L5 S1 Research Articles

Unilateral Biportal Endoscopy for Decompression of Extraforaminal Stenosis at the Lumbosacral Junction: Surgical Techniques and Clinical Outcomes.

ObjectiveThe aims of this study were to describe the unilateral biportal endoscopic (UBE) technique for decompression of extraforaminal stenosis at L5–S1 and evaluate 1-year clinical outcomes. Especially, we evaluated compression factors of extraforaminal stenosis at L5–S1 and described the surgical technique for decompression in detail. MethodsThirty-five patients who underwent UBE decompression for extraforaminal stenosis at L5–S1 between March 2018 and February 2019 were enrolled. Clinical results were analyzed using the MacNab criteria, the visual analogue scale (VAS) for back and leg pain, and the Oswestry Disability Index (ODI). Compression factors evaluated pseudoarthrosis within the transverse process of L5 and ala of sacrum, disc bulging with or without osteophytes, and the thickened lumbosacral and extraforaminal ligament. ResultsThe mean back VAS was 3.7±1.8 before surgery, which dropped to 2.3±0.8 at 1-year postoperative follow-up (p<0.001). There was a significant drop in postoperative mean VAS for leg pain from 7.2±1.1 to 2.3±1.2 at 1 year (p<0.001). The ODI was 61.5 before surgery and 28.6 (p<0.001). Pseudoarthrosis between the transverse process and the ala was noted in all cases (35 of 35, 100%). Pure disc bulging was seen in 12 patients (34.3%), and disc bulging with osteophytes was demonstrated in 23 patients. The thickened lumbosacral and extraforaminal ligament were identified in 19 cases (51.4%). No complications occurred in any of the patients. ConclusionIn the current study, good surgical outcomes without complications were achieved after UBE decompression for extraforaminal stenosis at L5–S1.

An Anatomical Clue for Minimizing Iliac Vein Injury During the Anterolateral Approach at L5-S1 Level: A Cadaveric Study.

ObjectiveThe injury to the common iliac vein (CIV) seems to be the most important concern during the anterior approach to the spine at L5–S1 level. We investigated the anatomy of the L5–S1 vertebral structures related to the CIV through a cadaveric study to find an anatomical clue for safe dissection of CIV. MethodsTen cadavers were prepared for this study. After removing the peritoneum and the presacral fascia, the section from the lower part of the L5 to the upper part of the S1 vertebral body was removed with the CIV attached. After decalcification, 2 sections in the vertical and horizontal directions were made for histological study. ResultsAn adipose tissue layer was present between the intervertebral disc and CIV. The adipose tissue layer in 6 cadavers was thin, and in 3 of these cadavers, the CIV was attached to the vertebral body and the disc. In the other 4 cadavers, the CIV was clearly separated from the vertebral body and the disc by the intervening adipose tissue layer (IATL). Under the microscope, a thin layer surrounding the anterior longitudinal ligament, periosteum, and disc was observed, and we named this structure the ‘perivertebral membrane.’ The perivertebral membrane was attached to the CIV when there was no IATL, but a potential space was detected under the membrane. ConclusionThere was a thin membrane, perivertebral membrane, between the CIV and L5–S1 disc. In cases with CIV adhesion to the disc due to the absence of IATL, the CIV may be mobilized indirectly through the perivertebral membrane.

A MORPHOMETRIC STUDY OF VENTRAL NERVE ROOTS AND RETROPERITONEAL VESSELS IN RELATION TO A MINIMALLY INVASIVE LATERAL APPROACH TO DETERMINE SAFE WORKING ZONE

