RESUMEN
STUDY DESIGN: ADAMTS5-deficient and wild type (WT) mice were chronically exposed to tobacco smoke to investigate effects on intervertebral disc degeneration (IDD). OBJECTIVE: The aim of this study was to demonstrate a role for ADAMTS5 in mediating tobacco smoking-induced IDD. SUMMARY OF BACKGROUND DATA: We previously demonstrated that chronic tobacco smoking causes IDD in mice because, in part, of proteolytic destruction of disc aggrecan. However, it was unknown which matrix proteinase(s) drive these detrimental effects. METHODS: Three-month-old WT (C57BL/6) and ADAMTS5 mice were chronically exposed to tobacco smoke (four cigarettes/day, 5âday/week for 6 months). ADAMTS-mediated cleavage of disc aggrecan was analyzed by Western blot. Disc total glycosaminoglycan (GAG) content was assessed by dimethyl methylene blue assay and safranin O/fast green histology. Vertebral osteoporosity was measured by microcomputed tomography. Human nucleus pulposus (hNP) cell cultures were also exposed directly to tobacco smoke extract (TSE), a condensate containing the water-soluble compounds inhaled by smokers, to measure ADAMTS5 expression and ADAMTS-mediated cleavage of aggrecan. Activation of nuclear factor (NF)-κB, a family of transcription factors essential for modulating the cellular response to stress, was measured by immunofluorescence assay. RESULTS: Genetic depletion of ADAMTS5 prevented vertebral bone loss, substantially reduced loss of disc GAG content, and completely obviated ADAMTS-mediated proteolysis of disc aggrecan within its interglobular domain (IGD) in mice following exposure to tobacco smoke. hNP cell cultures exposed to TSE also resulted in upregulation of ADAMTS5 protein expression and a concomitant increase in ADAMTS-mediated cleavage within aggrecan IGD. Activation of NF-κB, known to be required for ADAMTS5 gene expression, was observed in both TSE-treated hNP cell cultures and disc tissue of tobacco smoke-exposed mice. CONCLUSION: The findings demonstrate that ADAMTS5 is the primary aggrecanase mediating smoking-induced disc aggrecanolysis and IDD. Mouse models of chronic tobacco smoking are important and useful for probing the mechanisms of disc aggrecan catabolism and IDD. LEVEL OF EVIDENCE: N/A.
Asunto(s)
Proteína ADAMTS5/deficiencia , Degeneración del Disco Intervertebral/metabolismo , Disco Intervertebral/metabolismo , Fumar Tabaco/efectos adversos , Fumar Tabaco/metabolismo , Proteína ADAMTS5/biosíntesis , Adulto , Animales , Células Cultivadas , Femenino , Humanos , Disco Intervertebral/patología , Degeneración del Disco Intervertebral/patología , Degeneración del Disco Intervertebral/prevención & control , Masculino , Ratones , Ratones Endogámicos C57BL , Persona de Mediana Edad , FN-kappa B/metabolismo , Núcleo Pulposo/metabolismo , Núcleo Pulposo/patología , Fumar Tabaco/patologíaRESUMEN
STUDY DESIGN: A longitudinal study using biplane radiography to measure in vivo intervertebral range of motion (ROM) during dynamic flexion/extension, and rotation. OBJECTIVE: To longitudinally compare intervertebral maximal ROM and midrange motion in asymptomatic control subjects and single-level arthrodesis patients. SUMMARY OF BACKGROUND DATA: In vitro studies consistently report that adjacent segment maximal ROM increases superior and inferior to cervical arthrodesis. Previous in vivo results have been conflicting, indicating that maximal ROM may or may not increase superior and/or inferior to the arthrodesis. There are no previous reports of midrange motion in arthrodesis patients and similar-aged controls. METHODS: Eight single-level (C5/C6) anterior arthrodesis patients (tested 7â±â1 months and 28â±â6 months postsurgery) and six asymptomatic control subjects (tested twice, 58â±â6 months apart) performed dynamic full ROM flexion/extension and axial rotation whereas biplane radiographs were collected at 30âimages per second. A previously validated tracking process determined three-dimensional vertebral position from each pair of radiographs with submillimeter accuracy. The intervertebral maximal ROM and midrange motion in flexion/extension, rotation, lateral bending, and anterior-posterior translation were compared between test dates and between groups. RESULTS: Adjacent segment maximal ROM did not increase over time during flexion/extension, or rotation movements. Adjacent segment maximal rotational ROM was not significantly greater in arthrodesis patients than in corresponding motion segments of similar-aged controls. C4/C5 adjacent segment rotation during the midrange of head motion and maximal anterior-posterior translation were significantly greater in arthrodesis patients than in the corresponding motion segment in controls on the second test date. CONCLUSION: C5/C6 arthrodesis appears to significantly affect midrange, but not end-range, adjacent segment motions. The effects of arthrodesis on adjacent segment motion may be best evaluated by longitudinal studies that compare maximal and midrange adjacent segment motion to corresponding motion segments of similar-aged controls to determine if the adjacent segment motion is truly excessive. LEVEL OF EVIDENCE: 3.
