Effect of lumbar laminectomy on spinal sagittal alignment: a systematic review

Influence of decompression surgery on sagittal balance parameters in patients with lumbar spinal stenosis

In this study we investigated the effect that lumbar decompression for lumbar spinal stenosis (LSS) has on sagittal balance and its clinical significance. This was an observational cohort study for LSS cases treated with decompression surgery. Core Outcome Measures Index (COMI), EuroQoL (EQ-5D) and Oswestry Disability Index (ODI) were used preoperatively and at 1 year follow-up. Pelvic incidence (PI), pelvic tilt (PT), sagittal vertical axis (SVA) and lumbar lordosis (LL) were measured before and 1 year after surgery. Hierarchical clustering (HC) was performed to identify subgroups with distinct patterns of variation. Ninety-five patients were included, mean age of 63 years, with good/excellent outcome in 71.6%. The median difference between postoperative and preoperative LL was - 1.3o. Increased lumbar lordosis was correlated to ODI improvement (Pearson, r=-0.33). Three clusters were identified after HC. Patients in cluster 2 (31.6% ) had decrease in LL after surgery (mean values for cluster 1, 2, 3: 3.3o, -5.6o, 0.8o), increase in SVA (-5 mm, + 25 mm, -19 mm) and no improvement in ODI (-23.1, 3.77, -17.1). Lumbar decompression has little effect in lumbar lordosis and sagittal balance. Cluster analysis yielded a subgroup of patients with worse outcomes, associated to decrease of LL and increase of SVA after surgery.

Sagittal Realignment Following Decompression for Lumbar Spinal Stenosis in Elderly Patients: A Comprehensive EOS Imaging Analysis

BACKGROUND/OBJECTIVES

This study investigated whether decompression surgery for lumbar spinal stenosis can effectively improve sagittal alignment in elderly patients. With the growing focus on sagittal balance in spinal surgery, this study aimed to evaluate post-decompression alignment changes and identify the factors influencing these changes using the EOS imaging system.

METHODS

A retrospective analysis was conducted on 49 elderly patients who underwent decompression surgery alone for lumbar spinal stenosis. Radiologic parameters, measured using the EOS system, and clinical outcomes were assessed preoperatively, at two weeks postoperatively, and at one year postoperatively. Patients were grouped based on the improvement of the sagittal vertical axis (SVA) by 25 mm or more. A multivariate analysis was performed to identify factors affecting sagittal alignment changes.

RESULTS

Significant sagittal alignment improvements were observed postoperatively, including a notable increase in thoracic kyphosis and a decrease in SVA observed at one year. Clinical outcomes, such as the Oswestry disability index (ODI) and EQ-5D, significantly improved at both two weeks and one year postoperatively compared to preoperative values (all p-values < 0.05). Multivariate analysis revealed that greater preoperative SVA and higher ODI were significant predictors of sagittal alignment changes (odds ratio [OR] for SVA = 1.014, OR for ODI = 1.034).

CONCLUSIONS

Decompression surgery for lumbar spinal stenosis in elderly patients can result in significant improvements in sagittal alignment and clinical outcomes. The study suggests that decompression alone is a viable surgical option for elderly patients, particularly those with a greater preoperative sagittal imbalance and disability, even in the absence of major deformities.

Limited Improvement With Minimally Invasive Lumbar Decompression Alone for Degenerative Scoliosis With Cobb Angle Over 20°: The Impact of Decompression Location

STUDY DESIGN

Retrospective review of a prospectively collected multisurgeon registry.

OBJECTIVE

To evaluate the outcomes of minimally invasive (MI) decompression in patients with severe degenerative scoliosis (DS) and identify factors associated with poorer outcomes.

SUMMARY OF BACKGROUND CONTEXT

MI decompression has gained widespread acceptance as a treatment option for patients with lumbar canal stenosis and DS. However, there is a lack of research regarding the clinical outcomes and the impact of MI decompression location in patients with severe DS exhibiting a Cobb angle exceeding 20°.

MATERIALS AND METHODS

Patients who underwent MI decompression alone were included and categorized into the DS or control groups based on Cobb angle (>20°). Decompression location was labeled as "scoliosis-related" when the decompression levels were across or between end vertebrae and "outside" when the operative levels did not include the end vertebrae. The outcomes, including the Oswestry Disability Index (ODI), were compared between the propensity score-matched groups for improvement and minimal clinical importance difference (MCID) achievement at ≥1 year postoperatively. Multivariable regression analysis was conducted to identify factors contributing to the nonachievement of MCID in ODI of the DS group at the ≥1-year time point.

