Incremental value of magnetic resonance neurography of Lumbosacral plexus over non-contributory lumbar spine magnetic resonance imaging in radiculopathy: A prospective study

AIM: To test the incremental value of 3T magnetic resonance neurography(MRN) in a series of unilateral radiculopathy patients with non-contributory magnetic resonance imaging(MRI).METHODS: Ten subjects(3 men,7 women; mean age54 year and range 22-74 year) with unilateral lumbar radiculopathy and with previous non-contributory lumbar spine MRI underwent lumbosacral(LS) plexus MRN over a period of one year. Lumbar spine MRI performed as part of the MRN LS protocol as well as bilateral L4-S1 nerves,sciatic,femoral and lateral femoral cutaneous nerves were evaluated in each subject for neuropathy findings on both anatomic(nerve signal,course and caliber alterations) and diffusion tensor imaging(DTI)tensor maps(nerve signal and caliber alterations).Minimum fractional anisotropy(FA) and mean apparent diffusion coeffcient(ADC) of L4-S2 nerve roots,sciatic and femoral nerves were recorded.RESULTS: All anatomic studies and 80% of DTI imaging received a good-excellent imaging quality grading. In a blinded evaluation,all 10 examinations demonstrated neural and/or neuromuscular abnormality corresponding to the site of radiculopathy. A number of contributory neuropathy findings including double crush syndrome were observed. On DTI tensor maps,nerve signal and caliber alterations were more conspicuous. Although individual differences were observed among neuropathic appearing nerve(lower FA and increased ADC) as compared to its contralateral counterpart,there were no significant mean differences on statistical comparison of LS plexus nerves,femoral and sciatic nerves(P > 0.05).CONCLUSION: MRN of LS plexus is useful modality for the evaluation of patients with non-contributory MRI of lumbar spine as it can incrementally delineate the etiology and provide direct objective and non-invasive evidence of neuromuscular pathology.

Prediction of transitional lumbosacral anatomy on magnetic resonance imaging of the lumbar spine

AIM: To evaluate two simple angle measurements for predicting lumbosacral transitional vertebra (LSTV) in magnetic resonance imaging (MRI) studies of the spine. METHODS: The lumbar spine MRI studies of 50 subjects with LSTV and 50 subjects with normal lumbosacral anatomy were retrospectively evaluated. In each study, the mid-sagittal T2-weighted image was used to measure the angle formed by a line parallel to the superior surface of the sacrum and a line perpendicular to the axis of the scan table (A-angle), as well as the angle formed by a line parallel to the superior endplate of the L3 vertebra and a line parallel to the superior surface of the sacrum (B-angle). RESULTS: The total study population consisted of 100 subjects (46 males, 54 females, 51 ± 16 years old). There were no differences in age and sex between the two groups. Both A-angle and B-angle were significantly increased in subjects with LSTV compared to controls (P < 0.05). The optimal cut-off values of A-angle and B-angle for the prediction of LSTV were 39.8° (sensitivity = 80%, specificity = 80%, accuracy = 83%; 95% confidence interval = 74%-89%, P = 0.0001) and 35.9° (sensitivity = 80%, specificity = 54%, accuracy = 69%; 95% confidence interval = 59%-78%, P = 0.0005), respectively. CONCLUSION: On sagittal MR images of the lumbar spine, an increased A-angle and/or B-angle should alert the radiologist to the presence of LSTV.

Surgical treatment of sacral fractures following lumbosacral arthrodesis: Case report and literature review

Sacral fractures following posterior lumbosacral fusion are an uncommon complication. Only a few case series and case reports have been published so far. This article presents a case of totally displaced sacral fracture following posterior L4-S1 fusion in a 65-yearold patient with a 15-year history of corticosteroid use who underwent open reduction and internal fixation using iliac screws. The patient was followed for 2 years. A thorough review of the literature was conducted using the Medline database between 1994 and 2014. Immediately after the revision surgery, the patient's pain in the buttock and left leg resolved significantly. The patient was followed for 2 years. The weakness in the left lower extremity improved gradually from 3/5 to 5/5. In conclusion, the incidence of postoperative sacral fractures could have been underestimated, because most of these fractures are not visible on a plain radiograph. Computed tomography has been proved to be able to detect most such fractures and should probably be performed routinely when patients complain of renewed buttock pain within 3 mo after lumbosacral fusion. The majority of the patients responded well to conservative treatments, and extending the fusion construct to the iliac wings using iliac screws may be needed when there is concurrent fracture displacement, sagittal imbalance, neurologic symptoms, or painful nonunion.

