Higher Lumbar Levels Research Articles

Paraspinal Muscle Changes in Individuals with and without Chronic Low Back Pain over a 4-Month Period: A Longitudinal MRI Study.

Background and Objectives: Previous research has shown associations between atrophy and fatty infiltration of the lumbar paraspinal musculature and low back pain (LBP). However, few studies have examined longitudinal changes in healthy controls and individuals with LBP without intervention. We aimed to investigate the natural variations in lumbar paraspinal musculature morphology and composition in this population over a 4-month period. Materials and Methods: Healthy controls and individuals with LBP were age- and sex-matched and completed several self-administered questionnaires. MRIs of L1-L5 were taken at baseline, 2 months, and 4 months to investigate cross-sectional area (CSA), along with DIXON fat and water images. A total of 29 participants had clear images for at least one level for all three time points. Means and standard deviations were calculated for the participant demographics. A two-way repeated measures ANOVA was performed to investigate CSA, fat signal fraction, and CSA asymmetry. Results: A total of 27 images at L3/L4, 28 images at L4/L5, and 15 images at L5/S1 were included in the final analysis. There were significant main effects of group for psoas CSA at the L3/L4 level (p = 0.02) and erector spinae (ES) CSA % asymmetry at the L3/L4 level (p < 0.001). There was a significant main effect of time for lumbar multifidus (LM) CSA % asymmetry at L4/L5 level (p = 0.03). Conclusions: This study provides insights into LM, ES, and psoas morphology in both healthy controls and affected individuals over a 4-month period without any intervention. Our findings suggest that psoas CSA at higher lumbar levels and CSA % asymmetry in general may be a better indicator of pathology and the development of pathology over time. Evaluating natural variations in paraspinal musculature over longer time frames may provide information on subtle changes in healthy controls and affected individuals and their potential role in chronic LBP.

Pre and postnatal care characteristics and management features of children born with myelomeningocele in the post-folate fortification era of staple foods in Costa Rica (2004-2022).

To describe the clinical characteristics of pre- and postnatal care of children born with myelomeningocele in Costa Rica from 2004 to 2022 after the introduction of mandatory fortification of four major staple foods, describing the clinical features of this cohort including the size of the meningomyelocele, neurological level, presence of symptomatic Chiari II at birth, kyphosis, and the severity of hydrocephalus requiring cerebrospinal fluid (CSF) shunting. These results were compared against the pre-fortification historical data to determine favorable outcomes from this health policy. We performed a retrospective review of the clinical records of patients with myelomeningocele at the spina bifida clinic from the National Children's Hospital of Costa Rica who were born between 2004 and 2022, a period when staple food fortification was implemented in the country for four food staples (wheat and corn flour, rice, and dairy products). Pre and postnatal care data pertaining to the number of obstetric ultrasound studies, the trimester in which they were performed, the detection of myelomeningocele and associated hydrocephalus, gestational age and route of delivery, neurological level, myelomeningocele defect size, associated kyphosis and symptomatic Chiari II malformation at birth, time periods of myelomeningocele repair, and CSF shunting were examined. A descriptive comparative frequency analysis between myelomeningocele (MMC) defect size, CSF shunt insertion, symptomatic Chiari II, and kyphosis between the different functional levels was performed with the estimation of the Fisher's exact chi-square test by contingency tables, and 0.05 was set as significance level. Additionally, the postnatal features of this cohort were compared against pre-fortification historical data obtained from 100 live-born patients between 1995 and 1996. A total of 215 patients that were live born between 2004 and 2022 were eligible for analysis with a follow up ranging from 1 to 19years (median follow up: 7.9years). Among 99.1% of the mothers of patients who had prenatal consultations, 95.8% had an average of 3.8 obstetric ultrasound studies which led to a 59% prenatal detection rate of myelomeningocele. The pre and post fortification features showed a male/female ratio that changed from 0.92 to 1.25 respectively. Among these newborns, there was an increase from 54 to 64% cesarean sections as method for delivery. Only 26% of the pre fortification patients had the MMC defect repaired in the first 24h, 32% from 24 to 72h, 20% from 72h to 1week, and 22% later than 10days respectively which deeply contrasted with the post fortification cohort where 7.5% had the MMC defect repaired in less than 8h, 12.2% from 8 to 12h, 66.5% 12-24h, and 12.7% from 24 to 48h and 1% later than 48h, respectively (P < 0.01). Regarding the post fortification myelomeningocele anatomic and functional characteristics, defect size was measured as less than 3cm in 7% of cases, 3 to 5cm in 50% of cases, 5 to 7cm in 42% of cases, and greater than 7cm in 1% of cases. Thirteen percent of the cases had paraplegia due to a thoracic level, 10% had a high lumbar level, 58% had a middle lumbar level, 13% a lower lumbar level, and 6% only sacral compromise. When the data from the pre and post fortification cohorts were adjusted and compared, there was a reduction from thoracic/high lumbar cases from 26 to 23% (P < 0.56), with an increase of middle lumbar cases from 43 to 58% and a reduction from 25 to 13% of low lumbar cases (P < 0.01) while there was no change in the 6% percentage of sacral cases respectively. Lesions that were considered too extensive or larger than 7cm decreased from 7 to 1% while associated kyphotic deformities decreased from 6 to 1.4% (P < 0.01); symptomatic Chiari II malformation at birth also decreased from 7 to 2% in the pre- and post-fortification cohorts respectively with all these changes being statistically significant (P < 0.01). Seventy-nine percent and 80% of the pre and post FAF cohorts required CSF VP shunting with a mean time for insertion of 10days after spinal defect closure with no significant statistical change between the two groups. This study describes a four-staple folate fortified population of live-born patients with myelomeningocele lesions whose neurological level, defect size, and associated deformities such as spinal kyphosis and symptomatic Chiari II at birth suggest that folate fortification could have diminished the severity of this congenital disease.

