Stabilization Of Lumbar Spine Research Articles

Four-Rod Technique for Stabilization of Lumbar Spine in a case of Spine Metastases

Objective: The occurrence of spine metastases often indicates disseminated disease and portends a short-term prognosis in cancer patients. This study discusses the challenges in the surgical management of spinal metastases and evaluates the effectiveness of a 'Four-rod' technique in a patient with disseminated renal cell carcinoma. Case: A 40-year-old male with renal cell carcinoma and metastases presented with severe lower back pain and instability due to extensive vertebral destruction. Despite the poor prognosis, a 'Four-rod' construct was employed to stabilize the spine. Post-surgery, the patient experienced significant pain reduction and improved mobility. Conclusion: The 'Four-rod' technique minimized complications such as pseudoarthrosis and implant failure. It proved effective in stabilizing the spine without increasing operative time or blood loss, thereby enhancing the patient's quality of life. This study underscores the importance of addressing spinal instability in patients with metastatic disease and suggests that multiple-rod constructs may offer superior outcomes.

Effect Of Improving Lumbar Mobility, Spinal Stability ; With Core Stability Training To Achieve Per-sonal Best Runner

Running consists of simple basic movements, and to achieve these simple basic movements requires good mobility and stability, because the weakening of mobility and stability of the body causes misalignment or weakness of the legs so as to interfere with the absorption or propulsion phase in leg movement while running. Apply appropriate exercise methods to improve lumbar mobility and spinal stability. One training method that can be used is the core stability training method. Core stability is an exercise model to improve the ability to control the position of trunk movement through the pelvis and legs to allow optimal motion production. This study aims to ascertain whether core stability training can improve lumbar mobility and spinal stability in running athletes. The study used an experimental method with a research pattern using a group pretest-posttest design. 10 running athletes were sampled according to the criteria to be treated in the form of core stability training for 6 weeks. The athletes were assessed before and after training using the Functional Reach Test and Unilateral Hip Bridge Endurance. This study showed that there was a significant effect between core stability training and lumbar mobility (P = 0.000) and spinal stability (P = 0.000) in athletes. The results of this study show that the application of core stability exercises can increase the ability of lumbar mobility and spinal stability, so if the core stability exercises are done properly, they can increase stability in the spine and mobility in the lumbar, which causes dynamic limb movement to be more efficient. Key Words: athletics; Core Stability; Lumbar Mobility; spine stability.

Short-term lumbar disc and lumbar stability changes of one-hole split endoscope technique treatment of spinal stenosis

ObjectiveInvestigating the early biomechanical effects of the one-hole split endoscope (OSE) technique on lumbar spine after decompression surgery.MethodsA retrospective analysis was conducted on 66 patients with lumbar spinal stenosis (LSS) who underwent OSE technique surgery at the affiliated hospital of Binzhou Medical University from September 2021 to September 2022. The patients had complete postoperative follow-up records. The mean age was (51.73 ± 12.42) years, including 33 males and 33 females. The preoperative and postoperative imaging data were analyzed, including disc height (DH), foraminal height (FH), lumbar lordosis angle (LLA), changes in disc angle, anterior-posterior translation distance, and lumbar intervertebral disc Pfirrmann grading. The visual analogue scale (VAS) was applied to evaluate the severity of preoperative, postoperative day 1, postoperative 3 months, and final follow-up for back and leg pain. The Oswestry Disability Index (ODI) was applied to assess the functionality at all the listed time points. The modified MacNab criteria were applied to evaluate the clinical efficacy at the final follow-up.ResultsIn 66 patients, there were statistically significant differences (p < 0.05) in DH and FH at the affected segments compared to preoperative values, whereas no significant differences (p > 0.05) were found in DH and FH at the adjacent upper segments compared to preoperative values. There was no statistically significant difference in the LLA compared to preoperative values (p > 0.05). Both the affected segments and adjacent upper segments showed statistically significant differences in Pfirrmann grading compared to preoperative values (p < 0.05). There were no statistically significant differences in the changes in disc angle or anterior-posterior translation distance in the affected or adjacent segments compared to preoperative values (p > 0.05). The VAS scores for back and leg pain, as well as the ODI, significantly improved at all postoperative time points compared to preoperative values. Among the comparisons at different time points, the differences were statistically significant (p < 0.05). The clinical efficacy was evaluated at the final follow-up using the modified MacNab criteria, with 51 cases rated as excellent, 8 cases as good, and 7 cases as fair, resulting in an excellent-good rate of 89.39%.ConclusionsThe OSE technique, as a surgical option for decompression in the treatment of LSS, has no significant impact on lumbar spine stability in the early postoperative period. However, it does have some effects on the lumbar intervertebral discs, which may lead to a certain degree of degeneration.