Background: The minimally invasive lateral retroperitoneal transpsoas approach is a new method that was designed to minimize problems related with standard or minimally invasive anterior or posterior lumbar spine techniques. The current work used magnetic resonance imaging to determine the anatomic location of the ventral root and retroperitoneal arteries in respect to the vertebral body and to establish the anatomical safe zones. We examined lumbar spine MRI in 50 individuals retrospectively (L1-L2 to L5-S Method: 1 levels). The ventral root and surrounding major arteries were identied using axial T1 and T2 scans. Axial MR scans were utilized to determine the anterior-posterior (AP) diameter of the vertebral endplate, the overlap between the ventral root and the posterior border of the vertebra, and the overlap between the retroperitoneal big vessels and the anterior edge of the vertebra. The safe zone was then determined. From L1–L2 Results: to L5–S1, the mean AP diameter of the vertebral body and the overlap of the vertebral body with the nerve roots and retroperitoneal arteries grew gradually. When we examined the extent of overlap of retroperitoneal arteries with the ventral border of the lower vertebral body endplate, we discovered that the right vascular structures were more posterior than the left vascular structures. The safe working zone was 81.86 percent of the lower endplate of the sagittal diameter of the vertebral body at L1–L2, 70.03 percent at L2–L3, 69.32 percent at L3–L4, 50.08 percent at L4–L5, and 17.92 percent at L5–S1 levels. The Conclusion: retroperitoneal transpsoas method is a less invasive and more efcient alternative to the conventional posterior, open lumbar procedures. It can be used to treat trauma, degenerative disc disease, adult degenerative scoliosis, spondylosis with instability, spondylolisthesis, lumbar stenosis, and neighboring segment failure.

A finite element study of the relationship between upper body weight and the loads experienced by the human lumbosacral spine, and fusion instrumentation, in a standing upright posture

BackgroundA quantitative relationship between increasing upper body weight and both 1) non-instrumented lumbosacral joint loading and 2) fusion instrumentation reactions is established using a three-dimensional (3D) finite element model (FEM) of the human thoracolumbosacral spine. MethodsA 3D FEM of the thoracolumbosacral spine (both non-instrumented and instrumented with fusion instrumentation) is developed and validated against cadaveric spine specimens. Upper body weight loading is applied to simulate an individual with varying levels of body mass index (BMI) including 25 kg/m2, 30 kg/m2, 35 kg/m2, and 40 kg/m2. Maximum force/moment joint reactions from L1–S1 in the non-instrumented model are recorded. Maximum instrumentation reactions in the fusion model are recorded. FindingsWith BMI of 25 kg/m2 as a reference, nearly all joints experience amplified percent increases in joint loading compared to percent weight gain for each level of obesity studied. Considering spinal fusion instrumentation, rod stresses and pedicle screw reactions likewise experience amplified loading increases compared to body weight. Compressive force at L5–S1 increases by 47%, 86%, and 132% for total body weight increases of 20%, 40%, and 60%, respectively. Fusion rod stresses increase by 47%, 86%, and 128% for the same body weight increases. InterpretationsThis paper quantitatively illustrates the importance of nutrition and weight control as part of a comprehensive approach to low back pain management and treatment. Increases in loading on the joints in the lumbosacral spine and in fusion instrumentation are amplified when compared to the corresponding increases in body weight for various clinical levels of obesity. These results illustrate that moderate weight loss can produce significant lower back and spine benefits.

Human lumbosacral root and ligamentum flavum thicknesses: a magnetic resonance study.

This study investigated the lumbosacral plexus (LSP) nerve root thickness and ligamentum flavum (LF) thickness and correlated them with age and sex. These findings provided a useful data for spinal nerve root micro-anastomosis surgery and lumbar decompression surgery. This retrospective study was conducted with 350 individuals with ages ranging from 21 to 80 years under magnetic resonance imaging to evaluate the possible cause of a lower back pain. According to the morphometric measurements of the LSP root thickness, the diameter gradually increased from L1 to S1. L1 has the thinnest root (3.9 ± 0.81 mm) while S1 has the thickest root (5.45 ± 0.8 mm). The measurements revealed inconsiderable differences in the LSP thickness in relation to age, sex in the study population. Regarding the LF, the thickness of the LF was found to insignificantly increase with age. Besides, the LF thickness was inconsequentially higher in female. The mean thickness of the right LF at different spinal levels was measured (L2-L3 = 3.19 ± 0.27, L3-L4 = 3.38 ± 0.11 mm, L4-L5 = 3.71 ± 0.29 mm, and L5-S1 = 3.64 ± 0.21 mm). The mean thickness of the left LF was non-significantly higher. The LSP root and LF thicknesses not related to age or sex.

