Minimally Invasive Lumbar Decompression Versus Minimally Invasive Transforaminal Lumbar Interbody Fusion for Treatment of Low-Grade Lumbar Degenerative Spondylolisthesis

Radiographic Phenotype-Driven Clustering in Lumbar Decompression: Comparative Study of Outcome and Reoperation Risk

BACKGROUND CONTEXT

Lumbar spinal canal stenosis (LSCS) presents with various radiographic findings, often including concurrent degenerative changes. Prior studies have investigated the effects of individual radiographic findings and parameters separately using conventional methods such as logistic regression. However, applying these independent effects to real-world patients remains challenging due to an unknown interaction effect among multiple degenerative radiographic findings.

PURPOSE

To identify distinct patient phenotypes based on preoperative radiographic findings using unsupervised clustering and to evaluate their associations with postoperative patient-reported outcomes and reoperation rates.

STUDY DESIGN

Retrospective cohort study PATIENT SAMPLE: Patients undergoing single-level lumbar decompression OUTCOME MEASURES: Oswestry Disability Index (ODI), Short Form-12 physical component scale (SF-12 PCS), reoperation rates METHODS: Unsupervised clustering was performed using preoperative radiographic data from standing X-ray imaging and magnetic resonance imaging (MRI). Variable selection was optimized through preliminary correlation analysis, causal assessment using a directed acyclic graph, and expert review. A multivariable mixed-effects model was used to assess the impact of cluster membership on postoperative outcomes. Reoperation rates were compared using Kaplan-Meier survival analysis and Cox proportional hazards models.

RESULTS

Unsupervised clustering identified four distinct clusters base on 10 radiographic variables: cluster 1 as "Young and Less Degenerative Spine" (cluster Y), cluster 2 as "Combined Coronal and Sagittal Spondylosis" (cluster CS), cluster 3 as "Coronal Spondylosis Characterized by Laterolisthesis" (cluster C), and cluster 4 as "Sagittal Spondylosis Characterized by Degenerative Spondylolisthesis" (cluster S). Multivariable regression analysis, adjusting for comorbidity, sex, and body mass index have revealed cluster C demonstrated slower improvement in ODI (β = 5.4, SE = 2.7, p = 0.043) and SF-12 PCS (β = -2.9, SE = 1.4, p = 0.045) compared to cluster Y. Regarding reoperation, cluster CS showed the highest hazard ratio (24.3%, HR = 4.18, 95% CI: 1.48-13.07, p = 0.007) compared to cluster S with the lowest reoperation rate (6.8%).

CONCLUSION

Unsupervised clustering based on preoperative radiographic findings identified four distinct degenerative phenotypes in LSCS. Patients with coronal spondylosis was associated with slower improvements in disability and function compared to those with minimal degeneration. Additionally, patients with combined sagittal and coronal degeneration exhibited the highest reoperation rates. These findings highlight the clinical relevance of coronal and sagittal degeneration in surgical decision-making.

Distinct Recovery Patterns After Transforaminal Lumbar Interbody Fusion: Comparing Minimally Invasive and Open Approaches Using Mixed-Effects Segmented Regression

OBJECTIVE

While minimally invasive-transforaminal lumbar interbody fusion (MIS-TLIF) has shown superiority in key clinical metrics over the open approach, evidence regarding patient-reported outcomes remains limited. This study compared postoperative recovery trajectories and symptomatic improvement phases between MIS and open TLIF.

METHODS

This retrospective review included patients who underwent single-level MIS or open TLIF. Oswestry Disability Index (ODI) and Numerical Rating Scale (NRS) for back and leg pain were collected preoperatively and postoperatively. Segmented regression analysis with mixed-effects modeling, allowing for identification of distinct recovery phases, compared symptomatic trends between approaches.