RESULTS

A total of 253 patients (41 DS) were included in the study. Following matching for age, sex, osteoporosis status, psoas muscle area, and preoperative ODI, the DS groups exhibited a significantly lower rate of MCID achievement in ODI (DS: 45.5% vs. control 69.0%, P =0.047). The "scoliosis-related" decompression (odds ratio: 9.9, P =0.028) was an independent factor of nonachievement of MCID in ODI within the DS group.

CONCLUSIONS

In patients with a Cobb angle >20°, lumbar decompression surgery, even in the MI approach, may result in limited improvement of disability and physical function. Caution should be exercised when determining a surgical plan, especially when decompression involves the level between or across the end vertebrae.

LEVEL OF EVIDENCE

3.

Comparison of the Clinical and Radiological Outcomes of Full-Endoscopic Laminotomy and Conventional Subtotal Laminectomy for Lumbar Spinal Stenosis: A Randomized Controlled Trial

STUDY DESIGN

Randomized controlled trial.

OBJECTIVE

The primary objective of this study was to compare the short-term clinical and radiological outcomes of full-endoscopic lumbar laminotomy (FEL) with those of subtotal lumbar laminectomy (STL) for lumbar spinal stenosis (LSS).

METHODS

In this prospective randomized trial a total of 52 patients were enrolled from May 2016 to September 2021 after providing written informed consent. The authors investigated 45 patients who were followed up for more than 6 months.

RESULTS

There were significant improvements in visual analogue scale (VAS) and Oswestry Disability Index (ODI) scores after the operation in both groups. The FEL group tended to have significantly shorter hospital stay. Interestingly, a statistically significant increase in postoperative lumbar lordosis and segmental angle was observed in the FEL group and both groups, respectively. Spondylolisthesis was exacerbated or newly developed in five of the 21 patients (24%) in the STL group. In contrast, improvement in spondylolisthesis was observed in two of the 24 patients (8%) in the FEL group. There were no complications that resulted in fatal sequelae and no significant difference in the complication rate.

CONCLUSIONS

The clinical results of FEL were similar to those of STL. In addition, the results of FEL were superior to those of STL in terms of a decrease in the postoperative length of stay and radiologic instability, such as iatrogenic spondylolisthesis. The results of this study indicate that FEL is a comparable surgical method to STL for LSS.

How does cervical sagittal profile change after the spontaneous compensation of global sagittal imbalance following one- or two-level lumbar fusion

PURPOSE

This study aimed to evaluate the cervical sagittal profile after the spontaneous compensation of global sagittal imbalance and analyze the associations between the changes in cervical sagittal alignment and spinopelvic parameters.

METHODS

In this retrospective radiographic study, we analyzed 90 patients with degenerative lumbar stenosis (DLS) and sagittal imbalance who underwent short lumbar fusion (imbalance group). We used 60 patients with DLS and sagittal balance as the control group (balance group). Patients in the imbalance group were also divided into two groups according to the preoperative PI: low PI group (≤ 50°), high PI group (PI > 50°). We measured the spinal sagittal alignment parameters on the long-cassette standing lateral radiographs of the whole spine. We compared the changes of spinal sagittal parameters between pre-operation and post-operation. We observed the relationships between the changes in cervical profile and spinopelvic parameters.

RESULTS

Sagittal vertical axis (SVA) occurred spontaneous compensation (p = 0.000) and significant changes were observed in cervical lordosis (CL) (p = 0.000) and cervical sagittal vertical axis (cSVA) (p = 0.023) after surgery in the imbalance group. However, there were no significant differences in the radiographic parameters from pre-operation to post-operation in the balance group. The variations in CL were correlated with the variations in SVA (R = 0.307, p = 0.041). The variations in cSVA were correlated with the variations in SVA (R=-0.470, p = 0.001).

CONCLUSION

Cervical sagittal profile would have compensatory changes after short lumbar fusion. The spontaneous decrease in CL would occur in patients with DLS after the spontaneous compensation of global sagittal imbalance following one- or two-level lumbar fusion. The changes of cervical sagittal profile were related to the extent of the spontaneous compensation of SVA.

