Lumbar Vertebral Column Research Articles

Modic changes in the lumbar vertebral column of chondrodystrophic and non-chondrodystrophic dogs with intervertebral disc disease.

Modic changes (MC) are signs of vertebral pathology visible on magnetic resonance (MR) images that have been associated with low back pain (LBP) and disc degeneration in people. Multiple breeds of dogs also develop MCs and coincident back pain. However, the association between breed, MC, and spinal pathologies has yet to be fully elucidated. This study aimed to identify the prevalence of MC that occur spontaneously in the lumbar vertebral column of dogs diagnosed with intervertebral disc disease (IVDD) and examine their association with demographic criteria and the disc width index (DWI). Medical records and lumbar vertebral column MR images were examined from 104 dogs (831 intervertebral disc spaces and adjacent vertebrae), which were divided into three groups: chondrodystrophic dogs (CD; n =54) and non-chondrodystrophic dogs (NCD; n =30) with IVDD as the primary diagnosis, and control dogs (n =20) with other spinal diseases as their primary diagnosis. Increasing age and a diagnosis of IVDD were significantly associated with MC in dogs (p < 0.001 and p = 0.0062, respectively). In CD dogs with IVDD, Type 2 MC were most prevalent, whereas, in NCD dogs, Type 3 MC were the most prevalent type. Type 2 MC were distributed nearly equally across the lumbar vertebral column, while Type 3 MC were primarily detected at the level of L7-S1. This study demonstrated that MC developed spontaneously in dogs, are common in dogs diagnosed with IVDD, and the type observed varies by breed. Further research is needed to understand the pathogenesis of MC; however, the increased presence of Type 2 MC in CD dogs, similar to what is found in people with disc degeneration, suggests that CD dogs could serve as models for MC in people.

Lumbar spinal arachnoid diverticulum in a cat

AbstractA 5‐year‐old, domestic, shorthair, male, neutered cat was referred to the Companion Animal Clinic with a history of paraparesis and urinary incontinence, alongside recurrent urinary tract infections. Magnetic resonance imaging of the lumbar vertebral column revealed a space‐occupying spinal cyst‐like lesion located at the level of fifth and sixth lumbar vertebrae. Surgical treatment consisted of dorsal laminectomy and durectomy, resulting in decompression. Histopathology findings were indicative of spinal arachnoid diverticulum. Postoperatively, the cat exhibited gradual hindlimb and tail motor improvement, and recovery of voluntary urination. Complete resolution of the neurological signs was achieved at 3 months after surgery. No signs of recurrence were noted till the time of writing this report, 14 months postoperatively. To the authors’ knowledge, this is the first case report of a spinal arachnoid diverticulum in the lumbosacral vertebral column in a cat.

Variation of thoracolumbar vertebral morphology in anthropoid primates.

Morphological variation among extant primates in the lumbar vertebral column is well studied. However, knowledge concerning the thoracic spine, an important region responsible for supporting and facilitating movement in the upper trunk, remains relatively scarce. Consequently, our comprehension of the functional differentiation exhibited throughout the thoracolumbar vertebral column among various primate species remains constrained. In this study, we examined patterns of morphological variation in the thoracolumbar vertebral column of extant hominoids, cercopithecoids, and Ateles. We collected external shape data on 606 thoracic and lumbar vertebrae from Homo sapiens, Pan troglodytes, Hylobates lar, Macaca fuscata, Chlorocebus aethiops, Colobus guereza, Ateles geoffroyi, and A. belzebuth. Forty-four landmarks were obtained on the three-dimensional surface. Geometric morphometrics was used to quantify the centroid size and variation of the shapes of thoracic and lumbar vertebrae. Cercopithecoids exhibited greater variation in the size and shape of their thoracic and lumbar vertebrae compared to hominoids and Ateles. Although many vertebral features contributed to the observed variation throughout the thoracolumbar vertebral column within the taxon, the transverse and spinous processes exhibited relatively major contributions. Our results suggest that quadrupedal locomotion requires the functional differentiation between thoracic and lumbar vertebrae, and for hominoids, functional adaptation to orthograde posture necessitates a relatively more uniform shape of thoracic and lumbar vertebrae.

Lumbar vertebral bone density is decreased in horses with pituitary pars intermedia dysfunction.

