RESUMEN
In 1936, Walter Mercer described a new method for the operative treatment of patients with spondylolisthesis. Using a transabdominal approach in two patients he inserted iliac crest bone graft into the intervertebral disc. His publication in the Edinburgh Medical Journal caused a furore as the levels operated on did not reflect the description and one of the two patients died post-operatively. However, Mercer continued to promote the operation in his textbooks. The anterior approach to the lumbar spine is now performed routinely. This paper explores Mercer's contribution to anterior spinal surgery.
Asunto(s)
Dolor de la Región Lumbar/historia , Fusión Vertebral/historia , Espondilolistesis/historia , Historia del Siglo XX , Humanos , Dolor de la Región Lumbar/cirugía , Escocia , Fusión Vertebral/métodos , Espondilolistesis/cirugíaRESUMEN
This review paper discusses the process of disc degeneration and the current understanding of cellular degradation in patients who present with low back pain. The role of surgical treatment for low back pain is analysed with emphasis on the proven value of spinal fusion. The interesting and novel developments of stem cell research in the treatment of low back pain are presented with special emphasis on the importance of the cartilaginous end plate and the role of IL-1 in future treatment modalities.
Asunto(s)
Degeneración del Disco Intervertebral/complicaciones , Degeneración del Disco Intervertebral/terapia , Dolor de la Región Lumbar/etiología , Dolor de la Región Lumbar/terapia , HumanosRESUMEN
This article reviews the current knowledge of the intervertebral disc (IVD) and its association with low back pain (LBP). The normal IVD is a largely avascular and aneural structure with a high water content, its nutrients mainly diffusing through the end plates. IVD degeneration occurs when its cells die or become dysfunctional, notably in an acidic environment. In the process of degeneration, the IVD becomes dehydrated and vascularised, and there is an ingrowth of nerves. Although not universally the case, the altered physiology of the IVD is believed to precede or be associated with many clinical symptoms or conditions including low back and/or lower limb pain, paraesthesia, spinal stenosis and disc herniation. New treatment options have been developed in recent years. These include biological therapies and novel surgical techniques (such as total disc replacement), although many of these are still in their experimental phase. Central to developing further methods of treatment is the need for effective ways in which to assess patients and measure their outcomes. However, significant difficulties remain and it is therefore an appropriate time to be further investigating the scientific basis of and treatment of LBP.
Asunto(s)
Degeneración del Disco Intervertebral/etiología , Disco Intervertebral/fisiopatología , Dolor de la Región Lumbar/terapia , Humanos , Disco Intervertebral/anatomía & histología , Disco Intervertebral/fisiología , Dolor de la Región Lumbar/etiologíaRESUMEN
We have previously shown osteogenic differentiation of mouse embryonic stem (ES) cells and temporal enrichment with osteoblastic cells, by stimulation with serum-containing culture medium supplemented with beta-glycerophosphate, ascorbate, and dexamethasone. In our present study we have used similar culture conditions to further investigate osteogenic differentiation of mouse ES cells. Using reverse transcription-polymerase chain reaction (RT-PCR) we demonstrated the expression of genes associated with osteoblast differentiation including the bone matrix protein osteocalcin and the transcription factor Cbfa-1/runx2. Furthermore, results of cDNA microarray analysis, and subsequent RT-PCR analysis of differentiating ES cells after exposure to osteogenic stimuli, revealed a combination of upregulation of genes involved in osteoblast differentiation including osteopontin, HSP-47, and IGF-II coupled with downregulation of genes involved in differentiation of other phenotypes such as the neuroectoderm factor Stra-13. Finally, we have applied magnetically activated cell-sorting methods to ES cell cultures treated with osteogenic stimuli and, using an antibody to cadherin-11, have purified a subpopulation of cells with osteoblastic characteristics.