Analyzing isolated degeneration of lumbar facet joints: implications for degenerative instability and lumbar biomechanics using finite element analysis.

The facet joint contributes to lumbar spine stability as it supports the weight of body along with the intervertebral discs. However, most studies on the causes of degenerative lumbar diseases focus on the intervertebral discs and often overlook the facet joints. This study aimed to investigate the impact of facet joint degeneration on the degenerative changes and diseases of the lumbar spine. A finite element model of the lumbar spine (L1-S1) was fabricated and validated to study the biomechanical characteristics of the facet joints. To simulate degeneration of the facet joint, the model was divided into four grades based on the number of degenerative segments (L4-L5 or L4-S1) and the contact condition between the facet joint surfaces. Finite element analysis was performed on four spine motions: flexion, extension, lateral bending, and axial torsion, by applying a pure moment to the upper surface of L1. Important parameters that could be used to confirm the effect of facet joint degeneration on the lumbar spine were calculated, including the range of motion (ROM) of the lumbar segments, maximum von Mises stress on the intervertebral discs, and reaction force at the facet joint. Facet joint degeneration affected the biomechanical characteristics of the lumbar spine depending on the movements of the spine. When analyzed by dividing it into degenerative onset and onset-adjacent segments, lumbar ROM and the maximum von Mises stress of the intervertebral discs decreased as the degree of degeneration increased in the degenerative onset segments. The reaction force at the facet joint decreased with flexion and increased with lateral bending and axial torsion. In contrast, lumbar ROM of the onset-adjacent segments remained almost unchanged despite severe degeneration of the facet joint, and the maximum von Mises stress of the intervertebral discs increased with flexion and extension but decreased with lateral bending and axial torsion. Additionally, the facet joint reaction force increased with extension, lateral bending, and axial rotation. This analysis, which combined the ROM of the lumbar segment, maximum von Mises stress on the intervertebral disc, and facet joint reaction force, confirmed the biomechanical changes in the lumbar spine due to the degeneration of isolated facet joints under the load of spinal motion. In the degenerative onset segment, spinal instability decreased, whereas in the onset-adjacent segment, a greater load was applied than in the intact state. When conducting biomechanical studies on the lumbar spine, considering facet joint degeneration is important since it can lead to degenerative spinal diseases, including adjacent segment diseases.

Clinical &amp; Radiological Outcomes of Posterior Decompression &amp; Transforaminal Lumbar Interbody Fusion (TLIF) among Patients with Lumbar Spondylolisthesis – A Prospective Study

Introduction: Lumbar spondylolisthesis, a condition characterized by the displacement of one vertebra over another, often leads to chronic back pain and functional impairment. Posterior decompression and TLIF are used as surgical options for patients with lumbar spondylolisthesis. Aim of the Study: The aim of this study was to assess the clinical &amp; radiological outcomes of posterior decompression &amp; transforaminal lumbar interbody fusion (TLIF) among patients with lumbar spondylolisthesis. Methods: This prospective observational study was carried out at NITOR, Dhaka, Bangladesh, during the period from January 2020 to December 2021. Total 30 patients with degenerative lumbar spondylolisthesis were included in this study. Result: In this study, majority of participants were aged 41-50 (47%), predominantly female (60%). Clinical outcomes showed significant improvements post-treatment: low back pain and leg pain, measured by VAS, decreased substantially, and disability scores (ODI and Roland-Morris) also improved markedly. Quality of life, assessed by SF-36, showed notable enhancements in both physical and mental scores. Radiologically, there were significant improvements in disc and foraminal height, reduction in spondylolisthesis severity, and restoration of lumbar lordosis and spinal stability. The average surgery time was around 147.5 minutes, with a mean blood loss of 382.7 mL and an average hospital stay of 7.1 days. A 90% fusion rate was achieved at 1-year follow-up, with dural tears being the most common complication. Despite some complications, the majority of surgeries were completed safely. Conclusion: Posterior decompression and TLIF appear to be effective in treating lumbar spondylolisthesis, as evidenced by improved clinical and radiological outcomes.