Asunto(s)
Fenómenos Biomecánicos/fisiología , Vértebras Cervicales/cirugía , Rango del Movimiento Articular/fisiología , Rotación , Adulto , Femenino , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Movimiento , Fusión Vertebral/métodosRESUMEN
STUDY DESIGN: A prospective cohort. OBJECTIVE: The aim of this study was to prospectively observe donor site pain, health-related quality-of-life outcomes, and complications following harvest of tricortical anterior iliac crest bone graft (AICBG) for anterior cervical discectomy and fusion (ACDF). SUMMARY OF BACKGROUND DATA: Persistent donor site pain from the anterior iliac crest has been reported to range between 2% and 40%. This morbidity has led surgeons to consider interbody alternatives for ACDF, which carry additional costs. METHODS: We prospectively enrolled 50 patients from 2 tertiary care centers over the course of 1 year observing complications and patient-reported outcomes. Patients filled out SF-12 and numeric rating scale (NRS) for pain in the arm, neck, and donor site pre-operatively and at 1 week, 2 weeks, 6 weeks, 3 to 6 months, and 1 year postoperatively. Outcomes were compared with a control group undergoing ACDF with allograft or Polyether ether ketone cages at 1 year. RESULTS: The meanâ±âSD donor site pain at 1 week was 5.6â±â2.8 but decreased to 2.2â±â2.4 at 6 weeks and 1.1â±â1.8 at 1 year (Pâ<â0.001). Including the 3 patients who were lost to follow-up, 10% of patients may have experienced persistent moderate or worse pain at 1 year. Linear regression analysis demonstrated that preoperative opioid use was an independent risk factor for increased donor site pain at 1 and 2 weeks (Pâ<â0.05). There were no differences in outcomes at 1 year compared with the nonautograft group. There were 2 (4%) minor wound complications, both treated successfully with oral antibiotics. CONCLUSION: Tricortical AICBG for ACDF is not associated with major complications and only 4% of patients (potentially, maximum of 10%) experienced moderate, persistent donor site pain at 1 year. There is no difference in health-related outcomes between patients who have autograft with those who did not at 1 year. Preoperative opioid use is associated with increased donor site pain within the first 2 weeks postoperatively but not in the long term. At 6 weeks postoperatively, patients can expect the majority of their donor site pain to be resolved. LEVEL OF EVIDENCE: 2.
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Ilion/cirugía , Dolor Postoperatorio/epidemiología , Donantes de Tejidos/estadística & datos numéricos , Recolección de Tejidos y Órganos/efectos adversos , Adulto , Trasplante Óseo , Discectomía , Femenino , Humanos , Ilion/fisiopatología , Masculino , Persona de Mediana Edad , Análisis Multivariante , Estudios Prospectivos , Calidad de Vida , Fusión VertebralRESUMEN
To investigate the effects of proteins products of endothelial cells (ECs) on the annulus fibrosus (AF) cell metabolism in an in vitro culture. Human AF cells were expanded in monolayer cultures and treated with proteins from the medium of cell line HMEC-1 (Human Microvascular Endothelial Cells) (125µg/ml). After 72h of treatment RNA was isolated from AF cells for analysis of gene expression and the culture medium was collected for protein expression analysis. The qRT-PCR analysis demonstrated increased gene expression of matrix metalloproteinases (MMPs) in AF cells treated with protein products of endothelial cells compared with cells from control group of AF cells: MMP-1 243.10 times (p<0.05), MMP-2 1.37 time (p<0.05), MMP-3 39.83 times (p<0.05) and MMP-13 5.70 times (p<0.05). In contrast, tissue inhibitors of metalloproteinases (TIMPs) were suppressed; TIMP-2 (0.55 time) (p<0.05) and TIMP-3 (0.60 time) (p<0.05) in the exposed groups. The expression of aggrecan gene (0.83 time) (p<0.05), an important extracellular matrix component, was also reduced. MMP-1 and MMP-3 detection was performed, confirming the results of PCR by Western Blot technique. In this study, we observed that the proteins produced by ECs induced the MMPs expression and suppressed the TIMPs as well as the aggrecan in primary cells of the human intervertebral disc, targeting the development of potential treatments for intervertebral disc degeneration and associated discogenic pain.
