The Effect of Preoperative Neuropathic Pain and Nociceptive Pain on Postoperative Pain Intensity in Patients with the Lumbar Degenerative Disease Following Lateral Lumbar Interbody Fusion

The Role of Cage Placement Angle in Optimizing Short-Term Clinical Outcomes in Lateral Lumbar Interbody Fusion

OBJECTIVE

The purpose is to investigate the impact of cage angle on clinical outcomes and indirect decompression efficacy in patients undergoing lateral lumbar interbody fusion (LLIF).

METHODS

A retrospective review was conducted on 87 patients with single-level lumbar degenerative disease who underwent LLIF. Patients were grouped based on the angle of cage placement: minimal (0°-5°), mild (>5° ≤ 15°), and severe (>15°). Clinical outcomes assessed included pain intensity, functional improvement, and complication rates. Magnetic resonance imaging evaluations included measurements of canal diameter and central canal area pre- and postoperatively. Patient-reported outcomes were also analyzed using the Japanese Orthopedic Association Back Pain Evaluation Questionnaire.

RESULTS

Clinical and radiographic outcomes were significantly improved across all cage angle groups. Reductions in low back pain, leg pain, and numbness were significant in all groups, with no significant differences. Magnetic resonance imaging evaluations revealed significant increases in canal diameter and central canal area postoperatively, confirming effective indirect decompression. Japanese Orthopedic Association Back Pain Evaluation Questionnaire scores showed significant improvements in all domains, including low back pain, lumbar function, walking ability, social life function, and mental health. However, the severe angle group had higher rates of delayed cage subsidence. Complications such as transient motor weakness, thigh pain, numbness, and the need for revision surgery were consistent across groups, with no significant differences.

CONCLUSIONS

LLIF effectively treats LDD patients, providing significant short-term clinical and radiographic improvements regardless of cage angle. However, oblique cage placement increases the risk of cage subsidence, requiring careful surgical planning and postoperative following.

Does Bone Density Affect Outcomes in Lateral Lumbar Interbody Fusion? A Propensity Score-Matched Analysis of Preoperative Hounsfield Units

Background: This study aimed to assess whether preoperative Hounsfield unit (HU) values differ in short-term clinical outcomes after lateral lumbar interbody fusion (LLIF) surgery. Methods: In a retrospective analysis, 109 patients undergoing LLIF for lumbar degenerative diseases (LDD) were reviewed. Preoperative Computed Tomography (CT) scans measured HU values at the L1-L4 vertebrae, dividing patients into low and high HU groups. After conducting a cluster analysis of preoperative Hounsfield unit (HU) values, patients were categorized into low and high HU groups using propensity score matching (PSM). The outcomes measured one-year post-surgery included pain intensity (Numeric Rating Scales for Low Back Pain (NRSLBP), Leg Pain (NRSLP), and Leg Numbness (NRSLN)) and quality of life (Japanese Orthopedic Association Back Pain Evaluation Questionnaire: JOABPEQ). Results: After PSM, there were 26 patients in each group. Significant improvements were noted in both low and high HU groups post-surgery, with the low HU group showing a decrease in NRSLBP from 6.2 to 3.7, NRSLP from 7.4 to 2.5, and NRSLN from 6.4 to 3.0. The high HU group exhibited similar improvements (NRSLBP: 6.5 to 3.6, NRSLP: 6.3 to 2.5, NRSLN: 6.2 to 2.4). JOABPEQ scores improved significantly in both groups across all domains, with no significant differences observed. Preoperative HU values have little correlation with the short-term outcomes of pain and quality of life in LLIF surgery. Conclusions: This study suggests reconsidering the role of HU values following indirect decompression via LLIF, particularly in evaluating pain and patient-reported outcome measures in patients with LDD.

Factors Associated with Early Postoperative Pain after Lateral Lumbar Interbody Fusion

Introduction

Despite that lateral lumbar interbody fusion (LLIF) is a minimally invasive surgery, some patients complain of severe site pain immediately after the surgery. This study aimed to explore the extent of perioperative pain after LLIF, compare the degree of perioperative pain after LLIF with that after other surgical procedures, and evaluate the factors associated with severe pain in the early postoperative period.

Methods

In this study, 93 patients who underwent lumbar spine surgeries for lumbar degenerative diseases were analyzed. The patients were categorized into three groups based on the surgical procedure: Group L, LLIF with percutaneous pedicle screw (PPS); Group P, posterolateral fusion (PLF) or posterior lumbar interbody fusion (PLIF); and Group D, posterior decompression (fenestration). The extent of low back pain was evaluated using the visual analog scale (VAS) preoperatively and from postoperative days 1 to 14.