An innovative method of interosseous lumbar spine stabilization surgery using the dynamic implant in a professional athlete as a way to return to competitive activity as quickly as possible

Objective: surgical intervention for spinal pathologies in professional athletes represents a pertinent topic in contemporary sports medicine and neurosurgery, given the extended rehabilitation period and potential decline in competitive activity following spinal surgeries. In this clinical case we describe an innovative technique for stabilizing the lumbar spine in an elite adult professional athlete which enables rapid return to regular competitive activities without restrictions.Materials and methods: a clinical case involving the surgical treatment of lumbar spine instability with compression of neural structures caused by an intervertebral disc herniation is presented. An innovative method for spinal stabilization employing an interbody dynamic implant is outlined.Results: the implementation of this spinal stabilization method allowed an adult professional elite futsal player to resume active physical sport-specific activities without any limitations just three weeks post-surgery.Conclusion: this clinical observation illustrates that spinal fixation using this novel and original method ensures the stability of the operated segment during physical exertion of any intensity.

Clinical Results of 10-mm Endoscopic Minimally Invasive Interlaminar Decompression in the Treatment of Lumbar Spinal Stenosis with Degenerative Lumbar Scoliosis and Simple Lumbar Spinal Stenosis.

The number of patients with lumbar spinal stenosis (LSS) with degenerative lumbar scoliosis (DLS) is gradually increasing as the population ages. The purpose of this study was to evaluate the clinical outcomes of 10-mm endoscopic minimally invasive interlaminar decompression for LSS with DLS and simple LSS. The clinical data of 175 consecutive elderly patients with LSS were retrospectively analyzed. They were divided into LSS group and LSS with DLS group based on whether they were accompanied by DLS. Patient demographics, perioperative indicators, and clinical outcomes were recorded. Lumbar spine stability was assessed by imaging data. Meanwhile, visual analog scale (VAS) scores, Oswestry Disability Index (ODI) scores, and the modified Macnab criteria were used to assess clinical outcomes. There were 129 patients in the LSS group and 46 patients in the LSS with DLS group. Both groups had similar VAS and ODI scores preoperatively, and both were significantly lower postoperatively (P < 0.05). However, patients combined with DLS showed higher VAS scores for low back pain at 3 months and 1 year postoperatively (P < 0.05). In addition, postoperative LL and PI-LL were significantly improved in both groups (P < 0.05). However, patients in LSS with DLS group showed higher PT, PI and PI-LL before and after surgery. According to the modified Macnab criteria, the excellent and good rates were 92.25% and 89.13% in the LSS group and LSS with DLS group at the last follow-up, respectively. 10-mm endoscopic minimally invasive interlaminar decompression for LSS with or without DLS has shown satisfactory clinical outcomes. However, patients with DLS may have higher residual low back pain after surgery.

ID: 208698 Four-Year Durability of Restorative Neurostimulation Effectiveness in Patients With Refractory Chronic Low Back Pain

Mechanical chronic low back pain (CLBP) can be caused by impaired neuromuscular control of the lumbar spine stability. An implantable Restorative Neurostimulation system (ReActiv8® by Mainstay Medical) bilaterally stimulates the medial branches of the L2 dorsal rami for up to 30 minutes twice daily to override underlying inhibition of the multifidus muscles to facilitate motor control restoration. The ReActiv8-B randomized sham-controlled pivotal trial provided evidence of safety, effectiveness, and durability of this therapy (clinicaltrials.gov/show/NCT02577354).[1,2] Few if any prospective neuromodulation trials have shared efficacy, safety, and participant accountability outcomes beyond two years. Here we report the four-year results.

Biomechanical comparative study of midline cortical vs. traditional pedicle screw trajectory in osteoporotic bone