PREVALENCE AND CHARACTERISTICS OF UPPER LUMBAR DISC HERNIATIONS IN OUR PRACTICE: A RETROSPECTIVE ANALYSIS

ABSTRACT Introduction: Upper lumbar disc herniations (ULDH) are considered infrequent injuries (1-11%). They present, most often in older adults, with special clinical features that make diagnosis and therapeutic decision-making difficult. The prevalence, location, and management of these herniations and the medical history of our patients were analyzed. Methods: Sex, age, injury level, previous surgery, and patient treatment data from July 2018 to May 2021 were collected retrospectively. During this period, 179 patients underwent surgery, 33 of whom patients presented ULDH. Results: Thirty-three patients were included in the study (18 male and 15 female). Ages ranged from 39 to 85 years, with a predominance of elderly patients. The levels operated were L1-L2 in seven patients, L2-L3 in ten patients, L3-L4 in fourteen patients, and surgery in two levels (L2-L3, L3-L4) in two patients. In our practice, microdiscectomy is the preferred approach and was performed in all cases, with the addition of fusion in four of the 33 patients. Finally, a history of low lumbar disc herniation (LLDH) surgery was found in 16 patients. Conclusions: In our population, ULDHs are a rare entity with lower prevalence at the higher lumbar levels. They occur more frequently in elderly patients and clinical presentation can vary, which is a challenge for surgeons. In older adults, the development of lumbar kyphosis due to vertebral wedging is considered a risk factor for the development of ULDH. Surgical management by microdiscectomy is considered a technique with good results for this pathology. Level of Evidence III; Retrospective, longitudinal, descriptive, observational study.

Ossification and Fusion of the Vertebral Ring Apophysis as an Important Part of Spinal Maturation.

In scoliosis, most of the deformity is in the disc and occurs during the period of rapid growth. The ring apophyses form the insertion of the disc into the vertebral body, they then ossify and fuse to the vertebrae during that same crucial period. Although this must have important implications for the mechanical properties of the spine, relatively little is known of how this process takes place. This study describes the maturation pattern of the ring apophyses in the thoracic and lumbar spine during normal growth. High-resolution CT scans of the spine for indications not related to this study were included. Ossification and fusion of each ring apophysis from T1 to the sacrum was classified on midsagittal and midcoronal images (4 points per ring) by two observers. The ring apophysis maturation (RAM) was compared between different ages, sexes, and spinal levels. The RAM strongly correlated with age (R = 0.892, p < 0.001). Maturation differed in different regions of the spine and between sexes. High thoracic and low lumbar levels fused earlier in both groups, but, around the peak of the growth spurt, in girls the mid-thoracic levels were less mature than in boys, which may have implications for the development of scoliosis.

