Systematic Review and Critical Appraisal of Cauda Equina Syndrome Management During Pregnancy.

Cauda equina during pregnancy represents a rare entity, with data regarding optimal treatment being very scarce in the pertinent literature. Given the scarcity of current evidence on the topic, this study conducts a systematic review and analysis of existing literature concerning cauda equina syndrome (CES) management in pregnant women. A comprehensive search was performed across multiple databases, yielding 26 level IV peer-reviewed articles that met the inclusion criteria. These studies collectively encompassed 30 pregnant patients with CES, with a mean age of 31.2 years and an average gestational age of 26 weeks. Disc herniation emerged as the primary cause in 73% of cases. Regarding surgical interventions, the prone position was utilised in 70% of cases, with 73% receiving general anaesthesia. Notably, third-trimester spinal surgeries exhibited a higher complete recovery rate compared to earlier trimesters. Minimally invasive spinal surgery demonstrated superior outcomes in terms of complete recovery and reduced risk of persistent post-operative symptoms when compared to open approaches. Moreover, patients undergoing caesarean section (CS) after spinal surgery reported higher rates of symptom resolution and lower symptom persistence compared to those with CS before spinal surgery or vaginal delivery post-spinal surgery. Despite these study's findings, the overall evidence base remains limited, precluding definitive conclusions. Consequently, the study underscores the importance of multidisciplinary team discussions to formulate optimal treatment strategies for pregnant individuals presenting with CES. This highlights a critical need for further research to expand the knowledge base and improve the guidance available for managing CES in pregnant populations.

Lumbar disc herniation with radiculopathy: a comparison of NASS guidelines and ChatGPT.

Background: ChatGPT is an advanced language AI able to generate responses to clinical questions regarding lumbar disc herniation with radiculopathy. Artificial intelligence (AI) tools are increasingly being considered to assist clinicians in decision-making. This study compared ChatGPT-3.5 and ChatGPT-4.0 responses to established NASS clinical guidelines and evaluated concordance. Methods: ChatGPT-3.5 and ChatGPT-4.0 were prompted with fifteen questions from The 2012 NASS Clinical Guidelines for the diagnosis and treatment of lumbar disc herniation with radiculopathy. Clinical questions organized into categories were directly entered as unmodified queries into ChatGPT. Language output was assessed by two independent authors on September 26, 2023 based on operationally-defined parameters of accuracy, over-conclusiveness, supplementary, and incompleteness. ChatGPT-3.5 and ChatGPT-4.0 performance was compared via chi-square analyses. Results: Among the fifteen responses produced by ChatGPT-3.5, 7 (47%) were accurate, 7 (47%) were over-conclusive, fifteen (100%) were supplementary, and 6 (40%) were incomplete. For ChatGPT-4.0, ten (67%) were accurate, 5 (33%) were over-conclusive, 10 (67%) were supplementary, and 6 (40%) were incomplete. There was a statistically significant difference in supplementary information (100% vs. 67%; p=.014) between ChatGPT-3.5 and ChatGPT-4.0. Accuracy (47% vs. 67%; p=.269), over-conclusiveness (47% vs. 33%; p=.456), and incompleteness (40% vs. 40%; p=1.000) did not show significant differences between ChatGPT-3.5 and ChatGPT-4.0. ChatGPT-3.5 and ChatGPT-4.0 both yielded 100% accuracy for definition and history and physical examination categories. Diagnostic testing yielded 0% accuracy for ChatGPT-3.5 and 100% accuracy for ChatGPT-4.0. Nonsurgical interventions had 50% accuracy for ChatGPT-3.5 and 63% accuracy for ChatGPT-4.0. Surgical interventions resulted in 0% accuracy for ChatGPT-3.5 and 33% accuracy for ChatGPT-4.0. Conclusions: ChatGPT-4.0 provided less supplementary information and overall higher accuracy in question categories than ChatGPT-3.5. ChatGPT showed reasonable concordance to NASS guidelines, but clinicians should caution use of ChatGPT in its current state as it fails to safeguard against misinformation.

