Vertebral Motion Segment Research Articles

Structural and functional characteristics of the thoracolumbar multifidus muscle in horses.

The multifidus muscle fascicles of horses attach to vertebral spinous processes after crossing between one to six metameres. The fascicles within one or two metameres are difficult to distinguish in horses. A vertebral motion segment is anatomically formed by two adjacent vertebrae and the interposed soft tissue structures, and excessive mobility of a vertebral motion segment frequently causes osteoarthropathies in sport horses. The importance of the equine multifidus muscle as a vertebral motion segment stabilizer has been demonstrated; however, there is scant documentation of the structure and function of this muscle. By studying six sport horses postmortem, the normalized muscle fibre lengths of the the multifidus muscle attached to the thoracic (T)4, T9, T12, T17 and lumbar (L)3 vertebral motion segments were determined and the relative areas occupied by fibre types I, IIA and IIX were measured in the same muscles after immunohistochemical typying. The values for the normalized muscle fibre lengths and the relative areas were analysed as completely randomized blocks using an anova (P≤0.05). The vertebral motion segments of the T4 vertebra include multifidus bundles extending between two and eight metameres; the vertebral motion segments of the T9, T12, T17 and L3 vertebrae contain fascicles extending between two and four metameres The muscle fibres with high normalized lengths that insert into the T4 (three and eight metameres) vertebral motion segment tend to have smaller physiological cross-sectional areas, indicating their diminished capacity to generate isometric force. In contrast, the significantly decreased normalized muscle fibre lengths and the increased physiological cross-sectional areas of the fascicles of three metameres with insertions on T9, T17, T12, L3 and the fascicles of four metameres with insertions on L3 increase their capacities to generate isometric muscle force and neutralize excessive movements of the vertebral segments with great mobility. There were no significant differences in the values of relative areas occupied by fibre types I, IIA and IIX. In considering the relative areas occupied by the fibre types in the multifidus muscle fascicles attached to each vertebral motion segment examined, the relative area occupied by the type I fibres was found to be significantly higher in the T4 vertebral motion segment than in the other segments. It can be concluded that the equine multifidus muscle in horses is an immunohistochemically homogeneous muscle with various architectural designs that have functional significance according to the vertebral motion segments considered. The results obtained in this study can serve as a basis for future research aimed at understanding the posture and dynamics of the equine spine.

Regeneration of intervertebral disc by way using of allogeneic chondrocytes cultivated in vitro in the light of concept for restabilization of the spine(experimental investigation)

The intervertebral disc (ID) has low reparative capacity. In this regard, researcher aimed at improving the capacity of the re­parative structures are carried out. A variety of growth factors, mesenchymal stem cells, autologous and allogenic chondrocytes, etc are used for this purposes. Objective: to study the structure of the traumatized intervertebral disc after transplantation of allogenic chondroсуtes in combination with spinal restabiliza­tion using method of dynamic spine neutralization of vertebral motion unit (VMU). Methods for optimizing ID regeneration in the rat tail vertebral segment we selected high-density culture of chondrocytes obtained from the limb bud 7–10 day old rat embryos in which cells retain cartilaginous phenotype and gen­otype was confirmed by electron microscopy. Performed four se­ries of experiments: I — intact animals, II — ID injury (control), III — traumatic ID injury with dynamic neutralization (method G. Dubois et al, 1999), IV — ID injury with dynamic neutraliza­tion and transplantation of chondrocytes. One month the opera­tion the animals were euthanized, and a comparative morpho­logical analysis with morphometry was carried out. Results: it found that uncontrolled movements in the injured VMU lead to destructive changes in the ID. In terms of restabilization and dy­namic neutralization of the vertebral motor segment ID has been replaced by connective tissue, its height reduced. Chondrocyte culture is different from the fibrous ring and nucleus pulposus cells. However, with the introduction of chondrocytes in the in­jured ID and maintaining the controlled mobility of the VMU the proliferation of hyaline cartilage in its peripheral parts has been noted. Conclusion: combination of allogeneic chondro­cytes transplantation into disk and dynamic neutralization leads to the formation of hyaline cartilage territories and maintains the height of the injured ID.