RESULTS

Of 324 patients (268 MIS, 56 open), baseline demographics were similar except for greater preoperative leg pain in the MIS group (NRS: 6.0 vs. 5.0, p = 0.027). A segmented regression model identified 4 ODI recovery phases: postoperative disability phase (PDP, day 0 to 13), early improvement phase (day 13 to 28), late improvement phase (day 28 to 110), and plateau phase (later than day 110). The MIS group exhibited significantly lower disability exacerbation during PDP (β = 0.93 vs. 1.42 points per day, p = 0.008). Additionally, the plateau of NRS back occurred significantly earlier in the MIS group than in the open group (MIS, 26.7 ± 2.6 days vs. open, 51.7 ± 6.6 days, p < 0.001).

CONCLUSION

MIS-TLIF resulted in lower postoperative disability during the first 2 weeks compared to the open approach. Furthermore, low back pain achieved an earlier plateau in back pain by about 4 weeks in the MIS approach.

Clinical and Radiologic Predictors of Slower Improvement and Nonimprovement After Surgical Treatment of L4-L5 Degenerative Spondylolisthesis: Preliminary Results

STUDY DESIGN

Retrospective cohort.

OBJECTIVE

To identify the predictors of slower and nonimprovement after surgical treatment of L4-5 degenerative lumbar spondylolisthesis (DLS).

SUMMARY OF BACKGROUND DATA

There is limited evidence regarding clinical and radiologic predictors of slower and nonimprovement following surgery for L4-5 DLS.

METHODS

Patients who underwent minimally invasive decompression or fusion for L4-5 DLS and had a minimum of 1-year follow-up were included. Outcome measures were: (1) minimal clinically important difference (MCID), (2) patient acceptable symptom state (PASS), and (3) global rating change (GRC). Clinical variables analyzed for predictors were age, gender, body mass index (BMI), surgery type, comorbidities, anxiety, depression, smoking, osteoporosis, and preoperative patient-reported outcome measures (PROMs) (Oswestry disability index, ODI; visual analog scale, VAS back and leg; 12-Item Short Form Survey Physical Component Score, SF-12 PCS). Radiologic variables analyzed were slip percentage, translational and angular motion, facet diastasis/cyst/orientation, laterolisthesis, disc height, scoliosis, main and fractional curve Cobb angles, and spinopelvic parameters.

RESULTS

Two hundred thirty-three patients (37% decompression and 63% fusion) were included. At less than three months, high pelvic tilt (PT) (OR: 0.92, P= 0.02) and depression (OR: 0.28, P= 0.02) were predictors of MCID nonachievement and GRC nonbetterment, respectively. Neither retained significance at above six months and hence, were identified as predictors of slower improvement. At above six months, low preoperative VAS leg (OR: 1.26, P= 0.01) and high facet orientation (OR: 0.95, P= 0.03) were predictors of MCID nonachievement, high L4-5 slip percentage (OR: 0.86, P= 0.03) and L5-S1 angular motion (OR: 0.78, P= 0.01) were predictors of GRC nonbetterment, and high preoperative ODI (OR: 0.96, P= 0.04) was a predictor of PASS nonachievement.

CONCLUSIONS

High PT and depression were predictors of slower improvement and low preoperative leg pain, high disability, high facet orientation, high slip percentage, and L5-S1 angular motion were predictors of nonimprovement. However, these are preliminary findings and further studies with homogeneous cohorts are required to establish these findings.

