L5-S1 Disc Level Research Articles

A comparative cadaveric biomechanical study of bilateral FacetFuse® transfacet pedicle screws versus bilateral or unilateral pedicle screw-rod construct.

Achieving optimal immediate stability is crucial in lumbar fusion surgeries. Traditionally, four pedicle screws have been utilized to provide posterior stability at the L5-S1 level. However, the use of bilateral transfacet pedicle screws (TFPS) as an alternative construct has shown promising results in terms of biomechanical stability. This research paper investigates the biomechanical stability of TFPS with a lag design in comparison to equivalent-sized unilateral or bilateral fully threaded pedicle screw-rod (PSR) constructs at the L5-S1 disc level. The study assesses the immediate stability achieved by these constructs which have clinical implications in achieving lumbar segment fusion. We hypothesized that bilateral TFPS will yield immediate lumbar fixation that is comparable to unilateral or bilateral PSR constructs. Cadaveric biomechanical testing was conducted in vitro to evaluate the stability of posterior fixation using bilateral TFPS (FacetFuse®, LESSpine, Burlington, MA, USA), bilateral and unilateral PSR (PedFuse Return, LESSpine, Burlington, MA, USA) constructs measuring 5.0 mm × 40 mm. A comprehensive analysis of range of motion (ROM) and stability under various loading conditions was performed to a maximum of 7.5 Nm. The constructs were assessed for their ability to provide immediate stability at the L5-S1 disc level. Fourteen specimens were analyzed with an average age of 53.14±10.99 years and comparable bone mineral density. TFPS demonstrated a reduced ROM that was notably lower than that of unilateral PSR in all loading modes and was comparable to bilateral PSR, especially in extension and axial rotation (AR). The unilateral and bilateral PSR groups differed notably in lateral bending (LB) and AR. Bilateral TFPS demonstrated superior immediate stability than unilateral PSR and was an equivalent substitute to bilateral PSR constructs at the L5-S1 disc level. Further clinical investigations are necessary to validate these results and ascertain the long-term outcomes and advantages associated with the use of bilateral TFPS as an alternative construct. Our findings showed that bilateral TFPS could potentially reduce the number of required pedicle screws while achieving comparable stability in lumbar fusion procedures.

New ipsilateral full endoscopic interlaminar approach for L5-S1 foraminal and extraforaminal decompression: technique description and initial case series.

The L5-S1 interlaminar access described in 2006 by Ruetten et al. represented a paradigm shift and a new perspective on endoscopic spinal approaches. Since then, the spinal community has shown that both the traditional ipsilateral and novel contralateral interlaminar approaches to the L5-S1 foramen are good alternatives to transforaminal access. This study aimed to provide a technical description and brief case series analysis of a new endoscopic foraminal and extraforaminal approach for pathologies at the lumbar L5-S1 level using a new ipsilateral interlaminar approach. Thirty patients with degenerative stenotic conditions at the L5-S1 disc level underwent the modified interlaminar approach. The surgical time, blood loss, occurrence of complications, and clinical outcomes were recorded. The data were compiled in Excel and analyzed using R software version 4.2. All continuous variables are presented as the mean, median, minimum, and maximal ranges. For categorical variables, data are described as counts and percentages. Thirty patients were included in the study. The cohort showed significant improvements in all quality-of-life scores (ODI, visual analog scale of back pain, and visual analog scale of leg pain). Five cases of postoperative numbness and three cases of postoperative dysesthesia have been reported. No case of durotomy or leg weakness has been reported. The fundamental change proposed by this procedure, the new ipsilateral approach, presents potential advantages to surgeons by overcoming anatomical challenges at the L5-S1 level and by providing surgeon-friendly visualization and access. This approach allows for extensive foraminal and extraforaminal decompression, including the removal of hernias and osteophytosis, without causing neural retraction of the L5-S1 roots while maintaining the stability of the operated level.

