Changes In Disc Height Research Articles

Clinical Usefulness of X-Ray Findings for Non-specific Low Back Pain in Korean Farmers: FARM Study.

ObjectiveTo elucidate the association between non-specific low back pain (NSLBP) and spinal X-ray findings in Korean farmers: Farmers' Cohort for Agricultural Work-Related Musculoskeletal disorders (FARM) study.MethodsA total of 835 farmers (391 males, 444 females; mean age, 56.6±7.4 years) without red-flag signs of specific LBP were recruited. Presence of LBP more than one week or once a month with more than moderate degree of pain severity during the last year was assessed with a binary questionnaire (yes or no). Spinal degenerative changes were classified into disc height change (DHC) of L4-5 and L5-S1 (grade 0–5) and osteophyte formation of L5 (grade 0–5) by a radiologist based on X-ray findings. Additionally, spondylolisthesis, scoliosis and spondylolysis were assessed.ResultsGeneral prevalence of NSLBP was 40.7%, revealing a higher incidence of NSLBP in female and younger farmers compared to male and older farmers (χ2=23.3, p<0.001; χ2=4.54, p<05, respectively). Among X-ray findings, DHC (L5–S1) grade 4 revealed significantly higher relative risk of NSLBP compared to grade 0 (odds ratio, 5.00; 95% confidence interval, 2.05–12.20) after adjusting age and sex, while other X-ray findings were not associated with NSLBP.ConclusionThe NSLBP of Korean farmers was significantly related to lumbar disc degenerative changes, suggesting clinical usefulness of X-ray findings in assessing LBP in farmers.

Biomechanical and Endplate Effects on Nutrient Transport in the Intervertebral Disc.

Physical data are lacking on nutrient transport in human intervertebral discs (IVDs), which support regeneration. Our objective was to study nutrient transport in porcine IVDs to determine the effects of biomechanical and physiological factors. Invitro testing of whole porcine IVDs was performed under different loading conditions. Fifty cervical, thoracic, and lumbar discs with attached end plates were removed from 4 Yorkshire pigs (90-150 lbs). Discs were placed in Safranin O or Fast Green FCF histological stains in diffusion or diurnal compression-tested groups. The end plate was studied by the use of polyurethane to block it. Traction was studied with a mechanical testing frame. Discs were cut transversely and photographed. Images were analyzed for depth of annulus fibrosus (AF) stained. The nucleus pulposus (NP) was assigned a staining score. Results showed no difference in AF staining between the 2 stains (P= 0.60). The depth of AF staining did not increase (P= 0.60) due to convection or disc height change via diurnal loading. The NP in all open end plate samples was stained completely by day 3. NP staining was decreased in blocked end plate samples (P= 0.07) and AF staining was significantly less in traction samples than in diffusion-only samples (P= 0.04). This method showed that most small molecule nutrient transport occurs via the end plate. Compressive load was a negligible benefit or hindrance to transport. Traction hindered transport in the short term. This method can be used to study strategies for increasing nutrient transport in IVDs.

Lumbar Spine Paraspinal Muscle and Intervertebral Disc Height Changes in Astronauts After Long-Duration Spaceflight on the International Space Station.

Prospective case series. Evaluate lumbar paraspinal muscle (PSM) cross-sectional area and intervertebral disc (IVD) height changes induced by a 6-month space mission on the International Space Station. The long-term objective of this project is to promote spine health and prevent spinal injury during space missions and here on Earth. National Aeronautics and Space Administration (NASA) crewmembers have a 4.3 times higher risk of herniated IVDs, compared with the general and military aviator populations. The highest risk occurs during the first year after a mission. Microgravity exposure during long-duration spaceflights results in approximately 5 cm lengthening of body height, spinal pain, and skeletal deconditioning. How the PSMs and IVDs respond during spaceflight is not well described. Six NASA crewmembers were imaged supine with a 3 Tesla magnetic resonance imaging. Imaging was conducted preflight, immediately postflight, and then 33 to 67 days after landing. Functional cross-sectional area (FCSA) measurements of the PSMs were performed at the L3-4 level. FCSA was measured by grayscale thresholding within the posterior lumbar extensors to isolate lean muscle on T2-weighted scans. IVD heights were measured at the anterior, middle, and posterior sections of all lumbar levels. Repeated measures analysis of variance was used to determine significance at P < 0.05, followed by post-hoc testing. Paraspinal lean muscle mass, as indicated by the FCSA, decreased from 86% of the total PSM cross-sectional area down to 72%, immediately after the mission. Recovery of 68% of the postflight loss occurred during the next 6 weeks, still leaving a significantly lower lean muscle fractional content compared with preflight values. In contrast, lumbar IVD heights were not appreciably different at any time point. The data reveal lumbar spine PSM atrophy after long-duration spaceflight. Some FCSA recovery was seen with 46 days postflight in a terrestrial environment, but it remained incomplete compared with preflight levels. 4.