Bilateral synchronous UBE for unilateral laminotomy and bilateral decompression as a potentially effective minimally Invasive approach for two-level lumbar spinal stenosis

Currently, Unilateral biportal endoscopy is widely used in the surgical treatment of lumbar spinal stenosis. To investigate the feasibility of bilateral synchronous UBE to unilateral laminotomy and bilateral decompression(BS-UBE-ULBD) for treating two-level lumbar spinal stenosis (LSS). Sixty-four patients with two-level lumbar spinal stenosis (LSS) treated with BS-UBE-ULBD from October 2022 to January 2024 were retrospectively analyzed. All patients were treated with BS-UBE-ULBD. All 64 patients successfully underwent surgery, and the duration of surgery was 95-180 min, with an average of 119.92 ± 14.79 min. The average number of fluoroscopy was 3.02 ± 0.92. The average blood loss during the surgery was 73. 44 ± 36.70 ml. Postoperative lumbar CT showed that the spinal canal and bilateral nerve roots were fully decompressed. There were no postoperative complications, such as infection, severe nerve root injury, and lumbar instability. Complete follow-up data were obtained for all 64 cases. The VAS score of low back and leg pain and the ODI of lumbar function significantly (P < 0.05) improved at each follow-up time point. MacNab evaluation at 6 months after the surgery showed that the results were excellent in 48 cases, good in 14 cases, and fair in 2 cases. The excellent and good rate was 96. 88% (62/64). So BS-UBE-ULBD is a minimally invasive, highly effective, and safe procedure for 2-level LSS.Degenerative lumbar spinal stenosis (LSS) refers to clinical symptoms caused by the compression of the cauda equina, nerve root, and vascular complex. LSS can occur due to the abnormal shape and volume of the bony or fibrous structure after degenerative changes and the stenosis of the inner diameter of one or more lumens at a single level or multiple levels. It is a common cause of lumbago or lumbago and leg pain, which is common among middle-aged and elderly people1. LSS has become the most common cause of lumbar surgery among patients over 60 years of age2. However, traditional surgery necessitates extensive stripping of paraspinal muscles, which can easily lead to the ischemic injury of paraspinal muscles and atrophy after denervation. Therefore, traditional surgery may result in intractable back pain, stiffness, and discomfort after surgery3,4. Furthermore, as the posterior bone and soft tissue structures need to be extensively resected during the surgery, epidural scar and nerve compression are highly likely after the surgery. The high risk of general anesthesia cannot be ignored among elderly and weak patients2,5.Recently, with the rapid development of minimally invasive spine surgery, endoscopic surgery has been applied in the treatment of LSS6. Unilateral biportal endoscopy (UBE ) is more popular in treating LSS and is a more flexible operation, with small trauma, quick recovery, and a gentle learning curve. In addition, many studies have proven the good clinical efficacy of unilateral biportal endoscopy7. Multilevel spinal stenosis can be done simultaneously. Previously, the same operator decompressed multiple segments in turn8,9, but the operation lasted longer, and the corresponding problems, such as bleeding, high risk of anesthesia, and fluoroscopy frequency, increased.From October 2022 to June 2024, our hospital pioneered the use of Bilateral Synchronous UBE-unilateral Laminotomy and Bilateral Decompression (BS-UBE-ULBD) for two-level degenerative LSS. Sixty-four patients with two-segment LSS were treated with BS-UBE-ULBD, and the results were satisfactory.

Venous Thromboembolism Rates Have Not Decreased in Elective Lumbar Fusion Surgery from 2011 to 2020

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

This study aimed to (1) evaluate for any temporal trends in the rates of VTE, deep venous thrombosis (DVT), pulmonary embolism (PE), and mortality from 2011 to 2020 and (2) identify the predictors of VTE following lumbar fusion surgery.

METHODS

Annual incidences of 30-day VTE, DVT, PE, and mortality were calculated for each of the operation year groups from 2011 to 2020. Multivariable Poisson regression was utilized to test the association between operation year and primary outcomes, as well as to identify significant predictors of VTE.

RESULTS

A total of 121,205 patients were included. There were no statistically significant differences in VTE, DVT, PE, or mortality rates among the operation year groups. Multivariable regression analysis revealed that compared to 2011, operation year 2019 was associated with significantly lower rates of DVT. Age, BMI, prolonged operation time, prolonged length of stay, non-home discharge, anterior fusion, smoking status, functional dependence, and chronic steroid use were identified as independent predictors of VTE following lumbar fusion. Female sex, Hispanic ethnicity, and outpatient surgery setting were identified as protective factors from VTE in this cohort.