(083) CHRONIC VULVAR PAIN AND URINARY DISTURBANCES REVEALING A LARGE TARLOV CYST IN A 41-YEAR-OLD WOMAN: A CASE REPORT

Abstract Introduction Perineural cysts, also known as Tarlov cysts, are cerebrospinal fluid-filled nerve root cysts predominantly located at the sacral spine. While typically asymptomatic, large Tarlov cysts may elicit discomforting symptoms. Diagnostic challenges stem from limited understanding and symptom overlap with various disorders. Objective This case report explores the presentation of a 41-year-old female patient exhibiting symptoms of vulvar pain and urinary disturbances, which were ultimately attributed to a large Tarlov cyst, highlighting the complexities of diagnosis and management associated with this condition. Methods A 41-year-old female patient with a past medical history of linear scleroderma, chronic left hip pain with leg length discrepancy, and family history of endometriosis presented to her primary care physician with vulvar pain and urinary symptoms. She had burning vulvar pain, predominantly on the left side, radiating from the vulvar vestibule to the perineum, which gradually worsened over 6 months. She also had lower back pain radiating into her legs and calves, along with increased urinary frequency, urgency, retention and burning upon micturition. Patient underwent a 11-month treatment regimen following a referral to pelvic pain specialist, including being initiated on gabapentin and vaginal suppositories, which provided significant pain relief. However, over time, her vulvar pain gradually worsened, and gabapentin was replaced with pregabalin. She underwent six weeks of pelvic floor physical therapy and received a series of peripheral nerve blocks, including multiple pudendal nerve blocks, trigger point injections and hydrodissection of connective tissue around the nerves, yielding little pain relief. Due to persistent vulvar pain, the patient was referred to our clinic. Her examination revealed tenderness upon palpation over the lumbar-sacral spine and sacroiliac joint and para-spinal muscle spasm on the left side. She had provoked vestibulodynia that was predominately on the posterior aspect of the vestibule with a Q-tip test 8/10, and about 4/10 at anterior vestibule. She also continued to have tenderness in her pelvic floor muscles. Given her history and physical exam, a spinal pathology was suspected, and lumbosacral MRI was ordered. Results The lumbosacral MRI revealed a Tarlov cyst measuring 7.7 cm x 3.9 cm x 4.2 cm, extending from the L5-S1 disc level to the S3-S4 vertebral body junction. The patient was subsequently referred to a neurosurgeon who performed a twelve-hour surgery, including a dissection of the intrasacral meningeal cyst that was causing sacral nerve root compression and subsequent wrapping of the weakened right S2-S3 nerve roots. Postoperatively, the pain, although decreased, persisted due to nerve root thinning and long-term compression of the sacral nerve roots. She is currently being managed by our clinic, pain specialists and rehabilitation. A two-year recovery period is anticipated. Conclusions This case underscores the diagnostic challenge of vulvar pain in the context of a Tarlov cyst and emphasizes the necessity for heightened clinical suspicion and comprehensive evaluation. Additionally, the case highlights the importance of considering MRI of the lumbosacral spine as an early investigation in patients presenting with otherwise unexplained chronic vulvar pain, offering a valuable diagnostic tool for identifying conditions like Tarlov cysts that might otherwise remain elusive. Disclosure No.

Body Armor and Lumbar Disc Herniation in Young Military Veterans: A Case Series.

Soldiers on the battlefield are affected by heavy body armor and excessive march load. It is well known, but the long-term effects of this extra weight on the musculoskeletal system of military veterans, specifically the lumbar spine, are unclear. In Iraq and Afghanistan, most body armors weighed over 33 pounds (15 kg). These armors were 3 times heavier than those used in Vietnam. Chiropractors at the Fargo VA Hospital are seeing more young veterans with non-traumatic lower back pain. This article presents a perspective on the impact of body armor weight and excessive carry load on lumbosacral disc herniation with radicular pain in military veterans. This study is a retrospective case series. We used a convenient sampling method. We selected the first 10 military veterans who came to a Fargo VA chiropractor in late fall 2023. Each veteran filled out a VA Form 10-5345 to give us permission to access their electronic health records. All 10 veterans also completed a survey. The survey asked about their active combat status, the type and weight of their body armor, how long they wore the armor each day, how much weight they carried, and their opinion on the cause of their lower back pain (service related or not). The Fargo VA does not require an institutional review board for a case series. This study found that military veterans experience lower back pain at an average age of 35 years. This is at least 5 years earlier than non-service men. Lower back pain with disc herniation typically occurs at the L4-L5 and L5-S1 disc levels. All 10 veterans in the study believe that their lower back pain is related to their service. Sixty percent of the participants in the study have a service-connected disability because of back pain. For military veterans, onset of lower back pain from a disc herniation at a young age may be linked to carrying heavy body armor and loads. However, the small sample size of this case series limits causal relationship inferences.

The Impact of the Placement of the L5 Vertebra in Relation to the Intercrest Line on the Level of Disc Herniation.