A large animal model that recapitulates the spectrum of human intervertebral disc degeneration

The objective of this study was to establish a large animal model that recapitulates the spectrum of intervertebral disc degeneration that occurs in humans and which is suitable for pre-clinical evaluation of a wide range of experimental therapeutics. Degeneration was induced in the lumbar intervertebral discs of large frame goats by either intradiscal injection of chondroitinase ABC (ChABC) over a range of dosages (0.1U, 1U or 5U) or subtotal nucleotomy. Radiographs were used to assess disc height changes over 12 weeks. Degenerative changes to the discs and endplates were assessed via magnetic resonance imaging (MRI), semi-quantitative histological grading, microcomputed tomography (μCT), and measurement of disc biomechanical properties. Degenerative changes were observed for all interventions that ranged from mild (0.1U ChABC) to moderate (1U ChABC and nucleotomy) to severe (5U ChABC). All groups showed progressive reductions in disc height over 12 weeks. Histological scores were significantly increased in the 1U and 5U ChABC groups. Reductions in T2 and T1ρ, and increased Pfirrmann grade were observed on MRI. Resorption and remodeling of the cortical boney endplate adjacent to ChABC-injected discs also occurred. Spine segment range of motion (ROM) was greater and compressive modulus was lower in 1U ChABC and nucleotomy discs compared to intact. A large animal model of disc degeneration was established that recapitulates the spectrum of structural, compositional and biomechanical features of human disc degeneration. This model may serve as a robust platform for evaluating the efficacy of therapeutics targeted towards varying degrees of disc degeneration.

Influence of isobar ttl dynamic internal fixation system on adjacent segment degeneration by mri measurement of lumbar nucleus pulposus volume

?To investigate the influence of ISOBAR TTL dynamic internal fixation system on degeneration of adjacent intervertebral disc by MRI measurement of lumbar nucleus pulposus volume in treating lumbar degenerative disease after operation. ?Between March 2010 and October 2011, 34 patients with lumbar intervertebral disc herniation (23 cases of paracentral type and 11 cases of lateral type) underwent operation with ISOBAR TTL dynamic internal fixation system for fixation of single segment, and the clinical data were analyzed retrospectively. There were 20 males and 14 females, aged 39-62 years (mean, 47.5 years). The disease duration was 6-18 months (mean, 14 months). Involved segments included L4, 5 in 21 cases and L5, S1 in 13 cases. The X-ray films and MRI images were taken at 6, 12, 18, 24, 36, and 48 months after surgery. Based on X-ray films, the height of intervertebral space was measured using angle bisectrix method. The nucleus pulposus volume was measured based on the MRI scan. The postoperative change of nucleus pulposus volume and intervertebral disc height were used to evaluate the influence of ISOBAR TTL system on degeneration of adjacent intervertebral disc nucleus pulposus. ?Thirty patients were followed up 48 months. The height of intervertebral space showed no significant difference between at pre-and post-operation (P>0.05). The nucleus pulposus volume increased after operation, showing no significant difference at 6, 12, and 18 months when compared with preoperative value (P>0.05), but significant difference was found at 24, 36, and 48 months when compared with preoperative value (P<0.05). The height of nucleus pulposus increased after operation but the width was decreased; the values showed no significant difference at 6, 12, and 18 months when compared with preoperative ones, but showed significant difference at 24, 36, and 48 months when compared with preoperative ones (P<0.05). The diameter of nucleus pulposus at 18, 24, 36, and 48 months after operation was significantly langer than that at preoperation (P<0.05). ?ISOBAR TTL dynamic internal fixation system can prevent or delay the degeneration of intervertebral discs.