CONCLUSIONS

Rates of VTE after lumbar fusion have remained mostly unchanged between 2011 and 2020. Older age, higher BMI, longer operation time, prolonged length of stay, non-home discharge, anterior fusion, smoking, functional dependence, and steroid use were independent predictors of VTE after lumbar fusion, while female sex, Hispanic ethnicity, and outpatient surgery were the protective factors.

Impact of age on comparative outcomes of decompression alone versus fusion for L4 degenerative spondylolisthesis

PURPOSE

To compare the outcomes of decompression alone and fusion for L4-5 DLS in different age cohorts (< 70 years, ≥ 70 years).

METHODS

This retrospective cohort study included patients who underwent minimally invasive decompression or fusion for L4-5 DLS and had a minimum of 1-year follow-up. Outcome measures were: (1) patient-reported outcome measures (PROMs) (Oswestry Disability Index, ODI; Visual Analog Scale back and leg, VAS; 12-Item Short Form Survey Physical Component Score, SF-12 PCS), (2) minimal clinically important difference (MCID), (3) patient acceptable symptom state (PASS), (4) response on the global rating change (GRC) scale, and (5) complication rates. The decompression and fusion groups were compared for outcomes separately in the < 70-year and ≥ 70-year age cohorts.

RESULTS

233 patients were included, out of which 52% were < 70 years. Patients < 70 years showed non-significant improvement in SF-12 PCS and significantly lower MCID achievement rates for VAS back after decompression compared to fusion. Analysis of the ≥ 70-year age cohort showed no significant differences between the decompression and fusion groups in the improvement in PROMs, MCID/PASS achievement rates, and responses on GRC. Patients ≥ 70 years undergoing fusion had significantly higher in-hospital complication rates. When analyzed irrespective of the surgery type, both < 70-year and ≥ 70-year age cohorts showed significant improvement in PROMs with no significant difference.

CONCLUSIONS

Patients < 70 years undergoing decompression alone did not show significant improvement in physical function and had significantly less MCID achievement rate for back pain compared to fusion. Patients ≥ 70 years showed no difference in outcomes between decompression alone and fusion.

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 between minimally invasive and open transforaminal lumbar interbody fusion for the treatment of multi‑segmental lumbar degenerative disease: A systematic evaluation and meta‑analysis

The present study aimed to compare the differences between minimally invasive transforaminal lumbar fusion (MIS-TLIF) and open transforaminal lumbar fusion (TLIF) for multi-segmental lumbar degenerative disease regarding intraoperative indices and postoperative outcomes. PubMed, Web of Science, Embase, CNKI, Wanfang and VIP databases were searched for literature on MIS-TLIF and open TLIF in treating multi-segmental lumbar degenerative diseases. Of the 1,608 articles retrieved, 10 were included for final analysis. The Newcastle-Ottawa Scale and Review Manager 5.4 were used for quality evaluation and data analysis, respectively. The MIS-TLIF group was superior to the open TLIF group regarding intraoperative blood loss [95% confidence interval (CI): -254.33,-157.86; P<0.00001], postoperative in-bed time (95%CI: -3.49,-2.76; P<0.00001), hospitalization time (95%CI: -5.14,-1.78; P<0.0001) and postoperative leg pain Visual Analog Scale score (95%CI: -0.27,-0.13; P<0.00001). The fluoroscopy frequency for MIS-TLIF (95%CI: 2.07,6.12; P<0.0001) was significantly higher than that for open TLIF. The two groups had no significant differences in operation time, postoperative drainage volume, postoperative complications, fusion rate, or Oswestry Disability Index score. In treating multi-segmental lumbar degenerative diseases, MIS-TLIF has the advantages of less blood loss, shorter bedtime and hospitalization time and improved early postoperative efficacy; however, open TLIF has a lower fluoroscopy frequency.