To determine whether there is a correlation between a deeply seated L5 vertebra in relation to the intercrest line (ICL) and the level of degeneration of lumbar discs. The study included 152 patients who underwent surgery for lumbar disc herniation. After analyzing the radiographs, the patients were separated into two groups. Group 1 patients had an ICL that passed through the L4 corpus, and Group 2 patients had an ICL that passed through the L4-5 disc distance or the L5 vertebra. Group 1 patients were classified as having a deeply seated L5 vertebra, while Group 2 patients were classified as not having a deeply seated L5 vertebra. The study found that male patients had a significantly higher incidence of a deeply seated L5 vertebra compared to female patients (p=0.003). Patients who underwent surgery at the L4?5 level exhibited disc heights that were notably higher than those who underwent surgery at the L5-S1 level. In Group 1, 68% of the patients had surgery at the L4-5 level, compared to only 41.7% in Group 2 (p=0.009). When investigating the effects of the position of the L5 vertebra in relation to the ICL at the L4-5 and L5-S1 disc levels, the study found that having a deeply seated L5 vertebra protected against L5-S1 disc herniation and that L4-5 disc herniation was more common in these patients. This is believed to be due to the L5?S1 segment being less mobile when the L5 vertebra is deeply seated.

Adolescent Lumbar Intervertebral Disc Herniation: Conservative versus Surgical Treatment

BACKGROUND: Lumbar disc herniation (LDH) in adolescents is relatively a rare condition among those cases presented with low back pain. Trauma and genetics are the most common predisposing factors. Furthermore, the clinical presentations differ from those of the adults. Back pain is not all marked in adolescent patients. AIM: This study was subjected to discuss the etiology, diagnosis and treatment modalities, and the variable outcomes for both medical and surgical treatment of LDH in adolescents. PATIENTS AND METHODS: This prospective study was conducted on 20 patients (12 males, eight females) age range 10–19 years presenting with LDH, managed and treated conservatively and/or surgically in Neurosurgery Department at Kasr Al Ainy School of medicine, Cairo University in the period from October 2015 to September 2016 with 12-month follow-up period. RESULTS: In our study, 12 patients (60%) gave a positive family history, also nine cases (45%) had a history of back trauma before affection with LDH. All the cases (100%) were presented with sciatic pain while only half of them had low back pain, also two cases with motor deficit. After performing magnetic resonance imaging of lumbosacral spine, L5-S1 disc level was the most common level affected. All the patients were subjected to medical treatment which was effective in 40% of the cases and surgical treatment was the only curative method in 12 cases (60%). In this study, the outcome was excellent in 90% of cases where significant to complete relief of pain and significant improvement in the neurological deficits was achieved. CONCLUSION: Conservative treatment is less effective for adolescent LDH patients as compared with adults, even though it remains the fi rst-line treatment for adolescent LDH.

The effect of lumbar multifidus cross-sectional areas on transforaminal epidural steroid injection: An observational clinical study.

Multifidus has an important role in spinal stability, and multifidus degeneration causes long-term disability and low back pain. This study aimed to investigate the effect of multifidus cross-sectional area on transforaminal epidural steroid injections (TFESI). Patients with single-level disc herniation were included in the study. Total multifidus cross-sectional area (TM-CSA) and functional cross-sectional area (FM-CSA) were measured from axial T2 MRI of the patients, and FM-CSA/TM-CSA ratio was calculated for determination of muscle degeneration or fat infiltration. Numerical Rating Scale (NRS) scores at the pre-injection, 3rd week, and 3rd month visits were recorded. A decrease of 50% or more in the NRS score in the 3rd month was accepted as a treatment success (TS), and patients were divided into TS and treatment failure groups. A total of 120 patients were included in the study; 57 of the patients were female, and 63 of them were male. Of the patients included in the study, 68 had herniation at the L5-S1 disc level and 52 had herniation at the L4-L5 disc level. FM-CSA and FM-CSA/TM-CSA ratio were found to be significantly lower below the disc herniation level on the affected side (p<0.05). The affected side TM-CSA and FM-CSA were higher in the TS group and TM-CSA/FM-CSA ratios were equal in both groups. Multifidus CSA was found to be lower on the affected side. However, the effect of multifidus CSA on the success of TFESI has not been determined.

The structural, functional and electrophysiological assessment of paraspinal musculature of patients with ankylosing spondylitis and non-radiographic axial spondyloarthropathy.