Pathological fractures have been reported in equids with pituitary pars intermedia dysfunction (PPID) but their prevalence and pathogenesis is unknown. To compare: (1) bone mineral density (BMD) in weight bearing and nonweight bearing bones in PPID+ equids and aged and young PPID- controls; and (2) biomechanical properties of the fourth lumbar vertebral body in PPID+ equids and aged PPID- equids. Case-control study: five PPID+ equids and six aged and four young PPID- control horses. PPID status was based on clinical signs and necropsy examination of the pituitary gland (PG). The lumbar vertebral column, right front third metacarpus (MC3), left hind third metatarsus (MT3), and PG were removed after euthanasia. BMD was determined by quantitative computed tomography of regions of interest (ROI) in each bone and biomechanical testing was performed on the fourth lumbar vertebral body. Serum concentrations of parathormone (PTH), ionised Ca++ , 25-hydroxyvitamin D, and osteocalcin (OC) were also measured. Data were analysed using one-way ANOVA and correlation analyses. BMD of trabecular and cortical regions of interest (ROI) of the third, fourth (L4), and fifth lumbar vertebrae were significantly lower in PPID+ equids as compared with aged (p < 0. 001) and young (p < 0.01) PPID- controls. In contrast, no differences were found in BMD of trabecular or cortical ROIs of MC3 and MT3 between groups. No differences were detected in force at fracture, displacement at fracture, Young's modulus or strain of L4 between PPID+ and aged PPID- horses. No differences were found in serum PTH, ionised Ca++ , 25-hydroxyvitamin D, or OC concentrations between groups. Limited number of equids studied and variation in test results. BMD of nonweight bearing bones can be decreased with PPID and could increase risk of developing pathological fractures.

Osseous pathologic changes in the lumbar region of the equine vertebral column: A descriptive post-mortem study in three breeds.

Data on equine lumbar pathology hardly exist in breeds other than Thoroughbreds. To describe pathological changes of the osseous lumbar vertebral column in Warmblood horses, Shetland ponies and Konik horses. Descriptive post-mortem study. The lumbar vertebral columns of 34 Warmblood horses, 28 Shetland ponies, and 18 Konik horses were examined by computed tomography (CT). Osteoarthritis (OA) of articular processes (APJs), OA of intertransverse joints (ITJs), intervertebral disc (IVD) mineralisation, impingement of spinous (SPs) and transverse (TPs) processes and spondylosis were scored. Breed differences in prevalence and severity of pathologies were analysed by linear regression analysis and by calculating Spearman's rank correlation coefficients (rs). In Warmblood horses, the prevalence of OA of APJs, impingement of SPs and TPs was respectively 90%, 36%, and 35%, significantly higher than in the other breeds (p < 0.001). In Konik horses, IVD mineralisation (40%) and spondylosis (10%) were more frequent than in Warmbloods and Shetland ponies (p = 0.03). Severity score for OA of ITJs was highest in Shetland ponies (p < 0.001). For impingement of SPs, severity score was highest in Warmbloods (p = 0.03), and of TPs lowest in Shetland ponies (p = 0.003). For all parameters, except for spondylosis in Shetland ponies, there was a positive correlation between percentage of vertebrae affected and age, with IVD mineralisation scores increasing faster in Konik horses (p < 0.001). In all breeds, there was also a positive relation between scores of severity and age for OA of APJs and ITJs and for IVD mineralisation, with severity scores increasing faster in Shetland ponies (p = 0.04). Strong left/right correlations of the severity scores were seen for OA of the APJ, ITJ, impingement of TPs, and paramedian spondylosis (rs = 0.74-0.86, all p < 0.001). Clinical histories were not available. There are distinct breed differences between prevalence and severity of osseous pathologies of the lumbar spine. Warmblood horses have higher scores for most pathologies with IVD mineralisation being more important in Konik horses and OA of ITJs in Shetland ponies.

Development, calibration and validation of a comprehensive customizable lumbar spine FE model for simulating fusion constructs.

Instrumentation alters the biomechanics of the spine, and therefore prediction of all output quantities that have critical influence post-surgically is significant for engineering models to aid in clinical predictions. Geometrical morphological finite element models can bring down the development time and cost of custom intact and instrumented models and thus aids in the better inference of biomechanics of surgical instrumentation on patient-specific diseased spine segments. A comprehensive hexahedral morphological lumbosacral finite element model is developed in this work to predict the range of motions, disc pressures, and facet contact forces of the intact and instrumented spine. Facet contact forces are needed to predict the impact of fusion surgeries on adjacent facet contacts in bending, axial rotation, and extension motions. Extensive validation in major physiological loading regimes of the pure moment, pure compression, and combined loading is undertaken. In vitro, experimental corridor results from six different studies reported in the literature are compared and the generated model had statistically significant comparable values with these studies. Flexion, extension and bending moment rotation curves of all segments of the developed model were favourable and within two separately established experimental corridor windows as well as recent simulation results. Axial torque moment rotation curves were comparable to in vitro results for four out of five lumbar functional units. The facet contact force results also agreed with in vitro experimental results. The current model is also computationally efficient with respect to contemporary models since it uses significantly smaller number of elements without losing the accuracy in terms of response prediction. This model can further be used for predicting the impact of different instrumentation techniques on the lumbar vertebral column.