In silico feasibility assessment of extracorporeal delivery of low-intensity pulsed ultrasound to intervertebral discs within the lumbar spine

Low intensity pulsed ultrasound (LIPUS) may have utility for non-invasive treatment of discogenic lower back pain through stimulating, remodeling and accelerating healing of injured or degenerated intervertebral disc (IVD) tissues. This study investigates the feasibility of delivering LIPUS to lumbar IVDs between L2 and S1 spine vertebra using a planar extracorporeal phased array (8 × 8 cm, 1024 elements, 500 kHz). Three 3D anatomical models with heterogenous tissues were generated from patient CT image sets and used in the simulation-based analysis. Time-reversal acoustic modeling techniques were applied to optimize posterior-lateral placement of the array with respect to the body to facilitate energy deposition in discrete target regions spanning the annulus fibrosus and central nucleus of each IVD. Forward acoustic and biothermal simulations were performed with time-reversal optimized array placements and driving amplitude/phase settings to predict LIPUS intensity distributions at target sites and to investigate off-target energy deposition and heating potential. Simulation results demonstrate focal intensity gain of 5–168 across all IVD targets and anatomical models, with greater average intensity gain (>50) and energy localization in posterior, posterolateral, and lateral target sites of IVDs. Localized LIPUS delivery was enhanced in thinner patient anatomies and in the high lumbar levels (L2-L3 and L3-L4). Multiple amplitude/phasing illumination patterns could be sequenced at a fixed array position for larger regional energy coverage in the IVD. Biothermal simulations demonstrated that LIPUS-appropriate exposures of 100 mW cm−2 ISPTA to the target disc region would result in <1 °C global peak temperature elevation for all cases. Hence, simulations suggest that spatially-precise extracorporeal delivery of therapeutically relevant LIPUS doses to discrete regions of lumbar IVDs is feasible and may be useful in clinical management of discogenic back pain.

Spinopelvic Alignment Parameters in Spondylolisthesis Patients Compared to Nonspondylolisthesis Patients

Abstract Objective We aimed at describing spin pelvic alignment features in patients with degenerative spondylolisthesis (DS), in comparison with other patients complaining of low back pain but no evidence of spondylolisthesis on standard standing lateral lumbosacral X-ray. Methods In this prospective descriptive study, patients with low back pain included in two groups of DS and non-DS patients, according to preoperative lumbosacral X-ray in standard standing lateral position. Patient’s demographic characteristics, as well as spinopelvic alignment parameters including pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), lumbar lordosis, and facet joint orientation, were collected. DS patients were compared with non-DS, age-matched control group. Results DS patients were significantly obese (p = 0.031) and had a high PI (56.39 ± 11.5), SS (38.28 ± 10.32), and PT (18.52 ± 9.11), (p = 0.00, 0.01, 0.04, respectively). Moreover, segmental lordosis at L2–L3, L3–L4, and L5–S1 levels demonstrated a significant increase (p &lt; 0.05). Facet joints at L4–L5 level were located more sagittally (37.5 ± 7.07 vs. 40.71 ± 6.33). Conclusion PI, SS, and PT significantly increase in DS patients compared with non-DS group. Elevated segmental lordosis at high lumbar levels and sagittal orientation of facet joints were other features observed in DS patients.

The distribution of lumbar intervertebral angles in upright standing and extension is related to low back pain developed during standing

BackgroundLumbar lordosis measures are poorly related to clinical low back pain, however using a controlled exposure such as prolonged standing to identify pain groups may clarify this relationship. The purpose of this study was to determine the distribution of lumbar intervertebral angles in asymptomatic persons who do (pain developers) and do not (non-pain developers) develop low back pain during standing. MethodsSagittal plane lumbar spine radiographs of eight pain developers and eight non-pain developers were taken in three poses: upright standing, full extension and full flexion. Measures of vertebral end plate orientations from L1 to S1 were taken in each pose to compute: intervertebral angles, contribution of each level to the total curve, total lordosis, ranges of motion, relative pose positioning within the range of motion, vertebral shape, and lumbar spine recurve. Measures were compared between pain groups and lumbar levels. FindingsPain group differences in intervertebral angles and level contributions were greatest in the full extension pose, with pain developers having greater contributions from higher lumbar levels and fewer contributions from lower levels than non-pain developers. Pain group differences in intervertebral angle distributions were less pronounced in upright standing and non-existent in full flexion. No other measures differentiated pain groups. InterpretationsAlthough participants had similar gross-lumbar spine curvature characteristics, non-pain developers have more curvature at lower levels in upright standing and full extension. These differences in regional vertebral kinematics may partially be responsible for standing-induced low back pain.