Mini Anterior Lumbar Interbody Fusion: One Year Follow up for a Novel Device

Introduction This study is a prospective cohort observational trial, to evaluate the ROI-A (Radiolucent Open Implant-ALIF) and VerteBRIDGE plate construct, in the treatment of symptomatic lumbar degenerative disc disease. The principal advantage of anterior approach is that the risks associated with exploration of the spinal canal through a posterior approach can be avoided and damage to the muscles of the back is eliminated. The anterior approach offers superior visualization of the disc space itself, and can be done without disruption of the otherwise healthy posterior elements. The Mini ALIF retroperitoneal approach facilitates rapid patient recovery. Materials and Methods The ROI-A (Radiolucent Open Implant-ALIF) is made from PEEK (Polyetheretherketone), a medical grade plastic, and two metallic anchoring plates, marketed as VerteBridge, which provide both stability at the site of desired bony fusion and fixation of the implant to the vertebrae adjacent to the interbody device. Inclusion Criteria: 18 patients between the ages 31 and 65 years of age; Disc disease between L2-S1; Patients may have up to grade I spondylolisthesis or retrolesthesis at the involved site; Maximum two diseased vertebral motion segments to be instrumented; Has had no more than two previous non-fusion surgeries to the lumbar soine at the same level(s); Has failed to respond to an appropriate attempt at conservative treatment. Exclusion Criteria: More than two vertebral motion segments involved; Prior anterior, retroperitoneal approach; Has had previous anterior instrumented fusion at the proposed operative level; Higher than grade I spondylolisthesis or retrolisthesis at the involved level(s); Has reported active malignancy, localized or systemic infection; Morbid obesity, as defined by NIH Clinical Guidelines Body Mass Index (BMI > 40); Patients with a diagnosis of osteoporosis, osteopenia, Paget's or other metabolic bone disease; Patients who smoke more than 1 pack per day; Has an active workers compensation claim relative to the involved part. Outcome Measures: Subjects are evaluated clinically pre-operatively, 6 weeks and 12 months post op by the pain questionnaire (VAS), and function questionnaire (ODI); The radiological measures included the segmental lordosis, integrity of the construct, and presence of bridging bone; Fusion success is defined as presence of bridging bone, and postoperative intervertebral motion at 12 months which is less than 5 degrees, via manual radiographic angular measurements (Cobb Method) of the implanted level(s) on flexion and extension radiographs at the 12 month follow up visit. Results The VAS has improved from an average of 9 preop to an average of 2 postop. ODI score has reduced an average 30 points from preop measurement. 83% (15 patients) went on bony fusion at the radiological assessment 12 month post op. None of the patients underwent revision, removal of implant, supplemented fixation, or re-operation. One patient developed mechanical ileus for 48 hours postop, resolved with NG tube. Conclusion Mini anterior inter-body fusion is a valid option when treating degenerative/discogenic back pain, the ROI-A implant is a safe and simple, with satisfactory results up to 12 month, according to our pilot study.

Моделювання дегенеративних змін у хребтових рухових сегментах поперекового відділу хребта в експериментальних тварин

Доведено, що щільність кісткової тканини тіл хребців у поперековому відділі хребта вівці, свині й теляти в чотири рази вища, ніж у людини, що вказує на значно більше навантаження на поперековий відділ хребта в цих тварин порівняно з людиною. Існуючі експериментальні роботи доводять, що переважним об’єктом для моделювання дегенеративних змін у хребті є кролі, а також дрібні лабораторні тварини — щури та миші. Використовуючи їх, можна простежити розвиток вікових дегенеративних змін у міжхребцевих дисках у відносно короткі терміни, а також вивчити зміни в розташованих краніально і каудально суміжних хребтових рухових сегментах. У статті описано спосіб відтворення дегенеративних змін LV-LVI хребтових рухових сегментів поперекового відділу хребта у кролів.

The biological basis of degenerative disc disease: proteomic and biomechanical analysis of the canine intervertebral disc.