Mega-Cecum with Short Intraperitoneal Ascending Colon and Retrocecal Terminal Ileum: A Short Review and Case Report

The dissection of the abdominal cavity of an 81-year-old male donor revealed an unusually large cecum, filling the right iliac fossa and most part of the right side of the peritoneal cavity up to the fundus of the gall bladder. It was attached to the parietal peritoneum of the posterior abdominal wall by a short mesocecum. The ileocecal junction was shifted posterolaterally, closer to the posterolateral abdominal wall and the terminal ileum was found running from medial to lateral dorsal to the cecum (retrocecal) to reach the ileocecal junction. The cecum continued into a short intraperitoneal ascending colon with a long ascending mesocolon. The transitional area between the cecum and ascending colon was displaced medially close to the lumbar vertebral column. Since the ileocecal region is one of the common sites of different kinds of gastrointestinal diseases, such a complex variation can cause diagnostic and therapeutic difficulty that could result in failure of treatment as well as iatrogenic injuries during various procedures. Therefore, gastroenterologists, gastrointestinal surgeons and radiologists must be aware of such coexisting variations of the cecum, ileum and ascending colon.

Does the VDR gene polymorphism influence the efficacy of denosumab therapy in postmenopausal osteoporosis?

One of the challenges of personalized medicine is a departure from traditional pharmacology toward individualized, genotype-based therapies. Postmenopausal osteoporosis is a prevalent condition requiring intensive treatment, whose effects are measurable only after a long time, and the goal is bone fracture prevention. This study aimed to determine the influence of VDR gene variation on anti-osteoporotic one-year treatment with denosumab in 63 Polish women with postmenopausal osteoporosis. The correlation between bone mineral density (BMD) of the lumbar vertebral column (L1-L4) and femoral neck, and genotype distributions for the ApaI, BsmI, FokI, and TaqI variants of the VDR gene was analyzed. Bone fractures during denosumab therapy were also investigated. In the case of the Bsml polymorphism, female patients with BB and Bb genotypes had statistically significantly higher values of BMD and T-score/Z-score indicators, which persisted after a year of denosumab treatment. Our results indicated that the Bsml polymorphism contributes to better bone status, and, consequently, to more efficient biological therapy. The study did not reveal significant differences between changes (delta) in BMD and genotypes for the analyzed VDR gene loci. In the entire study group, one bone fracture was observed in one patient throughout the yearlong period of denosumab therapy. BB and Bb genotypes of the Bsml polymorphism of the VDR gene determine higher DXA parameter values both before and after one-year denosumab therapy in postmenopausal women with osteoporosis.

Lumbar overlordosis — towards the better understanding of the May-Thurner syndrome pathogenesis

Introduction: May-Thurner Syndrome (MTS) is a condition in which the left common iliac vein is compressed by the right common iliac artery, which together with intraluminal vein changes can lead to clinically symptomatic venous outflow obstruction. Patients having such pathology may suffer from symptoms of venous hypertension as well as lower leg deep venous thrombosis. In most of the MTS cases, static and continuous compression is observed which can also lead to the intraluminal spur formation. According to the literature, among the factors which can influence the severity of iliac vein compression, lumbar spinal degeneration can also be mentioned. Considering the aortic bifurcation anatomical conditions, also other, non — degenerative changes of the lumbar vertebral column segment can be taken into consideration. Aim: This study aimed to reveal the prevalence of the left common iliac vein compression in young healthy individuals as well as to assess the severity of the left iliac vein compression provoked by lumbar hyperlordosis. Material and methods: The study was performed on a group of 207 volunteers of both sexes, aged 21–27 yrs. using ultrasound examination to measure the diameter of the right common iliac vein as well as the diameter of the left common iliac vein in the area of the possible compression by the right iliac artery. In all the patients the measurements were performed in the supine position as well as in the provoked lumbar hyperlordosis position. In all the individuals the presence of the symptoms and signs of the lower leg chronic venous disease were investigated. Results: The mean anterior-posterior diameter of the right common iliac vein in the standard supine position in the whole study group was 5.71 mm (± 0.6 mm). The mean diameter of the left common iliac vein in a normal horizontal position was 4.87 mm (± 0.6 mm) with a range from 3.8 mm to 6.2 mm. In most of the cases, the difference between the left and iliac common vein diameter (when measured in the place of the right iliac artery crossing) did not exceed 20%. In 15.9% of the study subjects, the right and left iliac vein diameter difference ranges between 20–30% and in 2.41% only, the diameter difference over 30% was noticed (in none of the cases the stenosis exceeding 40% of the vein diameter was found). Looking for the effect of the overlordosis on the proclivity to decrease left iliac vein diameter, in the provoked hyperlordosis position the changes of the iliac vein diameter in the range of 21–30% were observed in 15.9% and over 30% in 2.4% of the study subjects. Hyperlordosis presence was also responsible for the shift towards lower left iliac vein diameter — in 36.2% of the patients, the left iliac vein diameter below 4 mm was noticed including 1.9% of individuals with a diameter not exceeding 3 mm. In the analysis, there was no statistically significant correlation between the presence of the reported CVD symptoms in the left leg and the reported diameter reduction between the right and left iliac veins in the population of the studied young individuals. Conclusions: Left common iliac vein compression may be anatomically conditioned at least in some of the young population individuals. Lumbar hyperlordosis influence on the left common iliac vein diameter suggests that also in healthily individuals, an incorrect spinal position can promote the occurrence of the left iliac vein compression. Further studies are needed to assess the haemodynamic influence of these findings on the lower leg venous outflow.