Paravertebral muscles are affected in spondyloarthritis. Decreased mobility of spine may lead to atrophy and fatty degeneration of these muscles. The objective of this study was to compare the sonographic, electrophysiological and magnetic resonance imaging (MRI) features of paraspinal muscles between patients with ankylosing spondylitis (AS) and non-radiographic axial spondyloarthritis (nr-axSpA). The patients who were diagnosed as AS with modified New York criteria and those as nr-axSpA with ASAS 2009 criteria were enrolled. Clinical evaluation, electrophysiological examination including nerve conduction studies and needle electromyography (EMG) for lower extremities and paraspinal mapping (PSM) were performed by the first examiner. The second examiner measured lumbar multifidus areas, graded the fatty degeneration of the muscle at different levels in T2 weighted axial MRI and also performed the ultrasonographic evaluation. A total of 19 patients with AS and 14 patients with nr-axSpA were evaluated. MRI of 2 patients with AS could not be obtained. Right lumbar multifidus area/vertebra area (MV ratio) was smaller in AS patients at L3 level (p 0,029); there were no significant differences in other levels. Fatty degeneration was also higher in AS patients in left multifidus at L5-S1 disc level (p 0,015). PSM scores that demonstrate the extent of denervation in paraspinal muscles were significantly higher in AS patients than in nr-axSpA patients (p < 0,001). Patients with AS have more fatty degeneration and denervation in paraspinal muscles. These processes may also contribute the severity of pain and disability. The relationship between paraspinal muscle denervation and progression of fatty degeneration should further be revealed.

A comparative study to evaluate disc degeneration on magnetic resonance imaging in patients with chronic low back pain and asymptomatic individuals

Objectives The present study aimed to investigate the association of disc degeneration with low back pain and the effect of ageing on disc degeneration in low back pain versus asymptomatic individuals. Methodology A total of 50 patients with chronic low back pain (Group A) were compared to 25 healthy controls (Group B). Both the groups were subjected to magnetic resonance imaging of the lumbar spine and the disc degeneration was measured by the Pfirrmann grading system. The study group (Group A) was further sub-grouped into A1 (lumbar spondylosis, n = 11), A2 (mechanical back pain, n = –13) and A3 (lumbar disc herniation, n = 26). Results There was a statistically significant difference in degeneration at the L4-L5 ( p = 0.001) and L5-S1 disc levels ( p = 0.001) between the two groups and contiguous disc involvement was more in low back pain patients. The subgroups of group A showed no statistically significant difference. Age showed a strong positive correlation ( r &gt; 0.5) at all the lumbar levels (except at the L5-S1, r = 0.487) with Pfirrmann grading in Group A ( p = 0.001). There was a weak positive correlation ( r = 0.414) between age and Pfirrmann grade in the controls ( p = 0.04) at the L4-L5 level only. Conclusions Significantly higher Pfirrmann grading on magnetic resonance imaging was found at the L4-5 and L5-S1 levels in symptomatic patients suggesting higher involvement of these levels. Progressive disc degeneration is seen with ageing but in patients with low back pain, it is significantly accelerated.

Low Back Pain Induced by Posterior Longitudinal Ligament Incision in Percutaneous Transforaminal Endoscopic Lumbar Discectomy.

ObjectiveTo illustrate the posterior longitudinal ligament is one of the tissue candidates who can contribute to low back pain (LBP).MethodsThis is a retrospective study. A series of 72 patients who underwent single‐level percutaneous endoscopic lumbar discectomy performed for lumbar disc herniation with LBP from June 2014 to June 2016 were examined. There are 42 males and 30 females. The ages of patients were 40 to 57 years, and the mean age was 49.8 years. The symptomatic disc level was at L4‐5 in 43 patients and L5S1 in 29 patients. Thirty‐two patients (19 patients in L4‐5 disc level, 13 patients in L5S1 disc level) had LBP (which was limited to the lower back and buttock area) before the operation. All of the operative approaches were performed under local anesthesia. A posterior body diagram (15 cm × 10 cm) was made for this study to record the pain distribution. The centered foci of low back pain were subjectively recorded before, during, and after the operation. The transforaminal endoscopic spine system technology was used in this study. Radiological examinations (X‐ray, computed tomography, and magnetic resonance imaging) were performed prior to and after surgery. The Visual Analogue Score (VAS) and Oswestry Disability Index (ODI) scores were taken before and after the surgery to observe the degree of pain. The VSA and ODI score before and after operation were expressed as mean ± SD, and compared by t‐test for statistical analysis.ResultsWhen inciting the posterior longitudinal ligament during the operation, all 72 patients had provoked low back pain. Forty‐three patients with symptomatic discs at L4‐5 had pain foci in the lower back and upper gluteal region under the L4 spinous process. Twenty‐nine patients with symptomatic discs at L5S1 had pain foci in the gluteal region under the S1 spinous process. The pain localizations of L4‐5 and L5S1 were different. After the surgery, the provoked low back pain disappeared, and had not returned in any of the patients at the 6‐month follow‐up. After the operation, one patient suffered from lower limb pain that he did not have before the operation, and the lower limb pain abated a few days later. Three patients had cerebrospinal fluid leakage and were treated with higher pressure applied on the incision and bed rest for 10 days. During the 6‐months follow‐up period, the mean VAS decreased from 5.97 ± 1.10 to 2.13 ± 0.78. The mean ODI score decreased from 23.14 ± 3.28 to 7.92 ± 1.85.ConclusionsThe intervertebral posterior longitudinal ligament may be one of the tissues from which low back pain originates.