Outcomes after selective nerve root blockade for lumbar radicular pain from lumbar disc hernia or lumbar spinal stenosis assessed by the PROMIS-29 - a prospective observational cohort study.

PURPOSE: Selective nerve root blocks (SNRB) are used both as a therapeutic and diagnostic tool for lumbar radicular pain. Most studies evaluate the effect of SNRB simply by its relation to pain reduction. It is well known that pain is associated with other factors such as depression, anxiety, inactivity and sleeping disorders, but these patient-related outcomes are seldom evaluated. This study evaluated the influence of SNRB on pain-related outcomes including depression, anxiety, fatigue, pain interference, activity and sleep. METHODS: One hundred three patients with lumbar radicular pain were treated with a SNRB. Patient-reported outcome measures (PROMs) were assessed with the PROMIS-29 for 12 weeks (84 days) following the SNRB. Patients were stratified based on their pain reduction at the 14-day follow up as responders (≥ 30% pain reduction) and non-responders (< 30% pain reduction). Post-treatment duration was estimated with the Kaplan-Meier analysis with return to baseline as an event. A paired t-test was used to compare pre- and post-treatment responses at specific time intervals. RESULTS: Forty-four percent (n = 45) of the patients were responders and showed significant improvement in all parameters throughout the 84-days follow-up, the exception was sleep that lost significance at day 70. The mean post-treatment duration among responders was 59 (52-67) days. Non-responders showed significant improvements in pain interference and pain intensity until day 35 and in ability for social participation until 21-day. CONCLUSION: SNRB can improve pain intensity, pain interference, physical function, fatigue, anxiety, depression, sleep disturbance and the ability to participate in social roles.

Deep Learning Assisted Classification of T1ρ-MR Based Intervertebral Disc Degeneration Phases.

BACKGROUND: According to the T1ρ value of nucleus pulposus, our previous study has found that intervertebral disc degeneration (IDD) can be divided into three phases based on T1ρ-MR, which is helpful for the selection of biomaterial treatment timing. However, the routine MR sequences for patients with IDD are T1- and T2-MR, T1ρ-MR is not commonly used due to long scanning time and extra expenses, which limits the application of T1ρ-MR based IDD phases. PURPOSE: To build a deep learning model to achieve the classification of T1ρ-MR based IDD phases from routine T1-MR images. STUDY TYPE: Retrospective. POPULATION: Sixty (M/F: 35/25) patients with low back pain or lower limb radiculopathy are randomly divided into training (N = 50) and test (N = 10) sets. FIELD STRENGTH/SEQUENCES: 1.5 T MR scanner; T1-, T2-, and T1ρ-MR sequence (spin echo). ASSESSMENT: The T1ρ values of the nucleus pulposus in intervertebral discs (IVDs) were measured. IVDs were divided into three phases based on the mean T1ρ value: pre-degeneration phase (mean T1ρ value >110 msec), rapid degeneration phase (mean T1ρ value: 80-110 msec), and late degeneration phase (mean T1ρ value <80 msec). After measurement, the T1ρ values, phases, and levels of IVDs were input into the model as labels. STATISTICAL TESTS: Intraclass correlation coefficient, area under the receiver operating characteristic curve (AUC), F1-score, accuracy, precision, and recall (P < 0.05 was considered significant). RESULTS: In the test dataset, the model achieved a mean average precision of 0.996 for detecting IVD levels. The diagnostic accuracy of the T1ρ-MR based IDD phases was 0.840 and the AUC was 0.871, the average AUC of 5-folds cross validation was 0.843. DATA CONCLUSION: The proposed deep learning model achieved the classification of T1ρ-MR based IDD phases from routine T1-MR images, which may provide a method to facilitate the application of T1ρ-MR in IDD. EVIDENCE LEVEL: 4 TECHNICAL EFFICACY: Stage 2.

Clinical therapeutic effect of self-prescribed Sanhanchushi Tongbi on lumbar disc herniation.