The association between lumbar lordosis preoperatively and changes in PROMs for lumbar spinal stenosis patients 2 years after spinal surgery: radiological and clinical results from the NORDSTEN-spinal stenosis trial

BACKGROUND

Patients with lumbar spinal stenosis (LSS) sometimes have lower lumbar lordosis (LL), and the incidence of LSS correlates closely with the loss of LL. The few studies that have evaluated the association between LL and clinical outcomes after non-instrumented surgery for LSS show conflicting results. This study investigates the association between preoperative LL and changes in PROMs 2 years after decompressive surgery.

METHOD

This prospective cohort study obtained preoperative and postoperative data for 401 patients from the multicenter randomized controlled spinal stenosis trial as part of the NORwegian degenerative spondylolisthesis and spinal STENosis (NORDSTEN) study. Before surgery, the radiological sagittal alignment parameter LL was measured using standing X-rays. The association between LL and 2-year postoperative changes was analyzed using the oswestry disability index (ODI), a numeric rating scale (NRS) for low back and leg pain, the Zurich claudication questionnaire (ZCQ), and the global perceived effect (GPE) score. The changes in PROMs 2 years after surgery for quintiles of lumbar lordosis were adjusted for the respective baseline PROMs: age, sex, smoking, and BMI. The Schizas index and the Pfirrmann index were used to analyze multiple regressions for changes in PROMs.

RESULTS

There were no associations in the adjusted and unadjusted analyses between preoperative LL and changes in ODI, ZCQ, GPE, and NRS for back and leg pain 2 years after surgery.

CONCLUSION

LL before surgery was not associated with changes in PROMs 2 years after surgery. Lumbar lordosis should not be a factor when considering decompressive surgery for LSS.

Enhanced Intervertebral Disc Repair via Genetically Engineered Mesenchymal Stem Cells with Tetracycline Regulatory System

The therapeutic potential of Mesenchymal stem cells (MSCs) for the treatment of Intervertebral disc (IVD) degeneration can be enhanced by amplifying specific cytokines and proteins. This study aimed to investigate the therapeutic potential of tetracycline-off system-engineered tonsil-derived mesenchymal stem cells (ToMSC-Tetoff-TGFβ1-IGF1-BMP7) for treating intervertebral disc (IVD) degeneration. ToMSCs were isolated from a tonsillectomy patient and genetically modified with four distinct plasmids via CRISPR/Cas9-mediated knock-in gene editing. Transgene expression was confirmed through immunofluorescence, western blots, and an enzyme-linked immunosorbent assay for transforming growth factor beta 1 (TGFβ1) protein secretion, and the effect of MSC-TetOff-TGFβ1-IGF1-BMP7 on disc injury was assessed in a rat model. The ToMSC-Tetoff-TGFβ1-IGF1-BMP7 treatment exhibited superior therapeutic effects compared to ToMSC-TGFβ1, and ToMSC-SDF1α implantation groups, stimulating the regeneration of nucleus pulposus (NP) cells crucial for IVD. The treatment showed potential to restore the structural integrity of the extracellular matrix (ECM) by upregulating key molecules such as aggrecan and type II collagen. It also exhibited anti-inflammatory properties and reduced pain-inducing neuropeptides. ToMSC-Tetoff-TGFβ1-IGF1-BMP7 holds promise as a novel treatment for IVD degeneration. It appears to promote NP cell regeneration, restore ECM structure, suppress inflammation, and reduce pain. However, more research and clinical trials are required to confirm its therapeutic potential.

Long-Term Changes in Sagittal Balance After Microsurgical Decompression of Lumbar Spinal Canal Stenosis in Elderly Patients: A Follow-Up Study for 5-Years After Surgery

OBJECTIVE

The purpose of this study is to investigate long-term changes in spinal sagittal balance after microsurgical decompression in lumbar canal stenosis (LCS).

METHODS

Fifty-two patients who underwent microsurgical decompression for symptomatic single level L4/5 spinal canal stenosis at our hospital were included in the study. All patients had standing full spine radiographs taken preoperatively, 1 year postoperatively, and 5 years postoperatively. Spinal parameters including sagittal balance were measured from the obtained images. First, preoperative parameters were compared with 50 age-matched asymptomatic volunteers. Next, the parameters before and after surgery were compared to examine long-term changes.