Morphometric Assessment of Pedicles of Indian Adult Lumbar Vertebrae: A Cross Sectional Study

Introduction: Lumbar vertebral column is exposed to various kinds of stress during locomotion. In erect posture weight transmitted through posterior part including pedicles. This causes deformities of this region as the age advances in many individuals. Proper correction of deformity is challenging. There have been advances in spinal fusion procedures and interspinous implantation of devices including pedicle screws. Use of unsuitable dimensions of screw may cause problem of destruction of pedicle. Correct metricular data of pedicle is necessary for choice of appropriate screw size. Aims and Objectives: 1) To measure the various dimensions in Indian adult human lumbar vertebral pedicles. 2) To prepare data of lumbar pedicles useful in various surgical procedures. Material and Methods: A Cross-sectional study was done on 45 dry, fully ossified human lumbar vertebral sets. The bones were grouped into typical (L1 to L4) and atypical (L5) lumbar vertebrae. The dimensions measured included pedicle length, height, thickness, axial length, transverse and sagittal angles. ‘Digital Vernier Caliper’ and Protractor were used. The data was analyzed statistically. Results: The mean length, height and thickness of typical vertebral pedicles increases gradually. In atypical (L5), pedicle thickness suddenly increases. The transverse angle of pedicle elevated gradually from L1 to L4 but at L5, it abruptly increased. Conclusions: The study reported significant differences in several dimensions of pedicles of typical as well as atypical lumbar vertebrae. These differences should be considered by neurosurgeons. KEY WORDS: Anatomy; Dimensions; Lumbar Vertebral Pedicle; Pedicle Screw Fixation.

A novel reconstructive approach of the lumbar vertebral column from 2D MRI to 3D models

IntroductionLow back pain (LBP), arising from the lumbar vertebral column (LVC), is a global burden, ranking highest in terms of disability. In the United Arab Emirates (UAE), there is a high prevalence of LBP in the adult population. As MRI has emerged as the mainstay in assessment of LVC-related conditions, this study aimed to reconstruct reproducible 3D LVC MRI models from 2D MRI scans. MethodsFollowing the extraction of serial 2D MRI scan slices from an existing image database, fifty 3D MRI models (n = 50) were retrospectively reconstructed (Mimics Innovation Suite ®) and analyzed through the bootstrapping technique. ResultsLumbar vertebral bodies depicted kidney and oval shapes, with an increasing frequency of the former traced from L1 to L5. Traction (10%) and claw (14%) osteophyte types were noted. The inferior rims of L2 (2%) and L4 (4%) presented with the co-existence of both osteophyte types, which was reflective of the same degenerative process. Morphometric dimensions of L1 were also determined: Anterior vertebral height: 29.6 ± 3.5 mm (28.6–30.5 mm); Posterior vertebral height: 26.8 ± 3.1 mm (25.9–29.6 mm); Superior vertebral width: 40.6 ± 3.8 mm (39.6–41.6 mm); Intervertebral disc height between L1 and L2: 15.9 ± 6.3 mm (14.3–17.7 mm). ConclusionA proof-of-concept in the reconstructive approach of the LVC was established, which introduces a process through which a normative simulated dataset can be obtained in the extended population. Additionally, these values will assist to detect structural disproportions and changes and contribute to pre-operative planning and artificial intervertebral disc implant design.