Asunto(s)
Separación Inmunomagnética/métodos , Análisis de Secuencia por Matrices de Oligonucleótidos/métodos , Osteoblastos/citología , Osteoblastos/fisiología , Células Madre/citología , Células Madre/fisiología , Ingeniería de Tejidos/métodos , Animales , Cadherinas , Técnicas de Cultivo de Célula/métodos , Diferenciación Celular/fisiología , Línea Celular , Perfilación de la Expresión Génica/métodos , Regulación del Desarrollo de la Expresión Génica/fisiología , Ratones , Osteogénesis/fisiologíaRESUMEN
We studied 27 patients with low back pain and unilateral L5 or S1 spinal nerve root pain. Significant radiological changes were restricted to the symptomatic root level, when compared with controls. Low back and leg pain were graded on a visual analogue scale. Dermatomal quantitative sensory tests revealed significant elevations of warm, cool and touch perception thresholds in the affected dermatome, compared with controls. These elevations correlated with root pain (warm v L5 root pain; r = 0.88, p < 0.0001), but not with back pain. Low back pain correlated with restriction of anteroposterior spinal flexion (p = 0.02), but not with leg pain. A subset of 16 patients underwent decompressive surgery with improvement of pain scores, sensory thresholds and spinal mobility. A further 14 patients with back pain, multilevel nerve root symptoms and radiological changes were also studied. The only correlation found was of low back pain with spinal movement (p < 0.002). We conclude that, in patients with single level disease, dermatomal sensory threshold elevation and restriction of spinal movement are independent correlates of sciatica and low back pain.
Asunto(s)
Dolor de la Región Lumbar/cirugía , Neuralgia/fisiopatología , Adulto , Anciano , Femenino , Humanos , Pierna , Dolor de la Región Lumbar/fisiopatología , Vértebras Lumbares , Masculino , Persona de Mediana Edad , Umbral del Dolor/fisiología , Rango del Movimiento Articular/fisiología , Ciática/fisiopatología , Umbral Sensorial/fisiología , Raíces Nerviosas Espinales/fisiologíaRESUMEN
We prospectively studied the incidence of methicillin-resistant Staphylococcus aureus (MRSA) colonisation and infection, the patterns and types of operation associated with MRSA acquisition in an orthopaedic and trauma unit in London, UK. Over the 12-month study period from January to December 2000, we found that 1.6% of the total admission was diagnosed to be either MRSA infected or colonised, with an average of three new MRSA cases detected per month. A significant proportion of patients (23%) were diagnosed within the first 48h of admission. Both hip joint surgery, especially emergency procedures for femoral neck fractures, and the presence of a wound presented higher risk of infection. The Intensive Care Unit (ICU) did not appear to be a significant source for intra-hospital dissemination among the orthopaedic patients. MRSA infection or colonisation contributed to an increased length of hospital stay; 88 days compared to 11 days on average for non-MRSA patients; 41% of the positive patients still carried MRSA on discharge. Our data show the importance of diagnosing MRSA in orthopaedic surgery and emphasises that understanding its epidemiology will be crucial to secure a decrease in the incidence of MRSA. Hand hygiene, patient screening, careful surveillance of infections and the prompt implementation of isolation policies, are essential components of control.
Asunto(s)
Procedimientos Ortopédicos/efectos adversos , Infecciones Estafilocócicas/microbiología , Staphylococcus aureus , Infección de la Herida Quirúrgica/microbiología , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Hospitales de Enseñanza , Humanos , Incidencia , Control de Infecciones/métodos , Londres/epidemiología , Masculino , Resistencia a la Meticilina , Persona de Mediana Edad , Estudios Prospectivos , Factores de Riesgo , Infecciones Estafilocócicas/epidemiología , Infecciones Estafilocócicas/prevención & control , Infección de la Herida Quirúrgica/epidemiología , Infección de la Herida Quirúrgica/prevención & control , Centros TraumatológicosRESUMEN
Antibiotics are often administrated prophylactically in spinal procedures to reduce the risk of infection of the disc space. It is still not known which antibiotics are able to penetrate the intervertebral disc effectively. In a prospective, randomised, double-blind clinical study, we examined the penetration of the intervertebral discs of two commonly used antibiotics, cefuroxime and gentamicin. The patients, randomised into two groups, received either 1.5 g of cefuroxime or 5 mg/kg of gentamicin prophylactically two hours before their intervertebral discs were removed. A specimen of blood, from which serum antibiotic levels were determined, was obtained at the time of discectomy. Therapeutic levels of antibiotic were detectable in the intervertebral discs of the ten patients who received gentamicin. Only two of the ten patients (20%) who received cefuroxime had a quantifiable level of antibiotic in their discs although therapeutic serum levels of cefuroxime were found in all ten patients. Our results show that cefuroxime does not diffuse into human intervertebral discs as readily as gentamicin. It is possible that the charge due to ionisable groups on the antibiotics can influence the penetration of the antibiotics. We therefore recommend the use of gentamicin in a single prophylactic dose for all spinal procedures in order to reduce the risk of discitis.