Results

The VAS score for postoperative pain decreased in a time-dependent manner in all three groups (P<0.01). Repeated measures analysis of variance (ANOVA) showed that the VAS in Group L was significantly higher than that in Group D (P<0.01). Time point analysis revealed that the VAS scores from postoperative days 1 to 9 in Group L were significantly higher than those in Group D (P<0.05). No significant difference was observed in the VAS scores of postoperative pain between Groups L and P on all postoperative days. The VAS score for early postoperative pain in Group L was significantly correlated with the change in disc height index (P<0.05, r=0.43) and tended to be associated with the grade of preoperative disc degeneration and the VAS score of preoperative low back pain (P=0.076-0.19).

Conclusions

This study is the first to evaluate the factors associated with pain during the early postoperative period of LLIF. Although LLIF is a minimally invasive surgery, severe pain may develop in patients with significant preoperative disc degeneration or following spinal correction surgery.

Impact of Osteoporosis on Short-Term Surgical Outcomes in Lumbar Degenerative Disease Patients Undergoing Lateral Lumbar Interbody Fusion: A Retrospective Analysis

OBJECTIVE

This retrospective study assesses the influence of osteoporosis on the short-term clinical outcomes of lateral lumbar interbody fusion (LLIF) surgery in patients with lumbar degenerative diseases (LDDs), focusing on complications, pain intensity, and quality of life (QOL) improvements. The primary aim of this study is to investigate the impact of osteoporosis on the short-term clinical outcomes following LLIF surgery in LDD patients, with a particular focus on the incidence of cage subsidence (CS) and overall patient well-being postoperatively.

METHODS

A retrospective review was conducted on 73 patients who underwent LLIF for LDD. Patients were categorized into 2 groups based on osteoporosis status determined by dual-energy X-ray absorptiometry scans: those with osteoporosis (n = 20) and those without osteoporosis (n = 53). Data collection included demographics, surgical details, complications, magnetic resonance imaging analysis, pain intensity, and QOL (Japanese Orthopaedic Association Back Pain Evaluation Questionnaire).

RESULTS

The groups had no significant differences regarding operative time, estimated blood loss, and hospital stay duration. However, the incidence of CS was 40% in patients with osteoporosis, compared to 17% in nonosteoporotic patients. Despite this, significant improvements in spinal canal dimensions were observed in both groups. Both groups experienced significant reductions in pain intensity, with notable improvements in functional outcomes assessed by the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire, indicating the overall effectiveness of LLIF in enhancing patient well-being and functionality, irrespective of osteoporosis status.

CONCLUSIONS

Osteoporosis increases the risk of CS in LLIF surgery for LDD patients but does not affect short-term pain relief and QOL improvements.

Short-Term Comparison Between Unilateral Versus Bilateral Percutaneous Pedicle Screw Fixation in Short-Level Lateral Lumbar Interbody Fusion-A Prospective Randomized Study

STUDY DESIGN

Prospective randomized controlled trial.

OBJECTIVES

No prospective studies have directly compared clinical and radiographic outcomes of unilateral vs bilateral instrumented lateral lumbar interbody fusion (LLIF) for lumbar degenerative disease (LDD). We compared the short-term radiographic, clinical outcomes, and some complications of the unilateral percutaneous pedicle screw (PPS) (UPS) vs bilateral PPS (BPS) fixation in short-level spinal fusion with LLIF for LDD.

METHODS

This was a prospective randomized controlled study of 33 patients who underwent UPS or BPS fixation after LLIF for LDD; 18 patients were assigned to the UPS group and 15 patients to the BPS group. Clinical outcomes, complication rates, and fusion rates were assessed.

RESULTS

The two groups were similar in age, sex, preoperative diagnosis, and level of surgery. Blood loss, length of hospital stay, and numeric rating scale score one year after surgery did not differ between groups. The operative time was longer in the BPS than UPS group (120.2 vs 88.8 min, respectively; P = .029). Both groups showed improvement in disc height and dural sac in the immediate postoperative computed tomography and magnetic resonance imaging, which did not differ significantly between groups. The subsidence grade and fusion rate did not differ, but cage subsidence was more severe in the UPS than BPS group.

CONCLUSION

Unilateral and bilateral PPS fixation after LLIF yielded similar short-term clinical and radiological outcomes. However, severe cage subsidence was more common in the UPS group, which suggests that BPS fixation after LLIF may be a better choice over the long term.