BACKGROUND: Lumbar disc herniation (LDH) commonly occurs during spinal surgery; LDH is on the increase in younger patients and is classified as "paralysis" and "back pain." Sanhanchushi Tongbi (SPST) is a customized prescription. It disperses cold, relieves pain, removes cold from the meridians and viscera, and treats neuropathic pain. However, few studies have investigated its mechanism of pain relief. AIM: To observe the clinical therapeutic effects on LDH treated with self-prescribed SPST. METHODS: A total of 211 patients with LDH syndrome were divided into two groups: 107 patients in the control group were treated with conventional massage combined with traction, and 104 patients in the observation group were treated with a combination of the control regimen and self-prescribed oral SPST. The patients were treated for 4 wk. Indices of traditional Chinese medicine (TCM) syndrome score and serum inflammatory factor levels were measured. RESULTS: After therapy, the TCM syndrome score in the observation group was significantly lower than that in the control group (P < 0.05). The main symptoms, clinical signs, daily activities, and Japanese Orthopedic Association scores in the observation group were significantly higher than those in the control group after therapy (P < 0.05). The levels of tumor necrosis factor-α, interleukin-6, and C-reactive protein were lower in the observation group than in the control group (P < 0.05). In the observation group, superoxide dismutase levels were significantly higher, whereas malondialdehyde levels were significantly lower, compared with the control group (P < 0.05). The overall efficacy rate in the observation group was 96.15%, which was substantially higher than that in the control group (88.79%; P < 0.05). CONCLUSION: Self-prescribed SPST can reduce the levels of inflammatory and pain-causing factors as well as lumbar pain in patients with LDH.

Comparison of biportal endoscopic and microscopic tubular paraspinal approach for foraminal and extraforaminal lumbar disc herniation.

OBJECTIVE: Foraminal and extraforaminal lumbar disc herniation (FELDH) is an important pathological condition that can lead to lumbar radiculopathy. The paraspinal muscle-splitting approach introduced by Reulen and Wiltse is a reasonable surgical technique. Minimally invasive procedures using a tubular retractor system have also been introduced. However, surgical treatment is considered more challenging for FELDH than for central or subarticular lumbar disc herniations (LDHs). Some researchers have proposed uniportal extraforaminal endoscopic lumbar discectomy through a posterolateral approach as an alternative for FELDH, but heterogeneous clinical results have been reported. Recently, the biportal endoscopic (BE) paraspinal approach has been suggested as an alternative. The aim of this study was to compare the clinical outcomes of BE and microscopic tubular (MT) paraspinal approaches for decompressive foraminotomy and lumbar discectomy (paraLD) in patients with FELDH. METHODS: Ninety-one consecutive patients with unilateral lumbar radiculopathy and FELDH underwent paraLD. Demographic and perioperative data were collected. Clinical outcomes were evaluated using the visual analog scale (VAS) for back and leg pain, the Oswestry Disability Index (ODI) for spinal disability, and the modified Macnab criteria for patient satisfaction. Postoperative complications and reoperation rates were also evaluated. RESULTS: In total, 76 patients were included in the final analysis. Among them, 43 underwent BE paraLD (group A) and the remaining 33 underwent MT paraLD (group B). The demographic and preoperative data were not statistically different between the groups. All patients showed significant improvements in VAS back, VAS leg, and ODI scores compared with baseline values (p < 0.05). The improvement in VAS back scores was significantly better in group A than in group B on postoperative day 2 (p < 0.001). However, all clinical parameters were comparable between the two groups after postoperative year 1 (p > 0.05). According to the modified Macnab criteria, 86.1% and 72.7% of the patients had excellent or good outcomes in groups A and B, respectively. No intergroup differences were observed (p = 0.367). In addition, there were no differences in the total operation time or amount of surgical drainage. Postoperative complications were not significantly different between the two groups (p = 0.301); however, reoperation rates were significantly higher in group B (p = 0.035). CONCLUSIONS: BE paraLD is an effective treatment for FELDH and is an alternative to MT paraLD. In particular, BE paraLD has advantages of early improvement in postoperative back pain and low reoperation rates.