The geometric curvature of the lumbar spine during restricted and unrestricted squats.

The main purpose of this study was to analyze the behavior of the geometric curvature of the lumbar spine during restricted and unrestricted squats, using a novel investigative method. The rationale for our hypothesis is that the lumbar curvature has different patterns at different spine levels depending on the squat technique used. Spine motion was collected via stereo-photogrammetric analysis in nineteen participants (11 males, 8 females). The reconstructed spine points at the upright neutral position and at the deepest position of the squat exercise were projected onto the sagittal plane of the trunk, a polynomial was fitted to the data, and were quantified the two-dimensional geometric curvature at lower, central and higher lumbar levels, besides the inclination of trunk and lumbosacral region, the overall geometric curvature and overall angle of the lumbar spine. The mean values for each variable were analysed with paired t-test (P<0.05). The lumbar presents a flexion from upright neutral posture to deepest point of the movement, but for the lower lumbar the flexion is less intense if the knees travel anteriorly past the toes. The trunk and the lumbosacral region lean forward in both squat techniques and these effects are also reduced in unrestricted squats. The data collected in the study are evidence that during barbell squats the lumbar curvature has different patterns at different spinal levels depending on the exercise technique. The lower lumbar spine appears to be less overloaded during unrestricted squats.

Age of independent sitting posture acquisition for children with myelomeningocele

Objective: To study the acquisition of independent sitting posture in patients with high lumbar and thoracic myelomeningocele (MMC). Method: Cross-sectional study in children aged between 6 months and 4 years with MMC. A research was done in medical records and report cards from children being followed in the physical therapy sector at Fernandes Figueira Institute (IFF), Rio de Janeiro, RJ, Brazil. Results: The sample comprised 16 children with MMC, 9 (56%) female and 7 (43%) male, 13 (81.2%) children with high lumbar level, and 3 (18.8%) with thoracic level. In relation to independent sitting posture, 13 (81.2%) achieved this objective. The average time to reach this posture was 16 months (9-31). The average time of physiotherapeutic following was 3 months (1-8). Among the 13 children who sat, 2 (15.4%) were thoracic and 11 (84.6%) high lumbar level cases. Most (15 – 93.8%) performed regular physical therapy. The average age to start treatment was 3 months (1-8). Conclusion: It was observed that the largest part of the sample acquired independent sitting posture, including the thoracic level cases that reached this goal in a younger age than the found in the literature. The results can be considered positive, reinforcing the early physiotherapeutic intervention for the acquisition of motor development, promotion of functionality, and improvement of quality of life of children with MMC.

Surgical Approaches to the Lumbar Hidden Zone: Current Strategies and Future Directions

Surgical Approaches to the Lumbar Hidden Zone: Current Strategies and Future Directions

Clinical and radiological outcomes of unilateral transforaminal lumbar interbody fusion

Background Interbody fusion techniques provide solid fixation, maintain the load-bearing capacity of the spine, maintain proper disc and foraminal heights, have higher fusion rates, and prevent implant failure. Unilateral transforaminal lumbar interbody fusion (TLIF) is a one-stage posterior approach to the disc space that allows unilateral larger cage insertion without violation of the spinal canal by avoiding dural retraction, which is advantageous in revision cases and in higher lumbar levels above L3. Aim The aim of the study was to describe the technique and study the clinical and radiological results of unilateral TLIF. Study design This is a retrospective study on 40 patients with different etiologies treated by unilateral TLIF. Patients and methods A retrospective analysis was performed on 40 patients who had undergone unilateral TLIF during the period from April 2006 to December 2008 for chronic low back pain and radicular leg pain of different etiologies, including isthmic and degenerative spondylolisthesis, and revision cases with failed conservative treatment of more than 3 months. Radiographic assessment was carried out by means of anteroposterior, lateral, and dynamic flexion-extension plain radiographs and MRI. Bony fusion was assessed using the Bridwell anterior fusion grading system. Functional assessment was made using the visual analogue scale (0-10) for back and leg pain and the Oswestry Disability Index questionnaire. Results Unilateral TLIF achieves statistically significant reduction in spondylolisthesis from an average of 35.55 ± 11.62% preoperatively to an average of 3.49 ± 3.29% postoperatively with minimal change seen at final follow-up with restoration of segmental lordosis in all patients. Disc and foraminal heights were restored and corrected from an average of 7.24 ± 1.30 and 13.53 ± 1.91 mm, respectively, preoperatively to 11.80 ± 1.075 and 19.76 ± 1.79 mm, respectively, postoperatively without significant change at last follow-up. Ninety percent of patients had G1 bony fusion and 10% had G2 bony fusion. No patient had G3 or G4 fusion. All patients showed significant postoperative improvement in leg and back pain immediately postoperatively and at last follow-up. Leg pain improved from 7.24 ± 0.61 to 2.26 ± 0.84 SD postoperatively and to 0.65 ± 0.70 SD at last follow-up, and back pain improved from 7.78 ± 0.86 to 2.76 ± 0.89 SD postoperatively and to 0.98 ± 0.75 SD at last follow-up. The average preoperative Oswestry Disability Index score improved from 54.95 ± 7.02 to 10.73 ± 3.28 SD at last follow-up. There were no major intraoperative complications. Conclusion Unilateral TLIF s a safe and effective technique. It provides good clinical and radiological outcomes in different lumbar spinal pathologies. It is especially effective and safe in revision cases with epidural fibrosis when the standard posterior lumbar interbody fusion technique is contraindicated.