MRI characteristics of ventral vertebral venous plexus occlusion due to lymphoma in a large breed dog.

Intravascular lymphoma is a rare presentation of lymphoma with a predilection to the central nervous system (CNS). A 9-year-old male-neutered Collie presented with a 3-month history of lymphadenopathy and a 6-day history of an acute onset, progressive, painful, symmetrical L4-S3 myelopathy. Magnetic resonance imaging revealed multifocal extradural spinal cord compressions from L3 to L6 secondary to a bilaterally enlarged and occluded ventral vertebral venous plexus (VVVP). Histopathology revealed low-grade lymphoma within the venous plexus in the lumbar vertebral column, tracheobronchial lymph nodes, and tonsils. Intravascular lymphoma should be considered a differential diagnosis for enlarged VVVP causing compression of the spinal cord.

10. Incomplete cefuroxime penetration to the anterior and posterior column of the lumbar spine: an experimental porcine study

BACKGROUND CONTEXT Surgical site infection following spine surgery is associated with increased morbidity and mortality. Perioperative antibiotic prophylaxis is a key factor in lowering the risk of acquiring an infection. Previous studies have assessed perioperative cefuroxime concentrations in the anterior column of the cervical spine with an anterior surgical approach. However, the majority of surgeries are performed in the posterior column and many surgeries involve the lumbar spine. PURPOSE The objective of this study was to compare the perioperative tissue concentrations of cefuroxime in the anterior and posterior column during lumbar spine surgery with a posterior surgical approach. STUDY DESIGN/SETTING In vivo experimental pharmacokinetics study of cefuroxime concentrations in an acute preclinical porcine model. OUTCOME MEASURES The primary end-point was the time above cefuroxime clinical breakpoint minimal inhibitory concentration (T>MIC) for Staphylococcus aureus of 4 µg/mL. The secondary end-point was tissue penetration (AUCtissue/AUCplasma). METHODS The lumbar vertebral column was exposed from L1 to L5 in eight female pigs. Microdialysis catheters were placed for sampling in the anterior column (vertebral body) and posterior column (posterior arch) within the same vertebra (L5). Cefuroxime (1.5 g) was administered intravenously. Microdialysates and plasma samples were continously obtained over eight hours. Cefuroxime concentration were quantified by ultra high-performance liquid chromatography tandem mass spectrometry. RESULTS Mean T>MIC 4 µg/mL (95% confidence interval) was 123 min (105-141) in plasma, 97 min (79-115) in the anterior column and 93 min (75-111) in the posterior column. Tissue penetration (95% confidence interval) was incomplete for both the anterior column 0.48 (0.40-0.56) and posterior column 0.40 (0.33-0.48). CONCLUSIONS T>MIC was comparable between the anterior and posterior column. Mean cefuroxime concentrations decreased below the clinical breakpoint MIC for S. aureus of 4 µg/mL after 123 min (plasma), 97 min (anterior column) and 93 min (posterior column). Open lumbar spine surgery often involves extensive soft tissue dissection, stripping and retraction of the paraspinal muscles which may impair the local blood flow exposing the lumbar vertebra to postoperative infections. A single intravenous administration of 1.5 g cefuroxime only provided sufficient prophylactic target tissue concentrations in the vertebrae of the lumber spine for up to 1.5 hours. This is shorter than the duration of most lumbar spine surgeries, and therefore alternative dosing regimens should be considered in posterior open lumbar spine surgeries lasting more than 1.5 hours. FDA DEVICE/DRUG STATUS cefuroxime (Approved for this indication). Surgical site infection following spine surgery is associated with increased morbidity and mortality. Perioperative antibiotic prophylaxis is a key factor in lowering the risk of acquiring an infection. Previous studies have assessed perioperative cefuroxime concentrations in the anterior column of the cervical spine with an anterior surgical approach. However, the majority of surgeries are performed in the posterior column and many surgeries involve the lumbar spine. The objective of this study was to compare the perioperative tissue concentrations of cefuroxime in the anterior and posterior column during lumbar spine surgery with a posterior surgical approach. In vivo experimental pharmacokinetics study of cefuroxime concentrations in an acute preclinical porcine model. The primary end-point was the time above cefuroxime clinical breakpoint minimal inhibitory concentration (T>MIC) for Staphylococcus aureus of 4 µg/mL. The secondary end-point was tissue penetration (AUCtissue/AUCplasma). The lumbar vertebral column was exposed from L1 to L5 in eight female pigs. Microdialysis catheters were placed for sampling in the anterior column (vertebral body) and posterior column (posterior arch) within the same vertebra (L5). Cefuroxime (1.5 g) was administered intravenously. Microdialysates and plasma samples were continously obtained over eight hours. Cefuroxime concentration were quantified by ultra high-performance liquid chromatography tandem mass spectrometry. Mean T>MIC 4 µg/mL (95% confidence interval) was 123 min (105-141) in plasma, 97 min (79-115) in the anterior column and 93 min (75-111) in the posterior column. Tissue penetration (95% confidence interval) was incomplete for both the anterior column 0.48 (0.40-0.56) and posterior column 0.40 (0.33-0.48). T>MIC was comparable between the anterior and posterior column. Mean cefuroxime concentrations decreased below the clinical breakpoint MIC for S. aureus of 4 µg/mL after 123 min (plasma), 97 min (anterior column) and 93 min (posterior column). Open lumbar spine surgery often involves extensive soft tissue dissection, stripping and retraction of the paraspinal muscles which may impair the local blood flow exposing the lumbar vertebra to postoperative infections. A single intravenous administration of 1.5 g cefuroxime only provided sufficient prophylactic target tissue concentrations in the vertebrae of the lumber spine for up to 1.5 hours. This is shorter than the duration of most lumbar spine surgeries, and therefore alternative dosing regimens should be considered in posterior open lumbar spine surgeries lasting more than 1.5 hours.

