vs. 91.3%, P > 0.05), PTED was advantageous in terms of the operative time, estimated blood loss, incision length, drainage time, drainage volume, length of hospital stay, and complications.

CONCLUSIONS

Both PTED and MIS-TLIF led to favorable outcomes in geriatric patients with LRS-DLS. In addition, PTED caused less severe trauma and fewer complications. In terms of perioperative quality-of-life and clinical outcomes, PTED could supplement MIS-TLIF in geriatric patients with LRS-DLS.

Minimally invasive versus open transforaminal lumbar interbody fusion for grade I lumbar spondylolisthesis: 5-year follow-up from the prospective multicenter Quality Outcomes Database registry

OBJECTIVE

Minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) has been used to treat degenerative lumbar spondylolisthesis and is associated with expedited recovery, reduced operative blood loss, and shorter hospitalizations compared to those with traditional open TLIF. However, the impact of MI-TLIF on long-term patient-reported outcomes (PROs) is less clear. Here, the authors compare the outcomes of MI-TLIF to those of traditional open TLIF for grade I degenerative lumbar spondylolisthesis at 60 months postoperatively.

METHODS

The authors utilized the prospective Quality Outcomes Database registry and queried for patients with grade I degenerative lumbar spondylolisthesis who had undergone single-segment surgery via an MI or open TLIF method. PROs were compared 60 months postoperatively. The primary outcome was the Oswestry Disability Index (ODI). The secondary outcomes included the numeric rating scale (NRS) for back pain (NRS-BP), NRS for leg pain (NRS-LP), EQ-5D, North American Spine Society (NASS) satisfaction, and cumulative reoperation rate. Multivariable models were constructed to assess the impact of MI-TLIF on PROs, adjusting for variables reaching p < 0.20 on univariable analyses and respective baseline PRO values.

RESULTS

The study included 297 patients, 72 (24.2%) of whom had undergone MI-TLIF and 225 (75.8%) of whom had undergone open TLIF. The 60-month follow-up rates were similar for the two cohorts (86.1% vs 75.6%, respectively; p = 0.06). Patients did not differ significantly at baseline for ODI, NRS-BP, NRS-LP, or EQ-5D (p > 0.05 for all). Perioperatively, MI-TLIF was associated with less blood loss (108.8 ± 85.6 vs 299.6 ± 242.2 ml, p < 0.001) and longer operations (228.2 ± 111.5 vs 189.6 ± 66.5 minutes, p < 0.001) but had similar lengths of hospitalizations (MI-TLIF 2.9 ± 1.8 vs open TLIF 3.3 ± 1.6 days, p = 0.08). Discharge disposition to home or home health was similar (MI-TLIF 93.1% vs open TLIF 91.1%, p = 0.60). Both cohorts improved significantly from baseline for the 60-month ODI, NRS-BP, NRS-LP, and EQ-5D (p < 0.001 for all comparisons). In adjusted analyses, MI-TLIF, compared to open TLIF, was associated with similar 60-month ODI, ODI change, odds of reaching ODI minimum clinically important difference, NRS-BP, NRS-BP change, NRS-LP, NRS-LP change, EQ-5D, EQ-5D change, and NASS satisfaction (adjusted p > 0.05 for all). The 60-month reoperation rates did not differ significantly (MI-TLIF 5.6% vs open TLIF 11.6%, p = 0.14).

CONCLUSIONS

For symptomatic, single-level grade I degenerative lumbar spondylolisthesis, MI-TLIF was associated with decreased blood loss perioperatively, but there was no difference in 60-month outcomes for disability, back pain, leg pain, quality of life, or satisfaction between MI and open TLIF. There was no difference in cumulative reoperation rates between the two procedures. These results suggest that in appropriately selected patients, either procedure may be employed depending on patient and surgeon preferences.