IntroductionIn lumbar spinal stabilization pedicle screws are used as standard. However, especially in osteoporosis, screw anchorage is a problem. Cortical bone trajectory (CBT) is an alternative technique designed to increase stability without the use of cement. In this regard, comparative studies showed biomechanical superiority of the MC (midline cortical bone trajectory) technique with longer cortical progression over the CBT technique. The aim of this biomechanical study was to comparatively investigate the MC technique against the not cemented pedicle screws (TT) in terms of their pullout forces and anchorage properties during sagittal cyclic loading according to the ASTM F1717 test.MethodsFive cadavers (L1 to L5), whose mean age was 83.3 ± 9.9 years and mean T Score of -3.92 ± 0.38, were dissected and the vertebral bodies embedded in polyurethane casting resin. Then, one screw was randomly inserted into each vertebra using a template according to the MC technique and a second one was inserted by freehand technique with traditional trajectory (TT). The screws were quasi-static extracted from vertebrae L1 and L3, while for L2, L4 and L5 they were first tested dynamically according to ASTM standard F1717 (10,000 cycles at 1 Hz between 10 and 110 N) and then quasi-static extracted. In order to determine possible screw loosening, there movements were recorded during the dynamic tests using an optical measurement system.ResultsThe pull-out tests show a higher pull-out strength for the MC technique of 555.4 ± 237.0 N compared to the TT technique 448.8 ± 303.2 N. During the dynamic tests (L2, L4, L5), 8 out of the 15 TT screws became loose before completing 10,000 cycles. In contrast, all 15 MC screws did not exceed the termination criterion and were thus able to complete the full test procedure. For the runners, the optical measurement showed greater relative movement of the TT variant compared to the MC variant. The pull-out tests also revealed that the MC variant had a higher pull-out strength, measuring at766.7 ± 385.4 N, while the TT variant measured 637.4 ± 435.6 N.ConclusionThe highest pullout forces were achieved by the MC technique. The main difference between the techniques was observed in the dynamic measurements, where the MC technique exhibited superior primary stability compared to the conventional technique in terms of primary stability. Overall, the MC technique in combination with template-guided insertion represents the best alternative for anchoring screws in osteoporotic bone without cement.

Biomechanical evaluation of Percutaneous endoscopic posterior lumbar interbody fusion and minimally invasive transforaminal lumbar interbody fusion: a biomechanical analysis

In order to analyze and evaluate the stability of lumbar spine and the risk of cage subsidence after different minimally invasive fusion operations, two finite element models Percutaneous endoscopic posterior lumbar interbody fusion (PE-PLIF) and minimally invasive transforaminal lumbar interbody Fusion (MIS-TLIF) were established. The results showed that compared with MIS-TLIF, PE-PLIF had better segmental stability, lower pedicle screw rod system stress, and lower risk of cage subsidence. The results suggest that the cage with appropriate height should be selected to ensure the segmental stability and avoid the risk of the subsidence caused by the cage with large height.

Development and validation of an automatic diagnostic tool for lumbar stability based on deep learning

To develop an automatic diagnostic tool based on deep learning for lumbar spine stability and validate diagnostic accuracy. Preoperative lumbar hyper-flexion and hyper-extension X-ray films were collected from 153 patients with lumbar disease. The following 5 key points were marked by 3 orthopedic surgeons: L4 posteroinferior, anterior inferior angles as well as L5 posterosuperior, anterior superior, and posterior inferior angles. The labeling results of each surgeon were preserved independently, and a total of three sets of labeling results were obtained. A total of 306 lumbar X-ray films were randomly divided into training (n=156), validation (n=50), and test (n=100) sets in a ratio of 3∶1∶2. A new neural network architecture, Swin-PGNet was proposed, which was trained using annotated radiograph images to automatically locate the lumbar vertebral key points and calculate L4, 5 intervertebral Cobb angle and L4 lumbar sliding distance through the predicted key points. The mean error and intra-class correlation coefficient (ICC) were used as an evaluation index, to compare the differences between surgeons' annotations and Swin-PGNet on the three tasks (key point positioning, Cobb angle measurement, and lumbar sliding distance measurement). Meanwhile, the change of Cobb angle more than 11° was taken as the criterion of lumbar instability, and the lumbar sliding distance more than 3 mm was taken as the criterion of lumbar spondylolisthesis. The accuracy of surgeon annotation and Swin-PGNet in judging lumbar instability was compared. ① Key point: The mean error of key point location by Swin-PGNet was (1.407±0.939) mm, and by different surgeons was (3.034±2.612) mm. ② Cobb angle: The mean error of Swin-PGNet was (2.062±1.352)° and the mean error of surgeons was (3.580±2.338)°. There was no significant difference between Swin-PGNet and surgeons (P>0.05), but there was a significant difference between different surgeons (P<0.05). ③ Lumbar sliding distance: The mean error of Swin-PGNet was (1.656±0.878) mm and the mean error of surgeons was (1.884±1.612) mm. There was no significant difference between Swin-PGNet and surgeons and between different surgeons (P>0.05). The accuracy of lumbar instability diagnosed by surgeons and Swin-PGNet was 75.3% and 84.0%, respectively. The accuracy of lumbar spondylolisthesis diagnosed by surgeons and Swin-PGNet was 70.7% and 71.3%, respectively. There was no significant difference between Swin-PGNet and surgeons, as well as between different surgeons (P>0.05). ④ Consistency of lumbar stability diagnosis: The ICC of Cobb angle among different surgeons was 0.913 [95%CI (0.898, 0.934)] (P<0.05), and the ICC of lumbar sliding distance was 0.741 [95%CI (0.729, 0.796)] (P<0.05). The result showed that the annotating of the three surgeons were consistent. The ICC of Cobb angle between Swin-PGNet and surgeons was 0.922 [95%CI (0.891, 0.938)] (P<0.05), and the ICC of lumbar sliding distance was 0.748 [95%CI(0.726, 0.783)] (P<0.05). The result showed that the annotating of Swin-PGNet were consistent with those of surgeons. The automatic diagnostic tool for lumbar instability constructed based on deep learning can realize the automatic identification of lumbar instability and spondylolisthesis accurately and conveniently, which can effectively assist clinical diagnosis.