Biomechanical response of decompression alone in lower grade lumbar degenerative spondylolisthesis--A finite element analysis

BACKGROUND

Previous studies have demonstrated the clinical efficacy of decompression alone in lower-grade spondylolisthesis. A higher rate of surgical revision and a lower rate of back pain relief was also observed. However, there is a lack of relevant biomechanical evidence after decompression alone for lower-grade spondylolisthesis.

PURPOSE

Evaluating the biomechanical characteristics of total laminectomy, hemilaminectomy, and facetectomy for lower-grade spondylolisthesis by analyzing the range of motion (ROM), intradiscal pressure (IDP), annulus fibrosus stress (AFS), facet joints contact force (FJCF), and isthmus stress (IS).

METHODS

Firstly, we utilized finite element tools to develop a normal lumbar model and subsequently constructed a spondylolisthesis model based on the normal model. We then performed total laminectomy, hemilaminectomy, and one-third facetectomy in the normal model and spondylolisthesis model, respectively. Finally, we analyzed parameters, such as ROM, IDP, AFS, FJCF, and IS, for all the models under the same concentrate force and moment.

RESULTS

The intact spondylolisthesis model showed a significant increase in the relative parameters, including ROM, AFS, FJCF, and IS, compared to the intact normal lumbar model. Hemilaminectomy and one-third facetectomy in both spondylolisthesis and normal lumbar models did not result in an obvious change in ROM, IDP, AFS, FJCF, and IS compared to the pre-operative state. Moreover, there was no significant difference in the degree of parameter changes between the spondylolisthesis and normal lumbar models after undergoing the same surgical procedures. However, total laminectomy significantly increased ROM, AFS, and IS and decreased the FJCF in both normal lumbar models and spondylolisthesis models.

CONCLUSION

Hemilaminectomy and one-third facetectomy did not have a significant impact on the segment stability of lower-grade spondylolisthesis; however, patients with LDS undergoing hemilaminectomy and one-third facetectomy may experience higher isthmus stress on the surgical side during rotation. In addition, total laminectomy changes the biomechanics in both normal lumbar models and spondylolisthesis models.

Minimally Invasive Decompression With Noninstrumented Facet Fusion Versus Minimally Invasive Transforaminal Lumbar Interbody Fusion for Stenosis Associated With Grade 1 Lumbar Degenerative Spondylolisthesis

STUDY DESIGN

Retrospective matched cohort study.

SUMMARY OF BACKGROUND DATA

With a growing interest in minimally invasive spine surgery (MIS), the question of which technique is the most advantageous for patients with low-grade degenerative lumbar spondylolisthesis (DLS) still remains unclear.

OBJECTIVE

To compare patient-reported outcomes, perioperative morbidity, and rates of reoperation between MIS decompression with either unilateral noninstrumented facet fusion (MIS-F) or with transforaminal interbody fusion (MIS-T) for grade 1 DLS.

METHODS

Twenty patients who underwent MIS-T and 20 patients with MIS-F were matched based on age, sex, and preoperative ODI, VAS back, and VAS leg. All patients had DLS with at least 4 millimeters of translation on standing radiographs. Exclusion criteria included prior level surgery, multilevel instability, disk impinging on the exiting nerve root, spondylolisthesis from significant facet arthropathy, or foraminal compromise from disk collapse. ODI, VAS back, VAS leg, and patient satisfaction measured by the North American Spine Society questionnaire were tracked at 3, 6, 12, and 24 months postoperatively. Minimum clinically important differences and substantial clinical benefits were calculated.