Minimally Invasive Instrumentation of the Cervical Spine: Past, Present, and Future

Posterior cervical instrumentation and fusion procedures are becoming more and more common with the aging population and rising numbers of multisegmental and revision procedures. The instrumentation of the cervical spine has so far been performed almost exclusively via open approaches. Over the past two decades, minimally invasive surgery (MIS) techniques have gained increasing popularity. To date, only a few attempts to instrument the cervical spine in a minimally invasive fashion have been reported. The following article, after a detailed review of the currently available literature, overviews MIS in dorsal cervical instrumentation and past, present and future techniques, and it discusses the current limitations. Nevertheless, and because of the multiple advantages of MIS instrumentation, a lot of work remains to be carried out to fully establish MIS procedures for posterior cervical instrumentation.

Utility of a fulcrum for positioning support during flexion-extension radiographs for assessment of lumbar instability in patients with degenerative lumbar spondylolisthesis

OBJECTIVE

The authors investigated a new standardized technique for evaluating lumbar stability in lumbar lateral flexion-extension (LFE) radiographs. For patients with lumbar spondylolisthesis, a three-part fulcrum with a support platform that included a semiarc leaning tool with armrests, a lifting platform for height adjustment, and a base for stability were used. Standard functional radiographs were used for comparison to determine whether adequate flexion-extension was acquired through use of the fulcrum method.

METHODS

A total of 67 consecutive patients diagnosed with L4-5 degenerative lumbar spondylolisthesis were enrolled in the study. The authors analyzed LFE radiographs taken with the patient supported by a fulcrum (LFEF) and without a fulcrum. Sagittal translation (ST), segmental angulation (SA), posterior opening (PO), change in lumbar lordosis (CLL), and lumbar instability (LI) were measured for comparison using functional radiographs.

RESULTS

The average value of SA was 5.76° ± 3.72° in LFE and 9.96° ± 4.00° in LFEF radiographs, with a significant difference between them (p < 0.05). ST and PO were also significantly greater in LFEF than in LFE. The detection rate of instability was 10.4% in LFE and 31.3% in LFEF, and the difference was significant. The CLL was 27.31° ± 11.96° in LFE and 37.07° ± 12.963.16° in LFEF, with a significant difference between these values (p < 0.05).

CONCLUSIONS

Compared with traditional LFE radiographs, the LFEF radiographs significantly improved the detection rate of LI. In addition, this method may reduce patient discomfort during the process of obtaining radiographs.

Comparison of local and regional radiographic outcomes in minimally invasive and open TLIF: a propensity score-matched cohort

OBJECTIVE

Local and regional radiographic outcomes following minimally invasive (MI) transforaminal lumbar interbody fusion (TLIF) versus open TLIF remain unclear. The purpose of this study was to provide a comprehensive assessment of local and regional radiographic parameters following MI-TLIF and open TLIF. The authors hypothesized that open TLIF provides greater segmental and global lordosis correction than MI-TLIF.

METHODS

A single-center retrospective cohort study of consecutive patients undergoing MI- or open TLIF for grade I degenerative spondylolisthesis was performed. One-to-one nearest-neighbor propensity score matching (PSM) was used to match patients who underwent open TLIF to those who underwent MI-TLIF. Sagittal segmental radiographic measures included segmental lordosis (SL), anterior disc height (ADH), posterior disc height (PDH), foraminal height (FH), percent spondylolisthesis, and cage position. Lumbopelvic radiographic parameters included overall lumbar lordosis (LL), pelvic incidence (PI)-lumbar lordosis (PI-LL) mismatch, sacral slope (SS), and pelvic tilt (PT). Change in segmental or overall lordosis after surgery was considered "lordosing" if the change was > 0° and "kyphosing" if it was ≤ 0°. Student t-tests or Wilcoxon rank-sum tests were used to compare outcomes between MI-TLIF and open-TLIF groups.