Cefuroxime concentrations in the anterior and posterior column of the lumbar spine – an experimental porcine study

BACKGROUND CONTEXTSurgical site infection following spine surgery is associated with increased morbidity and mortality. Perioperative antibiotic prophylaxis is a key factor in lowering the risk of acquiring an infection. Previous studies have assessed perioperative cefuroxime concentrations in the anterior column of the cervical spine with an anterior surgical approach. However, the majority of surgeries are performed in the posterior column and many surgeries involve the lumbar spine. PURPOSEThe objective of this study was to compare the perioperative tissue concentrations of cefuroxime in the anterior and posterior column during lumbar spine surgery with a posterior surgical approach. STUDY DESIGNIn vivo experimental pharmacokinetic study of cefuroxime concentrations in an acute preclinical porcine model. METHODSThe lumbar vertebral column was exposed from L1 to L5 in 8 female pigs. Microdialysis catheters were placed for sampling in the anterior column (vertebral body) and posterior column (posterior arch) within the same vertebra (L5). Cefuroxime (1.5 g) was administered intravenously. Microdialysates and plasma samples were continuously obtained over 8 hours. Cefuroxime concentrations were quantified by Ultra High Performance Liquid Chromatography Tandem Mass Spectrometry. The primary endpoint was the time above the cefuroxime clinical breakpoint minimal inhibitory concentration (T>MIC) for Staphylococcus aureus of 4 µg/mL. The secondary endpoint was tissue penetration (AUCtissue/AUCplasma). RESULTSMean T>MIC 4 µg/mL (95% confidence interval) was 123 min (105–141) in plasma, 97 min (79–115) in the anterior column and 93 min (75–111) in the posterior column. Tissue penetration (95% confidence interval) was incomplete for both the anterior column 0.48 (0.40–0.56) and posterior column 0.40 (0.33–0.48). CONCLUSIONST>MIC was comparable between the anterior and posterior column. Mean cefuroxime concentrations decreased below the clinical breakpoint minimal inhibitory concentration for S. aureus of 4 µg/mL after 123 minutes (plasma), 97 minutes (anterior column) and 93 minutes (posterior column). This is shorter than the duration of most lumbar spine surgeries, and therefore alternative dosing regimens should be considered in posterior open lumbar spine surgeries lasting more than 1.5 hours. CLINICAL SIGNIFICANCEOpen lumbar spine surgery often involves extensive soft tissue dissection, stripping and retraction of the paraspinal muscles which may impair the local blood flow exposing the lumbar vertebra to postoperative infections. A single intravenous administration of 1.5 g cefuroxime only provided sufficient prophylactic target tissue concentrations in the vertebra of the lumbar spine for up to 1.5 hours.