Evaluation of instrumentation and pedicle screw design for posterior lumbar fixation: A pre-clinical in vivo/ex vivo ovine model.

Stabilization procedures of the lumbar spine are routinely performed for various conditions, such as spondylolisthesis and scoliosis. Spine surgery has become even more common, with the incidence rates increasing ~30% between 2004 and 2015. Various solutions to increase the success of lumbar stabilization procedures have been proposed, ranging from the device's geometrical configuration to bone quality enhancement via grafting and, recently, through modified drilling instrumentation. Conventional (manual) instrumentation renders the excavated bony fragments ineffective, whereas the "additive" osseodensification rotary drilling compacts the bone fragments into the osteotomy walls, creating nucleating sites for regeneration. This study aimed to compare both manual versus rotary Osseodensification (OD) instrumentation as well as two different pedicle screw thread designs in a controlled split animal model in posterior lumbar stabilization to determine the feasibility and potential advantages of each variable with respect to mechanical stability and histomorphology. A total of 164 single thread (82 per thread configuration), pedicle screws (4.5× 35 mm) were used for the study. Each animal received eight pedicles (four per thread design) screws, which were placed in the lumbar spine of 21 adult sheep. One side of the lumbar spine underwent rotary osseodensification instrumentation, while the contralateral underwent conventional, hand, instrumentation. The animals were euthanized after 6- and 24-weeks of healing, and the vertebrae were removed for biomechanical and histomorphometric analyses. Pullout strength and histologic analysis were performed on all harvested samples. The rotary instrumentation yielded statistically (p= 0.026) greater pullout strength (1060.6N ± 181) relative to hand instrumentation (769.3N ± 181) at the 24-week healing time point. Histomorphometric analysis exhibited significantly higher degrees of bone to implant contact for the rotary instrumentation only at the early healing time point (6 weeks), whereas bone area fraction occupancy was statistically higher for rotary instrumentation at both healing times. The levels of soft tissue infiltration were lower for pedicle screws placed in osteotomies prepared using OD instrumentation relative to hand instrumentation, independent of healing time. The rotary instrumentation yielded enhanced mechanical and histologic results relative to the conventional hand instrumentation in this lumbar spine stabilization model.

Biomechanical Assessment of Lumbar Stability: Finite Element Analysis of TLIF with a Novel Combination of Coflex, and Pedicle Screws

Purpose Finite element analysis is frequently used for lumbar spine biomechanical analysis. The primary scope of this work is to illustrate, using finite element analysis, how the biomechanical behavior of the Transforaminal lumbar Interbody fusion (TLIF), along with a novel combination of the Interspinous process device (IPD) and pedicle screws, improves lumbar spine stability. Methods In this study, Unilateral Pedicle Screw Fixation (UPSF) and Bilateral Pedicle Screw Fixation (BPSF) were used. Four FE model was developed using ANSYS software, as follows: (1) Intact model; (2) TLIF with "U"-shaped Coflex-F IPD (UCF); (3) TLIF with Coflex-F and UPSF (UCF + UPSF); and (4) TLIF with Coflex-F and BPSF (UCF + BPSF). The intact model was subjected to four pure moments (10 Nm), and the results were validated with previous literature data. The intact model results correlated well with the literature data, and the model was validated. Three surgical models were subjected to 7.5 Nm four pure moments, Flexion (FL), Extension (ET), Lateral bending (LB), and Axial rotation (AR) and a 280N follower load. Results The surgical model results are compared with the intact model. The comprehensive analysis results show the UCF + BPSF surgical model gave a good advantage on range of motion, cage stress, Coflex-F stress, and endplate stress compared among the two models. Conclusions This study proposes that the UCF + BPSF system helps to reduce the stress on the implant and adjacent endplates and gives very good stability to the lumbar spine under the various static loading conditions.