Analisar o efeito de produtos proteicos de células endoteliais (CEs) sobre o metabolismo de células de ânulo fibroso (AF) em ambiente controlado de cultura celular in vitro. Células de AF humano foram expandidas em camada única e tratadas com proteínas obtidas a partir do meio de cultura de células da linhagem celular HMEC-1 (Human Microvascular Endothelial Cells) (125µg/ml). Após 72h de tratamento, isolou-se RNA das células de AF para análise da expressão gênica e coletou-se meio de cultura para análise de expressão proteica. A análise da qRT-PCR demonstrou aumento da expressão gênica das metaloproteinases de matriz (MMPs) nas células de AF tratadas com produtos proteicos das células endoteliais, em comparação com grupo controle de células de AF: MMP-1 243,10 vezes (p < 0,05), MMP-2 1,37 vezes (p < 0,05), MMP-3 39,83 vezes (p < 0,05) e MMP13 5,70 vezes (p < 0,05). Em contraste, os inibidores teciduais das metaloproteinases (TIMPs) apresentaram supressão da expressão gênica de TIMP-2 (0,55 vezes) (p < 0,05) e TIMP-3 (0,60 vezes) (p < 0,05) nos grupos expostos. A expressão do gene agrecan (0,83 vezes) (p < 0,05), componente importante da matriz extracelular, também estava diminuída. Foi realizada detecção de MMP-1 e MMP-3, confirmando os resultados de PCR através de técnica de Western Blot. Neste estudo observamos que proteínas produzidas pelas CEs induziram a expressão de MMPs e suprimiram a expressão de TIMPs e agrecan nas células primárias do disco intervertebral humano, objetivando desenvolvimento de potenciais terapias no tratamento da degeneração do disco intervertebral e dor discogênica associada.
Analizar el efecto de los productos de proteína de las células endoteliales (CEs) en el metabolismo celular del anillo fibroso (AF) en sistema in vitro de cultivo controlado. Las células del AF humano se ampliaron en monocapa y se las trató con las proteínas obtenidas a partir de los medios de cultivo de la línea de células HMEC-1 (Human Microvascular Endothelial Cells) (125µg/ml). Después de 72h de tratamiento, se aisló el ARN de las células de AF para el análisis de la expresión génica y se recogió el medio de cultivo para el análisis de expresión de la proteína. El análisis de qRT-PCR demostró una mayor expresión génica de las metaloproteinasas de matriz (MMP) en las células tratadas con productos de proteína de AF en las células endoteliales, en comparación con el grupo de control de células AF: MMP-1 243,10 veces (p < 0,05), MMP-2 1,37 veces (p < 0,05), MMP-3 39,83 veces (p < 0,05) y MMP-13 5,70 veces (p < 0,05). En contraste, los inhibidores tisulares de las metaloproteinasas (TIMP), presentaron supresión de la expresión del gen TIMP-2 (0,55 veces) (p < 0,05) y TIMP-3 (0,60 veces) (p < 0,05) en los grupos expuestos. La expresión génica de agrecano (0,83 veces) (p < 0,05), importante componente de la matriz extracelular, también se redujo. La detección de MMP-1 y de MMP-3 fue realizada y se confirmaron los resultados de la PCR mediante la técnica Western Blot. En el presente estudio se observó que las proteínas producidas por las CEs indujeron la expresión de MMP y suprimieron la expresión del TIMP y de agrecano en células primarias del disco intervertebral humano, con el objetivo de desarrollar posibles tratamientos para la degeneración del disco intervertebral y el dolor discogénico asociado.