Quantifying Satisfaction of Degenerative Lumbar Spinal Stenosis Patients in Post-lateral Lumbar Interbody Fusion Surgery: Establishing Critical JOABPEQ Cutoff Scores

OBJECTIVE

This retrospective study aimed to determine the Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ) cutoff scores for assessing patient satisfaction postlateral lumbar interbody fusion (LLIF) in degenerative lumbar spinal stenosis (DLSS) patients.

METHODS

Analyzing 136 DLSS patients (83 males, 53 females), the study evaluated demographics, pain (Numeric Rating Scale), and JOABPEQ outcomes (low back pain, lumbar function, walking ability, social life, mental health). Patient satisfaction was surveyed, and based on their responses, patients were categorized into "Beneficial" and "Nonbeneficial" groups. Statistical analysis encompassed the Kolmogorov-Smirnov test, t-tests, Mann-Whitney U test, and Receiver Operating Characteristic (ROC) curve analysis for JOABPEQ cutoff determination.

RESULTS

Postoperative improvements in JOABPEQ scores, especially in walking ability, social life function, and mental health, were significant. Pain intensity, assessed using the Numeric Rating Scale, also showed notable reductions. The Δ walking ability cutoff was set at 25.00, indicating substantial mobility improvement. This domain's area under the curve (AUC) was 0.815 (95% CI: 0.726-0.903), demonstrating high effectiveness in assessing patient satisfaction postsurgery. The study also found no significant differences in complication rates between groups for conditions like transient motor weakness, thigh pain/numbness, and revision surgery.

CONCLUSIONS

This study underscores the value of patient-centered outcomes in evaluating LLIF surgery success for DLSS. The identified JOABPEQ cutoff values provide a quantitative tool for assessing patient satisfaction, emphasizing the necessity of comprehensive postoperative evaluations beyond traditional clinical metrics for improved patient care and life quality.

Preoperative motor weakness and the impact on patient reported outcomes in lateral lumbar interbody fusion

This study measures the impact of preoperative motor weakness (MW) on Patient-Reported Outcome Measures (PROMs) in lateral lumbar interbody fusion (LLIF) patients. Retrospectively-sourced data from a prospectively-maintained, single-surgeon database created two cohorts of LLIF patients: patients with/without documented MW. Demographics/perioperative characteristics/PROMs were collected preoperatively and at six-weeks/final follow-up (FF). Studied outcomes were Patient-Reported Outcomes Measurement Information System Physical Function (PROMIS-PF), 12-Item Short Form (SF-12) Physical/Mental Component Score (PCS/MCS), Patient Health Questionnaire (PHQ-9), Visual Analog Scale Back/Leg Pain (VAS-BP/LP), and Oswestry Disability Index (ODI). Multivariable linear/logistic regression calculated/compared intercohort minimum clinically important difference (MCID). Mean postoperative follow-up time was 11.5 ± 7.52 months. In total, 214 LLIF patients from December 2010 to May 2023 were included, with 149 having documented MW. In Table 1, self-reported gender was significant between cohorts (p < 0.025). Other significant demographic characteristics were smoker status (p < 0.002), diabetes (p < 0.016), and CCI score (p < 0.011). Table 2 shows notably significant perioperative characteristics: spinal pathology (degenerative spondylolisthesis/foraminal stenosis/herniated nucleus pulposus) (p < 0.005, all), estimated blood loss/length of stay/postoperative day (POD)-zero narcotic consumption (p < 0.001, all). Table 3 outcomes/MCID achievement percentages demonstrated insignificant intercohort differences besides a weakly significant FF ODI score (p < 0.036). MW, a frequently reported symptom in spine surgery, is poorly studied in LLIF patients. Thus, this study evaluates MW impact on PROMs and notes no significant differences. However, one exception regarding FF disability scores was recorded. MW did not affect MCID achievement for our patient population. Therefore, the preliminary findings suggest preoperative MW imparts minimal influence on PROMs/MCID in LLIF patients.

Evaluating the Efficacy of IL-6 as Predictors of Lateral Lumbar Interbody Fusion Success: Insights From Pain Scores and JOABPEQ Assessments

STUDY DESIGN

A prospective study.

OBJECTIVES

This study aims to explore the correlation between interleukin (IL)- 6 levels in intervertebral disc (IVD) tissue and clinical outcomes in patients undergoing lumbar surgery for lumbar degenerative disease (LDD).

METHODS

This prospective study analyzed 32 patients (22 men and 10 women, average age 69.6 years) who underwent lateral lumbar interbody fusion (LLIF). IL-6 gene expression in IVD tissues collected during surgery was measured and correlated with pre- and postoperative clinical outcomes, including pain intensity assessed via Numeric Rating Scales (NRS) and quality of life (QOL) evaluated through the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ).