Surgical outcome of minimal invasive oblique lateral interbody fusion with percutaneous pedicle screw fixation in the treatment of adult degenerative scoliosis

Oblique lateral interbody fusion is performed for lumbar spinal restoration and stabilization, without extensive paraspinal muscle damage or massive bleeding. This study aimed to confirm the radiological and clinical outcomes of minimally invasive oblique lateral interbody fusion (OLIF) with percutaneous pedicle screw fixation (PPSF) as treatment for adult degenerative lumbar scoliosis. Medical records of 40 patients with degenerative lumbar spinal deformities who underwent selective OLIF and PPSF at our hospital between April 2018 and February 2021 were retrospectively reviewed. The study population comprised 7 male and 33 female patients aged 55-79 years. Standing radiography was performed, and the coronal cobb angle, distance between the C7 plumb line and central sacral vertical line, sagittal vertical axis, pelvic tilt, lumbar lordosis (LL), pelvic incidence (PI), and difference between PI and LL (PI-LL) were measured. Coronal scoliosis was defined as a lumbar coronal plane curve of > 15°. All patients achieved statistically significant improvements in coronal and sagittal alignment. The coronal cobb angle was corrected from 18.82° to 11.52°, and the central sacral vertical line was reduced from 18.30 mm to 15.47 mm. The sagittal vertical axis was significantly reduced from 45.95 mm to 32.72 mm. In contrast, the pelvic tilt and LL were minimally changed. For subgroup analyses, patients were divided into the convex and concave groups according to the direction of coronal curve correction. Vertebral body rotation was superior in the convex group than in the concave group. Furthermore, we checked for asymmetric facet degeneration at the upper instrumented vertebra (UIV) level at 1 year postoperatively. Of the 22 patients who underwent more than 3 level fusion surgery, 8 patients were confirmed the postoperative asymmetric facet degeneration in above UIV. Minor complications occurred in 16 patients, who recovered without any problems. Revision surgery was not performed in all cases. Minimally invasive OLIF with PPSF has a lower risk of complications and favorable surgical outcomes in patients with adult degenerative lumbar scoliosis. Access from the convex side is advantageous for the correction of the rotated vertebra. Extending the UIV level to the neutral vertebra can reduce the occurrence of postoperative asymmetric facet degeneration.

The Influence of Anticipation of Movement Starting Time on Feedforward Activation of Trunk Muscles during Rapid Shoulder Joint Movements.

This study aimed to clarify the differences in the onset of trunk muscle activity with and without anticipation of the movement starting time during rapid shoulder movements. Ten healthy men in a relaxed upright position performed rapid 135° flexion, 135° abduction, and 45° extension of the shoulder on the dominant hand side with and without anticipation of the movement starting time. They moved their shoulder joints following a 3-s countdown and a light stimulus in the anticipation and non-anticipation conditions, respectively. Electromyography of the anterior and posterior quadratus lumborum, transversus abdominis, internal oblique, external oblique, rectus abdominis, lumbar multifidus, lumbar erector spinae on the non-dominant hand side, and the middle deltoid on the dominant hand side were measured. The onset of activity of each trunk muscle relative to the onset of the middle deltoid was calculated. Two-way analysis of variance (eight trunk muscles × two anticipation conditions) was used to compare the onset of electromyographic activity of the trunk muscles in each direction of the shoulder movement. There were significant interactions between the muscles and anticipation conditions during shoulder abduction and extension. The onset of activity in the anterior and posterior quadratus lumborum, transversus abdominis, and internal oblique occurred earlier with anticipation of the movement starting time than without anticipation during shoulder abduction and extension. The anticipation of movement starting time may contribute to a reliable center of mass control within the support base and improve lumbar spine stability by hastening the onset of activity of the deep trunk muscles.

Biomechanical effects of cement discoplasty on the lumbar spinal unit.