RESULTS

Sagittal vertical axis (SVA) was significantly increased in the LCS cases compared to the volunteers (P = 0.03). Postoperative lumbar lordosis (LL) was significantly increased (P = 0.03). Postoperative mean SVA decreased but the difference was not significant (P = 0.12). Although there was no correlation between preoperative parameters and the Japanese Orthopedic Association score, postoperative pelvic incidence (PI)-LL and pelvic tilt changes correlated with changes in Japanese Orthopedic Association score (PI-LL; P = 0.0001, pelvic tilt; P = 0.04). However, after 5 years of surgery, LL decreased and PI-LL increased (LL; P = 0.08, PI-LL; P = 0.03). Sagittal balance began to deteriorate but was not significant (P = 0.31). At 5 years postoperatively, 18 of 52 patients (34.6%) were found to have L3/4 adjacent segment disease. Cases with adjacent segment disease showed significantly worse SVA and PI-LL (SVA; P = 0.01, PI-LL; P < 0.01).

CONCLUSIONS

In LCS, lumbar kyphosis improves and sagittal balance tends to improve after microsurgical decompression. However, after 5 years, adjacent intervertebral degeneration occurs more frequently and sagittal balance begins to deteriorate in about one third of cases.

Should patients with lumbar stenosis and grade I spondylolisthesis be treated differently based on spinopelvic alignment? A retrospective, two-year, propensity matched, comparison of patient-reported outcome measures and clinical outcomes from multiple sites within a single health system

BACKGROUND

Degenerative lumbar spondylolisthesis is one of the most common pathologies addressed by surgeons. Recently, data demonstrated improved outcomes with fusion in conjunction with laminectomy compared to laminectomy alone. However, given not all degenerative spondylolistheses are clinically comparable, the best treatment option may depend on multiple parameters. Specifically, the impact of spinopelvic alignment on patient reported and clinical outcomes following fusion versus decompression for grade I spondylolisthesis has yet to be explored.

PURPOSE

This study assessed two-year clinical outcomes and one-year patient reported outcomes following laminectomy with concomitant fusion versus laminectomy alone for management of grade I degenerative spondylolisthesis and stenosis. The present study is the first to examine the effect of spinopelvic alignment on patient-reported and clinical outcomes following decompression alone versus decompression with fusion.

STUDY DESIGN/SETTING

Retrospective sub-group analysis of observational, prospectively collected cohort study.

PATIENT SAMPLE

679 patients treated with laminectomy with fusion or laminectomy alone for grade I degenerative spondylolisthesis and comorbid spinal stenosis performed by orthopaedic and neurosurgeons at three medical centers affiliated with a single, tertiary care center.

OUTCOME MEASURES

The primary outcome was the change in Patient-Reported Outcome Measurement Information System (PROMIS), Global Physical Health (GPH), and Global Mental Health (GMH) scores at baseline and post-operatively at 4-6 and 10-12 months postoperatively. Secondary outcomes included operative parameters (estimated blood loss and operative time), and two-year clinical outcomes including reoperations, duration of postoperative physical therapy, and discharge disposition.

METHODS

Radiographs/MRIs assessed stenosis, spondylolisthesis, pelvic incidence, lumbar lordosis, sacral slope, and pelvic tilt; from this data, two cohorts were created based on pelvic incidence minus lumbar lordosis (PILL), denoted as "high" and "low" mismatch. Patients underwent either decompression or decompression with fusion; propensity score matching (PSM) and coarsened exact matching (CEM) were used to create matched cohorts of "cases" (fusion) and "controls" (decompression). Binary comparisons used McNemar test; continuous outcomes used Wilcoxon rank-sum test. Between-group comparisons of changes in PROMIS GPH and GMH scores were analyzed using mixed-effects models; analyses were conducted separately for patients with high and low pelvic incidence-lumbar lordosis (PILL) mismatch.

RESULTS

49.9% of patients (339) underwent lumbar decompression with fusion, while 50.1% (340) received decompression. In the high PLL mismatch cohort at 10-12 months postoperatively, fusion-treated patients reported improved PROs, including GMH (26.61 vs. 20.75, p<0.0001) and GPH (23.61 vs. 18.13, p<0.0001). They also required fewer months of outpatient physical therapy (1.61 vs. 3.65, p<0.0001) and had lower 2-year reoperation rates (12.63% vs. 17.89%, p=0.0442) compared to decompression-only patients. In contrast, in the low PLL mismatch cohort, fusion-treated patients demonstrated worse endpoint PROs (GMH: 18.67 vs. 21.52, p<0.0001; GPH: 16.08 vs. 20.74, p<0.0001). They were also more likely to require skilled nursing/rehabilitation centers (6.86% vs. 0.98%, p=0.0412) and extended outpatient physical therapy (2.47 vs. 1.34 months, p<0.0001) and had higher 2-year reoperation rates (25.49% vs. 14.71%,p=0.0152).