Geometric Mapping of the Lumbar Vertebral Column in the United Arab Emirates

Lower back pain, originating in the lumbar vertebral region, is often overlooked in the public healthcare system as it is deemed to be an undramatic problem. While treating it poses a challenge for orthopaedicians, lumbar spine disorders are also considered to be one of the most expensive ailments from a socio-economic perspective. Since eighty percent of the adult population in the United Arab Emirates (UAE) is reported to present with lumbar spine disorders, often attributed to ageing, fall from a height, and traffic-related injuries; this study developed a reproducible computational model of the lumbar vertebral column that was representative of the local and expatriate populations of the UAE. Serial 2D MRI scan slices of lumbar vertebral columns were extracted from an existing image database and were reconstructed into fifty 3D MRI models (n = 50). Morphometric evaluation and classification of morphological features of the lumbar vertebrae were then conducted. Although the first lumbar vertebral body appeared to be oval in shape (58%), the bodies of lumbar vertebrae (L) 2-5 were predominantly kidney-shaped. The presence of osteophytes was noted between L3-L4 (16%) and L4-L5 (16%), suggesting underlying degenerative changes. Mean values were also established for the anterior vertebral height (27.84±4.58mm), posterior vertebral height (25.42±2.64mm), superior vertebral width (43.93±10.84mm) and L1/L2 intervertebral disc height (15.34±8.27mm). As this study incorporated reference planes, a global coordinate system and geometric base shapes into the simulation process, the 3D MRI models may act as a reference against which normal and degenerative lumbar vertebral columns are assessed in clinical practice. It may also contribute to advances in diagnostic approaches, pre-operative planning, physical therapy and positive patient outcomes in the UAE healthcare system.

The Effects of Paraspinal Muscle Volume on Physiological Load on the Lumbar Vertebral Column: A Finite-Element Study.

Analytical biomechanical study using a finite-element (FE) model. We investigated the effects of paraspinal muscle volume to the physiological loading on the lower lumbar vertebral column using a FE model. The FE model analysis can measure the physiological load on the lumbar vertebral column. Which changes as the surrounding environment changes. In this study, our FE model consisted of the sacrum, lumbar spine (L3-L5), intervertebral discs, facet joints, and paraspinal muscles. Three-dimensional FE models of healthy lumbar spinal units were reconstructed. The physiological loads exerted on the lumbar vertebra column were evaluated by applying different paraspinal muscle volumes (without muscles, 50%, 80%, and 100% of healthy muscle volume). As the paraspinal muscle volume increased, the loads exerted on the vertebral column decreased. The mean load on the intervertebral disc was 1.42 ± 0.75 MPa in the model without muscle, 1.393 ± 0.73 MPa in the 50% muscle volume model, 1.367 ± 0.71 MPa in the 80% muscle volume model, and 1.362 ± 0.71 MPa in the 100% muscle volume model. The mean loads exerted on the posterior column of lumbar spine were 11.79 ± 4.70 MPa in the model without muscles, 11.57 ± 4.57 MPa in the model with 50% muscle volume, and 11.13 ± 4.51 MPa in the model with 80% muscle volume, and 10.92 ± 4.33 MPa in the model with 100% muscle volume. The mean pressure on the vertebral body in the model without paraspinal muscle, and with 50%, 80%, and 100% paraspinal muscle volume were 14.02 ± 2.82, 13.82 ± 2.62, 13.65 ± 2.61, and 13.59 ± 2.51 MPa, respectively. Using FEM, we observed that the paraspinal muscle volume decreases pressure exerted on the lumbar vertebral column. Based on these results, we believe that exercising to increase paraspinal muscle volume would be helpful for spinal pain management and preventing lumbar spine degeneration.Level of Evidence: N/A.

Simulated model of obesity and immediate metabolic disorders after gastric shunting with anastomosis in small laboratory animals

Objective. To study metabolic changes and peculiarities of mineral balance depending on the common loop length while constructing of the simulated model of gastric shunting with one anastomosis during 60 days.&#x0D; Materials and methods. Experimental simulation of gastric minishunting with one anastomosis of various length of bilio-pancreatic loop was constructed on the rats. In 10 rats the anastomosis was formatted on level of half of total length of small intestine (Group I), and also in 10 - a third part of general length of small intestine (Group II). Control Group consisted of 5 rats. The indices of the extra body mass loss and metabolic changes were compared.&#x0D; Results. In the rats of Group I the index of the body mass loss have constituted 16.6% (41.7 gm), and of the Group II -20.6% (53.2 gm). Lowering of indices of mineral and prion metabolism, comparing preoperative values, was observed in both Groups. Dystrophic changes in osseous tissue of vertebral bodies of lumbar vertebral column were noted in animals of both Groups, more pronounced - in Group II.&#x0D; Conclusion. The protein and mineral metabolism disorders may be observed not only in large resection volume, but in exclusion of half and more segment of small bowel from general transit, using gastric shunting, what lacks significant advantages in the extra body mass loss, but leads to more profound metabolic disorders.