Intraneural ganglion cyst of the lumbosacral plexus mimicking L5 radiculopathy:A case report

BACKGROUND Intraneural ganglion cysts are benign gelatinous masses that form within the epineurium of a peripheral nerve.Only few cases of intraneural ganglion cyst arising from the hip joint have been reported.CASE SUMMARY A previously healthy 65-year-old woman who had been experiencing left buttock pain radiating to the dorsum of the foot for 2 years visited our clinic.Prior to visiting the clinic,she underwent lumbar spine magnetic resonance imaging and received physiotherapy,pain killers,and epidural injections based on a presumptive diagnosis of spinal stenosis for 2 years in other hospitals.Repeat magnetic resonance imaging revealed joint connection of the articular branch of the hip joint and rostral extension of the cyst along the L5 spinal nerve near the L5-S1 neural foramen.The patient was diagnosed with intraneural ganglion cyst arising from the articular branch of the hip joint based on high-resolution magnetic resonance neurography.Using the arthroscopic approach,a cystic opening within the intra-articular space was detected,and cyst decompression was then performed.The pain in the left leg was significantly relieved during the 6-mo follow-up.CONCLUSION Although intraneural ganglion cysts arising from the hip joint are rare,they can cause typical radicular pain and mimic common L5 radiculopathy.Typical cyst ascent phenomenon starting from the termination of the articular branch on magnetic resonance imaging is a crucial finding indicative of intraneural ganglion cysts arising from the hip joint.

THE SIGNIFICANCE OF LUMBOSACRAL RADICULOGRAPHY

One hundred and twenty-three lumbosacral radiculography in 67 patients, with age range from 15 to 60 years, have been performed during 1984-1986. In this paper, the anatomical concept of the lumbosacral (L4, 5 and S1) nerve root canal and the technique of radiculography are reported. Basing on our results. we suggest different pathologic images of the nerve root canal. The indication and failing causes in performing radiculography are discussed. We believe that nerve root block would be of great diagnostic and therapeutic value in cases of lumbago and sciatica.

VALUE OF MOTOR EVOKED POTENTIALS BY MAGNETIC STIMULATION IN DIAGNOSIS OF LUMBOSACRAL RADICULOPATHY

Motor root conduction time(MRCT) was calculated by combining the magnetic stimulatiou eliciting motor evoked poentials (MEP)in lumbosacral region with F wave in popliteal rossa.Motor nerve conduction time(MNCT)and MRCT were calculated reliably from the tibialis and the soleal MEPS in 40 patients suffering from L5 or S1 radlculopathies owing to disc protrusion,and in 50 healthy controls.Meanwhile,corticals somatosensory evoked potentials(SEP)were recorded by segmental cutaneous nerve stimulation for comparison.The results showed that no differences were seen in MNCT in all patients,but MRCT was markedly prolonged in 85%or the patients,which was higher than the prolongation of SEP in 45% or the patients.It is concluded that magnetic stimulation of MEP is a useful technique ror non-invasive diagnosis of lumbosacral radlculopathies.

ELECTRODIAGNOSIS OF LUMBOSACRAL RADICULOPATHY

For diagnosiug lumbosacral radicuiopathy precisely, electromyogram(EMG),nerve conduction velocity(NCV),conventional H reflex and H reflex by nerve root stimulation were done in 79 patients with clinical symptoms and signs of lumbosacral radiculopathy.The rate or appearance fibrillation voltage and/or positive sharp wave in the paraspinal muscles was the highest among them.In the comparison of the affected and the healthy sides in patients with S1 radlculopathy,and of affected side and control group,H-M wave interval of H reflex by nerve root stimulation were significantly prolonged(P<0.01,P<0.05);compared with control group,the dirference or H-M wave interval between the two sides was also significantly prolonged (P<0. 05).But the differences were not so significant in patients with L5 radlculopathy.The results suggest that the abnormal changes or EMG or the paraspinal muscles and H reflex by nerve root stimulation are reliable methods of diagnosing lumbosacral radiculopathy, H reflex by nerve root stimulation can be used to differentiate L5 and S1 nerve root lesions,and measure motor conduction velocity(MCV)and sensory conduction velocity(SCV) or the proximal sciatic nerve.

