Risk Factors and Surgical Management of Recurrent Herniation after Full-Endoscopic Lumbar Discectomy Using Interlaminar Approach

Polyphenol-modified biomimetic bioadhesives for the therapy of annulus fibrosus defect and nucleus pulposus degeneration after discectomy

Discectomy is the surgical standard of care to relieve low back pain caused by intervertebral disc (IVD) herniation. However, there remains annulus fibrosus (AF) defect and nucleus pulposus (NP) degeneration, which often result in recurrent herniation (re-herniation). Herein, we develop a polyphenol-modified waterborne polyurethane bioadhesives (PPU-glues) to promote therapy prognosis after discectomy. Being composed of tannic acid (TA) mixed cationic waterborne polyurethane nanodispersions (TA/WPU+) and curcumin (Cur) embedded anionic waterborne polyurethane nanodispersions (Cur-WPU-), PPU-glue gels rapidly (<10 s) and exhibits low swelling ratios, tunable degradation rates and good biocompatibility. Due to the application of an adhesion strategy combing English ivy mechanism and particle packing theory, PPU-glue also shows considerable lap shear strength against wet porcine skin (≈58 kPa) and burst pressure (≈26 kPa). The mismatched particle sizes and the opposite charges of TA/WPU+ and Cur-WPU- in PPU-glue bring electrostatic interaction and enhance particle packing density. PPU-glue possesses superior reactive oxygen species (ROS)-scavenging capacity derived from polyphenols. PPU-glue can regulate extracellular matrix (ECM) metabolism in degenerated NP cells, and it can promote therapy biologically and mechanically in degenerated rat caudal discs. In summary, this study highlights the therapeutic approach that combines AF seal and NP augmentation, and PPU-glue holds great application potentials for post discectomy therapy. STATEMENT OF SIGNIFICANCE: Currently, there is no established method for the therapy of annulus fibrosus (AF) defect and nucleus pulposus (NP) degeneration after discectomy. Herein, we developed a polyphenol-modified biomimetic polyurethane bioadhesives (PPU-glue) with strong adhesive strength and superior bioactive property. The adhesion strategy that combined a particle packing theory and an English ivy mechanism was firstly applied to the intervertebral disc repair field, which benefited AF seal. The modified method of incorporating polyphenols was utilized to confer with ROS-scavenging capacity, ECM metabolism regulation ability and anti-inflammatory property, which promoted NP augmentation. Thus, PPU-glue attained the synergy effect for post discectomy therapy, and the design principle could be universally expanded to the bioadhesives for other surgical uses.

A three-stage concept of spine pathology treatment - a different perspective

Spinal pathologies develop in patients of all ages and may have various underlying factors. These factors include, among others, myofascial pain syndromes, disc herniation and spinal degeneration. Treatment alone, both causal and symptomatic, is not always sufficient in certain situations. The aim of this paper is to discuss the question of comprehensive treatment of spine pathologies focusing on a three-stage treatment concept. An important aspect is to determine the risk factors and their reduction, or at least modification, i.e. the first stage of the discussed treatment concept. Then, medical treatment aimed at a specific pathology, including both conservative and surgical methods, allows the cause of the pathology to be removed, i.e. the second stage of the discussed concept. And finally, timely and specialized, broadly understood rehabilitation allowing to maintain the effect of medical therapy. The implemented rehabilitation can be considered as the third stage of the discussed treatment concept.

Stability simulation analysis of targeted puncture in L4/5 intervertebral space for PELD surgery