Prospective and Observation Study of Selective Nerve Root Block on Patients with PIVD

Introduction: PIVD is the most common cause of lower back pain in old age. The most common site is L4 L5 to L5 S1 in about 95% cases, and about 90% cases are associated with radiculopathy.&#x0D; Methodology: This prospective study was conducted on 150 patients at the Jawahar Lal Nehru Hospital and Research Center between 2019 and 2021. We used 2–3 ml xylocaine and methylprednisolone. Results were assessed through clinical examination.&#x0D; Result: Of the 150 patients, 130 experienced excellent results with no pain for more than six months.&#x0D; Conclusion: We conclude that for mild cases, patients with PIVD have an alternative option of selective nerve root block other than surgery.

Comparison of percutaneous transforaminal endoscopic decompression and short-segment fusion in the treatment of elderly degenerative lumbar scoliosis with spinal stenosis

BackgroundDegenerative lumbar scoliosis (DLS) combined with spinal stenosis is increasingly being diagnosed in the elderly. However, the appropriate surgical approach remains somewhat controversial. The aim of this study was to compare the results of percutaneous transforaminal endoscopic decompression (PTED) and short-segment fusion for the treatment of mild degenerative lumbar scoliosis combined with spinal stenosis in older adults over 60 years of age.MethodsOf the 54 consecutive patients included, 30 were treated with PTED and 24 were treated with short-segment open fusion. All patients were followed up for at least 12 months (12–24 months). Patient demographics, and perioperative and clinical outcomes were recorded. Visual analog scale (VAS) scores, Oswestry disability index (ODI) scores, and modified Macnab criteria were used to assess clinical outcomes. At the same time, changes in disc height, segmental lordosis, coronal Cobb angle, and lumbar lordosis were compared.ResultsThe mean age was 68.7 ± 6.5 years in the PTED group and 66.6 ± 5.1 years in the short-segment fusion group. At 1 year postoperatively, both groups showed significant improvement in VAS and ODI scores compared with preoperative scores (p < 0.05), with no statistically significant difference between groups. However, VAS-Back and ODI were lower in the PTED group at 1 week postoperatively (p < 0.05). According to the modified Macnab criteria, the excellent rates were 90.0 and 91.6% in the PTED and short-segment fusion groups, respectively. However, the PTED group had a significantly shorter operative time, blood loss, postoperative hospital stay, postoperative bed rest, and complication rate. There was no significant difference in radiological parameters between the two groups preoperatively. At the last follow-up, there were significant differences in disc height, segmental lordosis at the L4–5 and L5–S1 levels, and Cobb angle between the two groups.ConclusionBoth PTED and short-segment fusion for mild degenerative lumbar scoliosis combined with spinal stenosis have shown good clinical results. PTED under local anesthesia may be an effective supplement to conventional fusion surgery in elderly patients with DLS combined with spinal stenosis.

PHYSIOTHERAPY REHABILITATION IN YOUNG PATIENT WITH IDIOPATHIC SCOLIOSIS

The cause of scoliosis is unknown. Males and females have almost the same rate of scoliosis; however, females have a 10-fold higher chance of curve progression. While many with scoliosis may not experience serious complications, it can lead to rib deformity and respiratory compromise, as well as cosmetic issues and emotional discomfort in some patients. However, it is the most common spinal deformity in adolescents. Physiotherapy Rehabilitation helps in correcting the deformity if functional deformity. A 20 year old female presented with dorso-lumbar scoliosis, L 4 – L5 disc bulge, Sacralization of L5 S1 diagnosed as adolescent idiopathic scoliosis. She had decreased muscular strength of back muscles, abdominals and pelvic floor muscles. She also complaint of radiating pain with tingling numbness in both lower limbs with restricted range of motion. Multiple tender points were present throughout her spinal musculature with muscle tightness. The Adam's forward bent test and a scoliometer calculation will help direct the use of radiologic tests for Cobb angle measurement and orthopaedic referrals. Proper conservative management with Prompt physical therapy which leads to achieve functional goals .The case report suggests that prompt structured physical rehabilitation led to improving functional goals progressively and significantly which is a major aspect leading to a successful recovery and better living.