Enhancing Transforaminal Full Endoscopic Discectomy: Efficacy of the Hand Down Outside-In (HDOI) Technique.

Endoscopic lumbar discectomy (ELD) is a key advancement in minimally invasive spinal surgery, particularly for lumbar disc herniation. Interlaminar endoscopic lumbar discectomy (IELD) and transforaminal endoscopic lumbar discectomy (TELD) are the two major methods used for FED. TELD, while less familiar to spine surgeons inexperienced in endoscopic surgery, presents challenges in visualizing the dura mater, a crucial aspect for reducing surgical complications. The hand down outside-in (HDOI) technique introduced by Dezawa enhances this visualization by positioning the cannula tip dorsally on the intervertebral disc and maneuvering it between the dura mater and disc to the spinal canal's midpoint. The cannula is then flipped to directly visualize the dura mater, enabling safe removal of the prolapsed disc material. A comparative study involving 20 patients treated from April 2020 to April 2022 examined the efficacy of the HDOI technique against conventional TELD. Each group, comprising ten patients, underwent ELD for lumbar disc herniation. While both groups showed similar improvements in clinical outcomes, as assessed using the Japanese Orthopedic Association (JOA) score and visual analogue scale (VAS) for pain, the HDOI group exhibited a 100% success rate for dura mater visualization, and this rate is significantly higher than the 60% observed in the conventional TELD group. Additionally, the time required for dura mater visualization was notably shorter for the HDOI technique. These results indicate that the HDOI technique not only enhances the safety and efficacy of TELD but may also encourage its wider use in clinical settings.

Assessment of Obesity as Risk Factor of Lumbar Disc Surgery: Retrospective Analysis of 598 Cases and Simulated Surgery on 3D-Printed Models.

(1) Background: Obesity poses known risks in surgery, including a prolonged operation time and postoperative complications. Given the rising obesity rates and frequent lumbar disc surgeries, understanding these risks is crucial. This study aims to assess the impact of obesity on operation duration and postoperative complications in lumbar disc prolapse surgery. (2) Methods: We retrospectively analyzed 598 patients with monosegmental disc herniation, correlating their body mass index (BMI) as a surrogate parameter for obesity with operation time. Excluding complex cases (multi-segmental herniations or recurrent herniations), complication rates and hospital stays were recorded. Simulated surgeries on 3D-printed models of varying obesity levels examined operation times and instrument suitability. (3) Results: Of these patients, 438 patients had a BMI of <30, and 160 patients had a BMI of ≥30. Complication rates showed no significant differences between groups. Linear regression analysis failed to establish a sole dependency of operation time on BMI, with R2 = 0.039 for the normal-weight group (BMI < 30) and R2 = 0.059 for the obese group (BMI ≥ 30). The simulation operations on the 3D-printed models of varying degrees of obesity showed a significant increase in the simulated operation time with higher levels of obesity. A geometrically inadequate set of surgical instruments was assumed to be a significant factor in the simulated increase in operating time. (4) Conclusions: While various factors influence operation time, obesity alone does not significantly increase it. However, simulated surgeries highlighted the impact of obesity, particularly on instrument limitations. Understanding these complexities is vital for optimizing surgical outcomes in obese patients.

Database analysis comparing incidence and complication rates between inpatient and outpatient laminotomies for lumbar disc herniation.