CONCLUSIONS

Lumbar laminectomy with fusion was superior to laminectomy in health-related quality of life and reoperation rate at two years postoperatively only for patients with sagittal malalignment, represented by high PILL mismatch. In contrast, the addition of fusion for patients with low-grade spondylolisthesis, spinal stenosis, and spinopelvic harmony (low PILL mismatch) resulted in worse quality of life outcomes and reoperation rates.

Spinal stability analysis of lumbar interbody fusion according to pelvic type and cage angle based on simplified spinal model with various pelvic indices

Recently, the objectives of lumbar interbody fusion (LIF) have been extended to include the correction of broader/relative indications in addition to spinal fixation. Accordingly, LIF must be optimized for sagittal alignment while simultaneously achieving decompression. Therefore, a representative model classified into three pelvic types, i.e., neutral pelvis (NP), anterior pelvis (AP), and retroverted pelvis (RP), was selected according to the pelvic index, and LIF was performed on each representative model to analyze Lumbar lordosis (LL) and the corresponding equivalent stress. The finite element (FE) model was based on a sagittal 2D X-ray image. The calculation efficiency and convergence were improved by simplifying the modeling of the vertebral body in general and its posterior portion in particular. Based on the position of the pelvis, according to the pelvic shape, images of patients were classified into three types: AP, RP, and NP. Subsequently, representative images were selected for each type. The fixation device used in the fusion model was a pedicle screw and a spinal rod of a general type. PEEK was used as the cage material, and the cage shape was varied by using three different cage angles: 0°, 4°, and 8°. Spinal mobility: The pelvic type with the highest range of motion (ROM) for the spine was the NP type; the AP type had the highest LL. Under a combination load, the NP type exhibited the highest lumbar flexibility (LF), which was 2.46° lower on average compared to the case where a pure moment was applied. Equivalent stress on the spinal fixation device: The equivalent stress acting on the vertebrae was lowest when cage 0 was used for the NP and AP type. For the RP type, the lowest equivalent stress on the vertebrae was observed when cage 4 was used. Finally, for the L5 upper endplate, the stress did not vary significantly for a given type of cage. In conclusion, there was no significant difference in ROM according to cage angle, and the highest ROM, LL and LF were shown in the pelvic shape of NP type. However, when comparing the results with other pelvic types, it was not possible to confirm that LF is completely dependent on LL and ROM.

Characteristics of Sagittal Spinopelvic Alignment Changes After Symptom Relief After Simple Lumbar Decompression

BACKGROUND

Sagittal spinopelvic alignment (SSPA) parameters are essential for the diagnosis of adult spinal deformities (ASDs) and their progression. Certain clinical symptoms that occur in patients with lumbar spinal stenosis (LSS) and herniated nucleus pulposus (HNP) may distort the SSPA and mimic ASD.

OBJECTIVE

To differentiate SSPA in symptomatic patients from asymptomatic patients within 10 minutes in the standing position.

METHODS

This retrospective cohort study evaluated changes in SSPA after simple lumbar decompression surgery in patients with LSS and HNP. Relative sagittal alignment (RSA), relative pelvic version, relative lumbar lordosis (RLL), Lordosis Distribution Index (LDI), and global alignment and proportion (GAP) values were calculated using the conventional Schwab classification method. First, the preoperative and postoperative SSPA parameters were compared. Second, patients were subgrouped into symptomatic within 10 minutes of standing (SP group) and other symptoms of LSS and HNP as controls. Changes in SSPA parameters after symptom relief after simple lumbar decompression surgery were compared between the two groups.

RESULTS

Overall, all SSPA parameters improved after surgery. However, after subgrouping, patients in the control group did not show significant SSPA alterations, except for LDI, whereas patients in the SP group significantly improved in terms of their RSA, RLL, LDI, and GAP values after symptom relief after surgery.

CONCLUSION

Patients with pain on standing within 10 minutes showed significant correction in RSA, RLL, and GAP values after simple lumbar decompression. Therefore, it is important to observe such clinical symptoms to avoid misdiagnosis of ASD.