Iatrogenic Giant Inferior Vena Cava

A 70 year old female patient with heart failure and severe pulmonary hypertension had an elevated cardiac output and high oxygen content in the inferior vena cava (IVC) during cardiac catheterisation. (A) Computed tomography angiography showed a large arteriovenous fistula (arrowhead) between the left common iliac vessels and an enlarged contrast enhanced IVC (asterisk), most likely caused by overlooked vessel trauma during a posterior L5–S1 spinal fusion procedure performed a decade previously. (B) The iliac artery defect was closed using an Advanta V12 9 × 32 mm covered stent (Getinge, Gothenburg, Sweden; arrow). The patient’s cardiovascular condition improved significantly.Image 1

Minimally Invasive Reconstruction of Vertebral Arch in Spondylolisthesis in Children and Adolescents.

The aim of the study was to assess the effectiveness of the minimally invasive technique used to reconstruct the vertebral arch with a pedicle screw hook system in grade I isthmic spondylolisthesis in comparison with the traditional technique of segment stabilization with interbody fusion.Materials and MethodsThe study included 26 patients aged from 11 to 17 years. The follow-up period lasted from 1 to 7 years. Two groups were formed: in group 1 (n=6), segments L5–S1 were stabilized using the traditional technique; in group 2 (n=20), the arch of the L5 vertebra was reconstructed by means of minimally invasive surgery. The pain syndrome was assessed in each study group using the visual analogue scale and Macnab criteria before and after surgery; blood loss, duration of surgery in minutes, and hospitalization in days were also measured.ResultsAccording to the Macnab scale, the two presented techniques did not show any statistically significant differences; however, when the arch synthesis technique was employed the spinal motion segment remained intact. Furthermore, in group 2, the volume of blood loss was smaller (44.0±19.6 compared to 300.0±130.4 ml, p<0.0001), the duration of the operation was 176.0±41.6 compared to 349.2±93.2 min, p<0.0001, and hospital stay was 6.9±1.6 compared to 10.0±2.1 days, p=0.0025 in the control group.ConclusionThe technique of vertebral arch reconstruction by a minimally invasive access gives the possibility to stabilize the spinal motion segment and to preserve biomechanics and movements in the spine. This technique allows for shorter inpatient stays for patients as well as earlier recovery and rehabilitation due to reduced surgery time and blood loss.

Influence of Lumbar Lordosis on Posterior Rod Strain in Long-Segment Construct During Biomechanical Loading: A Cadaveric Study.

ObjectiveThe lordotic shape of the lumbar spine differs substantially between individuals. Measuring and recording strain during spinal biomechanical tests is an effective method to infer stresses on spinal implants and predict failure mechanisms. The geometry of the spine may have a significant effect on the resultant force distribution, thereby directly affecting rod strain. MethodsSeven fresh-frozen cadaveric specimens (T12-sacrum) underwent standard (7.5 Nm) nondestructive sagittal plane tests: flexion and extension. The conditions tested were intact and pedicle screws and rods (PSR) at L1-sacrum. The posterior right rod was instrumented with strain gauges between L3–4 (index level) and the L5–S1 pedicle screw. All specimens underwent lateral radiographs before testing. Lordotic angles encompassing different levels (L5–S1, L4–S1, L3–S1, L2–S1, and L1–S1) were measured and compared with rod strain. Data were analyzed using Pearson correlation analyses. ResultsStrong positive correlations were observed between lordosis and posterior rod strain across different conditions. The L3–S1 lordotic angle in the unloaded intact condition correlated with peak rod strain at L3–4 with PSR during flexion (R=0.76, p=0.04). The same angle in the unloaded PSR condition correlated with peak strain in the PSR condition during extension (R=-0.79, p=0.04). The unloaded intact L2–S1 lordotic angle was significantly correlated with rod strain at L3–4 in the PSR condition during flexion (R=0.85, p=0.02) and extension (R=-0.85, p=0.02) and with rod strain at L5–S1 in the PSR condition during flexion (R=0.84, p=0.04). ConclusionLordosis measured on intact and instrumented conditions has strong positive correlations with posterior rod strain in cadaveric testing.