THE SIGNIFICANCE OF DERMATOMAL SOMATOSENSORY EVOKED POTENTIALS IN THE DIAGNOSIS OF LUMBOSACRAL NERVE ROOT COMPRESSION

in this study, conical somatosensory evoked potentials (SEPs)following electrical stimulation of the skin of LS and SI dermatomes were recorded cephalically and observed in 19 patients with clinically proved unilateral L5 or S1 nerve root compression, and the results were compared with those of the control group or 20 healthy volunteers and showed that dermatomal SEPs were abnormal in 12 with the rate of 63%,most or which showed abnomalities or the lateral latency difference. It is concluded that dermatomal SEP is a useful addition to the diagnosis or lumbosacral nerve root compression. When the unilateral nerve root is compressed the lateral latency dirference is a most sensitive criterion for indicating abnomality.

THE TREATMENT OF LUMBOSACRAL INSTABILITY BY THE DIAPASON SYSTEM

Objective. To introduce a new internal fixation system of spine and its characteristics. Methods. To review 16 patients with lumbosacral instability who were treated by this new technique, including their clinical outcomes and radiographic evaluation. Results. Fifteen patients gained complete recovery from their preoperative symptoms. One patient who had experienced two operations before and with problems of urinary and fecal incontinence and walking difficulty still had lower limb pain, muscle weakness and urinary incontinence after operation.There is no evidence of spine glide on X-ray, implant failure, neural complication or infection during follow up. Conclusion. Diapason system can achieve good early postoperative results with few complications and ease to use for lumbosacral instability.

Unilateral Reference Values for Hoffmann’s Reflex in Patients with Suspected Lumbosacral Radiculopathies

Unilateral reference values for Hoffmann’s amplitude could be applied to the diagnosis of lumbosacral radiculopathy, especially in patients with bilateral lesions. Here, we assessed Hoffmann’s reflex by measuring H-wave amplitude and the ratio of H-wave amplitude to M-wave amplitude (the H/M ratio). We performed a cross-sectional survey of patients from a Taiwan rehabilitation center (n = 64, age 20 - 87) who presented with lower back pain that radiated to the leg and received a referral for electrodiagnostic examinations. Reference values for H-wave profile parameters were determined using data from lumbosacral radiculopathy-negative patients (n = 10, age 22 - 53), who had normal big toe test results, ankle reflex test results, motor and sensory nerve conductive studies and F-wave latency and who displayed no evidence of radiculopathy in electromyography and imaging studies. The 50th percentile values for H/M ratio and H-wave amplitude were 28% and 6.25 mV, respectively. An H-wave profile th percentile (H/M ratio bosacral radiculopathy (n = 64). Approximately 41% of patients with an H-wave profile th percentile showed electromyography-confirmed chronic radiculopathy. Electromyography-confirmed current radiculopathy was observed in 35% of patients with an H/R

Biomechanical effects of posterior lumbar interbody fusion with vertical placement of pedicle screws compared to traditional placement

BACKGROUND The pedicle screw technique is widely employed for vertebral body fixation in the treatment of spinal disorders.However,traditional screw placement methods require the dissection of paraspinal muscles and the insertion of pedicle screws at specific transverse section angles(TSA).Larger TSA angles require more force to pull the muscle tissue,which can increase the risk of surgical trauma and ischemic injury to the lumbar muscles.AIM To study the feasibility of zero-degree TSA vertical pedicle screw technique in the lumbosacral segment.METHODS Finite element models of vertebral bodies and pedicle screw-rod systems were established for the L4-S1 spinal segments.A standard axial load of 500 N and a rotational torque of 10 N/m were applied.Simulated screw pull-out experiment was conducted to observe pedicle screw resistance to pull-out,maximum stress,load-displacement ratio,maximum stress in vertebral bodies,load-displacement ratio in vertebral bodies,and the stress distribution in pedicle screws and vertebral bodies.Differences between the 0-degree and 17-degree TSA were compared.RESULTS At 0-degree TSA,the screw pull-out force decreased by 11.35%compared to that at 17-degree TSA(P<0.05).At 0-degree and 17-degree TSA,the stress range in the screw-rod system was 335.1-657.5 MPa and 242.8-648.5 MPa,separately,which were below the fracture threshold for the screw-rod system(924 MPa).At 0-degree and 17-degree TSA,the stress range in the vertebral bodies was 68.45-78.91 MPa and 39.08-72.73 MPa,separately,which were below the typical bone yield stress range for vertebral bodies(110-125 MPa).At 0-degree TSA,the load-displacement ratio for the vertebral bodies and pedicle screws was slightly lower compared to that at 17-degree TSA,indicating slightly lower stability(P<0.05).CONCLUSION The safety and stability of 0-degree TSA are slightly lower,but the risks of screw-rod system fracture,vertebral body fracture,and rupture are within acceptable limits.