Asunto(s)
Humanos , Disco Intervertebral/citología , Técnicas de Cultivo de Célula , Metaloproteinasas de la Matriz , Células EndotelialesRESUMEN
LEVEL III: retrospective cohort study. OBJECTIVE: The aim of this study was to determine the rate of revision surgery and the occurrence of adjacent segment disease of patients undergoing ACDF for cervical radiculopathy and myelopathy using more modern-day instrumentation techniques. SUMMARY OF BACKGROUND DATA: Anterior cervical discectomy and fusion (ACDF) has long been the preferred treatment for cervical radiculopathy and myelopathy. METHODS: All patients undergoing ACDF between January of 2000 and December of 2010 were included. Age, sex, height, weight, body mass index, symptoms at presentation, number of levels fused, graft type, and smoking status were recorded. Outcomes included revision rate, reason for revision surgery, time to revision surgery, presence and grade of adjacent segment disease, distance from the instrumentation to the cranial and caudal endplate (plate-to-disc distance), and reporting of symptoms of adjacent segment disease at the final follow-up. RESULTS: A total of 672 patients were included in this study. The average duration of follow-up was 31 months. One hundred one (15%) patients underwent revision surgery. The reason for revision surgery was adjacent segment disease in 47 (47.5%), pseudarthrosis in 45 (45.5%) and a new problem at a nonadjacent level in 7 (7.1%) of those patients. The need for revision surgery was not affected by patient age, sex, body mass index, smoking status, symptoms at presentation, number of levels fused, plate-to-disc distance or graft type. CONCLUSION: The revision rate after ACDF is 15%. Most revisions were done for either adjacent segment disease or pseudarthrosis. No specific risk factors for revision surgery were identified in this study. LEVEL OF EVIDENCE: 3.
Asunto(s)
Vértebras Cervicales/cirugía , Discectomía/estadística & datos numéricos , Radiculopatía/cirugía , Fusión Vertebral/estadística & datos numéricos , Adulto , Anciano , Anciano de 80 o más Años , Vértebras Cervicales/patología , Discectomía/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Radiculopatía/patología , Reoperación/estadística & datos numéricos , Estudios Retrospectivos , Factores de Riesgo , Fusión Vertebral/métodos , Resultado del Tratamiento , Adulto JovenRESUMEN
STUDY DESIGN: Retrospective matched cohort study. OBJECTIVE: To compare mortality in elderly patients with odontoid fractures after operative and nonoperative treatment. In addition, to evaluate potential factors that may increase the risk of mortality in the geriatric population after odontoid fracture. SUMMARY OF BACKGROUND DATA: Odontoid fractures represent the most common cervical spine fracture in patients over 70. In this population controversy exists as to the optimal treatment of odontoid fractures, especially type II fractures. METHODS: A retrospective review of all odontoid fractures in patients 75 years of age or older at our institution from 1996 to 2010 was performed. Comorbidities were stratified using the Charlson comorbidity index. Mortality was determined at 3 months, 1, and 5 years. RESULTS: A total of 96 patients were identified of which 75 met inclusion criteria. The average age of patients included was 82.3 years. The average Charlson comorbidity score for those operated on (2.37) was not significantly different from the nonoperative group (2.46), (P=0.45). At 3 months the operative group had a significantly lower mortality rate than the nonoperative group (P=0.024). There was no significant difference in 1-year (P=0.42) or 5-year (P=0.21) mortality between the operative and nonoperative cohorts. Of the patients treated nonoperatively, those who died within 3 months of treatment had a significantly higher Charlson score (3.98) than those who survived (2.14). Patients who survived at least 1 year after surgery had a significantly lower Charlson score (1.53) than those who died (3.22) within that time frame after surgery (P=0.05). CONCLUSIONS: There was no significant difference between 1- and 5-year mortality in patients treated operatively or nonoperatively. Regardless of treatment Charlson score had a significant impact on mortality. Age significantly affected mortality in patients treated surgically.