Introduction: The application prospects of percutaneous endoscopic lumbar discectomy (PELD) as a minimally invasive spinal surgery method in the treatment of lumbar disc herniation are extensive. This study aims to find the optimal entry angle for the trephine at the L4/5 intervertebral space, which causes less lumbar damage and has greater postoperative stability. To achieve this, we conduct a three-dimensional simulated analysis of the degree of damage caused by targeted puncture-based trephine osteotomy on the lumbar spine. Methods: We gathered clinical CT data from patients to construct a lumbar model. This model was used to simulate and analyze the variations in trephine osteotomy volume resulting from targeted punctures at the L4/5 interspace. Furthermore, according to these variations in osteotomy volume, we created Finite Element Analysis (FEA) models specifically for the trephine osteotomy procedure. We then applied mechanical loads to conduct range of motion and von Mises stress analyses on the lumbar motion unit. Results: In percutaneous endoscopic interlaminar discectomy, the smallest osteotomy volume occurred with a 20° entry angle, close to the base of the spinous process. The volume increased at 30° and reached its largest at 40°. In percutaneous transforaminal endoscopic discectomy, the largest osteotomy volume was observed with a 50° entry angle, passing through the facet joints, with smaller volumes at 60° and the smallest at 70°. In FEA, M6 exhibited the most notable biomechanical decline, particularly during posterior extension and right rotation. M2 and M3 showed significant differences primarily in rotation, whereas the differences between M3 and M4 were most evident in posterior extension and right rotation. M5 displayed their highest stress levels primarily in posterior extension, with significant variations observed in right rotation alongside M4. Conclusion: The appropriate selection of entry sites can reduce lumbar damage and increase stability. We suggest employing targeted punctures at a 30° angle for PEID and at a 60° angle for PTED at the L4/5 intervertebral space. Additionally, reducing the degree of facet joint damage is crucial to enhance postoperative stability in lumbar vertebral motion units.

Analysis of risk factors for post-operative recurrence after percutaneous endoscopic lumbar discectomy in patients with lumbar disc herniation: a meta-analysis

BACKGROUND

This study aimed to systematically evaluate risk factors for post-operative recurrence after percutaneous endoscopic lumbar discectomy (PELD) in patients with lumbar disc herniation (LDH).

METHODS

The eligible studies were retrieved from PubMed, Embase, and Web of Science databases. Quality assessment was performed. The effects of binary variables (sex, Modic change (MC), type 2 diabetes (T2DM), and smoking) on post-operative recurrence were evaluated as odds ratio (OR) and 95% confidence interval (CI). The effects of continuous variables (sagittal range of motion (SROM), body mass index (BMI), and age) were assessed as weighted mean difference (WMD) and 95% CI. Sensitivity analysis and publication bias were conducted to evaluate the reliability of pooled results.

RESULTS

Eight studies were included, and their methodological quality was medium. MC (OR (95% CI) = 3.88 (2.24-6.74), P < 0.001), smoking (OR (95% CI) = 1.87 (1.45, 2.42), P < 0.001), T2DM (OR (95% CI) = 1.61 (1.12, 2.31), P = 0.010), SROM (WMD (95% CI) = 2.33 (0.95, 3.70), P = 0.001), BMI (WMD (95% CI) = 1.68 (1.37, 1.99) kg/m2, P < 0.001), and age (WMD (95% CI) = 9.95 (5.05, 14.86) years, P < 0.001) were significantly related to post-operative recurrence in patients with LDH after PELD. Significant publication bias was not observed among studies in all outcome indicators.

CONCLUSION

Our findings reveal that high levels of age, BMI, and SROM, history of T2DM or smoking, or more MC may be correlated with post-operative recurrence after PELD.

Study of the Distribution of Lumbar Modic Changes in Patients with Low Back Pain and Correlation with Lumbar Degeneration Diseases

Purpose

To study the distribution of lumbar Modic changes (MC) in low back pain patients, and to explore the relationship between Modic changes and age, gender, segment and lumbar degeneration diseases (disc degeneration, spinal stenosis, lumbar spondylolisthesis).

Patients and Methods

Modic changes were counted and analysed in 500 randomly selected patients who visited the outpatient clinic for lumbar spine MRI for low back pain from 2019 to 2022. The relationship between Modic changes and bulging disc, protrusion, extrusion, sequestration, Schmorl's node, spinal stenosis, and lumbar spondylolisthesis was studied. Data correlations were compared using the chi-square test, P<0.05 was considered a statistically significant difference.

Results

Modic changes were present in 184 segments. 58 were type I, 119 were type II, and 7 were type III. The number of Modic changes segments in L1-2, L2-3, L3-4, L4-5, and L5-S1 was 10, 22, 22, 58, and 72, respectively. Modic changes by gender occurred in 44 males and 82 females, and by age grouping were 0 cases in 10-19 years, 3 cases in 20-29 years, 6 cases in 30-39 years, 41 cases in 40-49 years, 64 cases in 50-59 years, 38 cases in 60-69 years, 15 cases in 70-79 years, and 5 cases in 80-89 years, respectively. Modic changes occurred in 56 with bulging disc, 45 with Protrusion, 57 with Extrusion and Sequestration, 32 with Schmorl's node, 32 with spondylolisthesis, and 56 with stenosis. Modic changes correlated with all of the above factors except bulging disc, and all differences were statistically significant (P<0.05).