RESULTS

IL-6 levels showed statistical correlations with postoperative intensity of low back pain (LBP) and several JOABPEQ domains. Patients with higher expression of IL-6 levels experienced more severe postoperative LBP and lower scores in lumbar function, walking ability, social life function, and mental health. The effectiveness rate of JOABPEQ scores was exceptionally high for low back pain (.548), walking ability (.677), and social functioning (.563), demonstrating the effectiveness of LLIF. The average operation time was 105.6 minutes, and the estimated blood loss was 85.6 mL.

CONCLUSIONS

The study underscores IL-6 as a potential biomarker for predicting surgical outcomes in LDD. High IL-6 levels correlate with worse postoperative LBP and lower QOL scores. Integrating molecular markers like IL-6 with patient-reported outcomes could provide a more comprehensive approach to postoperative care in spinal disorders, aiming to improve the overall QOL for LDD patients undergoing LLIF surgery.

Hounsfield Unit Values as an Adjunct Diagnostic Tool: Investigating Its Relationship with Bone Mineral Density and Vertebral Bone Quality in Lumbar Degenerative Disease Patients

OBJECTIVE

With an increasing prevalence of osteoporosis due to demographic shifts, accurate diagnostic methods are vital, particularly before spinal surgeries. This research investigated the correlation between bone mineral density T-scores of the lumbar spine and femoral neck, Hounsfield Unit (HU) values from computed tomography (CT), and vertebral bone quality (VBQ) scores from Magnetic Resonance Imaging (MRI) in patients with lumbar degenerative disease.

METHODS

We analyzed data from 100 patients with lumbar degenerative disease who underwent CT, dual-energy X-ray absorptiometry (DXA), and MRI between 2019 and 2023. HU values were measured individually from L1 to L4, while T-scores were obtained from DXA scans of the lumbar spine and the femoral neck. The VBQ scores were derived from T1-weighted MRIs.

RESULTS

A notable association between the lumbar and femoral neck T-scores and HU values was found. The VBQ score had a faint correlation with HU values and lacked any with the T-score. Notably, the HU values derived via the Youden index and regression closely matched. Lumbar spine HU values related to T-scores of 85.6 and 84.4 and femoral neck T-scores of 98.9 and 103.6, with a low T-score at 98.9 and 104.6.

CONCLUSIONS

This study underscores a strong correlation between bone mineral density and HU values from CT scans in lumbar degenerative disease patients, suggesting the utility of HU measurements as an adjunct diagnostic tool for osteoporosis. However, the correlation with the VBQ score remains weak. Further multicenter studies are essential for more robust validation.

Comprehensive Assessment of Indirect Decompression Through Lateral Lumbar Interbody Fusion for Degenerative Lumbar Spinal Stenosis: A Japanese Orthopedic Association Back Pain Evaluation Questionnaire-Based Analysis

STUDY DESIGN

A retrospective study.

OBJECTIVE

This study aimed to comprehensively evaluate the clinical outcomes of lateral lumbar interbody fusion (LLIF) as an indirect decompression technique for degenerative spondylolisthesis (DS) and concomitant degenerative lumbar spinal stenosis (DLSS) patients. We utilized the Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ) to assess treatment success and its impact on patient's quality of life (QOL).

METHODS

We included 124 patients who underwent LLIF. Pre- and postoperative JOABPEQ evaluations indicated treatment success. Subgroup analysis categorized patients' perceptions of surgery as beneficial or non-beneficial.

RESULTS

89% of patients (110/124) reported satisfaction with LLIF. Lateral lumbar interbody fusion achieved successful indirect decompression, increasing canal diameter and central canal area. Significant improvements occurred across all JOABPEQ domains, notably for low back pain, lumbar function, walking ability, social life function, and mental health. Patients who perceived the surgery as beneficial experienced fewer postoperative complications, lower numeric rating scale scores for pain relief, and greater functional outcome improvements compared to non-beneficial patients.

CONCLUSIONS

Our findings highlight the utility of JOABPEQ as a valuable and sensitive tool for assessing treatment effectiveness and patient-reported outcomes in DS and concomitant DLSS patients. Patients undergoing LLIF. The results affirm the favorable outcomes of LLIF as a surgical option for DLSS patients and emphasize the importance of considering patient perspectives when evaluating overall treatment success. The study provides valuable insights into the impact of indirect decompression on patients' QOL, supporting the effectiveness of LLIF as a minimally invasive technique for DLSS and DS management.

The Analysis of Preoperative Roussouly Classification on Pain Scores and Radiological Data in Lateral Lumbar Interbody Fusion for Patients with Lumbar Degenerative Disease

STUDY DESIGN

A retrospective observational study.