IntroductionIn the present study, we sought to quantify and contrast the secretome and biomechanical properties of the non-chondrodystrophic (NCD) and chondrodystrophic (CD) canine intervertebral disc (IVD) nucleus pulposus (NP).MethodsWe used iTRAQ proteomic methods to quantify the secretome of both CD and NCD NP. Differential levels of proteins detected were further verified using immunohistochemistry, Western blotting, and proteoglycan extraction in order to evaluate the integrity of the small leucine-rich proteoglycans (SLRPs) decorin and biglycan. Additionally, we used robotic biomechanical testing to evaluate the biomechanical properties of spinal motion segments from both CD and NCD canines.ResultsWe detected differential levels of decorin, biglycan, and fibronectin, as well as of other important extracellular matrix (ECM)-related proteins, such as fibromodulin and HAPLN1 in the IVD NP obtained from CD canines compared with NCD canines. The core proteins of the vital SLRPs decorin and biglycan were fragmented in CD NP but were intact in the NP of the NCD animals. CD and NCD vertebral motion segments demonstrated significant differences, with the CD segments having less stiffness and a more varied range of motion.ConclusionsThe CD NP recapitulates key elements of human degenerative disc disease. Our data suggest that at least some of the compromised biomechanical properties of the degenerative disc arise from fibrocartilaginous metaplasia of the NP secondary to fragmentation of SLRP core proteins and associated degenerative changes affecting the ECM. This study demonstrates that the degenerative changes that naturally occur within the CD NP make this animal a valuable animal model with which to study IVD degeneration and potential biological therapeutics.Electronic supplementary materialThe online version of this article (doi:10.1186/s13075-015-0733-z) contains supplementary material, which is available to authorized users.

BACK PAIN SYNDROME: MODERN APPROACHES TO THERAPY

Objective: to describe management tactics in patients with back pain syndrome and to give recommendations for the choice of non-drug and drug treatments (with main drug groups) and the duration of a treatment cycle. Materials and methods. The paper considers the basic mechanisms and causes of back pain syndromes (dorsalgias). It introduces the concept “dorsopathy” that characterizes the appearance of nonvisceral pain syndrome in the extremities and trunk, which is caused by degenerative processes in the vertebral motion segment. The authors provide a description of spondyloarthrosis, one of the main degenerative diseases of the spine, and give current principles of treatment for the major symptoms of the disease. Results. The main goal of treatment in patients with back pain is to relieve pain syndrome. Selective nonsteroidal anti-inflammatory drugs are the medicaments of choice. Conclusion. This paper covers current approaches to managing patients with spondyloarthrosis and gives recommendations regarding the treatment of the major disease manifestation – pain syndrome.

Дифференциальная диагностика болевого синдрома в нижней части спины и онкологических заболеваний в вертеброневрологической практике на поликлиническом этапе

A large number of diseases with different etiology and pathogenesis, at different stages of their development, can have a similar clinical manifestation - a pain in the lower back and proceed masked, namely, in the form of different variants of dorsopathies. Not all of these diseases are associated with degenerative-dystrophic processes in the vertebral motor segment and myofascial disorders. A number of cancer diseases may occur with lesions of the spine both primary and secondary. In turn, this causes a clinical picture that is similar to the symptoms of dorsopathy, however, it requires a completely different treatment. A latent cancer course, the absence of proper medical examination of the people, incomplete examination, at first glance "easy" patients can lead to serious diagnostic errors, and as a consequence, incorrect treatment, with all the ensuing irreparable to the patient´s health consequences. Such patients at any time may be on the appointments to specialist for vertebra-neurological patients (manual therapists, reflex therapists, osteopaths and others). Both beginners and experienced doctors should always remember this. The authors of this article draw attention to this. This article presents clinical picture and pain syndrome of the most common tumors and distinguishing features of it at the dorsopathies. This information, as well as clinical cases considered in this paper will allow the specialist to sus-pect possible oncological implications of pain in the patient and recommending further examination to avoid serious medical errors.

Therapeutic sustainability and durability of coflex interlaminar stabilization after decompression for lumbar spinal stenosis: a four year assessment.