Conclusion

The most common type of Modic changes is type II; Modic changes have correlation with age, gender, segment, lumbar disc herniation, lumbar spondylolisthesis, and lumbar spinal stenosis, and are a very important factor in low back pain.

How to spot the recurring lumbar disc? Risk factors for recurrent lumbar disc herniation (rLDH) in adult patients with lumbar disc prolapse: a systematic review and meta-analysis

Despite a fast-growing evidence-base examining the relationship of certain clinical and radiological factors such as smoking, BMI and herniation-type with rLDH, there remains much debate around which factors are clinically important. We conducted a systematic review and meta-analysis to identify risk factors for recurrent lumbar disc herniation (rLDH) in adults after primary discectomy. A systematic literature search was carried out using Ovid-Medline, EMBASE, Cochrane library and Web of Science databases from inception to 23rd June-2022. Observational studies of adult patients with radiologically-confirmed rLDH after ≥3 months of the initial surgery were included, and their quality assessed using the Quality-In-Prognostic-Studies (QUIPS) appraisal tool. Meta-analyses of univariate and multivariate data and a sensitivity-analysis for rLDH post-microdiscectomy were performed. Twelve studies (n=4497, mean age:47.3; 34.5% female) were included, and 11 studies (n=4235) meta-analysed. The mean follow-up was 38.4 months. Mean recurrence rate was 13.1% and mean time-to-recurrence was 24.1 months (range: 6-90 months). Clinically, older age (OR:1.04, 95%CI:1.00-1.08, n=1014), diabetes mellitus (OR:3.82, 95%CI:1.58-9.26, n=2330) and smoking (OR:1.80, 95%CI:1.03- 3.14, n=3425) increased likelihood of recurrence. Radiologically, Modic-change type-2 (OR:7.93, 95%CI:5.70-11.05, n=1706) and disc extrusion (OR:12.23, 95%CI:8.60-17.38, n=1706) increased likelihood of recurrence. The evidence did not support an association between rLDH and sex; BMI; occupational labour/driving; alcohol-consumption; Pfirmann- grade, or herniation-level. Older patients, smokers, patients with diabetes, those with type-2 Modic-changes or disc extrusion are more likely to experience rLDH. Higher quality studies with robust adjustment of confounders are required to determine the clinical bearing of all other potential risk factors for rLDH.

Risk factors for lumbar disc herniation recurrence after percutaneous endoscopic lumbar discectomy: a meta-analysis of 58 cohort studies

Recurrent lumbar disc herniation (rLDH) is one of the most serious complications and major causes of surgical failure and paralysis following percutaneous endoscopic lumbar discectomy (PELD). There are reports in the literature on the identification of risk factors associated with rLDH; however, the results are controversial. Therefore, we conducted a meta-analysis to identify risk factors for rLDH among patients following spinal surgery. PubMed, EMBASE, and the Cochrane Library were searched without language restrictions from inception to April 2018 for studies reporting risk factors for LDH recurrence after PELD. MOOSE guidelines were followed in this meta-analysis. We used a random effects model to aggregate odds ratios (ORs) with 95% confidence intervals (CIs). The evidence of observational studies was classified into high quality (class I), medium quality (class II/III), and low quality (class IV) based on the P value of the total sample size and heterogeneity between studies. Fifty-eight studies were identified with a mean follow-up of 38.8 months. Studies with high-quality (class I) evidence showed that postoperative LDH recurrence after PELD was significantly correlated with diabetes (OR, 1.64; 95% CI, 1.14 to 2.31), the protrusion type LDH (OR, 1.62; 95% CI, 1.02 to 2.61), and less experienced surgeons (OR, 1.54; 95% CI, 1.10 to 2.16). Studies with medium-quality (class II or III) evidence showed that postoperative LDH recurrence was significantly correlated with advanced age (OR, 1.11; 95% CI, 1.05 to 1.19), Modic changes (OR, 2.23; 95% CI, 1.53 to 2.29), smoking (OR, 1.31; 95% CI, 1.00 to 1.71), no college education (OR, 1.56; 95% CI, 1.05 to 2.31), obesity (BMI ≥ 25 kg/m²) (OR, 1.66; 95% CI, 1.11 to 2.47), and inappropriate manual labor (OR, 2.18; 95% CI, 1.33 to 3.59). Based on the current literature, eight patient-related and one surgery-related risk factor are predictors of postoperative LDH recurrence after PELD. These findings may help clinicians raise awareness of early intervention for patients at high risk of LDH recurrence after PELD.