Annular Repair Using High-density Collagen Gel with Riboflavin Crosslinkage: Preliminary Data from an in vivo Ovine Model

Introduction Discectomy of herniated intervertebral discs (IVDs) successfully alleviates neurological symptoms but fails to repair the iatrogenic annulotomy. This persistent annular defect post-discectomy is associated with increased risk of reherniation, progressive IVD degeneration, and chronic low back pain. Previously we demonstrated the ability of high-density collagen (HDC) gels to facilitate annular repair in a rodent model.1,3 This study aims to use HDC gel in an ovine model which has previously been used as a surrogate for the human spine.2 The goal of this study is create an effective ovine model for a herniated nucleus pulposus through a generated annular defect and to show that our HDC helps induce annular repair reduces the degenerative changes. Methods Sheep have had intervertebral discs violated to create an annular defect and induce a herniated nucleus pulposus. These sheep were laid in a lateral position with their right-side up. A longitudinal incision was made from their most caudal rib to their iliac crest 1-cm ventral to their transverse processes. Using a lateral approach, the soft tissue and muscle were dissected of their transverse processes to expose their vertebral bodies. The annular fibrosis (AF) defect was created with a 3.2 mm drill inserted to a 9–11 mm depth and then an 18-gauge needle was inserted to a maximum depth of 9–10 mm to injure the nucleus pulposus (NP) and induce a herniation through the annular defect. The violated IVDs were then randomized to either treatment with riboflavin-crosslinked HDC gel or no treatment. Thus far 4 IVDs were randomized to the control group and 4 IVDs to the treatment group. An in vivo MRI and post-mortem MRI were performed 6 weeks after the surgery to assess the degree of herniation of the nucleus pulposus. A post-mortem X-Ray was also obtained 6 weeks after the surgery to assess for any changes in disc height, which is a surrogate for degenerative disc changes. Results Of the 8 intervertebral disc which we induced an annular defect, we were able to induce nucleus pulposus herniation through the annulotomy in all levels as in the example in Fig. 1 . Our preliminary data so far shows no difference in the disc height index of the intervertebral discs that received HDC versus those that received no treatment at 6 weeks after the surgery. The average disc height index of the treated intervertebral discs was 0.78 ± 0.005, 0.77 ± 0.004 for the untreated, puncture-only intervertebral discs, and 0.82 ± 0.006 for the healthy discs. Conclusion Lumbar discectomy to treat disc herniation is one of the most commonly performed spinal procedures,1 with an estimated 300,000 cases per year in the United States.2 A ~5% to 15% of discectomy cases result in a reherniation of their nucleus pulposus3 through the annulotomy and is associated with compromised patients outcomes and increased health care costs.4 Our preliminary data show that we are able to effectively use an ovine model to simulate a herniated nucleus pulposus via a lateral approach to the lumbar vertebral. Experiments are ongoing to analyze the disc levels using T2 mapping on MRI to assess changes in the NP hydration and overall area as our group has done previously in the rat-tail model.5 If HDC is found to be efficacious in inducing annular repair in a large mammal model, the next step would be to progress to clinical trials in humans. [Figure: see text] References Laus M, Bertoni F, Bacchini P, Alfonso C, Giunti A. Recurrent lumbar disc herniation: what recurs? (A morphological study of recurrent disc herniation). Chir Organi Mov 1993;78(3):147–154 Carragee EJ, Han MY, Suen PW, Kim D. Clinical outcomes after lumbar discectomy for sciatica: the effects of fragment type and anular competence. J Bone Joint Surg Am 2003;85-A(1):102–108 Swartz KR, Trost GR. Recurrent lumbar disc herniation. Neurosurg Focus 2003;15(3):E10 Ambrossi GLG, McGirt MJ, Sciubba DM, et al. Recurrent lumbar disc herniation after single-level lumbar discectomy: incidence and health care cost analysis. Neurosurgery 2009;65(3):574–578, discussion 578 Grunert P, Hudson KD, Macielak MR, et al. Assessment of intervertebral disc degeneration based on quantitative magnetic resonance imaging analysis: an in vivo study. Spine 2014;39(6):E369–E378

Development of an ex vivo cavity model to study repair strategies in loaded intervertebral discs.

The aim of this study was to compare two approaches for the delivery of biomaterials to partially nucleotomised intervertebral discs in whole organ culture under loading. Such models can help to bridge the gap between in vitro and in vivo studies by assessing (1) suitability of biomaterial delivery and defect closure methods, (2) effect of mechanical loading and (3) tissue response. Mechanical performance of bovine discs filled with a hyaluronan-based thermoreversible hydrogel delivered through the annulus fibrosus (AF) or the bony endplate (EP) was evaluated under cyclic axial loading in a bioreactor. The loading protocol was optimised to achieve physiological disc height changes in nucleotomised discs. A loading regime of 0.06±0.02MPa, 0.1Hz, 6h daily was applied on the nucleotomised discs. Disc height and stiffness were tracked for 5days, followed by histological analyses. Creation of a defect is less demanding for AF approach, while sealing is superior with the EP approach. Dynamic compressive stiffness is reduced following nucleotomy, with no significant difference between the two approaches. Disc height loss was higher, disc height recovery was lower and region around the defect with reduced cell viability was smaller for AF-approached than EP-approached discs. Two alternative methods for biomaterial testing in whole organ culture under loading were developed. Such models bring insights on the ability of the biomaterial to restore the mechanical behaviour of the discs. From a clinical perspective, the cavity models can simulate treatment of nucleotomy after disc herniation in young patients, whereby the remaining nucleus pulposus is still functional and therefore at high risk of re-herniation, though the defect may differ from the clinical situation.