Global Sagittal Alignment and Clinical Outcomes after 1-3 Short-Segment Lumbar Fusion in Degenerative Spinal Diseases.

Study DesignLevel III retrospective study.PurposeWe investigated the impact of short-segment lumbar fusion on the restoration of global sagittal alignment and the correlations between spino-pelvic parameters and clinical outcomes.Overview of LiteratureSagittal imbalance leads to energy consumption and pain in maintaining a standing position. For adult spinal deformity, it is critical to create optimal lumbar lordosis (LL) in order to achieve restoration of sagittal imbalance. However, surgeons do not pay attention to correcting LL in short-segment lumbar fusion.MethodsA total of 69 patients with transforaminal lumbar interbody fusion (TLIF) for degenerative spinal disease were evaluated with a minimum 2-year follow-up. All patients underwent TLIF with hyper-lordotic angle cages to achieve higher LL. Radiological spino-pelvic parameters including sagittal vertical axis (SVA) and clinical outcomes using the Oswestry Disability Index (ODI) and Numeric Rating Scale (NRS) were evaluated.ResultsThe average LL was 35.8°±9.9° before surgery, 42.3°±9.3° 1 year after surgery, and 40.3°±10.2° 2 years after surgery (p<0.01). The average SVA was 43.1±6.2 mm before surgery, 21.2±4.9 mm 1 year after surgery, and 34.0±4.7 mm 2 years after surgery (p<0.01). The average LL and SVA improved in two- or three-segment fusion, but not in one-segment fusion. The correlation between ΔLL and ΔSVA was significant in all segment fusions. The correlation between ΔLL and ΔSVA was more significant at the L4–5 and L5–S1 segments than at L3–4. ODI was significantly correlated with SVA (p<0.05). NRS showed no correlation with the radiological parameters.ConclusionsTwo- or three-segment lumbar fusion using hyper-lordotic angle cages improved LL and SVA. A significant correlation between the correction of LL and SVA was found. Higher correction of LL using hyper-lordotic angle cages is thus recommended in short-segment lumbar fusion, since postoperative improvements of SVA significantly affect clinical outcomes.

Assessment of 3D Lumbosacral Vascular Anatomy for OLIF51 by Non-Enhanced MRI and CT Medical Image Fusion Technique.

Study design: Prospective study. Objective: Medical image fusion can provide information from multiple modalities in a single image. The present study aimed to determine whether three-dimensional (3D) lumbosacral vascular anatomy could be adequately portrayed using a non-enhanced CT–MRI medical image fusion technique. Summary of Background Data: Lateral lumbar interbody fusion has gained popularity for the surgical treatment of adult spinal deformity (ASD). Oblique lumbar interbody fusion at L5–S1 (OLIF51) is receiving considerable attention as a method of creating good L5–S1 lordosis. Access in OLIF51 requires evaluation of the vascular anatomy in the lumbosacral region. Conventional imaging modalities need a contrast medium to describe the vascular anatomy. Methods: Participants comprised 15 patients with ASD or degenerative lumbar disease who underwent corrective surgery at our hospital between January 2020 and June 2021. A 3D vascular image with bony structures was obtained by fusing results from MRI and CT. We processed the merged image and measured the distance between left and right common iliac arteries and veins at two levels: the lower end of the L5 vertebral body (Window A) and the upper end of the S1 vertebral body (Window B). Results: The mean sizes of Window A and Window B were 29.7 ± 10.7 mm and 36.9 ± 10.3 mm, respectively. The mean distance from the bifurcation to the lower end of the L5 vertebra was 23.7 ± 10.9 mm. Coronal deviation of the bifurcation was, from center to left, 12.6 ± 12.3 mm, and the distance from the center of the L5 vertebral body to the bifurcation was 0.79 ± 7.3 mm. Only one case showed a median sacral vein (6.7%). Clinically, we performed OLIF51 in 12 of the 15 cases (80%). Conclusion: Evaluating 3D lumbosacral vascular anatomy using a non-enhanced MRI and CT medical image fusion technique is very useful for OLIF51, particularly for patients in whom the use of contrast medium is contraindicated.