Background: Lumbar disc herniation (LDH) is a common condition that can be characterized with disabling pain. While most patients recover without surgery, some still require operative intervention. The epidemiology and trends of laminotomy for LDH have not been recently studied, and current practice patterns might be different from historical norms. This study aimed to investigate the trends of inpatient and outpatient laminotomies for LDH and compare complication rates between these two sites of service. Methods: A large, national database was utilized to identify patients > 8 years old who underwent a laminotomy for LDH between 2009 and 2019. Two cohorts were created based on site of surgery: inpatient versus outpatient. The outpatient cohort was defined as patients who had a length of stay less than 1 day without any associated hospitalization. Epidemiologic analyses for these cohorts were performed by demographics. Patients in both groups were then 1:1 propensity-score matched based on age, sex, insurance type, geographic region, and comorbidities. Ninety-day postoperative complications were compared between cohorts utilizing multivariate logistic regressions. Results: The average incidence of laminotomy for LDH was 13.0 per 10,000 persons-years. Although the national trend in incidence had not changed from 2009 to 2019, the proportion of outpatient laminotomies significantly increased in this time period (p=.02). Outpatient laminotomies were more common among younger and healthier patients. Patients with inpatient laminotomies had significantly higher rates of surgical site infections (odds ratio [OR] 1.61, p<.001), venous thromboembolism (VTE) (OR 1.96, p<.001), hematoma (OR 1.71, p<.001), urinary tract infections (OR 1.41, p<.001), and acute kidney injuries (OR 1.75, p=.001), even when controlling for selected confounders. Conclusions: Our study demonstrated an increasing trend in the performance of laminotomy for LDH toward the outpatient setting. Even when controlling for certain confounders, patients requiring inpatient procedures had higher rates of postoperative complications. This study highlights the importance of carefully evaluating the advantages and disadvantages of performing these procedures in an outpatient versus inpatient setting.

Paravertebrally-Injected Multifunctional Hydrogel for Sustained Anti-Inflammation and Pain Relief in Lumbar Disc Herniation.

Pain caused by lumbar disc herniation (LDH) severely compromises patients' quality of life. The combination of steroid and local anesthetics is routinely employed in clinics to alleviate LDH-induced pain. However, the approach only mediates transient efficacy and requires repeated and invasive lumbar epidural injections. Here a paravertebrally-injected multifunctional hydrogel that can efficiently co-load and controlled release glucocorticoid betamethasone and anesthetics ropivacaine for sustained anti-inflammation, reactive oxygen species (ROS)-removal and pain relief in LDH is presented. Betamethasone is conjugated to hyaluronic acid (HA) via ROS-responsive crosslinker to form amphiphilic polymer that self-assemble into particles with ropivacaine loaded into the core. Solution of drug-loaded particles and thermo-sensitive polymer rapidly forms therapeutic hydrogel in situ upon injection next to the herniated disc, thus avoiding invasive epidural injection. In a rat model of LDH, multifunctional hydrogel maintains the local drug concentration 72 times longer than free drugs and more effectively inhibits the expression of pro-inflammatory cytokines and pain-related molecules including cyclooxygenase-2 (COX-2) and prostaglandin E2 (PGE2). Therapeutic hydrogel suppresses the LDH-induced pain in rats for 12 days while the equivalent dose of free drugs is only effective for 3 days. This platform is also applicable to ameliorate pain caused by other spine-related diseases.

Enhanced deep leaning model for detection and grading of lumbar disc herniation from MRI.

Lumbar disc herniation is one of the most prevalent orthopedic issues in clinical practice. The lumbar spine is a crucial joint for movement and weight-bearing, so back pain can significantly impact the everyday lives of patients and is prone to recurring. The pathogenesis of lumbar disc herniation is complex and diverse, making it difficult to identify and assess after it has occurred. Magnetic resonance imaging (MRI) is the most effective method for detecting injuries, requiring continuous examination by medical experts to determine the extent of the injury. However, the continuous examination process is time-consuming and susceptible to errors. This study proposes an enhanced model, BE-YOLOv5, for hierarchical detection of lumbar disc herniation from MRI images. To tailor the training of the model to the job requirements, a specialized dataset was created. The data was cleaned and improved before the final calibration. A final training set of 2083 data points and a test set of 100 data points were obtained. The YOLOv5 model was enhanced by integrating the attention mechanism module, ECAnet, with a 3 × 3 convolutional kernel size, substituting its feature extraction network with a BiFPN, and implementing structural system pruning. The model achieved an 89.7% mean average precision (mAP) and 48.7 frames per second (FPS) on the test set. In comparison to Faster R-CNN, original YOLOv5, and the latest YOLOv8, this model performs better in terms of both accuracy and speed for the detection and grading of lumbar disc herniation from MRI, validating the effectiveness of multiple enhancement methods. The proposed model is expected to be used for diagnosing lumbar disc herniation from MRI images and to demonstrate efficient and high-precision performance.