Approved treatment modalities for the surgical management of lumbar spinal stenosis encompass a variety of direct and indirect methods of decompression, though all have varying degrees of limitations and morbidity which potentially limit the efficacy and durability of the treatment. The coflex(®) interlaminar stabilization implant (Paradigm Spine, New York, NY), examined under a United States Food and Drug Administration (US FDA) Investigational Device Exemption (IDE) clinical trial, is shown to have durable outcomes when compared to posterolateral fusion in the setting of post-decompression stabilization for stenotic patients. Other clinical and radiographic parameters, more indicative of durability, were also evaluated. The data collected from these parameters were used to expand the FDA composite clinical success (CCS) endpoint; thus, creating a more stringent Therapeutic Sustainability Endpoint (TSE). The TSE allows more precise calculation of the durability of interlaminar stabilization (ILS) when compared to the fusion control group. A retrospective analysis of data generated from a prospective, randomized, level-1 trial that was conducted at 21 US sites was carried out. Three hundred forty-four per-protocol subjects were enrolled and randomized to ILS or fusion after decompression for lumbar stenosis with up to grade 1 degenerative spondylolisthesis. Clinical, safety, and radiographic data were collected and analyzed in both groups. Four-year outcomes were assessed, and the TSE was calculated for both cohorts. The clinical and radiographic factors thought to be associated with therapeutic sustainability were added to the CCS endpoints which were used for premarket approval (PMA). Success rate, comprised of no second intervention and an ODI improvement of ≥ 15 points, was 57.6% of ILS and 46.7% of fusion patients (p = 0.095). Adding lack of fusion in the ILS cohort and successful fusion in the fusion cohort showed a CCS of 42.7% and 33.3%, respectively. Finally, adding adjacent level success to both cohorts and maintenance of foraminal height in the coflex cohort showed a CCS of 36.6% and 25.6%, respectively. With additional follow-up to five years in the U.S. PMA study, these trends are expected to continue to show the superior therapeutic sustainability of ILS compared to posterolateral fusion after decompression for spinal stenosis. There are clear differences in both therapeutic sustainability and intended clinical effect of ILS compared to posterolateral fusion with pedicle screw fixation after decompression for spinal stenosis. There are CCS differences between coflex and fusion cohorts noted at four years post-op similar to the trends revealed in the two year data used for PMA approval. When therapeutic sustainability outcomes are added to the CCS, ILS is proven to be a sustainable treatment for stabilization of the vertebral motion segment after decompression for lumbar spinal stenosis.

OVERVIEW: FEATURES OF VERTEBROGENIC LUMBOSACRAL CHRONIC PAIN SYNDROME

There are a biopsychosocial pain model, it consist of biological (anatomical, physiological), sociocultural (level of education, traditions) and psychological (cognitive, affective, behavioural) components. Also there are nociception (myofascial) and neuropathic (compression radiculopathy) components. The anatomical condition of the vertebral-motor segment often not correlated with the severity of pain syndrome. Assess the state of the peripheral segmental apparatus, peripheral nerves of the lower extremities, you can use stimulation ENMG.

Fibronectin expression in the intervertebral disc of monkey.

Fibronectin, a large dimeric plasma glycoprotein found only in vertebrates, is a core component of several extracellular matrices. Integrin receptors regulate different cell activities. Fibronectin expression patterns in intervertebral disc have not been extensively studied. The aim of this study was to evaluate the distribution of fibronectin in the different regions of the intervertebral disc, and in intervertebral discs of different levels of monkeys. Spines of nine 3-4 year-old cynomolgus monkeys (Macaca fascicularis) were studied. From every spine, 5 vertebral motion segments were sectioned (C5-C6, T3-T4, T9-T10, L2-L3, L4-L5) producing forty-five vertebral motion segments. These were bisected in the sagittal plane. Immunohistochemical studies were performed using specific antibodies to detect fibronectin. A positive immunoreaction for fibronectin was found in the endplates, in the peripheral annulus fibrosus, and in the longitudinal ligaments. There was no fibronectin immunoreactivity in the nucleus pulposus and in the central annular region close to the nucleus pulposus. There were no differences in immunoreactivity to fibronectin among discs of different levels and discs of different monkeys. Fibronectin may exert a role in the organization of the extracellular matrix of the intervertebral discs. Identifying the structural features of the intervertebral disc extracellular matrix may help to understand the mechanisms of intervertebral disc pathology.

Prevalence and causes of back pain syndromes in children

We present a review of literature devoted to epidemiology, and the nosological and syndromal structure of back pain in children. The data of our own study of school-aged children with back pain are presented. The structure of back pain syndromes in 105 children has been analyzed using the medical aid appealability data. The results of a comprehensive clinical and instrumental study demonstrated that the children mostly had lumbosacral pain (52.4% of cases); neck pain was observed in 29.5% of cases; while thoracic pain syndromes were observed in 18.1% of cases. Congenital defect of the connective tissue was diagnosed in 16.19% of children; congenital abnormalities of the spine, in 15.2%; scoliosis (idiopathic and secondary), in 8.6%; and Scheuermann-Mau's disease, in 5.71%. The conclusion has been made about the high prevalence of back pain in schoolchildren. Muscular tonic syndromes were prevailing in the clinical structure in children; radicular syndromes were less frequent. Musculoskeletal disorders were the main causes of back pain. Congenital defect of the connective tissue was often observed, which was revealed as functional instability of the vertebral motor segment, spondylolisthesis due to weak ligaments, and disc protrusions. Congenital abnormalities of the spine, scoliosis, and Scheuermann-Mau' disease were observed less often.