Aquisição e Permanência da Marcha com Órtese Longa na Mielomeningocele Nível Lombar Alto

Introduction. The objective of this study was to estimate the mean time for acquisition of ambulation in patients with upper lumbar (UL) myelomeningocele (Mye) using long orthosis (LO); to estimate determinants of persistently using LO. Method. Children from 5 to 17 years of age, with UL Mye, that used LO and received physical therapy for ambulation. Patients were screened by a medical listing, selecting only those with high lumbar level. A questionnaire was ad­ministered on the patient and physical examination. Results. The patients were divided into group 1 (5 to 10 years and 11 months) and group 2 (11 to 16 years and 11 months). The study included 51 patients, 28 from Group 1 and Group 2. Mean time for ambulation using LO was 2.1 years; use of LO was maintained for a mean of 1.9 years after being discharged from physical therapy. Factors positively associated with ambulation were age of training onset and duration of training (p=0.0151 e r2 0.1146), number of surgeries (p=0.074), deformities, overweight and motivation. Conclusion. Earlier onset of training for ambulation and duration of training are associated with increased maintenance of LO use. Use of LO decreases with age (when children seek increased functionality).

The influence of sex, age and BMI on the degeneration of the lumbar spine

Previous research on lumbar spine osteophyte formation has focused on patterned development and the relation of age and sex to degeneration within the vertebral bodies. The inclusion of osteophytes originating on the laminae and body mass index (BMI) may result in a more complete evaluation. This study investigates lumbar osteophyte development on the laminae and vertebral bodies to determine whether osteophyte development: (i) is related bilaterally, at different lumbar levels, and superior and inferior margins; (ii) on the laminae and vertebral bodies are reciprocally dependent responses; (iii) is correlated with sex, age and/or BMI. Seventy-six individuals (39 females, 37 males) were randomly selected from a modern skeletal collection (Bass Donated Collection). Osteophyte development was scored in eight regions on each vertebra at all five lumbar levels. A factor analysis considered all 40 scoring regions and Pearson's correlation analyses assessed the relatedness of age and BMI with the consequent factors. The factor analysis separated the variables into two similar factors for males and females defined as: (i) superior and inferior vertebral body scores and (ii) superior laminar scores at higher lumbar levels. The factor analysis also determined a third factor for females defined as: (iii) inferior laminar scores at lower lumbar levels. The severity of vertebral body osteophytes increased with age for both sexes. Additionally for females, as BMI increased, osteophyte severity increased for both the superior laminar margins higher in the column and the vertebral bodies. Dissimilarities between the factors in males and females and the correlation of BMI to osteophyte severity exclusively in females provide evidence for different biomechanical processes influencing osteophyte development.