Percutaneous cement discoplasty (PCD) is used to treat patients with low back and leg pain due to the intervertebral disc vacuum phenomena. Whether PCD can restore lumbar spinal stability remains unknown. The purpose of our in vitro study was to evaluate the biomechanical changes brought about by PCD. Eight fresh pig lumbar spines were tested in the following order: intact, after nucleotomy, and after discoplasty. Flexion/extension, lateral bending, and axial rotation were induced by pure moments. The range of motion and neutral zone were recorded. A CT scan was performed to assess the injection volume of the bone cement and to observe whether the bone cement was fractured. After removing the facet joint, a compression failure test was conducted to observe the fracture of bone cement. Compared with nucleotomy, range of motion (ROM) after discoplasty was reduced only in lateral flexion (P < 0.05). The results of the neutral zone showed that the neutral zones in flexion-extension and lateral bending were significantly reduced after discoplasty (P < 0.05). The neutral zone was more sensitive to changes in lumbar stability than ROM. Bone cement slides were observed during the biomechanical test. The CT scan and compression failure test showed that bone cement fracture was more likely to occur at the puncture channel in the annulus fibrosus region. In all, the biomechanical study indicates that discoplasty helps enhance the stability of the lumbar spine in flexion-extension and lateral bending, which explains how PCD works for low back pain. Fractures and sliding of bone cement were observed after discoplasty, and this was more likely to occur at the puncture channel in the annulus fibrosus region. This suggests that bone cement displacement after PCD may cause nerve compression.

Age-related radiographic parameters difference between the degenerative lumbar spinal stenosis patients and healthy people and correlation analysis

ObjectivesTo identify age-related radiographic risk factors for degenerative lumbar spinal stenosis (DLSS) and analyze correlations among them.MethodsA total of 180 cases were enrolled in this study, and lumbar magnetic resonance was performed. Among them, 93 cases suffered DLSS and lumbar dynamic X-ray was examined. And following parameters were measured and evaluated: intervertebral disk height (IDH), the ratio of IDH(IDHL4-5/L3-4), initial IDH of L4-5(iIDHL4-5) in the DLSS group, disk degeneration (DD), cartilaginous endplate failure (CEF), Modic changes, the thickness of ligamentum flavum (LF), range of intervertebral motion (ROM), facet joint opening (FJO), facet joint angle (FJA), the standard cross-sectional area (SCSA) of the multifidus, erector spinae, and psoas major muscles. The data of two groups were compared, and the possible risk factors of DLSS were analyzed.ResultsCompared with the control group, the DLSS group had higher IDH except for L4-5 and larger iIDHL4-5 (P < 0.05). Significant differences were shown in CEF and the thickness of LF at L1-S1 and DD at L4-5 (P < 0.05). The DLSS group had smaller SCSA of multifidus, erector spinae, and psoas major muscles but greater FJA, FJO (P < 0.05). And the risk of DLSS increased when iIDHL4-5 ≥ 10.73 mm, FJA ≥ 52.03° , or FJO ≥ 3.75 mm. IDH positively correlated with SCSA of multifidus and psoas major muscles and ROM at L1-S1 (P < 0.05). DD showed negative linear relations with SCSA of multifidus and psoas muscle and positive linear relation with CEF at L1-2, L2-3, and L5-S1 (P < 0.05).ConclusionLarger initial disk height and excessive CEF may induce DLSS by increasing intervertebral mobility to promote DD, and atrophied paravertebral muscles by weakening the stability of lumbar spine.

Biomechanical Evaluation of Transforaminal Lumbar Interbody Fusion with Coflex-F and Pedicle Screw Fixation: Finite Element Analysis of Static and Vibration Conditions.

ObjectiveTo investigate the biomechanics of transforaminal lumbar interbody fusion (TLIF) with interspinous process device (IPD) or pedicle screw fixation under both static and vibration conditions by the finite element (FE) method.MethodA validated FE model of the L1‐5 lumbar spine was used in this study. This FE model derived from computed tomography images of a healthy female adult volunteer of appropriate age. Then the model was modified to simulate L3‐4 TLIF. Four conditions were compared: (i) intact; (ii) TLIF combined with bilateral pedicle screw fixation (BPSF); (iii) TLIF combined with U‐shaped IPD Coflex‐F (CF); and (iv) TLIF combined with unilateral pedicle screw fixation (UPSF). The intact and surgical FE models were analyzed under static and vibration loading conditions respectively. For static loading conditions, four motion modes (flexion, extension, lateral bending, and axial rotation) were simulated. For vibration loading conditions, the dynamic responses of lumbar spine under sinusoidal vertical load were simulated.ResultUnder static loading conditions, compared with intact case, BPSF decreased range of motion (ROM) by 92%, 95%, 89% and 92% in flexion, extension, lateral bending and axial rotation, respectively. While CF decreased ROM by 87%, 90%, 69% and 80%, and UPSF decreased ROM by 84%, 89%, 66% and 82%, respectively. Compared with CF, UPSF increased the endplate stress by 5%–8% in flexion, 7%–10% in extension, 2%–4% in lateral bending, and decreased the endplate stress by 16%–19% in axial rotation. Compared with CF, UPSF increased the cage stress by 9% in flexion, 10% in extension, and decreased the cage stress by 3% in lateral bending, and 13% in axial rotation. BPSF decreased the stress responses of endplates and cage compared with CF and UPSF. Compared BPSF, CF decreased the facet joint force (FJF) by 6%–13%, and UPSF decreased the FJF by 4%–12%. During vibration loading conditions, compared with BPSF, CF reduced maximum values of the FJF by 16%–32%, and vibration amplitudes by 22%–35%, while UPSF reduced maximum values by 20%–40%, and vibration amplitudes by 31%–45%.ConclusionCompared with other surgical models, BPSF increased the stability of lumbar spine, and also showed advantages in cage stress and endplate stress. CF showed advantages in IDP and FJF especially during vertical vibration, which may lead to lower risk of adjacent segment degeneration. CF may be an effective alternative to pedicle screw fixation in TLIF procedures.