Distribution of Young's modulus at various sampling points in a human lumbar spine vertebral body

BACKGROUND CONTEXTMathematical modeling for creating computer spine models is one of the basic methods underlying many scientific publications. The accuracy of strength parameters of tissues introduced into such models translates directly into the reliability of obtained results. Experimental determination of Young's modulus (E) in various areas of spongy bone tissue seems to be crucial for creating a reliable spine model without excessive simplifications in the form of a single E value for the whole vertebral body. PURPOSEThe aim of the study was to determine Young's modulus in different parts of the lumbar vertebral column for samples subjected to compression and bending. STUDY DESIGNCylindrical spongy bone tissue samples were subjected to bending and compression strength tests. METHODSThe study included 975 pathologically unchanged samples of spongy bone tissue harvested from the lumbar vertebrae of 15 male donors. The samples were subjected to compression or bending strength tests and then Young's modulus was determined for each sample depending on its location in the vertebral body. The samples were tested differently between given locations within one vertebra as well as between vertebrae. RESULTSCompressed specimens are characterized by highly significantly different Young's modulus values depending on the location in the vertebral body. Samples No. 7 and No. 9 in the anterior part of the vertebral body have highly significantly higher Young's modulus values compared to those in the posterior part of the vertebral body for all lumbar vertebrae. Samples subjected to bending showed significant differences (p<.05) between samples located closer to the vertebral canal (No.16, No.17) and samples located further away (No.14, No.15) with higher values for the samples located in the posterior part of the vertebral body. CONCLUSIONSAccommodating the anisotropic structure of spongy bone in computer models and the application of different Young's module values for areas within one vertebral body will allow one to obtain realistic results of computer simulations used. CLINICAL SIGNIFICANCEDetermining the exact strength parameters of spongy bone tissue within one vertebra and changes in these properties in subsequent vertebrae will allow to create more accurate computer models of the lumbar spine and the whole spine. This, in turn, will translate into more reliable computer simulations used, among others, to determine the risk of fractures or osteoporotic changes, or simulation of the procedure of spinal fusion.

Spinal anesthesia in surgical treatment of lumbar spine tumors

ObjectiveThis study aims to show the feasibility of spinal anesthesia in lumbar spinal tumor surgery; share our data and experience. Patients and methods: A retrospective review of 14 patients with high risk for general anesthesia due to severe comorbidities was carried out. Patients who underwent surgeries under spinal anesthesia for lumbar vertebral column or spinal cord tumors at a single center between 2007–2019 were evaluated. The final pathological diagnosis, operation time, and surgical procedures were analyzed. Also, preoperative and postoperative advantages and disadvantages were determined. A comparison was performed with other 184 patients who were operated for spinal tumors in the same period under general anesthesia. ResultsMaximum operation time was found 220 min, and the average operation time was 166 min. The most primary diagnosis was vertebral column metastasis. The mean age was 65.5 years. None of the patients required general anesthesia during surgery; however, two patients needed additional spinal anesthesia preoperatively, which was performed by the surgeon. Lumbar decompression and fusion were the most performed procedures. ConclusionSpinal anesthesia is a feasible and useful method of anesthesia in lumbar spinal tumor surgery for especially elderly patients with American Society of Anesthesiologists (ASA) 3 or 4 score and high risk of general anesthesia.

Kinematic Analysis of Gait in a Patient with Nonspecific Low Back Pain

Low back pain is one of the most commonly encountered musculoskeletal diseases in modern society, and it is estimated that about 70 to 85% of the population has experienced low back pain. Individuals with low back pain usually modify the pattern of movement during gait to protect themselves, that is, they use different strategies of trunk movement and lower limbs protectively to avoid painful movements. However, in the long term, these repeated and prolonged changes and tensions during gait can cause mechanical dysfunctions, overloading the lumbar vertebral column and consequently causing damage. The objective of this study was to analyze gait kinematics in patients classified in the low back pain subgroups and to identify the possible biomechanical changes of the movement in these individuals. It is a cross-sectional observational study composed of a convenience sample of 17 patients, 24.6 ± 3.0 years old, from the Federal University of Santa Catarina located in the city of Araranguá-SC. Individuals classified in the manipulation subgroup obtained better results in the length of the gait, hip angle in the initial phase of gait and gait speed. The directional preference group obtained a smaller step length and passed. The traction group had the longest running time compared to the other subclassification groups of low back pain. Through the present study, it is possible to affirm that patients with nonspecific chronic low back pain present changes in gait. The individuals classified in the directional preference subgroup were the ones that had the lowest performance in the analyzed variables when compared to the subgroups of traction, manipulation and stabilization.