Clinical validity of two different grading systems for lumbar central canal stenosis: Schizas and Lee classification systems.

ObjectiveTo assess the learnability of two magnetic resonance imaging (MRI) grading systems for lumbar central canal stenosis based on inter-observer agreement and test-retest reliability of doctors with no prior knowledge of the two systems.Materials and methodsTwo clinical fellows, one novice radiology resident, one neurosurgeon, and one orthopedic surgeon, who were unaware of the two qualitative MRI grading systems prior to this study, acquainted themselves with the teaching files. All five observers independently assessed the LCCS grade of 70 patients using T2-weighted axial magnetic resonance images at the L2-3, L3-4, L3-4, and L5-S1 disc levels. Analysis was performed twice at an interval of two months.ResultsThe inter-observer agreement among all five readers was excellent and test-retest reliability was moderate to excellent for both the Schizas and Lee systems. Positive percentage agreements were found to be over 0.8 in almost all observers with relatively narrow 95% confidence limits.ConclusionBoth Schizas and Lee MRI grading systems for LCCS are reliable grading systems, and can be used as a learnable method for both clinicians and radiologists.

Anatomical Feasibility of Right Oblique Approach for L5-S1 Oblique Lumbar Interbody Fusion

We compared left and right vascular anatomy at the L5-S1 disc space and validated the anatomical feasibility of the right oblique approach for L5-S1 oblique lumbar interbody fusion. Axial T2-weighted magnetic resonance imaging studies at the L5-S1 disc level were used to study 274 subjects (164 women and 110 men; average age, 62.97 years). The distance from the center of the L5-S1 disc to the medial wall of the left or right vessel was measured. Using the vessel position, 3 groups were established: medial, middle, and lateral. To describe the morphological configuration, the vessel type and the presence of perivascular adipose tissue (PVAT) around the vessels were identified on both sides. The vessels on the left L5-S1 disc space were located 12.47 mm from the midline and most subjects (209subjects; 76.3%) were included in the medial or middle group. On the right side, the vessels were located more laterally (16.93 mm; P= 0.000) and most subjects (248subjects; 90.5%) were in the middle or lateral group. On the left side, vessels were mostly veins (260 subjects; 94.9%) and 139 subjects (50.7%) had PVAT. On the right side, the vessels were mostly arteries (213 subjects; 77.7%) and 242 (88.3%) had PVAT. The vessels on the right side of the L5-S1 disc were located more laterally, and most vessels on the right side were arteries accompanying PVAT, which might minimize vessel manipulation. These results indicate that the right side of the L5-S1 disc could provide feasible access for oblique lumbar interbody fusion at L5-S1.

P35. Transforaminal full-endoscopic lumbar discectomy at the L5-S1 disc level: anatomical considerations and operability