RESULTS

A total of 267 patients were included in the study, 114 (43%) who underwent MI-TLIF and 153 (57%) who underwent open TLIF, with an average follow-up of 56.6 weeks (SD 23.5 weeks). After PSM, there were 75 patients in each group. At the latest follow-up both MI- and open-TLIF patients experienced significant improvements in assessment scores obtained with the Oswestry Disability Index (ODI) and the numeric rating scale for low-back pain (NRS-BP), without significant differences between groups (p > 0.05). Both MI- and open-TLIF patients experienced significant improvements in SL, ADH, and percent corrected spondylolisthesis compared to baseline (p < 0.001). However, the MI-TLIF group experienced significantly larger magnitudes of correction with respect to these metrics (ΔSL 4.14° ± 4.35° vs 1.15° ± 3.88°, p < 0.001; ΔADH 4.25 ± 3.68 vs 1.41 ± 3.77 mm, p < 0.001; percent corrected spondylolisthesis: -10.82% ± 6.47% vs -5.87% ± 8.32%, p < 0.001). In the MI-TLIF group, LL improved in 44% (0.3° ± 8.5°) of the cases, compared to 48% (0.9° ± 6.4°) of the cases in the open-TLIF group (p > 0.05). Stratification by operative technique (unilateral vs bilateral facetectomy) and by interbody device (static vs expandable) did not yield statistically significant differences (p > 0.05).

CONCLUSIONS

Both MI- and open-TLIF patients experienced significant improvements in patient-reported outcome (PRO) measures and local radiographic parameters, with neutral effects on regional alignment. Surprisingly, in our cohort, change in SL was significantly greater in MI-TLIF patients, perhaps reflecting the effect of operative techniques, technological innovations, and the preservation of the posterior tension band. Taking these results together, no significant overall differences in LL between groups were demonstrated, which suggests that MI-TLIF is comparable to open approaches in providing radiographic correction after surgery. These findings suggest that alignment targets can be achieved by either MI- or open-TLIF approaches, highlighting the importance of surgeon attention to these variables.

Clinical outcomes, complications and fusion rates in endoscopic assisted intraforaminal lumbar interbody fusion (iLIF) versus minimally invasive transforaminal lumbar interbody fusion (MI-TLIF): systematic review and meta-analysis

This meta-analysis aims to determine the clinical outcomes, complications, and fusion rates in endoscopic assisted intra-foraminal lumbar interbody fusion (iLIF) and minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) for lumbar degenerative diseases. The MEDLINE, Embase, and Cochrane Library databases were searched. The inclusion criteria were: five or more consecutive patients who underwent iLIF or MI-TLIF for lumbar degenerative diseases; description of the surgical technique; clinical outcome measures, complications and imaging assessment; minimum follow-up of 12 months. Surgical time, blood loss, and length of hospital stay were extracted. Mean outcome improvements were pooled and compared with minimal clinically important differences (MCID). Pooled and direct meta-analysis were evaluated. We identified 42 eligible studies. The iLIF group had significantly lower mean intra-operative blood loss, unstandardized mean difference (UMD) 110.61 mL (95%CI 70.43; 150.80; p value < 0.0001), and significantly decreased length of hospital stay (UMD 2.36; 95%CI 1.77; 2.94; p value < 0.0001). Visual analogue scale (VAS) back, VAS leg and Oswestry disability index (ODI) baseline to last follow-up mean improvements were statistically significant (p value < 0.0001), and clinically important for both groups (MCID VAS back > 1.16; MCID VAS leg > 1.36; MCID > 12.40). There was no significant difference in complication nor fusion rates between both cohorts. Interbody fusion using either iLIF or MI-TLIF leads to significant and clinically important improvements in clinical outcomes for lumbar degenerative diseases. Both procedures provide high rates of fusion at 12 months or later, without significant difference in complication rates. iLIF is associated with significantly less intraoperative blood loss and length of hospital stay.

Study registration: PROSPERO international prospective register of systematic reviews: Registration No. CRD42020180980, accessible at https://www.crd.york.ac.uk/prospero/ April 2020.

Does reduction of the Meyerding grade correlate with outcomes in patients undergoing decompression and fusion for grade I degenerative lumbar spondylolisthesis?