Asunto(s)
Antibacterianos/administración & dosificación , Profilaxis Antibiótica/métodos , Cefuroxima/administración & dosificación , Cefalosporinas/administración & dosificación , Gentamicinas/administración & dosificación , Desplazamiento del Disco Intervertebral/cirugía , Infección de la Herida Quirúrgica/prevención & control , Adulto , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Resultado del TratamientoRESUMEN
Assessment of spinal intersegmental motion has been a focus for research and has depended on radiographic techniques. Radiographic techniques are limited because of ionizing radiation exposure, magnification errors, and image quality. Interventional magnetic resonance scanners, however, allow dynamic imaging in the scanner in different positions. Twelve healthy subjects were scanned using a General Electric Signa SP10 open interventional magnetic resonance scanner. Subjects were scanned while they were in the supine position and during sitting in flexed and extended positions. Measurements of lumbar curvature and intersegmental motion were made from the sagittal images obtained. The results showed that it was possible to obtain repeatable measures of intersegmental rotation and translation from open magnetic resonance images of the spine in flexed and extended positions. These measures of motion are in agreement with previous data and suggest that the greatest motion occurs at the L4-L5 level. The use of interventional magnetic resonance imaging for assessing lumbar intersegmental mobility seems promising.
Asunto(s)
Vértebras Lumbares/fisiología , Imagen por Resonancia Magnética/métodos , Adulto , Fenómenos Biomecánicos , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Rango del Movimiento ArticularRESUMEN
OBJECTIVE: To evaluate the association between vertebral "end plate sclerosis" and neck pain. DESIGN: A retrospective study was carried out of lateral cervical spine radiographs with a Picture Archive and Communication System (PACS). PATIENTS: Two hundred patients' files were randomly assessed, comprising four equal groups, A to D. The mean ages of the patients were 62+/-7.4 years, 61+/-7.5 years, 40+/-5.6 years and 23+/-5.6 years respectively. In group A, all patients had symptoms of neck pain and a radiographic diagnosis of "end plate sclerosis" of the cervical spine. In groups B to D, asymptomatic patients were recruited and their age groups were 50-69, 30-49 and 10-29 years respectively. Using the PACS, the radiographic density and the sagittal diameter, thickness and area of the end plates at the C5 level were measured. RESULTS AND CONCLUSIONS: No significant differences were found in the radiographic density of the end plates either between the symptomatic and asymptomatic groups (groups A and B), or between different age groups (groups B, C and D). A significant increase in end plate area and thickness was found, however, in both group B (P<0.005) and group C (P<0.01) in comparison with group D. This indicates that the extent of end plate sclerosis increases with age. Our results suggest that the radiographic density of cervical vertebral end plates correlates neither with neck pain nor with increasing age. The radiological sign of "end plate sclerosis" may be over-reported, further limiting its value in the assessment of patients with cervical spondylosis.