RESULTS

MIS-F and MIS-T resulted in decreased ODI at 3, 6, and 12 months following the index procedure. Sixty percent of MIS-F and 83% of MIS-T patients reached minimum clinically important difference at 1 year postoperatively; however, using the threshold of 30% ODI reduction from baseline, 67% of MIS-F and 83% MIS-T ( P = 0.25) achieved this goal. Forty-three percent of MIS-F and 59% of MIS-T patients met substantial clinical benefits. Satisfaction at 1 year, measured by a score of 1 or 2 on the North American Spine Society questionnaire, was 64% for MIS-F and 83% for MIS-T.

CONCLUSIONS

MIS-F and MIS-T are effective treatment options for spinal stenosis associated with low-grade DLS. Both techniques result in comparable patient-reported outcomes and satisfaction up to 2 years and have similar long-term reoperation rates. More evidence is required to delineate optimal selection characteristics for MIS-F versus MIS-T.

Association between history of lumbar spine surgery and paralumbar muscle health: a propensity score-matched analysis

BACKGROUND CONTEXT

Prior studies have suggested that muscle strength and quality may be associated with low back pain. Recently, a novel magnetic resonance imaging (MRI)-based lumbar muscle health grade was shown to correlate with health-related quality of life scores after spine surgery. However, the potential association between history of lumbar spine surgery and paralumbar muscle health requires further investigation.

PURPOSE

To compare MRI-based paralumbar muscle health parameters between patients with versus without a history of surgery for degenerative lumbar spinal disease.

STUDY DESIGN/SETTING

Retrospective cohort study.

PATIENT SAMPLE

Consecutive series of patients who presented to the spine surgery clinic of a single surgeon.

OUTCOME MEASURES

MRI-based measurements of paralumbar cross-sectional area (PL-CSA), Goutallier grade, lumbar indentation value (LIV).

METHODS

A retrospective analysis was performed on a consecutive series of patients of a single surgeon, and patients were included based on availability of lumbar MRI. Axial T2-weighted lumbar MRIs were analyzed for PL-CSA, Goutallier classification, and LIV. Measurements were performed at the center of disc spaces from L1 to L5. Patients with and without history of spine surgery were matched based on age, sex, race, ethnicity, and body mass index (BMI) via propensity score matching. Normality of each muscle health variable was assessed using Kolmogorov-Smirnov test. Mann-Whitney U test or independent t-test performed to compare the matched cohorts, as appropriate.

RESULTS

A total of 615 patients were assessed. For final analysis, 89 patients with a history of previous spine surgery were matched with 89 patients without a history of spine surgery. There were no statistically significant differences in age, sex, race, ethnicity, or BMI between the matched cohorts. History of spine surgery was generally associated with worse lumbar muscle health. At all 4 intervertebral levels between L1-L5, PL-CSA was significantly smaller among patients with history of spine surgery. At L4-L5, patients with prior spine surgery had significantly smaller PL-CSA/BMI. Patients with prior spine surgery were found to have greater fatty infiltration of the muscles, with higher average Goutallier grades at levels L1-L2, L2-L3, and L4-L5. In addition, history of spine surgery was associated with smaller LIV at L1-L2, L3-L4, and L4-L5.

CONCLUSIONS

The current study demonstrates that history of lumbar spine surgery is associated with worse paralumbar muscle health based on quantitative and qualitative measurements on MRI. On average, patients with history of spine surgery were found to have smaller cross-sectional areas of the paralumbar muscles, greater amounts of fatty infiltration based on Goutallier classification, and smaller lumbar indentation values.

Poor muscle health and low preoperative ODI are independent predictors for slower achievement of MCID after minimally invasive decompression

BACKGROUND CONTEXT

Although some previous studies have analyzed predictors of nonimprovement, most of these have focused on demographic and clinical variables and have not accounted for radiological predictors. In addition, while several studies have examined the degree of improvement after decompression, there is less data on the rate of improvement.

PURPOSE

To identify the risk factors and predictors (both radiological and nonradiological) for slower as well as nonachievement of minimal clinically important difference (MCID) after minimally invasive decompression.