Posterior epidural migration of a lumbar disc fragment: a series of 6 cases

The migration of a lumbar intervertebral disc fragment to the posterior epidural space is a rare complication of lumbar disc herniation (LDH), mostly diagnosed intraoperatively. The authors describe a series of 6 patients with a posterior epidural migration of a lumbar intervertebral disc fragment (PEMLIF) and provide a systematic review of the literature. The authors undertook a retrospective case series of patients with PEMLIF who underwent surgery for LDH between February 2007 and June 2010. In 6 (1.04%) of 572 patients a diagnosis of PEMLIF was established. In addition, a systematic review of the literature produced 41 additional cases reported since 1973. The authors analyzed epidemiological, clinical, and imaging features, as well as surgical treatment and outcome of this infrequent form of LDH. This study represents the largest case series to analyze the distinguishing features of PEMLIF. Including the authors' cases, 37 male (78.72%) and 10 female (21.28%) patients (mean age 54.08 years) appear in the literature. Although the predominant clinical disturbance was related to cauda equina compression in 22 patients (46.80%), 19 patients (40.42%) presented with typical symptoms of sciatica or anterior thigh pain. In 27 patients (57.44%), PEMLIFs were localized at high lumbar levels. Magnetic resonance imaging was used in 36 cases. The PEMLIF appeared iso- to hypointense on T1-weighted imaging and had a variable intensity on T2-weighted imaging. After administration of Gd, 85.71% of lesions exhibited a peripheral ring. The preoperative diagnosis was never related to PEMLIF in 68% of cases. The PEMLIF was totally resected in all patients. An additional discectomy was performed in 31 patients (65.95%). Information was incomplete in 1 case. Of the remaining 46 patients, all improved postoperatively: total recovery was achieved in 33 cases (71.74%), subtotal recovery in 2 cases (4.35%), and improvement in 11 cases (23.91%). The postoperative outcome appeared not to depend on the duration or the degree of preoperative neurological deficits or the size of disc fragment. The migration of a lumbar intervertebral disc fragment to the posterior epidural space is a rare event, occurring in an advanced working-age population. Clinical presentation is indistinguishable from the typical LDH, but overall cauda equina symptoms are far more common. High lumbar levels are more affected. Magnetic resonance imaging characteristics are difficult to differentiate from those of other entities. Ring enhancement after Gd administration is common. Outcomes in patients with cauda equina symptoms appear better than those in patients with standard ventral compression.

Use of a personalized hybrid biomechanical model to assess change in lumbar spine function with a TDR compared to an intact spine

Total disc replacements (TDRs) have been employed with increasing frequency in recent years with the intention of restoring natural motion to the spine and reducing adjacent level trauma. Previous assessments of the TDRs have subjectively measured patient satisfaction, evaluated sagittal range of motion via static imaging, or examined biomechanical loading in vitro. This study examined the kinematics and biomechanical loading of the lumbar spine with an intact spine compared to a TDR inserted at L5/S1 in the same spine. A validated biologically driven personalized dynamic biomechanical model was used to assess range of motion (ROM) and lumbar spine tissue forces while a subject performed a series of bending and lifting exertions representative of normal life activities. This analysis concluded that with the insertion of a TDR, forces are of much greater magnitude in all three directions of loading and are concentrated at both the endplates and the posterior element structures compared to an intact spine. A significant difference is seen between the intact spine and the TDR spine at levels above the TDR insertion level as a function of supporting an external load (lifting). While ROM within the TDR joint was larger than in the intact spine (yet within the normal ranges under the unloaded bending conditions), the differences between spines were far greater in all three planes of motion under loaded lifting conditions. At levels above the TDR insertion, larger ROM was present during the lifting conditions. Sagittal motions were often greater at the higher lumbar levels, but there appeared to be less lateral and twisting motion. Collectively, this analysis indicates that the insertion of a TDR significantly alters the function of the spine.