Chapter 39 - The degenerative spine: pattern recognition and guidelines to image interpretation

Degenerative disease of the spine, in the form of intervertebral disc degeneration and bony growth, causing osteophytes and impinging upon the spinal canal and neural foramina, is the most frequent disorder affecting the spine. In this chapter we first discuss briefly the indications for computed tomography or magnetic resonance imaging in suspected degenerative spine disease. We then describe changes of disc height, signal intensity, and disc contour with aging and repeated microtrauma, as well as the imaging techniques most appropriate to image them. A grading system for lumbar disc changes is provided. Stenosis of the canal and neural foramina is reviewed next, concluding with a description of degenerative changes affecting the vertebral endplates and bone marrow.

Minimally Invasive TLIF Using Unilateral Approach and Single Cage at Single Level in Patients over 65.

Background. Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) is a widely accepted surgical procedure. But there are only a few reports of MIS-TLIF using the unilateral approach and single cage in elderly patients. Objective. The study investigated the clinical and radiological outcomes of MIS-TLIF using the unilateral approach and single cage in the patients over 65 years of age. Methods. Thirty-eight patients were followed for a mean of 15.5 ± 11.61 months. Radiological data include fusion rate, change of disc height, and central canal area. The numeric rating scale (NRS) and Oswestry disability index (ODI) were used to assess clinical outcomes. Results. The mean age of these patients at operation was 71.82 ± 4.71 years (range, 65–82 years). Evidence of fusion was observed radiologically in 64.71% at 6 months and 87.5% at 12 months after surgery, giving a final fusion rate of 100%. The mean NRS scores for back and leg pain and ODI scores improved significantly at the final follow-up. Conclusions. Clinical and radiologic outcomes of MIS-TLIF using unilateral approach and single cage in elderly patients indicate an acceptable method for the treatment of various kinds of lumbar spinal diseases.

Annular puncture with tumor necrosis factor-alpha injection enhances painful behavior with disc degeneration in vivo

Background ContextPainfulintervertebral disc degeneration is extremely common and costly. Effective treatments are lacking because the nature of discogenic pain is complex with limited capacity to distinguish painful conditions from age-related changes in the spine. Hypothesized sources of discogenic pain include chronic inflammation, neurovascular ingrowth, and structural disruption. PurposeThis study aimed to investigate inflammation, pro-neurovascular growth factors, and structural disruption as sources of painful disc degeneration Study Design/SettingThis study used an in vivo study to address these hypothesized mechanisms with anterior intradiscal injections of tumor necrosis factor-alpha (TNFα), pro-neurovascular growth factors: nerve growth factor and vascular endothelial growth factor (NGF and VEGF), and saline with additional sham surgery and naïve controls. Depth of annular puncture was also evaluated for its effects on structural and painful degeneration. MethodsRat lumbar discs were punctured (shallow or deeper puncture) and intradiscally injected with saline, TNFα, or NGF and VEGF. Structural disc degeneration was assessed using X-ray, magnetic resonance imaging (MRI), and histology. The rat painful condition was evaluated using Von Frey hyperalgesia measurements, and substance P immunostaining in dorsal root ganglion (DRG) was performed to determine the source of pain. ResultsSaline injection increased painful responses with degenerative changes in disc height, MRI intensity, and morphologies of disc structure and cell. TNFα and NGF/VEGF accelerated painful behavior, and TNFα-injected animals had increased substance P in DRGs. Deeper punctures led to more severe disc degeneration. Multiple regression analysis showed that the painful behavior was correlated with disc height loss. ConclusionsWe concluded that rate and severity of structural disc degeneration was associated with the amount of annular disruption and puncture depth. The painful behavior was associated with disc height loss and discal inflammatory state, whereas pro-inflammatory cytokines might play a more important role in the level of pain, which might have resulted from enhanced DRG sensitization. These in vivo painful disc degeneration models with different severities of structural changes may be useful for investigating discogenic pain mechanisms and for screening therapies, although interpretations must note the differences between all surgically induced animal models and the human condition.