Moderate to Severe Multifidus Fatty Atrophy is the Risk Factor for Recurrence After Microdiscectomy of Lumbar Disc Herniation

OBJECTIVE

We attempted to investigate the potential risk factors of recurrent lumbar disc herniation (rLDH) after tubular microdiscectomy.

METHODS

We retrospectively analyzed the data of patients who underwent tubular microdiscectomy. The clinical and radiological factors were compared between the patients with and without rLDH.

RESULTS

This study included 350 patients with lumbar disc herniation (LDH) who underwent tubular microdiscectomy. The overall recurrence rate was 5.7% (20 of 350). The visual analogue scale (VAS) score and Oswestry Disability Index (ODI) at the final follow-up significantly improved compared with those preoperatively. There was no significant difference in the preoperative VAS score and ODI between the rLDH and non-rLDH groups, while the leg pain VAS score and ODI of the rLDH group were significantly higher than those of the non-rLDH group at final follow-up. This suggested that rLDH patients had a worse prognosis than non-rLDH patients even after reoperation. There were no significant differences in sex, age, body mass index, diabetes, current smoking and drinking, disc height index, sagittal range of motion, facet orientation, facet tropism, Pfirrmann grade, Modic changes, interdisc kyphosis, and large LDH between the 2 groups. Univariate logistic regression analysis revealed that rLDH was associated with hypertension, multilevel microdiscectomy, and moderate-severe multifidus fatty atrophy (MFA). A multivariate logistic regression analysis indicated that MFA was the sole and strongest risk factor for rLDH after tubular microdiscectomy.

CONCLUSION

Moderate-severe MFA was a risk factor for rLDH after tubular microdiscectomy, which can serve as an important reference for surgeons in formulating surgical strategies and the assessment of prognosis.

A 9-year retrospective cohort of patients with lumbar disc herniation: Comparison of patient characteristics and recurrence frequency by smoking status

To evaluate the association between smoking status and patient characteristics and to identify risk factors associated with recurrence in patients who underwent surgery for lumbar disc herniation (LDH). This retrospective study was carried out at Lokman Hekim University, Ankara, Turkey between January 1, 2021 and January 1, 2022. The medical data of patients who underwent microsurgical discectomy for LDH were retrospectively recorded. Patients with any reemergence of LDH within a 6-month period after surgery were defined as having recurrent LDH. A total of 1109 patients were included in the study and mean age was 50.7 ± 14.3 years. The frequency of hernia at L2-L3 and L3-L4 levels was higher in the nonsmoker group (P < .001). The frequency of cases with Pfirrmann Grade 4 degeneration was higher in the nonsmoker group than in smokers and ex-smokers (P < .001). Protrusion-type hernias were more common in nonsmokers (P = .014), whereas paracentral hernias were more common in smokers (P < .001). The overall frequency of recurrence was 20.4%, and was higher in smokers than in non-smokers and ex-smokers (P < .001). Multivariable logistic regression revealed that current smoking (OR: 2.778, 95% CI [confidence interval]: 1.939-3.980, P < .001), presence of Pfirrmann Grade 4&5 disc degeneration (OR: 4.217, 95% CI: 2.966-5.996, P < .001), and paracentral herniation (OR: 5.040, 95% CI: 2.266-11,207, P < .001) were associated with higher risk of recurrence, whereas presence of sequestrated disc was associated with lower risk of recurrence (OR: 2.262, 95% CI:0.272-0.717, P = .001). Taken together, our data show that smoking, increased degree of degeneration and paracentral hernia increase the risk of LDH recurrence, while sequestrated disc appears to decrease risk. Taking steps to combat smoking in individuals followed for LDH may reduce the risk of recurrence in LDH patients.