Negative biomechanical effects of large grade nuclectomy in the transforaminal endoscopic discectomy increased the risk of adjacent segment diseases: A finite element study

PurposeThe protection of articular processes (AP) in the transforaminal endoscopic discectomy (TED) was proven to optimise post-operative biomechanical environments. Published studies reported a large grade of nuclectomy leading to poor prognosis, but the underlying biomechanical mechanism was unclearly illustrated. This study aimed to investigate the changes of biomechanical environments after an in-out TED with intact AP and a large grade of nuclectomy and an out-in TED with limited foraminoplasty and a smaller grade of nuclectomy. MethodsA previously constructed and validated lumbo–sacral model was used in this study, and in-out TED with intact AP and out-in TED with limited foraminoplasty, a smaller grade of nuclectomy was simulated. Biomechanical changes in the L5–S1 segment related to the degeneration acceleration were computed under different directional loading conditions. ResultsPost-operative biomechanical changes after the out-in TED with limited foraminoplasty were slight, except for the facet contact pressure under the extension position. By contrast, significant biomechanical deterioration, both in the adjacent disc and zygapophyseal joints, is observed under extension in the model after the in-out TED with large nuclectomy. ConclusionA large grade of nuclectomy is regarded as an independent risk factor of adjacent segment disease in the caudal functional spinal unit after the in-out TED.

Alleviating Paravertebral Muscle Spasm after Radiofrequency Ablation Treatment of Hypersensitive Basivertebral and Sinuvertebral Nerves for Chronic Discogenic Back Pain

Paraspinal muscle spasm caused by pain from a lumbar degenerative disc is frequently investigated in patients with low back pain. Radiofrequency ablation (RFA) surgery could alleviate paraspinal muscle spasms. We performed RFA surgery on the high-intensity zone (HIZ) and hypersensitive sinuvertebral and basivertebral nerves to evaluate its outcome. The paravertebral muscle cross-sectional area (CSA) was measured on magnetic resonance imaging (MRI) before and after surgery to evaluate the effect of RFA surgery on the paravertebral muscle. Prospective cohort study. A single spine surgery center. A comparative study was performed on 2 different uniportal spinal endoscopic surgery groups; 23 patients who underwent RFA surgery for chronic discogenic back pain and 45 patients who underwent posterior decompression surgery for lumbar spinal stenosis with 12 months of follow-up. Paravertebral muscle cross-sectional area, Schiza grade, Modic type, and HIZ size were measured on pre- and post-operative MRI. An endoscopic video review was performed to evaluate the presence of intraoperative twitching and grade the degree of epidural neovascularization and adhesion. Visual analog scale VAS, modified Oswestry Disability Index, ODI and MacNab's criteria were evaluated for outcome measures. Intraoperative endoscopic video evaluation showed neovascularization and adhesion adjacent to the disc and pedicle. In the RFA surgery group, there were 7 patients (30.43%) with grade 2 and 16 (69.57%) with grade 3 neovascularization; intraoperative twitching was observed in 19 out of 23 patients (82.61%). After performing an RFA on the sinuvertebral and basivertebral nerves for the treatment of discogenic back pain, the results showed significant improvement in pain and disability scores. The mean CSA of the paraspinal muscle in the RFA surgery group was significantly increased after surgery at the L4-L5 and L5-S1 levels (L4-L5: 3901 ± 1096.7 mm² to 4167 ± 1052.1 mm², P = 0.000; L5-S1: 3059 ± 968.5 mm² to 3323 ± 1046.2 mm², P = 0.000) compared to preoperative CSA. This study was limited by its small sample size. Hypersensitive sinuvertebral and basivertebral nerves are strongly associated with epidural neovascularization with adhesion and the pathological pain pathway in degenerative disc disease. Epidural neovascularization with adhesion reflects aberrant neurological connections, which are associated with reflex inhibitory mechanisms of the multifidus muscle, which induces spasm. RFA treatment of the region of epidural neovascularization with adhesion effectively treated chronic discogenic back pain and could induce paraspinal muscle spasm release.