BACKGROUND CONTEXT Transforaminal full-endoscopic lumbar discectomy (TELD) is a minimally invasive procedure for the surgical treatment of lumbar disc herniation (LDH). It can be performed under local anesthesia and requires a skin incision of only 8 mm, with minimal disruption of the spinal structures including ligaments and muscles. However, performing TELD for the lower lumbar spine is associated with some anatomical problems, such as interference with the iliac crest. This study sought to assess the operability of TELD at the L5-S1 disc level. PURPOSE The purpose of this study is to assess a three-dimensional relationship between the trajectory of TELD and the iliac crest, and the operability of TELD at the L5-S1 disc level compared with the L4-L5 disc level using CT images. STUDY DESIGN/SETTING This is a retrospective study using 323 multiplanar abdominal computed tomography (CT) scans. PATIENT SAMPLE We retrospectively reviewed multiplanar abdominal CT scans of 323 consecutive patients (203 male and 120 female) in our hospital from April 2009 to March 2013. The mean age was 66.5 (range 15-89) years old. OUTCOME MEASURES The operability of the TELD at the L5-S1 disc level was the outcome measure. METHODS We defined the tangent line in the iliac crest and the superior articular process of the caudal spine as the trajectory line of TELD, and evaluated the maximum inclination angle of the trajectory of the TELD (α angle) at the L4–L5 and the L5-S1 disc levels. Assuming the use of an oblique viewing endoscope at 25°, we defined α angle≥65° as the operability of TELD. RESULTS (1) The relationship between the iliac crest and disc level: The trajectory of the TELD interfered with the iliac crest at L4-L5 in 40.2% (right) and 54.5% (left) of the subjects, and at L5-S1 in 99.7% and 100% of the subjects. (2) The maximum inclination angle of the trajectory of TELD: the α angles were 84.3° and 82.3° at the L4-L5, and 56.8° and 55.2° at L5-S1. (3) Operability of TELD: At L4-L5, TELD could be performed in 94.4% and 90.4% of the subjects. In contrast, at L5-S1 the procedure could be performed in 24.1% and 19.2% of the subjects (male: 15.8% and 10.8%, female: 38.3% and 33.3%). CONCLUSIONS From the results of this study, the trajectory of TELD can be limited by the surrounding anatomical structure. The maximum inclination angle indicates that TELD for the central type of LDH at the L5-S1 disc level is more technically demanding than TELD at the L4-L5 disc level because of the interference of the iliac crest. However, in the clinical setting, such anatomical particularities can be overcome by using a hand-down technique with the possible addition of a foraminoplasty when we perform TELD at the L5-S1 disc level. Because the maximum inclination angle is defined by the iliac crest and ventrolateral aspect of the superior articular process, it makes sense that we remove the superior articular process partially. After widening the neural foramen after foraminoplasty, the working cannula could easily and safely pass through the foramen without touching the exiting nerve root, and be close to the herniated disc. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Peri-operative Radiological Factors Predicting Outcome of Discogenic Cauda Equina Syndrome

Background Data: Acute cauda equina syndrome (CES) is a rare disorder considered as a neurosurgical emergency. It can be devastating in some circumstances. Outcome can be predicted by certain preoperative radiological and clinical items.Purpose: To evaluate and analyse the effect of radiological criteria either pre- or postoperative on the final outcome of acute cauda equina syndrome.Study Design: A prospective clinical case study on 27 patients who were presented by manifestations of CES from May 2014 to September 2017.Patients and Methods: Between May 2014 to May 2017 a total of 27 consecutive patients with discogenic acute cauda equina syndrome underwent decompressive surgery (laminectomy and discectomy) with a follow-up at 6 and 12 months postoperative. Preoperative and postoperative clinical assessments were done by using Visual Analogue Scale (VAS) for analysing pain and full neurological examination. Surgical outcome was assessed using Oswestry Disability Index (ODI) and Japanese Orthopedic Association (JOA) scale. Recovery rate (RR) was calculated in final follow up for each patient. In all cases, preoperative and at the last follow-up control a neuro-radiographic MRI assessment was done. Level of affection, size and direction of prolapsed disc, presence of lumbar canal stenosis, degree of decompression (laminectomy), and the presence of disc residual disc, were all thoroughly analyzed with evaluating the correlation with clinical outcome.Results: At final follow-up visit, we found that radiological factors had significant effect on the overall clinical outcome. L5-S1 disc level had the most favourable outcome when compared to other affected level. A statically significant correlation was found between degree of decompression and overall clinical improvement (P=0.001). Residual disc fragments had a direct relation to incomplete recovery from preoperative symptoms although statistically insignificant (P=0.93).Conclusion: Full and thorough study of the pre- and postoperative radiological findings of the patients presented with discogenic cauda equina syndrome has an important prognostic value that can give a prediction for the surgical outcome and the overall clinical improvement. The degree of decompression and presence of canal stenosis was the most important outcome predictor factors. (2017ESJ148)

Anatomical considerations of the iliac crest on percutaneous endoscopic discectomy using a transforaminal approach