Asunto(s)
Disco Intervertebral/patología , Enfermedades de la Columna Vertebral/patología , Adolescente , Adulto , Anciano , Vértebras Cervicales/diagnóstico por imagen , Niño , Femenino , Humanos , Disco Intervertebral/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Dolor de Cuello/diagnóstico por imagen , Dolor de Cuello/etiología , Radiografía , Sistemas de Información Radiológica , Estudios Retrospectivos , Esclerosis/patología , Enfermedades de la Columna Vertebral/diagnóstico por imagenRESUMEN
The aim of this study was to investigate the influence of initial resting posture on range of motion of the lumbar spine in 18 normal subjects. Subjects resting posture and active range of motion was measured using the CA-6000 Spinal Motion Analyser (OSI, USA) in five test positions, namely in flat standing and with a variety of heel raises. Analysis showed that there was no significant correlation between subject's normal resting posture and active range of motion. However, when subjects resting posture was artificially altered with heel raises, significant effects on the active range of motion were demonstrated. Increasing heel height significantly influenced resting posture in the sagittal plane only. As heel height increased, the lumbar lordosis decreased and a significant reduction in the range of lumbar spine flexion (P<0.001) was observed. Simulating pelvic asymmetry influenced resting posture in the frontal plane and significant effects on the range of lateral flexion (P<0.05) were observed. These results have important clinical implications in terms of using range of motion of the lumbar spine as an examination tool and suggest that studies using range of motion as an outcome measure should consider initial resting posture.
Asunto(s)
Vértebras Lumbares/fisiología , Postura , Rango del Movimiento Articular , Adulto , Análisis de Varianza , Fenómenos Biomecánicos , Femenino , Humanos , Modelos Lineales , MasculinoRESUMEN
STUDY DESIGN: This was a prospective pilot study to investigate the global motion characteristics of the spondylolysis and spondylolisthesis populations. OBJECTIVES: The aim of this study is to determine the influence of a spondylolisthesis or a spondylolysis on global spinal motion and to establish whether this is dependent on the cause of the slip or the degree/grade of the slip. SUMMARY OF BACKGROUND DATA: The condition of spondylolisthesis has been extensively discussed in the literature with respect to its etiology and management. However, the mechanics and movement of the spine in relation to pathology and the effect of this condition on function have received scant attention. METHODS: The motion of the lumbar spine was investigated in 31 patients (19 men, 12 women, mean age 47.7 +/- 17.8 years) who were diagnosed as having either a lumbar spondylolysis or a spondylolisthesis. These patients were compared with a preexisting database of 203 normal subjects (100 men, 103 women, mean age 39.8 +/- 13.4 years). Patients were graded according to the type of spondylolisthesis or spondylolysis they had, and the extent of slip was rated using Meyerding's classification (1932) and measured directly using methods of Boxall et al (1979) and Wiltse et al (1983). RESULTS: Direct measurements of the extent of slip using Boxall et al (1979) and Wiltse et al (1983) methods were found to have no significant correlation with the resultant range of motion (ROM) or the speed of movement. This study suggests that motion parameters are influenced by the grade of slip in patients with spondylolisthesis, and the type of spondylolisthesis i.e., whether isthmic or degenerative. In the A-P flexion-extension plane, the results indicate that subjects with a defect only, i.e., a spondylolysis, and thus no slip present with a spinal hypermobility (P < 0.01). Subjects with an isthmic slip tend to be either slightly hypermobile or within the anticipated range of motion, whereas those subjects with a degenerative slip tend to be hypomobile (P < 0.05). Movements into lateral flexion were restricted in both the isthmic and degenerative spondylolisthesis patients, whereas rotation was only influenced by the level at which the defect occurred. In terms of degree of displacement, in higher grades of displacement, there was a trend towards hypermobility. CONCLUSIONS: The findings of this study suggest that the grade and type of spondylolisthesis do influence global motion parameters. This information may be useful in the clinical assessment of this patient group.