The poro-elastic behaviour of the intervertebral disc: A new perspective on diurnal fluid flow

Diurnal disc height changes, due to fluid in- and outflow, are in equilibrium while daytime spinal loading is twice as long as night time rest. A direction-dependent permeability of the endplates, favouring inflow over outflow, reportedly explains this; however, fluid flow through the annulus fibrosus should be considered. This study investigates the fluid flow of entire intervertebral discs. Caprine discs were preloaded in saline for 24h under four levels of static load. Under sustained load, we modulated the disc׳s swelling pressure by exchanging saline for demineralised water (inflow) and back to saline (outflow), both for 24h. We measured disc height creep and used stretched exponential models to determine time-constants. During inflow disc height increased in relation to applied load, and during outflow disc height decreased to preload levels. When comparing in- and outflow phases, there was no difference in creep, and time-constants were similar indicating no direction-dependent resistance to fluid flow in the entire intervertebral disc. Results provoked a new hypothesis for diurnal fluid flow: in vitro time-constants for loading are shorter than for unloading and in vivo daytime loading is twice as long as night time unloading, i.e. in diurnal loading the intervertebral disc is closer to loading equilibrium than to unloading equilibrium. Per definition, fluid flow is slower close to equilibrium than far from equilibrium; therefore, as diurnal loading occurs closer to loading equilibrium, fluid inflow during night time unloading can balance fluid outflow during daytime loading, despite a longer time-constant.

Risk factors for lumbar intervertebral disc height narrowing: a population-based longitudinal study in the elderly.

BackgroundThe progression of disc degeneration is generally believed to be associated with low back pain and/or degenerative lumbar diseases, especially in the elderly. The purpose of this study was to quantitatively evaluate changes in lumbar disc height using radiographic measurements and to investigate risk factors for development of disc height narrowing of the elderly.MethodsFrom 1997 to 2007, 197 village inhabitants at least 65 years-old who participated in baseline examinations and more than four follow-up examinations conducted every second year were chosen as subjects for this study. Using lateral lumbar spine radiographs of each subject, L1-L2 to L5-S1 disc heights were measured. The subjects were divided into two groups according to the rate of change in disc height: mildly decreased (≤20 % decrease) and severely decreased (>20 % decrease). A stepwise multiple logistic regression analysis was used to select those factors significantly associated with disc height narrowing.ResultsDisc height at each intervertebral disc (IVD) level decreased gradually over ten years (p < 0.01, an average 5.8 % decrease of all disc levels). There was no significant difference in the rate of change in disc height among the IVD levels. Female gender, radiographic knee osteoarthritis and low back pain at baseline were associated with increased risk for disc height narrowing.ConclusionsWe conducted the first population-based cohort study of the elderly that quantitatively evaluated lumbar disc height using radiographic measurements. The risk factors identified in this study would contribute to a further understanding the pathology of disc degeneration.

The effect of simulated microgravity on lumbar spine biomechanics: an in vitro study.

Disc herniation risk is quadrupled following spaceflight. This study tested the hypothesis that swelling-induced disc height increases (comparable to those reported in spaceflight) stiffen the spine and elevate annular strain and nuclear pressure during forward bending. Eight human lumbar motion segments were secured to custom-designed testing jigs and subjected to baseline flexion and compression and pure moment flexibility tests. Discs were then free-swelled in saline to varying supraphysiologic heights consistent with prolonged weightlessness and re-tested to assess biomechanical changes. Swelling-induced disc height changes correlated positively with intradiscal pressure (p<0.01) and stiffening in flexion (p<0.01), and negatively with flexion range of motion (p<0.05). Swelling-induced increases in disc height also led to increased annular surface strain under combined flexion with compression. Disc wedge angle decreased with swelling (p<0.05); this loss of wedge angle correlated with decreased flexion range of motion (R (2)=0.94, p<0.0001) and decreased stiffness fold change in extension (p<0.05). Swelling-induced increases in disc height decrease flexibility and increase annular strain and nuclear pressure during forward bending. These changes, in combination with the measured loss of lordotic curvature with disc swelling, may contribute toward increased herniation risk. This is consistent with clinical observations of increased disc herniation rates after microgravity exposure and may provide the basis for future countermeasure development.