Comparison of spinous process-splitting laminectomy versus posterolateral fusion for lumbar degenerative spondylolisthesis.

Although several studies have recently shown that spinous process-splitting laminectomy (SPSL) maintains lumbar spinal stability by preserving posterior ligament components and paraspinal muscles as compared with conventional laminectomy, evidence is scarce on the treatment outcomes of SPSL limited to lumbar degenerative spondylolisthesis. We herein compare the surgical results and global alignment changes for SPSL versus posterolateral lumbar fusion (PLF) without instrumentation for lumbar degenerative spondylolisthesis. A total of 110 patients with Grade 1 lumbar degenerative spondylolisthesis who had undergone SPSL (47 patients) or PLF (63 patients) with minimum 1-year follow-up were retrospectively enrolled from a single institutional database. Mean operating time per intervertebral level and intraoperative blood loss per intervertebral level were comparable between the SPSL group and PLF group. Japanese Orthopaedic Association scores, Oswestry disability index, and visual analog scale scores were significantly and comparably improved at 1year postoperatively in both groups as compared with preoperative levels. The numbers of vertebrae with slip progression to Grade 2 and slip progression of 5% or more at 1year postoperatively were similar between the groups. In the SPSL group, mean pelvic tilt (PT) was significantly decreased at 1year postoperatively. In the PLF group, mean lumbar lordosis (LL) was significantly increased, while mean sagittal vertical axis, PT, and pelvic incidence-LL were significantly decreased at 1year after surgery. Compared with PLF without instrumentation, SPSL for Grade 1 lumbar degenerative spondylolisthesis displayed comparable results for slip progression and clinical outcomes at 1year postoperatively.

Clinical Efficacy of Large-Channel Percutaneous Lumbar Endoscopic Decompression in the Treatment of Lumbar Spinal Stenosis Secondary to Old Compression Fractures

We sought to explore the clinical efficacy of lumbar spinal stenosis (LSS) secondary to old vertebral compression fractures (OVCF) treatment by large-channel percutaneous endoscopic lumbar decompression. Medical data for a total of 17 patients diagnosed with LSS secondary to OVCF and treated with large-channel percutaneous endoscopic lumbar decompression in our institution from January 2019 to January 2021 were collected. The dural sac cross-sectional area and morphologic grading of the magnetic resonance imaging cross-sectional area were recorded. Lumbar spine stability was assessed using the White-Panjabi scoring system. Visual analog scale and Japanese Orthopaedic Association scores were used to evaluate the surgical efficacy, and the SF-36 health questionnaire was used to evaluate the quality of life of patients. Type and probability of complications were also recorded. The operative segments of the enrolled patients were all in the lower lumbar spine. One-year follow-up post operation showed that the dural sac cross-sectional area was significantly enlarged compared with preoperation, and the morphologic grade was significantly improved (P < 0.05). There was no difference in White-Panjabi score between preoperation and postoperation (P > 0.05). Visual analog scale and Japanese Orthopaedic Association scores at each follow-up time point after operation were higher than those before operation and were significantly improved (P < 0.05). The SF-36 health survey score at 1 year after operation was significantly higher than that before operation (P < 0.05). The complication rate was 6%. Large-channel percutaneous lumbar endoscopic decompression has an evident clinical effect in the treatment of LSS secondary to OVCF and has little effect on the stability of the lumbar spine, which is worthy of clinical application.