Asunto(s)
Vértebras Lumbares/fisiopatología , Movimiento/fisiología , Rango del Movimiento Articular/fisiología , Espondilolistesis/fisiopatología , Espondilólisis/fisiopatología , Adulto , Cinerradiografía , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Inestabilidad de la Articulación/diagnóstico por imagen , Inestabilidad de la Articulación/patología , Inestabilidad de la Articulación/fisiopatología , Dolor de la Región Lumbar/diagnóstico por imagen , Dolor de la Región Lumbar/patología , Dolor de la Región Lumbar/fisiopatología , Vértebras Lumbares/diagnóstico por imagen , Vértebras Lumbares/patología , Masculino , Persona de Mediana Edad , Análisis de Regresión , Espondilolistesis/diagnóstico por imagen , Espondilolistesis/patología , Espondilólisis/diagnóstico por imagen , Espondilólisis/patologíaRESUMEN
Pluripotent embryonic stem (ES) cells have the potential to differentiate to all fetal and adult cell types and might represent a useful cell source for tissue engineering and repair. Here we show that differentiation of ES cells toward the osteoblast lineage can be enhanced by supplementing serum-containing media with ascorbic acid, beta-glycerophosphate, and/or dexamethasone/retinoic acid or by co-culture with fetal murine osteoblasts. ES cell differentiation into osteoblasts was characterized by the formation of discrete mineralized bone nodules that consisted of 50-100 cells within an extracellular matrix of collagen-1 and osteocalcin. Dexamethasone in combination with ascorbic acid and beta-glycerophosphate induced the greatest number of bone nodules and was dependent on time of stimulation with a sevenfold increase when added to ES cultures after, but not before, 14 days. Co-culture with fetal osteoblasts also provided a potent stimulus for osteogenic differentiation inducing a fivefold increase in nodule number relative to ES cells cultured alone. These data demonstrate the application of a quantitative assay for the derivation of osteoblast lineage progenitors from pluripotent ES cells. This could be applied to obtain purified osteoblasts to analyze mechanisms of osteogenesis and for use of ES cells in skeletal tissue repair.
Asunto(s)
Diferenciación Celular , Embrión de Mamíferos/citología , Osteoblastos/citología , Osteogénesis , Células Madre/citología , Animales , Antioxidantes/farmacología , Ácido Ascórbico/farmacología , Huesos/citología , Línea Celular , Linaje de la Célula , Células Cultivadas , Técnicas de Cocultivo , Dexametasona/farmacología , Glucocorticoides/farmacología , Glicerofosfatos/farmacología , Humanos , Inmunohistoquímica , Ratones , Microscopía Confocal , Osteoblastos/fisiología , Células Madre/efectos de los fármacos , Células Madre/fisiología , Tretinoina/farmacologíaRESUMEN
The precise dimensions of the lumbar vertebrae and discs are critical for the production of appropriate spinal implants. Unfortunately, existing databases of vertebral and intervertebral dimensions are limited either in accuracy, study population or parameters recorded. The objective of this study is to provide a large and accurate database of lumbar spinal characteristics from 126 digitised computed tomographic (CT) images, reviewed using the Picture Archiving Communication System (PACS) coupled with its internal measuring instrumentation. These CT images were obtained from patients with low back pain attending the spinal clinic at the Hammersmith Hospitals NHS Trust. Measurements of various aspects of vertebral dimensions and geometry were recorded, including vertebral and intervertebral disc height. The results from this study indicated that the depth and width of the vertebral endplate increased from the third to the fifth lumbar vertebra. Anterior vertebral height remained the same from the third to the fifth vertebra, but the posterior vertebral height decreased. Mean disc height in the lower lumbar segments was 11.6 +/- 1.8 mm for the L3/4 disc, 11.3 +/- 2.1 mm for the L4/5, and 10.7 +/- 2.1 mm for the L5/S1 level. The average circumference of the lower endplate of the fourth lumbar vertebra was 141 mm and the average surface area was 1,492 mm2. An increasing pedicle width from a mean of 9.6 +/- 2.2 mm at L3 through to 16.2 +/- 2.8 mm at L5 was noted. A comprehensive database of vertebral and intervertebral dimensions was generated from 378 lumbar vertebrae from 126 patients measured with a precise digital technique. These results are invaluable in establishing an anthropometric model of the human lumbar spine, and provide useful data for anatomical research. In addition this is important information for the scientific planning of spinal surgery and for the design of spinal implants.