Dynamic motion characteristics of the lower lumbar spine: implication to lumbar pathology and surgical treatment.

Many studies have reported on the segmental motion range of the lumbar spine using various in vitro and in vivo experimental designs. However, the in vivo weightbearing dynamic motion characteristics of the L4-5 and L5-S1 motion segments are still not clearly described in literature. This study investigated in vivo motion of the lumbar spine during a weight-lifting activity. Ten asymptomatic subjects (M/F: 5/5; age: 40-60 years) were recruited. The lumbar segment of each subject was MRI-scanned to construct 3D models of the L2-S1 vertebrae. The lumbar spine was then imaged using a dual fluoroscopic imaging system as the subject performed a weight-lifting activity from a lumbar flexion position (45°) to maximal extension position. The 3D vertebral models and the fluoroscopic images were used to reproduce the in vivo vertebral positions along the motion path. The relative translations and rotations of each motion segment were analyzed. All vertebral motion segments, L2-3, L3-4, L4-5 and L5-S1, rotated similarly during the lifting motion. L4-5 showed the largest anterior-posterior (AP) translation with 2.9 ± 1.5 mm and was significantly larger than L5-S1 (p < 0.05). L5-S1 showed the largest proximal-distal (PD) translation with 2.8 ± 0.9 mm and was significantly larger than all other motion segments (p < 0.05). The lower lumbar motion segments L4-5 and L5-S1 showed larger AP and PD translations, respectively, than the higher vertebral motion segments during the weight-lifting motion. The data provide insight into the physiological motion characteristics of the lumbar spine and potential mechanical mechanisms of lumbar disease development.

In Vivo Cervical Facet Joint Capsule Deformation During Flexion–Extension

Nonrandomized controlled cohort. To characterize subaxial cervical facet joint kinematics and facet joint capsule (FJC) deformation during in vivo, dynamic flexion-extension. To assess the effect of single-level anterior arthrodesis on adjacent segment FJC deformation. The cervical facet joint has been identified as the most common source of neck pain, and it is thought to play a role in chronic neck pain related to whiplash injury. Our current knowledge of cervical facet joint kinematics is based on cadaveric mechanical testing. Fourteen asymptomatic controls and 9 C5-C6 arthrodesis patients performed full range of motion flexion-extension while biplane radiographs were collected at 30 Hz. A volumetric model-based tracking process determined 3-dimensional vertebral position with submillimeter accuracy. FJC fibers were modeled and grouped into anterior, lateral, posterior-lateral, posterior, and posterior-medial regions. FJC fiber deformations (total, shear, and compression-distraction) relative to the static position were determined for each cervical motion segment (C2-C3 through C6-C7) during flexion-extension. No significant differences in the rate of fiber deformation in flexion were identified among motion segments (P = 0.159); however, significant differences were observed among fiber regions (P < 0.001). Significant differences in the rate of fiber deformation in extension were identified among motion segments (P < 0.001) and among fiber regions (P = 0.001). The rate of FJC deformation in extension adjacent to the arthrodesis was 45% less than that in corresponding motion segments in control subjects (P = 0.001). In control subjects, FJC deformations are significantly different among vertebral levels and capsule regions when vertebrae are in an extended orientation. In a flexed orientation, FJC deformations are different only among capsule regions. Single-level anterior arthrodesis is associated with significantly less FJC deformation adjacent to the arthrodesis when the spine is in an extended orientation. 4.