Lumbar Disc Height Change and Association with Farming Type in Korean Farmers

PM&RVolume 7, Issue 9S p. S89-S89 Best Musculoskeletal Medicine Research Poster Presentation Lumbar Disc Height Change and Association with Farming Type in Korean Farmers Sora Baek MD, PhD, Sora Baek MD, PhD Kangwon Naional University Hospital, Chuncheon, Korea (the Republic of)Search for more papers by this authorHee-won Park, Hee-won Park Kangwon Naional University Hospital, Chuncheon, Korea (the Republic of)Search for more papers by this authorEun Kyoung Kang MD, PhD, Eun Kyoung Kang MD, PhD Kangwon Naional University Hospital, Chuncheon, Korea (the Republic of)Search for more papers by this author Sora Baek MD, PhD, Sora Baek MD, PhD Kangwon Naional University Hospital, Chuncheon, Korea (the Republic of)Search for more papers by this authorHee-won Park, Hee-won Park Kangwon Naional University Hospital, Chuncheon, Korea (the Republic of)Search for more papers by this authorEun Kyoung Kang MD, PhD, Eun Kyoung Kang MD, PhD Kangwon Naional University Hospital, Chuncheon, Korea (the Republic of)Search for more papers by this author First published: 08 September 2015 https://doi.org/10.1016/j.pmrj.2015.06.034Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume7, Issue9SSeptember 2015Pages S89-S89 RelatedInformation

Comparison of posterior lumbar interbody fusion (PLIF) with autogenous bone chips and PLIF with cage for treatment of double-level isthmic spondylolisthesis

IntroductionSpondylolytic defects involving multiple vertebral levels are rare. It is reported that only 1.48% of patients with back pain were diagnosed with multi-level spondylolysis. The incidence of multiple-level spondylolisthesis is even rarer, so far there have been few reports of multi-level isthmic spondylolisthesis in the literature. The aim of this study is to evaluate clinical and radiological outcomes of two different fusion techniques for treatment of double-level isthmic spondylolisthesis. MethodsFifty-four patients who were managed surgically for treatment of double-level symptomatic isthmic spondylolisthesis were included in this study. Between May 2004 and September 2012, 29 consecutive patients underwent posterior lumbar interbody fusion (PLIF) with autogenous bone chips (group I) at Foshan Hospital of Traditional Chinese Medicine, Guangdong, China. Between March 2005 and December 2013, 25 consecutive patients underwent PLIF with cage (group II) at Zhujiang Hospital of Southern Medical University, Guangdong, China. The mean follow-up periods were 27.2 and 26.8 months, respectively. ResultsThe mean VAS scores of back and leg pain significantly decreased from 7.2 to 2.2 and 5.8 to 2.1 in the group I and from 7.0 to 1.9 and 6.1 to 1.8 in the group II, respectively. In the group I, mean ODI scores improved significantly from 54% to 14.2% and, in the group II, from 60% to 12.6%. In both groups, VAS and ODI scores significantly changed from pre- to postoperatively (p<0.001), but postoperative outcome between groups was statistically not significant. Solid union was observed in 27 of 29 patients (89.6%) in the group I and in 22 of 25 patients (88%) in the group II, without statistically significant differences (p>0.05). In both groups, changes in disc height, degree of listhesis, and whole lumbar lordosis between the pre- and postoperative periods were significant. ConclusionClinical and functional outcomes demonstrate no significant differences between groups in treating back and leg pain of adult patients with double-level isthmic spondylolisthesis.

Improvement of Segmental Lordosis in Transforaminal Lumbar Interbody Fusion: A Comparison of Two Techniques.

Study Design Retrospective review. Objective The purpose of this study was to determine the radiographic impact of a transforaminal lumbar interbody fusion (TLIF) versus a cantilever TLIF technique on segmental lordosis, segmental coronal alignment, and disk height. Methods A retrospective review was done of all patients undergoing TLIF procedures from 2006 to 2011 by three spine surgeons. Traditional TLIF versus cantilever TLIF results were compared, and radiographic outcomes were assessed. Results One hundred one patients were included in the study. Patients undergoing the cantilever TLIF procedure had a significantly greater change in segmental lordosis and disk height compared with those who underwent the traditional procedure (p > 0.0001). Conclusions The cantilever TLIF technique can lead to greater change in segmental lordosis based upon radiographic outcomes.

Intervention of rAAV-hTERT-Transducted Nucleus Pulposus Cells in Early Stage of Intervertebral Disc Degeneration: A Study in Canine Model.