Background ContextPercutaneous endoscopic discectomy is a minimally invasive procedure for the surgical treatment of lumbar disc herniation (LDH). It can be performed under local anesthesia and requires a skin incision of only 8 mm, with minimal disruption of the spinal structures including ligaments and muscles. However, performing percutaneous endoscopic discectomy with a transforaminal approach (TF-PED) for the lower lumbar spine is associated with some anatomical problems, such as interference from the iliac crest. This study sought to assess the operability of TF-PED for the lower lumbar spine. PurposeThe purpose of this study was to assess a three-dimensional relationship between the trajectory of TF-PED and the iliac crest, and the operability of TF-PED at the lower lumbar disc levels (L4–L5 and L5–S1) using CT images. Study DesignThis is a retrospective study using 323 multiplanar abdominal computed tomography (CT) scans. Patient SampleWe retrospectively reviewed contrast-enhanced multiplanar abdominal CT scans of 323 consecutive patients (203 male and 120 female) in our hospital from April 2009 to March 2013. The mean age was 66.5 (range 15–89) years old. Outcome MeasuresThe operability of the TF-PED was the outcome measure. Materials and MethodsWe defined the tangent line in the iliac crest and the superior articular process of the caudal spine as the trajectory line of TF-PED, and evaluated the maximum inclination angle of the trajectory of the TF-PED (α angle) at the L4–L5 and the L5–S1 disc levels. Assuming the use of an oblique viewing endoscope at 25°, we defined α angle≥65° as the operability of TF-PED. Results(1) Relationship between iliac crest and disc level: The trajectory of the TF-PED interfered with the iliac crest at L4–L5 in 40.2% (right) and 54.5% (left) of the subjects, and at L5–S1 in 99.7% and 100% of the subjects. (2) The maximum inclination angle of the trajectory of TF-PED: the α angles were 84.3° and 82.3° at the L4–L5, and 56.8° and 55.2° at L5–S1. (3) Laterality of the α angle: At both disc levels, the mean age of the subjects with a laterality of ≥10° was significantly higher than that of subjects with a laterality of <10°. (4) Operability of TF-PED: At L4–L5, TF-PED could be performed in 94.4% and 90.4% of the subjects. In contrast, at L5–S1 the procedure could be performed in 24.1% and 19.2% of the subjects (male: 15.8% and 10.8%, female: 38.3% and 33.3%). ConclusionsFrom the results of this study, the trajectory of TF-PED can be limited by the surrounding anatomical structures. The maximum inclination angle indicated that treatment for the central type of LDH at the L5–S1 disc level was considered more difficult than that at the L4–L5 disc level because of the iliac crest. In the clinical setting, such anatomical particularities can be overcome by using a more perpendicular approach (hand-down technique) with the possible addition of a foraminoplasty. Moreover, we found that we must consider the laterality of the trajectory of TF-PED in terms of the patients' age or sex.

Magnetic resonance imaging of lumbar trunk parameters in chronic low backache patients and healthy population: a comparative study.

The aim of this study was to evaluate the lumbar trunk parameters by MRI and investigate their association with chronic low backache. Fifty patients (26 males and 24 females) with mean age 33.54±8.33years with a history of low back pain (LBP) of minimum 3 consecutive months constituted the study group (Group A). To match with the study group, 15 normal healthy volunteers (9 males and 6 females) with no history of back pain were selected (Group B). Both the groups were subjected to magnetic resonance imaging of lumbosacral spine and lumbar trunk parameters were calculated. Trunk width, depth and skin angle were comparable at L3-L4, L4-L5 and L5-S1 disc levels; significant difference with regard to disc angle of L3-L4 (p=0.005) and L4-L5 (p=0.02) and cross-sectional area (CSA) of disc at L4-L5 level (p=0.01) was observed between two groups. There was a tendency of smaller CSA of paraspinal and abdominal oblique muscles in Group A patients, but the measurements were not statistically different from Group B patients. Rectus abdominis muscles showed a unique pattern of larger CSA at L3-L4 and L4-L5 disc levels and smaller CSA at L5-S1 in LBP patients. Intervertebral disc degenerative changes on MRI were observed in 27 (54%) patients in the Group A; and none of the Group B participants showed degenerative changes. Tendency of smaller trunk musculature CSA may be a cause or a result of chronic LBP. A unique pattern of larger CSA at L3-L4 and L4-L5 disc levels and smaller CSA at L5-S1 of Rectus abdominis muscles is observed in LBP patients compared to healthy persons. Differences in disc angles and CSA of disc at L3-L4 and L4-L5 levels between the two groups signify that these may be the predisposing factors leading to LBP due to abnormal load/stress transmission and precipitating early degenerative changes in the disc.

Needle Tip Position and Bevel Direction Have No Effect in the Fluoroscopic Epidural Spreading Pattern in Caudal Epidural Injections: A Randomized Trial.