Asunto(s)
Interpretación de Imagen Asistida por Computador , Vértebras Lumbares/anatomía & histología , Adulto , Anciano , Anciano de 80 o más Años , Antropometría , Bases de Datos Factuales , Femenino , Humanos , Vértebras Lumbares/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Valores de Referencia , Sacro/anatomía & histología , Sacro/diagnóstico por imagen , Tomografía Computarizada por Rayos XRESUMEN
Osteomyelitis is a major cause of morbidity worldwide but there are few data investigating pathogenesis of infection and no investigations into local secretion of proinflammatory cytokines in patients. Tumour necrosis factor-alpha (TNF), interleukin (IL)-6 and IL-8 concentrations were measured in pus of infected bone from 30 Zambian patients with chronic osteomyelitis (principally caused by Staphylococcus aureus), in plasma, and after lipopolysaccharide stimulation of whole-blood leucocytes. Patients had reduced body mass index compared to controls (P = 0.025) and an acute-phase response. Elevated concentrations of proinflammatory cytokines were detected in bone compared to plasma (all P < 0.0002). Bone IL-8 concentrations were greater than IL-8 levels after lipopolysaccharide stimulation of whole blood (P < 0.01). In contrast, systemic and ex-vivo-stimulated concentrations of proinflammatory cytokine were similar in patients and controls, despite differences in body mass index and an acute-phase response. In summary, we observed marked local TNF, IL-6 and IL-8 secretion in established bacterial osteomyelitis without systemic cytokine release.
Asunto(s)
Interleucina-6/metabolismo , Interleucina-8/metabolismo , Osteomielitis/metabolismo , Infecciones Estafilocócicas , Factor de Necrosis Tumoral alfa/metabolismo , Adolescente , Niño , Femenino , Humanos , Masculino , Osteomielitis/microbiología , Infecciones por Salmonella/complicaciones , Infecciones por Salmonella/metabolismo , Infecciones Estafilocócicas/metabolismo , Supuración/microbiologíaRESUMEN
PURPOSE: Single photon emission computed tomography (SPECT) bone scans of the lumbar spine were evaluated in the management of patients with low back pain and suspected spondylolysis. MATERIALS AND METHODS: Thirty-three patients (mean age, 30 years) with high clinical suspicion of pars interarticularis defects were included in the study. The results of lumbar radiographs and SPECT bone scintigraphy were compared and the influence of these results on patient management was evaluated. RESULTS: Twenty-six of the 33 patients had abnormal results of lumbar radiographs. Of the 21 patients with radiographs indicating spondylolysis, six had abnormal uptake in the pars regions on bone scintigraphy. One patient with normal results of lumbar radiographs had a SPECT bone scan showing uptake in the region of the pars interarticularis. CONCLUSIONS: SPECT bone scanning of the lumbar spine has a role in the treatment of patients with symptomatic spondylolysis.
Asunto(s)
Dolor de la Región Lumbar/diagnóstico por imagen , Vértebras Lumbares/diagnóstico por imagen , Espondilólisis/diagnóstico por imagen , Tomografía Computarizada de Emisión de Fotón Único , Adulto , Femenino , Humanos , Masculino , Radiografía , Radiofármacos , Espondilólisis/terapia , Medronato de Tecnecio Tc 99mAsunto(s)
Procedimientos Ortopédicos/normas , Esterilización/métodos , Infección de la Herida Quirúrgica/prevención & control , Drenaje/normas , Guantes Quirúrgicos , Historia del Siglo XX , Humanos , Procedimientos Ortopédicos/efectos adversos , Grupo de Atención al Paciente/normas , Ropa de Protección/normas , Esterilización/historia , Infección de la Herida Quirúrgica/etiología , Transporte de Pacientes/normas , Estados UnidosRESUMEN
Our aim was to investigate whether nitric oxide synthase (NOS) isoforms, responsible for the generation of NO, are expressed during the healing of fractures. To localise the sites of expression compared with those in normal bone we made standardised, stabilised, unilateral tibial fractures in male Wistar rats. Immunostaining was used to determine the precise tissue localisation of the different NOS isoforms. Western blotting was used to assess expression of NOS isoform protein and L-citrulline assays for studies on NOS activity. Control tissue was obtained from both the contralateral uninjured limb and limbs of normal rats. Immunohistochemistry showed increased expression of endothelial NOS (eNOS) to be strongest in the cortical blood vessels and in osteocytes in the early phase of fracture repair. Western blot and image analysis confirmed this initial increase. Significantly elevated calcium-dependent NOS activity was observed at day 1 after fracture. Inducible NOS (iNOS) was localised principally in endosteal osteoblasts and was also seen in chondroblasts especially in the second week of fracture healing. Western blotting showed a reduction in iNOS during the early healing period. Significantly reduced calcium-independent NOS activity was also seen. No neuronal NOS was seen in either fracture or normal tissue. Increased eNOS in bone blood vessels is likely to mediate the increased blood flow recognised during fracture healing. eNOS expression in osteocytes may occur in response to changes in either mechanical or local fluid shear stress. The finding that eNOS is increased and iNOS reduced in early healing of fractures may be important in their successful repair.