To investigate the efficacy of recombinant adeno-associated virus (rAAV)-human telomerase reverse transcriptase (hTERT)-transducted nucleus pulposus cells (NPCs) in disc degeneration process in a canine disc degeneration model. The intervertebral disc degeneration of lumbar (L) 1-2, L3-4, and L5-6, from 12 female mongrels was prepared with the 20-gauge biopsy gun. Four weeks after animal model preparation, intervention experiment with rAAV-hTERT-transducted NPCs was conducted: group A, L1-2, serum-free medium with rAAV-hTERT modified NPCs; group B, L3-4, serum-free medium with NPCs; group C, L5-6, serum-free medium alone. Canines underwent digital radiography and magnetic resonance imaging 1 day before intervention, and 4, 8, and 12 weeks after intervention to evaluate the change of disc height and hydration status of interventional intervertebral discs. Twelve weeks after intervention, histological, biomechanical, and biochemical studies were carried out. The rAAV-hTERT-transducted NPCs were constructed successfully. The mRNA level of hTERT from rAAV-hTERT-transfected NPCs increased obviously. There was no significant change of disc height index observed between groups and within groups. The relative grayscale index (RGI) was maintained 8 weeks after the intervention in group A, whereas in group B and group C, the RGI decreased significantly (p<0.05). No significant differences of the angle of lateral bending and extension-flexion bending were observed in group A compared with other groups (p>0.05). The morphology of disc structure was preserved in group A. In group B, the structure of inner annulus was broken down and the jelly-like nucleus pulposus (NP) tissue transmitted into the fibrocartilaginous tissue. In group C, the jelly-like NP tissue was completely replaced by fibrocartilaginous tissue. In the NP, the content of proteoglycan (PG) and collagen II was higher in group A than in group C (p<0.05). The content of PG was 13, 8.9, and 15.6 times higher than the content of collagen II in group A, group B, and group C, respectively. In 12 weeks of observation, rAAV-hTERT-transducted NPCs could delay the degeneration process in the canine model which was superior than the capacity of NPCs in preserving structure integrity, content of extracellular matrix, and mechanical stability.

Adjacent Segment Disease After Posterior Lumbar Interbody Fusion: Based on Cases With a Minimum of 10 Years of Follow-up.

Retrospective case-controlled study. To investigate the incidence of adjacent segment degeneration (ASD) and the associated risk factors during a period of at least 10 years after posterior lumbar interbody fusion (PLIF). ASD is a problematic sequelae after spinal fusion surgery. Few long-term follow-up studies have investigated ASD after PLIF; thus, magnetic resonance imaging (MRI) data available for the evaluation of postoperative changes associated with ASD are limited. One hundred one patients were retrospectively enrolled. The minimum follow-up was 10 years after surgery. Preoperative and postoperative (2, 5, and 10 yr after surgery) Radiographs and MRI images were evaluated. Disc height, vertebral slip, and intervertebral angle were examined on radiographical images. Disc degeneration and spinal stenosis on MRI images were evaluated. Risk factors for developing early-onset radiographical ASD were evaluated using a multivariate logistic regression analysis. The degenerative changes in disc height, vertebral slip, and intervertebral angle on radiographs 10 years after surgery were found in 12, 36, and 17 cases, respectively, at the cranial-adjacent level and in 3, 6, and 11 cases, respectively, at the caudal-adjacent level. Increased disc degeneration and spinal stenosis worsening were observed in 62 and 68 cases, respectively, at the cranial-adjacent level and in 25 and 12 cases, respectively, at the caudal-adjacent level on MRI 10 years after surgery. Ten patients (9.9%) required reoperation, and 80% of revision surgeries were performed more than 5 years after the initial surgery. High pelvic incidence was a risk factor for developing early-onset radiographical ASD. The majority of the reoperations for ASD were performed more than 5 years after the initial lumbar fusion surgery, although the progression of radiographical ASD began in the early postoperative period. A high degree of pelvic incidence was a risk factor for developing early-onset radiographical ASD. Obtaining appropriate lumbar lordosis in PLIF is important for preventing ASD. 4.