Percutaneous endoscopic interlaminar discectomy for high-grade migrated lumbar disc herniation: clinical efficacy and safety assessment.

PURPOSE: This study aimed to assess the clinical effectiveness and safety of percutaneous endoscopic interlaminar discectomy (PEID) in the management of high-grade migrated Lumbar disc herniation (LDH). METHODS: A total of 328 patients who underwent PEID for high-grade migrated LDH between May 2020 and January 2023 in our hospital were selected. Patients were categorized into high-grade migrated group and low-grade migrated group according to preoperative MRI findings. The preoperative and postoperative evaluations of clinical outcomes, such as Visual Analogue Scale (VAS) for lower backs and legs, Oswestry Disability Index (ODI), and modified MacNab criteria for surgical success, were compared between groups. RESULTS: No statistically significant differences were found in hospitalization time, surgery time, intraoperative hemorrhage, number of intraoperative fluoroscopies, or incision length between the two groups. The lower back and leg VAS scores and ODI exhibited a statistically significant decrease in both groups across all postoperative time intervals. However, the difference between the two groups was not statistically significant. Postoperative nerve root stimulation symptoms were reported in two and three cases in the high-grade migrated group and low-grade migrated group, respectively. One patient in the high-grade migrated group underwent reoperation due to re-herniation at the same segment. There was no significant difference in the rate of excellent-good cases between the two groups, with an overall rate of 94.7%. CONCLUSION: In treating high-grade migrated disc herniation, PEID offers advantages such as reduced trauma, small incision, quicker recovery and satisfactory clinical safety and efficacy.

Effects of Multimodal Physical Therapy on Pain, Disability, H-reflex, and Diffusion Tensor Imaging Parameters in Patients With Lumbosacral Radiculopathy Due to Lumbar Disc Herniation: A Preliminary Trial.

Background Lumbosacral radiculopathy (LSR) due to lumbar disc herniation (LDH) is a condition caused by mechanical compression of nerve roots. Various physical therapy interventions have been proposed for the conservative management of LSR due to LDH. However, the study of physical therapy interventions in a multimodal form is lacking. Additionally, the effect of physical therapy on diffusion tensor imaging (DTI) parameters of the compressed nerve root has not been studied. This study aimed to investigate the effects of multimodal physical therapy (MPT) on pain, disability, soleus H-reflex, and DTI parameters of the compressed nerve root in patients with chronic unilateral LSR due to LDH. Methods A prospective preliminary pre-post clinical trial with a convenience sample was conducted. A total of 14 patients with chronic unilateral LSR due to paracentral L4-L5 or L5-S1 LDH were recruited for the study. Participants received a total of 18 sessions of a six-week MPT program that consisted of electrophysical agents, manual therapy interventions, and core stability exercises. Electrophysical agents involved interferential current and hot pack. Manual therapy interventions included myofascial release, side posture positional distraction, passive spinal rotation mobilization, and high-velocity low-amplitude manipulation. Visual analog scale (VAS), Roland-Morris Disability Questionnaire (RMDQ), soleus H-reflex amplitude, side-to-side amplitude (H/H) ratio, fractional anisotropy (FA), and apparent diffusion coefficient (ADC) of the compressed nerve root were measured at baseline and post-intervention. Results There were significant improvements in VAS, RMDQ, H/H ratio, FA, and ADC of the compressed nerve root. Furthermore, significant improvement was found in the affected side compared with the contralateral side in H-reflex amplitude. Conclusions The observations of this preliminary trial suggest that MPT is a successful intervention in patients with chronic unilateral LSR due to LDH. Regarding DTI parameters of the compressed nerve root, FA increased and ADC decreased. Future studies with a control group, large sample sizes, and longer follow-up periods are needed.