Asunto(s)
Curación de Fractura/fisiología , Óxido Nítrico Sintasa/metabolismo , Óxido Nítrico/metabolismo , Animales , Endotelio Vascular/enzimología , Endotelio Vascular/patología , Inducción Enzimática/fisiología , Fracturas del Fémur/enzimología , Fracturas del Fémur/patología , Fijación Intramedular de Fracturas , Masculino , Ratas , Ratas WistarRESUMEN
An experimental model of fracture healing has been used to investigate whether nitric oxide mediated vascular reactivity, determined using laser Doppler flowmetry, is present in bone after a fracture. Times corresponding to Days 0, 1, 3, 7, 14, and 28 after fracture were used to study the injured and contralateral limbs in response to bolus intravenous administration of nitric oxide inhibitor, N-nitro-L-arginine methyl ester, and nitric oxide stimulator, acetylcholine. N-nitro-L-arginine methyl ester administration (1 mumol/kg, 10 mumol/kg, and 100 mumol/kg) caused a dose dependent increase in systemic blood pressure in each of the assessment groups; however, there was no statistical difference between the groups. Doppler flow readings at the fracture site showed measurable changes in local vascular reactivity after drug administration. At Day 1 after fracture, the magnitude of unit change in vascular reactivity in response to N-nitro-L-arginine methyl ester (1 mumol/kg, 10 mumol/kg, and 100 mumol/kg) was significantly higher in the fractured limb compared with the contralateral limb and also when compared with other points of assessment. These results show that nitric oxide mediated vasoreactivity is present about a fracture site and is maximal in the early healing phase, before returning to basal levels as healing progresses. This is compatible with an initial restoration of blood flow at a fracture site by nitric oxide dependent vasodilation of preexisting blood vessels, followed by ingrowth of less nitric oxide dependent angiogenic vessels during the later phase of repair.
Asunto(s)
Huesos/irrigación sanguínea , Curación de Fractura/efectos de los fármacos , Óxido Nítrico/farmacología , Vasodilatadores/farmacología , Acetilcolina/administración & dosificación , Acetilcolina/farmacología , Animales , Presión Sanguínea/efectos de los fármacos , Huesos/efectos de los fármacos , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/administración & dosificación , Inhibidores Enzimáticos/farmacología , Estudios de Seguimiento , Inyecciones Intravenosas , Flujometría por Láser-Doppler , Masculino , NG-Nitroarginina Metil Éster/administración & dosificación , NG-Nitroarginina Metil Éster/farmacología , Neovascularización Fisiológica/fisiología , Óxido Nítrico/administración & dosificación , Óxido Nítrico/antagonistas & inhibidores , Óxido Nítrico Sintasa/antagonistas & inhibidores , Ratas , Ratas Wistar , Flujo Sanguíneo Regional/fisiología , Vasodilatadores/administración & dosificación , Vasodilatadores/antagonistas & inhibidoresRESUMEN
We have measured the dynamic movement of the lumbar spine in 57 patients with degenerative lumbar disc disease. Each completed a questionnaire which recorded pain and subjective signs and symptoms. From plain lateral radiographs, the subjects were graded using the criteria of Kellgren and Lawrence and those of Lane et al, which are both based on the severity of degenerative changes. Measurements of the height of the disc space and the vertebral height were obtained and expressed as a ratio. We found no relationship between the characteristics of spinal movement and the overall grading of degenerative disc disease with either system. Both were influenced (p < 0.01) by age, walking distance, severity of symptoms, drug intake and frequency of pain. The present systems for grading degenerative disc disease from plain lateral radiographs have limited application.