OBJECTIVE

The type of sagittal profile defined by Roussouly has affected spinal degeneration and surgical outcome. This study aimed to investigate the effect of preoperative Roussouly classification on pain intensity and radiological data of patients with lumbar degenerative disease who underwent indirect decompression with lateral lumbar interbody fusion (LLIF).

METHODS

We retrospectively investigated 102 patients who underwent LLIF without direct decompression. Patients were subdivided into 4 groups according to the Roussouly classification determined from preoperative full-length and lateral spine X-rays, and classified according to Roussouly types I, II, and IV in the nonstandard group and Roussouly type III in the standard group.

RESULTS

The nonstandard group showed improved sagittal vertical axis and lumbar lordosis after LLIF surgery, but the midsagittal canal diameter and axial central canal area of the thecal sac using T2-weighted sagittal and axial magnetic resonance imaging were smaller than those in the standard group. On the other hand, each numeric rating scale score 1 year after surgery improved in all patients. Changes in numeric rating scale scores in low back pain, leg pain, and numbness were not statistically significant between Roussouly classification types.

CONCLUSIONS

These results suggest that the nonstandard group may have less indirect decompression effect from LLIF than the standard group. In the short term, we show for the first time after LLIF surgery that preoperative sagittal spinal alignment and the pelvic position may not significantly impact pain improvement.

Analysis of intervertebral disc CCR6 and IL-6 gene levels with short-term postoperative low back pain after spinal fusion in lumbar degenerative disease

Background

Previous studies have reported that specific pro-inflammatory cytokines or chemokines are more highly expressed in painful than in nonpainful intervertebral discs (IVDs). However, few studies have investigated their correlation with postsurgical outcomes or the relationship between postoperative pain and inflammatory cytokines in IVDs. Thus, the present study examined the correlation among the gene expression levels of pro-inflammatory cytokines and chemokines in IVD tissues removed during surgery and low back pain (LBP), leg pain (LP), and leg numbness (LN) at one year after spinal fusion surgery in patients with a lumbar degenerative disease (LDD).

Methods

Chemokine and cytokine gene expression levels were measured in IVD samples from 48 patients with LDD. The associations between chemokine and cytokine gene expression levels and pain intensity (numeric rating scale [NRS]) were also analyzed. A correlation analysis was performed between gene expression in each IVD and preoperative and postoperative pain intensity.

Results

In the preoperative analysis, CCR6 was associated with NRSLBP (r = -0.291, P = 0.045). Postoperative pain analysis revealed correlations between postoperative NRSLBP and CCR6 (r = -0.328, P = 0.023) and between postoperative NRSLBP and IL-6 (r = -0.382, P = 0.007). Furthermore, patients with high postoperative LBP intensity (NRSLBP ≥ 7) also had high LBP intensity (NRSLBP ≥ 6) before surgery, and a correlation was observed (r = 0.418, P = 0.003). None of the gene mRNAs correlated with NRSLP or NRSLN, respectively.

Conclusions

CCR6 and IL-6 gene expression in the IVD was associated with postoperative LBP intensity and may indicate a need for postoperative pain management.

Treatment of Lumbar Degenerative Disease by Lateral Lumbar Interbody Fusion in Patients Under and Over 80 Years of Age

OBJECTIVES

The purpose of this study was to compare clinical and radiological results of lateral lumbar interbody fusion (LLIF) for lumbar degenerative disease in patients under the age of 80 years with those over the age of 80 years.

METHODS

One hundred two patients who underwent LLIF without direct decompression were enrolled, including 92 patients who were less than 80 years (group A) and 10 over 80 years (group B). All patients were evaluated using numerical evaluation scale scores for low back pain, leg pain, and leg numbness, as well as demographic data, surgical data, and imaging data before and after LLIF surgery.

RESULTS

Patients over the age of 80 years were found to have longer hospital stays (P = 0.006) and more postoperative muscle weakness (P = 0.011) and endplate injuries (P = 0.038). In addition, each numerical evaluation scale score improved significantly from preoperative to postoperative (P < 0.001). However, the changes in scores between preoperative and postoperative for each numerical evaluation scale were not significantly different between the 2 groups. Statistically significant increases in lumbar lordosis preoperatively compared with postoperatively were observed in patients under 80 years but did not change in those over 80 years.

CONCLUSIONS

These data suggest a need for awareness of intraoperative endplate injury and postoperative motor weakness. Critically, indirect decompression with LLIF in lumbar degenerative disease in patients over age 80 as well as those under age 80 has shown satisfactory clinical and radiological results. This study shows that age alone should not prevent older people from undergoing LLIF.