OBJECTIVE

Reduction of Meyerding grade is often performed during fusion for spondylolisthesis. Although radiographic appearance may improve, correlation with patient-reported outcomes (PROs) is rarely reported. In this study, the authors' aim was to assess the impact of spondylolisthesis reduction on 24-month PRO measures after decompression and fusion surgery for Meyerding grade I degenerative lumbar spondylolisthesis.

METHODS

The Quality Outcomes Database (QOD) was queried for patients undergoing posterior lumbar fusion for spondylolisthesis with a minimum 24-month follow-up, and quantitative correlation between Meyerding slippage reduction and PROs was performed. Baseline and 24-month PROs, including the Oswestry Disability Index (ODI), EQ-5D, Numeric Rating Scale (NRS)-back pain (NRS-BP), NRS-leg pain (NRS-LP), and satisfaction (North American Spine Society patient satisfaction questionnaire) scores were noted. Multivariable regression models were fitted for 24-month PROs and complications after adjusting for an array of preoperative and surgical variables. Data were analyzed for magnitude of slippage reduction and correlated with PROs. Patients were divided into two groups: < 3 mm reduction and ≥ 3 mm reduction.

RESULTS

Of 608 patients from 12 participating sites, 206 patients with complete data were identified in the QOD and included in this study. Baseline patient demographics, comorbidities, and clinical characteristics were similarly distributed between the cohorts except for depression, listhesis magnitude, and the proportion with dynamic listhesis (which were accounted for in the multivariable analysis). One hundred four (50.5%) patients underwent lumbar decompression and fusion with slippage reduction ≥ 3 mm (mean 5.19, range 3 to 11), and 102 (49.5%) patients underwent lumbar decompression and fusion with slippage reduction < 3 mm (mean 0.41, range 2 to -2). Patients in both groups (slippage reduction ≥ 3 mm, and slippage reduction < 3 mm) reported significant improvement in all primary patient reported outcomes (all p < 0.001). There was no significant difference with regard to the PROs between patients with or without intraoperative reduction of listhesis on univariate and multivariable analyses (ODI, EQ-5D, NRS-BP, NRS-LP, or satisfaction). There was no significant difference in complications between cohorts.

CONCLUSIONS

Significant improvement was found in terms of all PROs in patients undergoing decompression and fusion for lumbar spondylolisthesis. There was no correlation with clinical outcomes and magnitude of Meyerding slippage reduction.

Does transforaminal lumbar interbody fusion induce lordosis or kyphosis? Radiographic evaluation with a minimum 2-year follow-up

OBJECTIVE

Conflicting reports exist about whether transforaminal lumbar interbody fusion (TLIF) induces lordosis or kyphosis, ranging from decreasing lordosis by 3.71° to increasing it by 18.8°. In this study, the authors' aim was to identify factors that result in kyphosis or lordosis after TLIF.

METHODS

A single-center, retrospective study of open TLIF without osteotomy for spondylolisthesis with a minimum 2-year follow-up was undertaken. Preoperative and postoperative clinical and radiographic parameters and cage specifics were collected. TLIFs were considered to be "lordosing" if postoperative induction of lordosis was > 0° and "kyphosing" if postoperative induction of lordosis was ≤ 0°.

RESULTS

A total of 137 patients with an average follow-up of 52.5 months (range 24-130 months) were included. The overall postoperative disc angle (DA) and segmental lordosis (SL) increased by 1.96° and 1.88° (p = 0.003 and p = 0.038), respectively, whereas overall lumbar lordosis remained unchanged (p = 0.133). Seventy-nine patients had lordosing TLIFs with a mean SL increase of 5.72° ± 3.97°, and 58 patients had kyphosing TLIFs with a mean decrease of 3.02° ± 2.98°. Multivariate analysis showed that a lower preoperative DA, lower preoperative SL, and anterior cage placement were correlated with the greatest increase in postoperative SL (p = 0.040, p < 0.001, and p = 0.035, respectively). There was no difference in demographics, cage type or height, or spinopelvic parameters between the groups (p > 0.05). Linear regression showed that the preoperative DA and SL correlated with SL after TLIF (R2 = 0.198, p < 0.001; and R2 = 0.2931, p < 0.001, respectively).