Lower thoracic syndrome – A differential screen for back pain following vertical compression injury: A case report

A 36-year-old male experienced left sided back and radiating flank pain, following a fall on his buttock. A detailed medical evaluation ruled out the presence of red flags. Initial examination revealed positive findings of comparable local tenderness over the left T11, T12 and left paraspinal area, and a 2 cm shortening of the left leg. 8 treatment visits for a period of 4 weeks addressed mechanical dysfunction at the T11, T12, lumbar and pelvic region, comprising manual therapy, therapeutic exercise and pain relieving modalities. Reduction of local tenderness, back and radiating flank pain was observed. Additionally, resolution of the persistent apparent shortening of his left leg was observed, following a high velocity thrust (HVT) manipulation of the T11, T12 segments. The vertebral motion segment of T11, T12, the thoracoabdominal nerves, the 12th rib, the quadratus lumborum and the serratus posterior inferior are speculated to be potential symptom mediators. The findings in the case report suggest the lower thoracic region to be included during the evaluation process of back pain, especially when the mechanism of injury is a vertical compression.

Can pathoanatomical pathways of degeneration in lumbar motion segments be identified by clustering MRI findings

BackgroundMagnetic Resonance Imaging (MRI) is the gold standard for detailed visualisation of spinal pathological and degenerative processes, but the prevailing view is that such imaging findings have little or no clinical relevance for low back pain. This is because these findings appear to have little association with treatment effects in clinical populations, and mostly a weak association with the presence of pain in the general population.However, almost all research into these associations is based on the examination of individual MRI findings, despite its being very common for multiple MRI findings to coexist. Therefore, this proof-of-concept study investigated the capacity of a multivariable statistical method to identify clusters of MRI findings and for those clusters to be grouped into pathways of vertebral degeneration.MethodsThis study is a secondary analysis of data from 631 patients, from an outpatient spine clinic, who had been screened for inclusion in a randomised controlled trial. The available data created a total sample pool of 3,155 vertebral motion segments. The mean age of the cohort was 42 years (SD 10.8, range 18–73) and 54% were women.MRI images were quantitatively coded by an experienced musculoskeletal research radiologist using a detailed and standardised research MRI evaluation protocol that has demonstrated high reproducibility. Comprehensive MRI findings descriptive of the disco-vertebral component of lumbar vertebrae were clustered using Latent Class Analysis. Two pairs of researchers, each containing an experienced MRI researcher, then independently categorised the clusters into hypothetical pathoanatomic pathways based on the known histological changes of discovertebral degeneration.ResultsTwelve clusters of MRI findings were identified, described and grouped into five different hypothetical pathways of degeneration that appear to have face validity.ConclusionsThis study has shown that Latent Class Analysis can be used to identify clusters of MRI findings from people with LBP and that those clusters can be grouped into degenerative pathways that are biologically plausible. If these clusters of MRI findings are reproducible in other datasets of similar patients, they may form a stable platform to investigate the relationship between degenerative pathways and clinically important characteristics such as pain and activity limitation.

Biomechanical evaluation of two different vertebral interbody devices by using QCT-based case-specific nonlinear finite element models

Interbody devices are widely used to replace the degenerated discs of the spine. For this purpose, a novel methodology uses cement instead of conventional spacers, which is hypothesized to provide smoother transition of forces, lower risk of bone tissue damage, thus smaller subsidence, reduced risk of further pathological deformations and other complications. This new treatment approach has been compared with the conventional method experimentally by mechanical loading of human vertebral motion segments treated with either of these. The present study aimed at complementing the that work with finite element analysis and, by performing in silico mechanical testing of QCT-based case specific models incorporating the elasto-plastic behavior of bone, providing better understanding of experimental results, in particular, the differences between the two sample groups equipped with the different spacer types. This report presents the applied numerical methodology as well as the first results, which are in line with the experimental ones. Besides providing deeper insight into the experimental outcomes, these models are expected to provide a basis for virtual parameter analysis studies, which may help to optimize the surgical procedure. DOI: 10.17489/biohun/2013/1/20

Investigation of coupled bending of the lumbar spine during dynamic axial rotation of the body