Adjacent Segment Degeneration after Posterior Lumbar Interbody Fusion: Based on Cases with a Minimum of 10 years of Follow-Up

Introduction Adjacent segment degeneration (ASD) is problematic sequelae after spinal fusion surgery. ASD is observed in 36 to 84% of patients followed-up for 5 years after lumbar fusion surgery. However, there are few reports of long-term follow-up studies after PLIF, although 75% of cases requiring reoperation for ASD were discovered &gt; 4 years after the initial surgery. Moreover, there are limited reports describing changes related to disc degeneration and spinal stenosis on magnetic resonance imaging (MRI) after PLIF. The purpose of this study is to investigate the incidence of ASD and the associated risk factors over at least 10 years after PLIF. Material and Methods This study was a retrospective case-controlled study. A total of 167 patients who underwent PLIF were enrolled at a single spine center from April 1996 to May 2003. The inclusion criteria included age (&gt; 21 years at the time of surgery), magnitude of scoliosis (Cobb angle &lt; 15 degrees), and no additional decompression surgery at the level adjacent to the PLIF area. Overall, 66 patients were excluded in addition to those who did not meet these criteria, because they had not been followed up for at least 10 years. Finally, 101 patients (41 males, 60 females) with a mean age of 56.4 ± 15.3 years (range: 23–79 years) were included. The mean duration of follow-up was 11.6 ± 2.2 years (range: 10–17 years). Seventy patients had degenerative spondylolisthesis, 15 had spondylolytic spondylolisthesis, 11 had lumbar disc herniation, and 5 had spinal canal stenosis. Posterior lumbar interbody fusion was performed using pedicle screws, two carbon cages, and autologous iliac-crest bone graft. Preoperative and postoperative (2, 5, and 10 years after surgery) X-ray and MRI images were evaluated. Disc height, vertebral slip, and intervertebral angle were examined on X-ray images. Disc degeneration and spinal stenosis on MRI images were evaluated. Patients who developed severe spinal canal stenosis or exhibited listhesis (&gt; 3 mm) within 5 years after surgery were defined as having early-onset radiographic ASD. Risk factors for developing early-onset radiographic ASD were evaluated using a multivariate logistic regression analysis. Results The degenerative changes in disc height, vertebral slip, and intervertebral angle on X-ray 10 years after surgery were 12, 35, and 17%, respectively, at the cranial-adjacent level and 4, 7, and 13%, respectively, at the caudal-adjacent level. The incidences of disc degeneration and spinal stenosis were 61 and 29%, respectively, at the cranial-adjacent level and 67 and 14%, respectively, at the caudal-adjacent level on MRI 10 years after surgery. Ten patients (9.9%) required reoperation, and 80% of revision surgeries were performed &gt; 5 years after the initial surgery. High pelvic incidence was a risk factor for developing early-onset radiographic ASD. Conclusion The majority of the reoperation for ASD was performed &gt; 5 years after the initial lumbar fusion surgery, although the progression of radiographic ASD began in the early postoperative period. A high pelvic incidence was a risk factor for developing early-onset radiographic ASD. Obtaining appropriate lumbar lordosis in PLIF is important for preventing ASD.

Fat infiltration of paraspinal muscles is associated with low back pain, disability, and structural abnormalities in community-based adults

Background contextLow back pain and disability are major public health problems and may be related to paraspinal muscle abnormalities, such as a reduction in muscle size and muscle fat content. PurposeThe aim of this study was to examine the associations between paraspinal muscle size and fat content with lumbar spine symptoms and structure. Study design/settingThis was a community-based magnetic resonance imaging (MRI) cohort study. Patient sampleA total of 72 adults not selected on the basis of low back pain were included in the study. Outcome measuresThe outcomes measured were lumbar modic change and intervertebral disc height. Pain intensity and disability were measured from the Chronic Pain Grade Questionnaire at the time of MRI. MethodsThe cross-sectional area (CSA) and amount of fat in multifidus and erector spinae (high percentage defined by >50% of muscle) were measured, and their association with outcome was assessed. ResultsMuscle CSA was not associated with low back pain/disability or structure. High percentage of fat in multifidus was associated with an increased risk of high-intensity pain/disability (odds ratio [OR], 12.6; 95% confidence interval [CI], 2.0–78.3; p=.007) and modic change (OR, 4.3; 95% CI, 1.1–17.3; p=.04). High fat replacement of erector spinae was associated with reduced intervertebral disc height (β=−0.9 mm; 95% CI, −1.4 to −0.3; p=.002) and modic change (OR, 4.9; 95% CI, 1.1–21.9; p=.04). ConclusionsParaspinal fat infiltration, but not muscle CSA, was associated with high-intensity pain/disability and structural abnormalities in the lumbar spine. Although cause and effect cannot be determined from this cross-sectional study, longitudinal data will help to determine whether disabling low back pain and structural abnormalities of the spine are a cause or result of fat replacement of paraspinal muscles.