DESIGN

Retrospective cohort.

PATIENT SAMPLE

Patients who underwent minimally invasive decompression for degenerative lumbar spine conditions and had a minimum of 1-year follow up were included. Patients with preoperative Oswestry Disability Index (ODI) <20 were excluded.

OUTCOME MEASURE

MCID achievement in ODI (cut off 12.8).

METHODS

Patients were stratified into two groups (achieved MCID, did not achieve MCID) at two timepoints (early ≤3 months, late ≥6 months). Nonradiological (age, gender, BMI, comorbidities, anxiety, depression, number of levels operated, preoperative ODI, preoperative back pain) and radiological (MRI - Schizas grading for stenosis, dural sac cross-sectional area, Pfirrmann grading for disc degeneration, psoas cross-sectional area and Goutallier grading, facet cyst/effusion; X-ray - spondylolisthesis, lumbar lordosis, spinopelvic parameters) variables were assessed with comparative analysis to identify risk factors and with multiple regression models to identify predictors for slower achievement of MCID (MCID not achieved by ≤3 months) and nonachievement of MCID (MCID not achieved at ≥6 months).

RESULTS

A total of 338 patients were included. At ≤3 months, patients who did not achieve MCID had significantly lower preoperative ODI (40.1 vs 48.1, p<0.001) and worse psoas Goutallier grading (p=.048). At ≥6 months, patients who did not achieve MCID had significantly lower preoperative ODI (38 vs 47.5, p<.001), higher age (68 vs 63 years, p=.007), worse average L1-S1 Pfirrmann grading (3.5 vs 3.2, p=.035), and higher rate of pre-existing spondylolisthesis at the operated level (p=.047). When these and other probable risk factors were put into a regression model, low preoperative ODI (p=.002) and poor Goutallier grading (p=.042) at the early timepoint and low preoperative ODI (p<.001) at the late timepoint came out as independent predictors for MCID nonachievement.

CONCLUSION

After minimally invasive decompression, low preoperative ODI and poor muscle health are risk factors and predictors for slower achievement of MCID. For nonachievement of MCID, low preoperative ODI, higher age, greater disc degeneration, and spondylolisthesis are risk factors and low preoperative ODI is the only independent predictor.

Pain improvement and reoperation rate after full-endoscopic decompression for lateral recess stenosis: a 10-year follow-up

PURPOSE

To share long-term clinical outcomes and our experience with full-endoscopic interlaminar decompression (FEI) for lateral recess stenosis (LRS).

METHODS

We included all patients who underwent FEI for LRS from 2009 to 2013. VAS for leg pain, ODI, neurological findings, radiographic findings, and complications were analyzed at one week, one month, three months, and one year postoperation. The telephone interview for local patients with simple questions was done approximately ten years after the operation. International patients receive an email with the same questionnaire as local patients during the same follow-up period.

RESULTS

One hundred and twenty-nine patients underwent FEI for LRS with complete data during 2009-2013. Most of the patients (70.54%) had LRS radiculopathy for less than one year, mainly L4-5 (89.92%), followed by L5-S1 (17.83%). Early outcomes three months after surgery showed that most patients (93.02%) reported significant pain relief, and 70.54% reported no pain at their ODI scores were significantly reduced from 34.35 to 20.32% (p = 0.0052). In contrast, the mean VAS for leg pain decreased substantially by 3.77 points (p < 0.0001). There were no severe complications. At ten years of follow-up, 62 patients responded to the phone call or email. 69.35% of the patients reported having little or no back or leg pain, did not receive any further lumbar surgery, and were still satisfied with the result of the surgery. There were six patients (8.06%) who underwent reoperation.

CONCLUSION

FEI for LRS was satisfactory at 93.02%, with a low complication rate during the early follow-up period. Its effect seems to decline slightly in the long term at a 10-year follow-up. 8.06% of the patients subsequently underwent reoperation.