Differences of Sagittal Lumbosacral Parameters between Patients with Lumbar Spondylolysis and Normal Adults

Background： Recent studies have suggested an association between elevated pelvic incidence （PI） and the development of lumbar spondylolysis. However, there is still lack of investigation for Hart Chinese people concerning the normal range ofspinopelvic parameters and relationship between abnormal sagittal parameters and lumbar diseases. The objective of the study was to investigate sagittal lumbosacral parameters of adult lumbar spondylolysis patients in Han Chinese population. Methods： A total of 52 adult patients with symptomatic lumbar spondylolysis treated in the General Hospital of Armed Police Force （Beijing, China） were identified as the spondylolysis group. All the 52 patients were divided into two subgroups, Subgroup A： 36 patients with simple lumbar spondylolysis, and Subgroup B： 16 patients with lumbar spondylolysis accompanying with mild lumbar spondylolisthesis （slip percentage 〈30%）. Altogether 207 healthy adults were chosen as the control group. All patients and the control group took lumbosacral lateral radiographs. Seven sagittal lumbosacral parameters, including PI, pelvic tilt （PT）, sacral slope （SS）, lumbar lordosis （LL）, L5 incidence, L5 slope, and sacral table angle （STA）, were measured in the lateral radiographs. All the parameters aforementioned were compared between the two subgroups and between the spondylolysis group and the control group with independent-sample t-test. Results： There were no statistically significant differences of all seven sagittal lumbosacral parameters between Subgroup A and Subgroup B. PI, PT, SS, and LL were higher （P 〈 0.05） in the spondylolysis group than those in the control group, but STA was lower （P 〈 0.001 ） in the spondylolysis group. Conclusions： Current study results suggest that increased PI and decreased STA may play important roles in the pathology of lumbar spondylolysis in Han Chinese population.

Tuina for Leg Length Discrepancy and Lumbosacral Pain Due to Sacroiliac Joint Subluxation

Objective： To observe theclinical effect of tuina reduction manipulation on leg length discrepancy and lumbosacral pain due to sacroiliac joint subluxation. Methods： A total of 60eligible cases were randomly allocated into an observation group and a control group, 30 in each group. Cases in the observation group were treated with conventional tuina plus reduction manipulation of sacroiliac joint subluxation; whereas cases in the control group were treated with conventional tuina plus acupuncture. The clinical effects were observed after 10 times of treatment. In addition, the relapse rates were observed 2 months after treatment. Results： The total effective rate in the observation group was 80.0%, versus 50.0% in the control group, showing a statistically significant difference （P＆lt;0.05）. The relapse rate of lumbosacral pain in the observation group was 12.5%, versus 66.7% in the control group, showing a statistically significant difference （P＆lt;0.01）. The relapse rate of leg length discrepancy in the observation group was 16.7%, versus 80.0% in the control group, showing a statistically significant difference （P＆lt;0.01）. Conclusion： Tuina reduction manipulation can obtain substantial therapeutic effect for leg length discrepancy and lumbosacral pain due to sacroiliac joint subluxation, coupled with a low relapse rate.

Rebuilding motor function of the spinal cord based on functional electrical stimulation

Rebuilding the damaged motor function caused by spinal cord injury is one of the most serious challenges in clinical neuroscience.The function of the neural pathway under the damaged sites can be rebuilt using functional electrical stimulation technology.In this study,the locations of motor function sites in the lumbosacral spinal cord were determined with functional electrical stimulation technology.A three-dimensional map of the lumbosacral spinal cord comprising the relationship between the motor function sites and the corresponding muscle was drawn.Based on the individual experimental parameters and normalized coordinates of the motor function sites,the motor function sites that control a certain muscle were calculated.Phasing pulse sequences were delivered to the determined motor function sites in the spinal cord and hip extension,hip flexion,ankle plantarflexion,and ankle dorsiflexion movements were successfully achieved.The results show that the map of the spinal cord motor function sites was valid.This map can provide guidance for the selection of electrical stimulation sites during the rebuilding of motor function after spinal cord injury.