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Apófisis Odontoides/patología , Apófisis Odontoides/cirugía , Fracturas de la Columna Vertebral/mortalidad , Fracturas de la Columna Vertebral/cirugía , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/mortalidad , Resultado del Tratamiento , Estados Unidos/epidemiologíaAsunto(s)
Gráficos por Computador , Descompresión Quirúrgica , Diagnóstico por Computador , Hipoestesia/prevención & control , Dolor de la Región Lumbar/prevención & control , Vértebras Lumbares/cirugía , Dimensión del Dolor/métodos , Parestesia/prevención & control , Radiculopatía/cirugía , Autoinforme , Femenino , Humanos , MasculinoRESUMEN
STUDY DESIGN: Nonrandomized controlled cohort. OBJECTIVE: 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. SUMMARY OF BACKGROUND DATA: 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. METHODS: 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. RESULTS: 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). CONCLUSION: 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. LEVEL OF EVIDENCE: 4.
Asunto(s)
Vértebras Cervicales/fisiopatología , Cápsula Articular/fisiopatología , Enfermedades de la Columna Vertebral/fisiopatología , Articulación Cigapofisaria/fisiopatología , Adulto , Fenómenos Biomecánicos , Estudios de Casos y Controles , Vértebras Cervicales/diagnóstico por imagen , Vértebras Cervicales/cirugía , Femenino , Humanos , Imagenología Tridimensional , Cápsula Articular/diagnóstico por imagen , Cápsula Articular/cirugía , Masculino , Persona de Mediana Edad , Interpretación de Imagen Radiográfica Asistida por Computador , Rango del Movimiento Articular , Enfermedades de la Columna Vertebral/diagnóstico por imagen , Enfermedades de la Columna Vertebral/cirugía , Fusión Vertebral , Tomografía Computarizada por Rayos X , Resultado del Tratamiento , Articulación Cigapofisaria/diagnóstico por imagen , Articulación Cigapofisaria/cirugíaRESUMEN
STUDY DESIGN: Cross sectional study. OBJECTIVE: The goal of this study is to identify relationships between objectively measured and subjectively scored parameters and reported pain. SUMMARY OF BACKGROUND DATA: Studies have demonstrated the unreliability of magnetic resonance imaging (MRI)-based parameters to identify pathological pain generators of chronic low back pain, but they were based on visual inspection and subjective assessment of lumbar disc features. Advancements in computer image analysis provide objective measurements of lumbar disc features. METHODS: Two radiologists evaluated 39 axial and sagittal T1- and T2-weighted MR images of patients with chronic axial low back pain (age, >65 yr) and graded 4 subjective lumbar disc parameters (T2 signal intensity, nucleus shape, Modic changes, and osteophyte formation) whose sum is the cumulative MRI score. Objective parameter, MRI index, was calculated as the product of the measured lumbar disc area and total disc MRI signal intensity. Discs were sorted from least to the most degenerated relative to each parameter. Pearson correlation coefficient and multiple linear regression analysis were performed between the reported pain score and each parameter. RESULTS: The most and least degenerated discs in each patient, as assessed by MRI index, had the highest negative and positive correlation coefficient and regression weight contribution, respectively. All subjective parameters had low correlation coefficients and regression goodness of fit. CONCLUSION: Although limited by small sample size, the objective parameter, MRI index, can be a potential imaging biomarker used to identify possible pain generators. This study presents a potential new application of MR imaging in identifying pain generators of patients with chronic low back pain.