Factors affecting disc angle restoration in oblique lateral interbody fusion at L5–S1

BACKGROUND CONTEXTOptimal restoration of the L5–S1 disc angle (DA) is an important surgical goal in spinal reconstructive surgery. Anterior approach is beneficial for L5–S1 DA reconstruction and fusion. However, factors associated with a greater DA restoration in oblique lateral interbody fusion (OLIF) at L5–S1 have not been studied. PURPOSEThis study aimed to identify factors that aid in achieving a greater DA in OLIF at L5–S1. STUDY DESIGN/SETTINGA retrospective analysis. PATIENT SAMPLEThis study involved 61 consecutive patients who underwent OLIF at L5–S1 for lumbar degenerative disease and were followed for more than 1 year. Patients with incomplete data or posterior column osteotomy at L5–S1 were excluded. OUTCOME MEASURESThe L5–S1 DA was measured preoperatively, postoperatively, and at the last follow-up on standing lateral lumbar radiographs. The associations between demographics and/or surgical and/or radiological factors and the L5–S1 DA at the last follow-up were analyzed using multiple regression analysis. METHODSDemographics and surgical factors were reviewed from the medical records with respect to age, sex, body mass index, bone mineral density, diagnosis, surgery level, cage parameters (cage lordotic angle and height), laminectomy performed and/or not performed, estimated blood loss, operative time, configuration of the left common iliac vein. Radiological factors were measured with respect to sagittal parameters, the L5–S1 disc parameters, and the postoperative cage parameters. RESULTSThe mean preoperative DA at L5–S1 was 5.4±5.0°, which increased to 18.9±5.6° postoperatively (p<.001) and was maintained as 16.5±5.9° at the last follow-up (p<.001). The preoperative DA, end plate lesions, anterior spur, facet joint osteoarthritis, or cage position at L5–S1 did not affect the DA at the last follow-up (all p>.05). Multiple regression analysis showed four independent variables, including increased age, increased cage lordotic angle, laminectomy performed, and absence of cage subsidence as the factors associated with the greater DA at L5–S1. CONCLUSIONSOLIF at L5–S1 showed favorable DA restoration regardless of the preoperative conditions. To achieve a greater DA, surgeons should try to distract the anterior disc space for insertion of a larger lordotic cage. Laminectomy during posterior fixation is recommended for achieving additional DA restoration.

2021 Canadian Spine Society Abstracts.

# Abstract 45. Determining clinically important improvement following surgery for degenerative conditions of the spine: analysis of the Canadian Spine Outcomes and Research Network (CSORN) Registry {#article-title-2} There is significant variability in clinically important improvement (CII)

Effect of extracorporeal shock wave therapy on pain intensity, functional abilities, and trunk range of motion in patients with chronic lumbar disc prolapse: A randomized clinical trial