The Effect of Active Knee Extension in Sitting on Lumbopelvic Curvature in Individuals with Clinically Tight Hamstring Muscles: A Cross-Sectional Reliability Study

Relative flexibility between the hamstring and lumbar extensor muscles, which can be evaluated using lumbopelvic curvature during active knee extension in sitting, can sometimes be assessed in physical therapy. However, reliability for its quantitative measure has not been established yet and its establishment was the aim of the current study. Twenty-seven individuals with clinically tight hamstring muscles were recruited. On two separate sessions, the lumbopelvic curvature was evaluated in sitting when the right knee was moved from 90&deg flexion to 10&deg flexion on 15 occasions using a flexible ruler by two examiners on Day 1 and one on Day 2. Lines drawn tangential to the lumbopelvic curvature were traced at T12 and S2 vertebral levels and the angle between the two vertical lines was calculated. Using Day 1 data, the minimum number of repetitions and inter-examiner reliability were assessed. Inter-session reliability was also examined. As a result, there was no statistical difference (P?> 0.05) in the mean absolute difference between the mean value of N-1 and N repetitions (6 ≤ N ≤ 15) in the lumbopelvic curvature angle, indicating that five was considered the minimum number of repetitions. Intraclass correlation coefficient (ICC)(1, 5)?for the inter-session reliability and ICC(2, 5)?for the inter-examiner reliability was 0.97 and 0.93, respectively, indicating excellent reliability. The measure for the lumbopelvic curvature during active knee extension in sitting, which was established in the current study, will be a foundation for further research regarding the relative flexibility of the lumbar and adjunct regions.

A novel technique for sacropelvic fixation using image-guided sacroiliac screws:a case series and biomechanical study

In this study, we sought to assess the safety and accuracy of sacropelvic fixation performed with image-guided sacroiliac screw placement using postoperative computed tomography and X-rays. The sacroiliac screws were placed with navigation in five patients. Intact specimens were mounted onto a six-degrees-of-freedom spine motion simulator. Long lumbosacral constructs using bilateral sacroiliac screws and bilateral S1 pedicle and iliac screws were tested in seven cadaveric spines. Nine sacroiliac screws were well-placed under an image guidance system(IGS);one was placed poorly without IGS with no symptoms. Both fixation techniques significantly reduced range of motion(P<0.05) at L5-S1. The research concluded that rigid lumbosacral fixation can be achieved with sacroiliac screws,and image guidance improves its safety and accuracy. This new technique of image-guided sacroiliac screw insertion should prove useful in many types of fusion to the sacrum, particularly for patients with poor bone quality,complicated anatomy, infection, previous failed fusion and iliac harvesting.

Measurement Reliability for Evaluating Lumbopelvic Curvature during Active Knee Extension in Sitting Using a Flexible Ruler in Individuals with Clinically Tight Hamstring Muscles: A Secondary Analysis

In a previous study, we established reliability of a method for determining the angle of lumbopelvic sagittal alignment during active knee extension in sitting (AKEiS) using a flexible ruler and image analysis software (2-point-Method). In addition to this method, a flexible ruler can also be used to measure lumbopelvic sagittal alignment without image analysis software. This study primarily aimed to investigate the minimum number of repetitions, inter-session reliability and inter-examiner reliability of two alternative methods of measurement in a secondary analysis of our previous study. A flexible ruler was used to measure lumbopelvic curvature during AKEiS when the knee reached 10° flexion from 27 individuals with clinically tight hamstring muscles and subsequently analyzed. Lumbopelvic sagittal alignment was evaluated for the region between T12 and S2 using the maximum depth to the curvature (Max-Method) or depth to the curvature at the middle point between T12 and S2 vertebral levels (Mid-Method). It was determined that four repetitions for the Max-Method and 11 repetitions for the Mid-Method were required for the minimum number of repetitions, respectively. Inter-session reliability and inter-examiner reliability were assessed using Intraclass Correlation Coefficients and were 0.91 and 0.91 for the Max-Method and 0.90 and 0.91 for the Mid-Method, respectively. The current study suggests that the Mid-Method would not be recommended for use in the clinical setting as 11 repetitions of data sampling is required. The 2-point-Method or Max-Method may be promising but the ideal measurement method will be identified when the validity of these methods has been established.