The flow patterns of caudal epidural in upper lumbar spinal pathology

Epidural steroid injections are an important therapeutic modality employed by spinal surgeons in the treatment of patients with chronic low back pain with or without lumbar radiculopathy. The caudal epidural is a commonly used and well-established technique; however, little is known about the segmental level of pathology that may be addressed by this intervention. This prospective study of over 50 patients aimed to examine the spreading pattern of this technique using epidurography. The effect of variation in Trendelenburg tilt and the eradication of lumbar lordosis on the cephalic distribution of the injectate were investigated. 52 patients with low back pain and radiculopathy underwent caudal epidural. All had 20 ml volume injected, comprised of 5 ml contrast (Ultravist™ Schering) 2 ml Triamcinolone (Adcortyl™ Squibb) and 13 ml local anaesthetic (1% lignocaine). Patients were randomised to either 0° or 30° of Trendelenburg tilt, as referenced from the lumbar spine. Patients were further randomised to presence or absence of lumbar lordosis, which was eradicated using a flexion device placed beneath the prone patient. A lateral image of each sacrum was obtained, to identify variations in sacral geometry particularly resistant to cephalic spread of injectate. The highest segment reached on fluoroscopy was recorded post injection. Fifty-two patients with a mean age of 50 years underwent caudal epidural. Thirty-one were in 0° head tilt, with 21 in 30° of head tilt. In each of these groups, 50% had their lumbar lordosis flattened prior to caudal injection. The median segmental level reached was L3, with a range from T9 to L5. Eradication of lumbar lordosis did not significantly alter cephalic spread of injectate. There was a trend for 30° tilt to extend the upper level reached by caudal injection (p=0.08). There were no adverse events in this series. Caudal epidural is a reliable and relatively safe procedure for the treatment of low back pain. Pathology at L3/4 and L4/5 and L5/S1 can be approached by this technique. Although in selected cases thoracic and high lumbar levels can be reached, this is variable. If pathology at levels above L3 needs to be addressed, we propose a 30° head tilt may improve cephalic drug delivery. The caudal route is best reserved for pathology below L3.

Ambulation follow-up in patients with myelomeningocele treated at the Associação de Assistência à Criança Deficiente (AACD) in São Paulo, Brazil

Myelomeningocele (MMC) is a congenital malformation of the vertebral column and spinal cord, characterized by flaccid paraplegia and sensitive alteration below the lesion level, accompanied by neurological, urological and orthopedic impairment. The patients can be classified as thoracic (T), high lumbar (HL), low lumbar (LL) and sacral (S) or asymmetric. Objective: to describe the profile of the patients treated at the MMC Clinic of the Assistance Association to the Defective Child - AACD – SP, considering variables related to the gait pattern. Methods: review of files of the patients seen at the initial assessment during the year 2000, aged younger than one year and their follow-up until their last visit to clinic in the year 2004. Results: A total of 230 patients were seen at the initial assessment at the MMC Clinic of AACD - SP in the year 2000. Of these, 64 (27%) were younger than 1 year at the first assessment. Of these, 11% did not return to the Clinic after the initial assessment and two patients died. Mean age at the last visit to the Clinic was 3.5 years. When the neurological level at the return assessment was analyzed, we found: 43% of Thoracic level, 20% of High Lumbar level, 28% of Low Lumbar level, 2% Sacral level and 6% Asymmetric. When the gait pattern was analyzed, we observed that 57% of them were not ambulators, 7% were non-functional ambulators, 25% were home ambulators and 11% were community ambulators. Among the ambulating patients, the average age at the start of gait was 3 years. It is known that patients with lower neurological levels tend to maintain the gait for longer periods. As these patients tend to become less active and lose gait ability with the passing years (mainly due to obesity and orthopedic deformities), it is essential to study the age at acquisition of gait ability. When we analyzed the presence of orthopedic deformities in the column, we observed that 57% of the patients did not present deformities, 9% presented thoracolumbar scoliosis, 32% presented kyphosis and 1% presented hyperlordosis. Tethered spinal cord syndrome occurred in 36% of the patients. Conclusion: The higher functional levels are associated to a later acquisition of gait, as well as more orthopedic deformities and higher need for auxiliary means.

Cluster Analysis as a Method for Determining Size Ranges for Spinal Implants: Disc Lumbar Replacement Prosthesis Dimensions from Magnetic Resonance Images

Statistical analysis of clinical radiologic data. To develop an objective method for finding the number of sizes for a lumbar disc replacement. Cluster analysis is a well-established technique for sorting observations into clusters so that the "similarity level" is maximal if they belong to the same cluster and minimal otherwise. Magnetic resonance scans from 69 patients, with no abnormal discs, yielded 206 sagittal and transverse images of 206 discs (levels L3-L4-L5-S1). Anteroposterior and lateral dimensions were measured from vertebral margins on transverse images; disc heights were measured from sagittal images. Hierarchical cluster analysis was performed to determine the number of clusters followed by nonhierarchical (K-means) cluster analysis. Discriminant analysis was used to determine how well the clusters could be used to classify an observation. The most successful method of clustering the data involved the following parameters: anteroposterior dimension; lateral dimension (both were the mean of results from the superior and inferior margins of a vertebral body, measured on transverse images); and maximum disc height (from a midsagittal image). These were grouped into 7 clusters so that a discriminant analysis was capable of correctly classifying 97.1% of the observations. The mean and standard deviations for the parameter values in each cluster were determined. Cluster analysis has been successfully used to find the dimensions of the minimum number of prosthesis sizes required to replace L3-L4 to L5-S1 discs; the range of sizes would enable them to be used at higher lumbar levels in some patients.