Objectives. This research aimed to assess the impact of extracorporeal shock wave therapy (ESWT) on pain severity, functional abilities, and trunk range of motion in patients with lumbar disc prolapse (LDP). Methods. Design of study was randomized clinical study. Forty male patients had disc prolapse at L5–S1 spine segment with chronic pain. Patients have been randomly divided to two equal groups. The patients in study group received extracorporeal shock wave therapy (ESWT) in addition to conventional physical therapy program. Patients in control group were treated with the conventional physical therapy program which composed of electrotherapy using TENS (15 minutes) and exercise program. Visual analogue scale (VAS) was used to evaluate pain. Functional disability was evaluated by Oswestry disability index (ODI). The Back range of motion device (BROM) has been utilized to measure trunk motion (flexion, extension, side bending, external and internal rotation). For all patients prior to and after six weeks of the therapy program, all outcome measures were evaluated. Results. In the research and control groups, there was a substantial reduction in post-treatment VAS and ODI as compared to pre-therapy (p &gt; 0.001). In both groups, there was a substantial increase in post-therapy ROM compared to pre-therapy (p &gt; 0.001). The comparison among the study and post-therapy control groups showed a substantial decrease in the study group’s VAS and ODI relative to the control group (p &gt; 0.001). There was also a substantial increase in the study group’s trunk flexion, extension, and rotation relative to that of the control group (p &gt; 0.01). Conclusion. The ESWT had a significant analgesic effect and improved functional abilities relative to the conventional physiotherapy program in patients with LDP. Also ESWT had substantial enhancements in trunk ROM relative to conventional physiotherapy.

Extreme cases in percutaneous transforaminal endoscopic surgery: case series and brief review of the literature

Purpose Percutaneous transforaminal endoscopic decompression (PTED) is a minimally invasive method of surgical treatment of miscellaneous spinal conditions. We describe our experience with PTED in extreme cases of foraminal stenosis (FS) in adult degenerative scoliosis (ADS), recurrent foraminal stenosis (RFS) after previous open decompression surgery and adjacent segment disease (ASD) after previous lumbar fusion. Methods Twenty-one (21) patients with FS encountered in the clinical framework of ADS (n = 6), previous open decompression surgery (n = 8) and ASD (n = 7) were prospectively reviewed. Patients were preoperatively assessed via clinical and radiologic evaluation. All patients underwent PTED in 2018–2019. Postoperative evaluation was conducted with clinical examination and evaluation of Visual Analogue Scale (VAS), Oswestry Disability Index (ODI) and modified MacNab criteria in predetermined chronic intervals in a 1–2 years follow-up. Results All patients were successfully managed with PTED. Operated levels were L3–L4 (19.0%), L4–L5 (52.4%) and L5–S1 (28.6%). No major perioperative complications were recorded. VAS and ODI scores were demonstrated to exhibit a clinically and statistically significant (p < 0.05) amelioration in all patients’ categories directly postoperatively, which was preserved until the end of follow-up. Overall outcomes according to modified MacNab criteria were excellent in 12 patients (57.1%), good in 6 (28.6%) and fair in 3 (14.3%) patients. Conclusions PTED is safe and effective in extreme cases of FS encountered in patients with ADS, previous posterior open decompression surgery and ASD after previous spinal fusion.

Retrospective study of minimally invasive surgery verses open laminectomy or laminectomy with diskectomy

Background: Minimally invasive spine surgeries (MIS) are often considered superior to their open counterparts in view of smaller incisions, reduced blood loss, less post-operative pain and less hospital stay. In this study, we compared the clinical outcome of MIS and open procedure of lumbar laminectomy/discectomy. The objective of this study was to compare clinical outcome between the MIS and open procedure of lumbar laminectomy/discectomy.Methods: This was a retrospective study conducted at Government medical college, Kottayam, Kerala, India where we studied the patients who underwent MIS and open laminectomy/laminectomy with discectomy during the period January 2018 to January 2020.Results: We studied a total of 200 patients, among which 60% were males with a mean age of 50.58 years and 40% were females with a mean age of 53.59 years, 45.5% had L5 S1 IVDP, 30% had L4/5 IVDP, and 24.5% had L4/5 lumbar canal stenosis, 75.5% underwent laminectomy with discectomy and the rest (24.5%) underwent laminectomy with foraminotomy, 60% underwent open surgery and 40% underwent MIS.Conclusions: MIS was superior to its open analog in terms of intra operative blood loss as well as hospital stay. But open surgeries required less operation time, less C arm exposure, had better pain control and functional outcome and less recurrence in our study.