Little is known about the coupled motions of the spine during functional dynamic motion of the body. This study investigated the in vivo characteristic motion patterns of the human lumbar spine during a dynamic axial rotation of the body. Specifically, the contribution of each motion segment to the lumbar axial rotation and the coupled bending of the vertebrae during the dynamic axial rotation of the body were analyzed. Eight asymptomatic subjects (M/F, 7/1; age, 40-60 years) were recruited. The lumbar segment of each subject was MRI scanned for construction of 3D models of the vertebrae from L2 to S1. The lumbar spine was then imaged using a dual fluoroscopic system while the subject performed a dynamic axial rotation from maximal left to maximal right in a standing position. The 3D vertebral models and the fluoroscopic images were used to reproduce the in vivo vertebral motion. In this study, we analyzed the primary left-right axial rotation, the coupled left-right bending of each vertebral segment from L2 to S1 levels. The primary axial rotations of all segments (L2-S1) followed the direction of the body axial rotation. Contributions of each to the overall segment axial rotation were 6.7° ± 3.0° (27.9 %) for the L2-L3, 4.4° ± 1.2° (18.5 %) for the L3-L4, 6.4° ± 2.2° (26.7 %) for the L4-L5, and 6.4° ± 2.6° (27.0 %) for the L5-S1 vertebral motion segments. The upper segments of L2-L3 and L3-L4 demonstrated a coupled contralateral bending towards the opposite direction of the axial rotation, while the lower segments of L4-L5 and L5-S1 demonstrated a coupled ipsilateral bending motion towards the same direction of the axial rotation. Strong correlation between the primary axial rotation and the coupled bending was found at each vertebral level. We did not observe patterns of coupled flexion/extension rotation with the primary axial rotation. This study demonstrated that a dynamic lumbar axial rotation coupling with lateral bendings is segment-dependent and can create a coordinated dynamic coupling to maintain the global dynamic balance of the body. The results could improve our understanding of the normal physiologic lumbar axial rotation and to establish guidelines for diagnosing pathological lumbar motion.

SURGICAL CORRECTION OF SPINAL DEFORMITY IN IDIOPATHIC SCOLIOSIS: THE HISTORY AND CURRENT STATE (REVIEW)

The article presents the historical and contemporary aspects of the state of the question correct scoliosis spine with dorsal and ventral spinal systems. The variants of spinal deformity correction method from Harrington to modern surgical techniques using both hook and metal screw. Detailed technological aspects of surgical interventions for the correction of spinal deformity using a variety of spinal structures. A comparative estimate of the correction of spinal deformity, the impact on the result of the initial mobility of the spine, level metallofiksatsii vertebral-motor segment, as well as the degree of true derotation vertebrae at the top of the curvature in a variety of surgical procedures. Describes the advantages and disadvantages of options for surgery.

Segmental spinal canal volume in patients with degenerative spondylolisthesis

Background contextLumbar degenerative spondylolisthesis (DS), typically characterized by the forward slippage of the superior vertebra of a lumbar motion segment, is a common spinal pathological condition in elderly individuals. Significant deformation and volume changes of the spinal canal can occur because of the vertebral slippage, but few data have been reported on these anatomic variations in DS patients. Whether to restore normal anatomy, such as reduction of the slippage and restoration of disc height, is still not clear in surgery. PurposeThis study was designed to determine the volume change of the spinal canal and detect specific anatomic factors affecting the spinal canal volume in DS patients. Study design/settingA case-control study. MethodsNine asymptomatic volunteers (mean age 54.4) and 9 patients with L4/L5 DS (mean age 73.4) were recruited. All patients had intermittent claudication and different extent low back pain, and two patients also had leg pain. L4/L5 vertebral motion segment unit of each subject was reconstructed using three-dimensional computed tomography or magnetic resonance images in a solid modeling software. In vivo lumbar vertebral motion during functional postures (supine, standing upright, flexion, and extension) was determined using a dual fluoroscopic imaging technique. The volume of the spinal canal was measured at each functional posture. Various anatomic parameters (disc height, cross-sectional area of the canal, left-right diameter of the canal, anterior-posterior diameter of the canal, slippage, posture, intervertebral disc angle [DA], etc.) that may potentially affect the canal volume were also measured, and their correlations with the volume change of spinal canal were analyzed. This study was funded by a 2-year, $275,000 grant from the National Institutes of Health. ResultsOn average, spinal canal volume was larger at supine and flexion postures than at stand and extension postures in both the DS and the asymptomatic groups. Spinal canal volume of the DS patients were significantly lower than that of the asymptomatic subjects under all the four postures (p<.05). Correlation analysis showed that spinal canal volume was strongly affected by the posterior disc height (Pearson correlation coefficient γb=0.822) and the slippage percentage (γb=−0.593) and moderately affected by the anterior disc height (γb=0.300) and the DA (γb=−0.237). ConclusionsThe volume of spinal canal is affected by multiple factors. Increased spinal canal volume at supine and flexion positions may explain the clinical observations of relief of symptoms at these postures in DS patients. The data also suggest that reduction of slipped vertebral body, decrease of DA, intervertebral distraction, and decompression could all be effective to increase the canal volume of DS patients thus to relieve clinical symptoms.