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Dolor Crónico/diagnóstico , Degeneración del Disco Intervertebral/diagnóstico , Disco Intervertebral/patología , Dolor de la Región Lumbar/diagnóstico , Vértebras Lumbares/patología , Imagen por Resonancia Magnética , Dimensión del Dolor , Percepción del Dolor , Factores de Edad , Anciano , Anciano de 80 o más Años , Dolor Crónico/etiología , Dolor Crónico/patología , Dolor Crónico/psicología , Estudios Transversales , Femenino , Humanos , Degeneración del Disco Intervertebral/complicaciones , Degeneración del Disco Intervertebral/patología , Degeneración del Disco Intervertebral/psicología , Modelos Lineales , Dolor de la Región Lumbar/etiología , Dolor de la Región Lumbar/patología , Dolor de la Región Lumbar/psicología , Masculino , Valor Predictivo de las Pruebas , Índice de Severidad de la EnfermedadRESUMEN
STUDY DESIGN: Case control study. OBJECTIVE: To quantify precisely and compare intervertebral segmental contributions to cervical spine flexion-extension during continuous, functional flexion-extension in asymptomatic subjects with patients who underwent single-level anterior arthrodesis. SUMMARY OF BACKGROUND DATA: Segmental contributions to cervical flexion-extension have traditionally been determined using single images collected at full flexion and full extension. These calculations neglect midrange motion and assume that percent contributions to motion remain constant throughout the entire flexion-extension range of motion (ROM). METHODS: Six patients with single-level (C5-C6) anterior arthrodesis and 18 asymptomatic control subjects performed flexion-extension while biplane radiographs were collected at 30 images per second. A previously validated tracking process determined 3-dimensional vertebral position with submillimeter accuracy during continuous flexion-extension. Mixed-effects models of segmental percent contribution to C2-C7 flexion-extension were developed to identify differences in percent contribution within each motion segment, among motion segments, and between controls and patients who underwent arthrodesis over the full ROM. RESULTS: The C2-C3, C3-C4, and C4-C5 motion segments made their maximum contributions during the midrange of motion. The C5-C6 and C6-C7 motion segments, in contrast, made their maximum contributions near the start and end of the ROM. Arthrodesis patients' contribution from the C4-C5 motion segment increased significantly over the range of motion from 30% to 95% of the total flexion-extension ROM (average increased contribution of 5.1%) and arthrodesis patients' contribution from the C6-C7 motion segment increased significantly over the entire flexion-extension ROM (average increased percentage contribution of 8.9%) in comparison to controls. CONCLUSION: Cervical motion segment contributions to flexion-extension change significantly during the flexion-extension motion. The largest change in percent contribution to motion, relative to controls, occurs at the C6-C7 motion segment, over the entire ROM, suggesting a potential mechanical mechanism for the clinical observation of increased incidence of adjacent segment degeneration at C6-C7 rather than at C4-C5 after C5-C6 arthrodesis.
Asunto(s)
Artrodesis/efectos adversos , Vértebras Cervicales/fisiología , Movimiento/fisiología , Rango del Movimiento Articular/fisiología , Adulto , Artrodesis/tendencias , Fenómenos Biomecánicos/fisiología , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
STUDY DESIGN: Laboratory based controlled in vivo study. OBJECTIVE: To determine the in vivo effects of oral glucosamine sulfate on intervertebral disc degeneration. SUMMARY OF BACKGROUND DATA: Although glucosamine has demonstrated beneficial effect in articular cartilage, clinical benefit is uncertain. A Centers for Disease Control report from 2009 reported that many patients are using glucosamine supplementation for low back pain, without significant evidence to support its use. Because disc degeneration is a major contributor of low back pain, we explored the effects of glucosamine on disc matrix homeostasis in an animal model of disc degeneration. METHODS: Eighteen skeletally mature New Zealand White rabbits were divided into 4 groups: control, annular puncture, glucosamine, and annular puncture + glucosamine. Glucosamine treated rabbits received daily oral supplementation with 107 mg/d (weight based equivalent to human 1500 mg/d). Annular puncture surgery involved puncturing the annulus fibrosus of 3 lumbar discs with a 16-gauge needle to induce degeneration. Serial magnetic resonance images were obtained at 0, 4, 8, 12, and 20 weeks. Discs were harvested at 20 weeks for determination of glycosaminoglycan content, relative gene expression measured by real time polymerase chain reaction, and histological analyses. RESULTS: The magnetic resonance imaging index and nucleus pulposus area of injured discs of glucosamine treated animals with annular puncture was found to be lower than that of degenerated discs from rabbits not supplemented with glucosamine. Consistent with this, decreased glycosaminoglycan was demonstrated in glucosamine fed animals, as determined by both histological and glycosaminoglycan content. Gene expression was consistent with a detrimental effect on matrix. CONCLUSION: These data demonstrate that the net effect on matrix in an animal model in vivo, as measured by gene expression, magnetic resonance imaging, histology, and total proteoglycan is antianabolic. This raises concern about this commonly used supplement, and future research is needed to establish the clinical relevance of these findings.