Background. Caudal epidural steroid injections (CESIs) are an effective treatment for pain. If the injection spreads in a specific pattern depending on the needle position or bevel direction, it would be possible to inject the agent into a specific and desired area. Objectives. We conducted a prospective randomized trial to determine if the needle position and bevel direction have any effect on the epidural spreading pattern in CESI. Methods. Demographic data of the patient were collected. During CESI, the needle position (middle or lateral) and direction (ventral or dorsal) were randomly allocated. Following fluoroscope-guided injection of 4 mL contrast media and 10 mL of injectates, the epidural spreading patterns (ventral or dorsal, bilateral or lateral) were imaged. Results. In the 210 CESIs performed, the needle tip position and bevel direction did not influence the epidural spreading patterns at L4-5 and L5-S1 disc levels. A history of Lumbar spine surgery was associated with a significantly limited spread to each disc level. A midline needle tip position was more effective than the lateral position in spreading to the distant disc levels. Conclusions. Neither the needle tip position nor the bevel direction affected the epidural drug spreading pattern during CESI.

The clinical importance of lumbosacral transitional vertebra in patients with adolescent idiopathic scoliosis.

Retrospective review of radiographs. The objective of this study was to (1) determine the prevalence of lumbosacral transitional vertebra (LSTV) with computed tomography (CT) and (2) correlate LSTV presence with lumbar disc degeneration at each level by magnetic resonance imaging. LSTV is a frequently observed abnormality. Although its prevalence in patients with adolescent idiopathic scoliosis (AIS) has been shown, no studies have yet examined the clinical importance of LSTV in patients with AIS. This study included 385 consecutive patients who underwent surgery for AIS at a single center. Plain radiographs and CT scans were used to detect LSTV. Disc degeneration was analyzed at the L3-4, L4-5, and L5-S1 disc levels with magnetic resonance imaging. The difference in disc degeneration at each level by the presence of LSTV was also analyzed. The effect of lumbar curve type on the disc degeneration of each level was then determined. To minimize confounding factors, logistic regression analysis was performed. The overall prevalence of LSTV in patients with AIS confirmed by CT scans was 12.2% (47/385). The proportion of grade II or more disc degeneration at the L4-5 level was higher in the LSTV(+) group than in the LSTV(-) group (29.8% vs.19.2%) although it was not statistically significant (P = 0.093). Large lumbar curves showed a positive correlation with disc degeneration at the L5-S1 level (P = 0.022). The prevalence of LSTV in patients with AIS was 12.2%. A trend of early degeneration in L4-5 level discs was found in patients with AIS with LSTV although it was not statistically confirmed. Disc degeneration at the L5-S1 level is related to a large lumbar curve. If patients with AIS with large lumbar curves have LSTV, consideration should be given to stopping the distal fusion at L3 instead of L4. 4.

339 Life-time cumulative lift load and lumbar disc degeneration

ObjectivesLumbar disc degeneration (LDD) has been associated with cumulative lift load. However, dose-response relationship has not been established in Asia workers. The goal of this study is to investigate whether...

Combined Measurement of Nerve Root Blood Flow and Electrophysiological Values

A total of 15 patients with lumbar disc herniation at the L5-S1 disc level who underwent microendoscopic discectomy were examined. The nerve root blood flow and electrophysiological values were measured during an intraoperative straight-leg-raising (SLR) test. To investigate the relationships between nerve root blood flow changes and the electrophysiological values during an intraoperative SLR test. It is unknown how the electrophysiological values are affected by nerve root blood flow changes during an SLR test. We measured S1 nerve root blood flow and electrophysiologically evaluated the nerve root using the compound muscle action potentials (CMAPs) from the gastrocnemius muscle after S1 nerve root stimulation during an intraoperative SLR test. Subsequently, we analyzed the relationships between the nerve root blood flow changes and the electrophysiological values. Before discectomy, there were sharp decreases in the nerve root blood flow after 1 and 3 minutes of the SLR test (P < 0.001), and the amplitudes of the CMAPs deteriorated significantly (P < 0.001). Significant correlations were found between the decrease ratio for the nerve root blood flow during the SLR test and the deterioration ratio for the amplitude of the CMAPs. After discectomy, the blood flow increased significantly (P = 0.001). When the SLR test was performed again, the blood flow showed no significant decreases. The average amplitudes of the CMAPs were significantly ameliorated (P < 0.01). When the SLR test was performed again, no significant differences were found for the average amplitudes after 1 and 3 minutes of the test. Significant correlations were found between the decrease ratio for the nerve root blood flow and the deterioration ratio for the amplitude of the CMAPs. The present results demonstrate that temporary ischemic changes in the nerve root cause transient conduction disturbances.