Modeling of object movement capability in the spinal cord injured population

Static biomechanical modeling has revealed that human reaching and object movement capabilities are dependent on both torso and upper extremity muscle strengths, and the ability to maintain balance throughout the movement. This paper describes data and biomechanical models that can be used to understand the dynamic motions of people with and without thoracic level spinal cord injuries (SCIs) while moving objects around in their environments. This paper also discusses how data gathered in the Human Motion Simulation (HUMOSIM) Laboratory from volunteer subjects performing various seated tasks are used in multi-joint inverse biomechanical models to predict both shoulder moments and body center of pressure locations. The results demonstrate that when symptomatic control subjects moved a box from a small table in front of them to a shoulder-high shelf, it was performed in a smooth fashion that could be well modeled and understood with the use of sequential static biomechanical models. The motions of those subjects with thoracic and high lumbar level SCIs, however, contained an additional dynamic component. The dynamic component revealed that healthy, active SCI subjects were quite capable of extending the distance over which they can move objects to rigid shelves by using a ballistic motion technique. This dynamic motion allows them to move objects to shelves located over twice the distance predicted by static models of such motions, but also raises questions of safety due to falling forward if the object being moved does not land securely on the shelf. These types of motions also are shown to cause much higher (by about 30%) shoulder moments, thus raising the risk of injury to shoulder tissues in people with SCIs. Relevance to industry This paper shows that biomechanical models for predicting the capabilities of people to move objects when they have thoracic level spinal cord injuries (SCIs) will require dynamic elements to be carefully considered. It is believed that the results of the data and biomechanical modeling included in this study provide a scientific basis for improving design guides, so that in the future such workplaces will better accommodate people with SCIs.

Cross-sectional area of the lumbar back muscles as a function of torso flexion

Objective. Quantification of the maximum anatomical cross-sectional area of the lumbar back muscles as a function of torso flexion angle and development of prediction equations as a function of torso flexion and anthropometric measures. Background. Cross-sectional areas of the lumbar back muscles used as inputs into biomechanical models have traditionally been derived from subjects lying in the neutral supine posture. However, it is known that the cross-sectional area of muscle is altered as the torso angle changes. Design. Experimental design consisted of a two-factor multivariate analysis of variance on the cross-sectional area of the lumbar torso muscle across the lumbar levels, as a function of gender and torso angle. Hierarchical linear regression was utilized to assess the association between cross-sectional area and individual and torso posture characteristics. Method. Axial MRI scans, through and parallel to each of the lumbar intervertebral discs at four torso flexion positions were obtained from subjects in a lateral recumbent posture. Cross-sectional areas were quantified and converted into anatomical cross-sectional areas utilizing known fascicle orientations. Results. The maximum anatomical cross-sectional area was located between the L 3/L 4 and L 4/L 5 level in the neutral posture. The anatomical cross-sectional areas at the L 4/L 5 and L 5/S 1 decreased during torso flexion, however, the percent change varied as a function of the individual level. The majority of the anatomical cross-sectional area variability was explained by gender and body mass. Lumbar curvature explained a larger proportion of the anatomical cross-sectional area variability at the lower lumbar levels than at the higher lumbar levels. Conclusions. The maximum anatomical cross-sectional area of the lumbar back muscles occur at the neutral torso posture and did not decrease as a function of torso flexion. When using maximum anatomical cross-sectional area or specific lumbar level anatomical cross-sectional areas, it appears necessary to account for gender and body mass. At the lower lumbar levels, knowledge of spinal curvature plays an increasing role in the estimation of the size of the lumbar torso muscle cross-sectional area. Relevance This research indicates the lower lumbar level trunk muscle anatomical cross-sectional area decrease as torso flexion increases, however, the maximum lumbar trunk muscle anatomical cross-sectional area does not vary as a function of torso flexion. Accounting for gender, body mass, torso characteristics and lumbar curvature may help increase accuracy of anatomical cross-sectional area prediction, as well as muscle force predictions from biomechanical models.