Comparison of Percutaneous Endoscopic Transforaminal Discectomy, Chemonucleolysis, Microdiscectomy, and Microendoscopic Discectomy for Symptomatic Lumbar Disc Herniation: One-year Follow-up Clinical Results and Disc Degeneration.

This study compared the 1-year clinical outcomes and disc degeneration rates after transforaminal full-endoscopic lumbar discectomy (TF-FED), condoliase injection, open discectomy (OD), and microendoscopic discectomy (MED) for lumbar disc herniation (LDH). In total, 279 patients with LDH were divided into four treatment groups: TF-FED, OD, MED, and condoliase injection. Outcomes were evaluated on the basis of the complication rate, Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ), visual analog scale (VAS) scores, and the modified MacNab criteria. Surgical and hospital costs were assessed. Disc degeneration and endplate bone marrow edema were evaluated using magnetic resonance images. The mean postoperative JOABPEQ, VAS, or modified MacNab scores among the four groups had no significant differences. Additionally, the nerve injury or reoperation rate among the TF-FED, OD, and MED groups had no significant difference. However, the reoperation rate with condoliase injection was high because of residual disc herniation. Surgical and hospital costs were lower with condoliase injection and higher with OD and MED than those with TF-FED. With TF-FED and condoliase injection, the Pfirrmann grade progressed, and the disc height was significantly smaller than that with OD and MED. Endplate bone marrow edema was more common with condoliase injection and TF-FED. All groups had good outcomes. TF-FED and condoliase injection may reduce the burden of surgery because they can be performed under local anesthesia with little blood loss and low medical costs but tend to be associated with disc degeneration and endplate bone marrow edema. A randomized controlled study with a larger sample is needed.

Prosthesis optimization and mechanical analysis of artificial lumbar disc replacement.

BACKGROUND: Artificial lumbar disc replacement is an effective method for the treatment of lumbosacral degenerative diseases. An appropriate artificial intervertebral disc device is of great significance for the maintenance of spinal stability and activity. METHODS: Two finite element models of ProDisc-L prosthesis replacement and improved prosthesis replacement were constructed by using the finite element model of complete lumbar L1-L5 segment established by CT image data. The mechanical properties of the surgical models before and after improvement were analyzed and evaluated. RESULTS: The ProDisc-L group and the improved group showed similar lumbar's ROM and maintained a similar ROM with the normal lumbar spine. There was no significant change in the intervertebral disc's pressure between the adjacent segments of the two prosthesis groups compared with the normal group, but the stress value of the improved prosthesis group was slightly lower than that of the ProDisc-L group. In addition, the improved prosthesis replacement has more reasonable stress distribution. CONCLUSIONS: Compared with the ProDisc-L prosthesis, the improved prosthesis can reduce the pressure in the intervertebral disc of the adjacent segment, the contact stress of the facet joint and the artificial prosthesis, which provides reference for the subsequent design of the prosthesis structure.

The Differences on the Fatty Infiltration of Paraspinal Muscles between Single- and Multiple-level Intervertebral Disc Degeneration in Patients with Lumbar Disc Herniation.