Posterior all-pedicle screw instrumentation combined with multiple chevron and concave rib osteotomies in the treatment of adolescent congenital kyphoscoliosis

Background contextCongenital kyphoscoliosis is a disorder that often requires surgical treatment. Although many methods of surgical treatment exist, posterior-only vertebral column resection with instrumentation and fusion seem to have become the gold standard for very severe and very rigid curves. Multiple chevron and concave rib osteotomies have been previously reported to be effective in the treatment of neglected severe idiopathic curves. We hypothesized that this method may also be used successfully in the treatment of congenital kyphoscoliosis. PurposeTo evaluate the effectiveness and safety of multiple chevron osteotomies combined with concave rib osteotomy and posterior pedicle screw instrumentation. Study designRetrospective chart review in the spine service of a large university hospital. Patient sampleAdolescent patients undergoing a specific surgical treatment for the indication of rigid congenital kyphoscoliotic deformity. Outcome measuresRadiographic images were used for the measurement of deformity correction. The Turkish version of the Scoliosis Research Society 22 (SRS-22) Patient Questionnaire has been used as a clinical outcome measure in the patient population. MethodsA retrospective chart review was performed. Patients admitted to Hacettepe Hospital Spine Center during the period of 2005 to 2009 were included. Criteria for inclusion were as follows: adolescent age group (10–16 years); congenital kyphoscoliosis; formation and/or segmentation defect of at least two vertebral motion segments; surgical treatment of deformity by posterior all-pedicle screw instrumentation, multiple chevron osteotomies, and multiple concave rib osteotomies; follow-up of at least 24 months; and a complete set of preoperative, postoperative, and follow-up standing posteroanterior and lateral full spinal radiographs. The patients' hospital records and X-rays were reviewed. Duration of surgery, intraoperative blood loss, postoperative transfusion requirements, postoperative stay in postanesthesia care unit (PACU), time of hospitalization, and complications were recorded. Deformity in both coronal and sagittal planes was analyzed for correction and maintenance of the correction in preoperative, postoperative, and follow-up radiographs. Patients' health-related quality of life was assessed using the SRS-22 questionnaire at the final follow-up. ResultsEighteen patients met the inclusion criteria. Their average age was 13.6 years (range, 11–16 years). Chevron osteotomies were performed at apical segments (three to seven levels) and concave rib osteotomies at Cobb-to-Cobb (five to eight levels). No patient had preoperative cord compression because of the sharply angulated deformity or neurologic deficit. The average preoperative scoliosis was 66.0° (range, 31°–116°), 52.4° (range, 22°–85°) on flexibility X-rays, and became 24.9° (range, 12°–52°) postoperatively. The average preoperative global kyphosis (T2–T12) of 75.9° (range, 50°–106°) became 49.5° (range, 18°–66°). The average preoperative local kyphosis of 71.9° (range, 35°–114°) became 31.4° (range, −44° to 64°). The average intraoperative bleeding was 989 cc, surgical time was 292 minutes, and intraoperative transfusion was 2.3 units. The maximum PACU stay was overnight. There were no neurologic complications except one pneumothorax and one pneumonia. The average follow-up was 34.3 months. At follow-up, average scoliosis was 27.5° (range, 10°–50°), global kyphosis was 50.3° (range, 28°–73°), and local kyphosis was 36.9°(range, −36° to 58°). Performed on the last follow-up, the average scores for the five domains of SRS-22 were 4.3, 4.4, 4.2, 4.1, and 4.8 for function, pain, self-image, mental health, satisfaction, and total, respectively. ConclusionsMultiple chevron and concave rib osteotomies with posterior instrumentation provide an acceptable rate of deformity correction and maintenance of correction at 2 years with acceptable intraoperative bleeding, surgical time, postoperative morbidity, and rate of complications. It can be considered as an alternative in the treatment of rigid congenital curves involving more than three levels or multiple curves separated by at least two segments that would otherwise require multiple vertebral resections.