CONCLUSIONS

Whether a TLIF induces kyphosis or lordosis depends on the preoperative DA, preoperative SL, and cage position. Less-lordotic segments became more lordotic postoperatively, and highly lordotic segments may lose lordosis after TLIF. Cages placed more anteriorly were associated with more lordosis.

MIS-TLIF versus O-TLIF for single-level degenerative stenosis: study protocol for randomised controlled trial

INTRODUCTION

Patients with symptomatic single-level combination of degenerative stenosis and low-grade spondylolisthesis are often treated by nerve root decompression and spinal fusion. The gold standard is traditional open decompression and fusion, but minimally invasive method is more and more prevailing. However, there is lack of high-quality studies comparing these two techniques in order to obtain the advantages and certain indications to use one of these methods. The current study includes clinical, safety and radiological endpoints to determine the effectiveness of minimally invasive decompression and fusion (MIS-TLIF) over the traditional open one (O-TLIF).

METHODS AND ANALYSIS

All patients aged 40-75 years with neurogenic claudication or bilateral radiculopathy caused by single-level combination of degenerative stenosis and low-grade spondylolisthesis, confirmed by MRI with these symptoms persisting for at least 3 months prior to surgery, are eligible. Patients will be randomised into MIS-TLIF or traditional O-TLIF. The primary outcome measure is Oswestry Disability Index at 3-month follow-up term. The secondary outcomes are patient-reported outcome measures by the number of clinical scales, radiological parameters including sagittal balance parameters, safety endpoints and cost-effectiveness of each method. All patients will be analysed preoperatively, as well as on the 14th day of hospital stay (or on the day of hospital discharge), 3 months, 6 months, 12 months and 24 months postoperatively. The study has the design of a parallel group to demonstrate the non-inferior clinical results of MIS-TLIF compared with the traditional O-TLIF.

ETHICS AND DISSEMINATION

The study will be performed according to Helsinki Declaration. The study protocol was approved by the Local Ethical Committee of Priorov National Medical Research Center of Traumatology and Orthopedics in August 2020. Preliminary and final results will be presented in peer-reviewed journals, especially orthopaedic and spine surgery journals, at national and international congresses.

TRIAL REGISTRATION NUMBER

NCT04594980.

Percutaneous Transforaminal Endoscopic Decompression for Geriatric Patients with Central Spinal Stenosis and Degenerative Lumbar Spondylolisthesis: A Novel Surgical Technique and Clinical Outcomes

Purpose

Percutaneous transforaminal endoscopic decompression (PTED) is an ultra-minimally invasive surgical option for patients that does not involve the same amount of destabilizing facet joint removal as a traditional laminectomy. The objective of this study was to describe the procedure of PTED under local anesthesia for geriatric patients with central spinal stenosis and degenerative lumbar spondylolisthesis (CSS-DLS).

Materials and Methods

From January 2016 to December 2018, 30 consecutive geriatric patients who underwent surgery for single-level CSS-DLS were retrospectively reviewed. All patients were followed for at least 12 months (12–24 months). The visual analog scale (VAS) scores, Oswestry disability index (ODI) scores and modified MacNab criteria were used to evaluate the clinical results.

Results

The mean age was 73.1±6.0 years. Follow-up ranged from 12 to 36 months. The mean±SD values of the preoperative VAS for leg pain and ODI were 7.4±1.0 and 67.2±8.4, respectively. The values improved to 2.2±1.1 and 19.9±8.1 at 12 months postoperatively. The outcomes of the modified MacNab criteria showed that 93.3% of patients obtained a good-to-excellent rate. The percent slippage of spondylolisthesis before surgery (13.8±2.5%) and at the end of follow-up (14.0±2.5%) was not significantly different.

Conclusion

PTED under local anesthesia could be a useful supplement to traditional decompression in geriatric patients with CSS-DLS.