OBJECTIVE: Multiple-level Intervertebral disc degeneration (IDD) in patients with lumbar disc herniation (LDH) is related to postoperative re-herniation and low back pain. Although many investigators believed that there is an interdependence between paraspinal muscles degeneration and IDD, few studies focused on the fatty infiltration of paraspinal muscles on single- and multiple-level IDD in patients with LDH. This study aims to investigate the difference on the fatty infiltration of paraspinal muscles between single- and multiple-levels IDD in patients with LDH. and to explore in patients with LDH whether fatty infiltration is a potential risk factor for multiple-level IDD. METHODS: This study was conducted as a retrospective observational analysis of 82 patients with LDH from January 1, 2020 to December 30, 2020 in our hospital were enrolled. Twenty-seven cases had single-level IDD (Group A), and 55 cases had multiple-level IDD (Group B). We measured the mean computed tomography (CT) density value of the paraspinal muscles, including multifidus (MF), erector spinae (ES) and psoas muscle (PM) at each disc from L1 to S1. Subgroups were set to further analyze the odds ratio (OR) of fatty infiltration of paraspinal muscles in different sex and BMI groups. We measured sagittal angles and analyzed the relationships between these angles and IDD. Finally, we use logistic regression, adjusted for other confounding factors, to investigate whether fatty infiltration is an independent risk factor for multi-level IDD. RESULTS: The average age in multi-level IDD (51.40 ± 15.47 years) was significantly higher than single-level IDD (33.37 ± 7.10 years). The mean CT density value of MF, ES and PM in single-level IDD was significantly higher than multi-level IDD (all ps < 0.001). There was no significant difference of the mean value of angles between the two groups. No matter being fat (body mass index [BMI] > 24.0 kg/m2) or normal, patients with low mean muscle CT density value of MF and ES are significantly easier to suffer from multiple-level IDD. In the pure model, the average CT density value of the MF, ES and PM is all significantly associated with the occurrence of multi-IDD. However, after adjusting for various confounding factors, only the OR of the average CT density value for MF and ES remains statistically significant (OR = 0.810, 0.834, respectively). CONCLUSIONS: In patients with LDH, patients with multiple-level IDD have more severe fatty infiltration of MF and ES than those with single-level IDD. Fatty infiltration of MF and ES are independent risk factors for multiple-level IDD in LDH patients.

Surgical Strategy for Lumbar Disc Herniation based on the MSU Classification: Percutaneous Endoscopic Lumbar Discectomy versus Transforaminal Lumbar Interbody Fusion: A 5-year Retrospective Study.

OBJECTIVE: Currently, there is no established guideline on whether to opt for percutaneous endoscopic lumbar discectomy (PELD) or traditional transforaminal lumbar interbody fusion (TLIF) surgery based on specific types of lumbar disc herniation (LDH). Based on the Michigan State University (MSU) classification system, this study conducted a medium- to long-term follow-up analysis of two surgical methods over 5 years for the first time, aiming to provide empirical evidence to assist in making more informed decisions before surgery for LDH treatment. METHODS: This was a retrospective study that included 273 patients with single-level LDH who underwent PELD or TLIF treatment at our hospital between January 1, 2016, and December 31, 2018. Detailed metrics included preoperative and postoperative visual analogue scale (VAS) scores and Oswestry disability index (ODI) at 1-day, 1-week, 1-year, and 5-year follow-ups. Complications, recurrences, and 5-year postoperative modified MacNab criteria scores were also recorded. Statistical methods included independent sample t-tests, repeated measures analysis of variance (ANOVA), and χ2 tests. RESULTS: Classified into seven groups according to the MSU classification, it was found that there was an improvement in the VAS and ODI scores at four postoperative follow-ups (p < 0.001). PELD showed better results than TLIF in reducing pain and improving the ODI scores in the classifications of 3B, 2B, and 2C (p < 0.05). TLIF demonstrated consistent superiority over PELD in 2A, 2AB, 3A, and 3AB classifications (p < 0.05). The total recurrence rate in the PELD group (11.05%) within 5 years after surgery was higher (p < 0.05) than that in the TLIF group (3.96%). These were mainly concentrated in the 2A, 2AB, 3A, and 3AB types. Moreover, the rate of excellent and good outcomes in the PELD was higher than in the TLIF but no significant difference (χ2 = 1.0568, p = 0.5895). CONCLUSION: This study suggests that PELD and TLIF may relieve LDH, but have advantages under different MSU classifications. The MSU classification has specific guiding significance and could aid in the surgical selection of PELD or TLIF to achieve optimal treatment outcomes for patients with lumbar disc herniation.