Concomitant Retroperitoneal Intramuscular Hemangioma and Intravascular Papillary Endothelial Hyperplasia: An Unusual Case Report

Primary retroperitoneal tumors are rare, and benign retroperitoneal tumors are exceptionally rare. Herein, we present a very rare case of benign concomitant retroperitoneal intramuscular hemangioma and intravascular papillary endothelial hyperplasia, with the unusual presentation of lumbosacral plexopathy. After surgical treatment and rehabilitation, the patient recovered uneventfully. This case report should serve to remind physicians of the rare condition of a retroperitoneal tumor leading to a neurological deficit.

针刺配合腰骶刺络放血治疗慢性前列腺炎

Objective:To observe the effect of acupuncture and bloodletting therapy at the lumbosacral region for chronic prostatitis.Methods:A total of 36 patients with chronic prostatitis were collected,and treated in the Department of Acupuncture and Moxibustion and the External Treatment Center of Chinese Medicine,Affiliated Hospital of Shandong University of Traditional Chinese medicine.The patients were treated with acupuncture,combined with bloodletting therapy at the lumbosacral region.The treatment for 4 weeks was as one course and 2 consecutive courses of treatment were required.The therapeutic effect,including the score of the National Institute of Health-Chronic prostatitis symptom index(NIH-CPSI),was assessed.Results:After 1 and 2 courses of treatment,the symptom scores and NIH-CPSI total score were all reduced as compared with that before treatment,respectively(all P<0.01).After 2 courses of treatment,the score of each symptom and NIH-CPSI total score were reduced as compared with that after 1 course of treatment,respectively(all P<0.01).Regrading the 3 syndromes/patterns of chronic prostatitis in the patients,i.e.downward invasion of damp heat,qi and blood stagnation and liver qi stagnation,after 1 and 2 courses of treatment,NIH-CPSI total scores were all reduced as compared with that before treatment(all P<0.01).Additionally,after 2 courses of treatment,NIH-CPSI total score of each syndrome/pattern was reduced as compared with that after 1 course of treatment(all P<0.01).For kidney yin deficiency,after 2 courses of treatment,NIH-CPSI total score was reduced as compared with that either before treatment or after 1 course of treatment(both P<0.01).The total effective rate was 91.67%after 1 course of treatment and 97.22%after 2 courses of treatment.No obvious adverse events occurred during the treatment.Conclusion:The combined treatment with acupuncture and bloodletting therapy at the lumbosacral region effectively relieves the symptoms of chronic prostatitis and improves the quality of life in the patients.

An integrative insight into the synsacral canal of fossil and extant Antarctic penguins

The lumbosacral-canal system in birds most likely operates as a sense organ involved in the control of balanced walking and perching,but our knowledge of it is superficial.Penguins constitute interesting objects for the study of this system due to their upright walking,but only the Humboldt penguin,Spheniscus humboldti,and some incomplete fossil penguin synsacra have been studied in this respect.Here,we give an integrative comparative in-sight into the synsacral canal of extant Emperor penguin,Aptenodytes forsteri,Adelie penguin,Pygoscelis adeliae,and Eocene giant Anthropornis and/or Palaeeudyptes Antarctic penguins,using computed tomography imaging and associated data-extraction methodologies,complemented by analytical approaches ranging from geometric morphometrics to modularity,curvature,and wavelet analyses.We document that the variability in the number of synsacro-lumbar vertebrae is evolutionarily conserved,and all studied synsacra possess osteological correlates of the lumbosacral-canal system.We also found that Eocene and extant Antarctic penguins were separable on the basis of the main direction of the shape-related(size-independent)variability within said system,and A.forsteri was unique in the entire studied set in terms of the relative cranial shift of this compound structure.Moreover,we suggest that the evolutionary processes,shaping both the terrestrial posture and gait,were responsible,in extant penguins,for the increased simplicity and stability of the synsacral canal cross-sectional periodic patterns,as well as pave the way for the lumbosacral-canal system modularity characterized by reduced atomization/complexity.