Epidural fibrosis following spinal surgery is common, and subsequent reoperations are more technically challenging with higher complication rates. A safe and effective therapeutic solution to this difficult clinical problem has yet to be realized. Previous research has demonstrated the effectiveness of alanyl-glutamine in reduction of peritoneal adhesions in a rat abdominal sepsis model. I hypothesized that alanyl-glutamine may be similarly efficacious in minimizing epidural fibrosis in a rat laminectomy model. Rats were randomized into three groups: no surgery, laminectomy/normal saline and laminectomy/alanyl-glutamine (1g/kg). The surgical groups underwent a lumbar laminectomy with instillation of either normal saline or alanyl-glutamine into the peridural space. Thirty days after surgery, the rats were euthanized and the spinal columns prepared for histological evaluation. A blinded veterinary pathologist and a less experienced student independently graded the extent and maturity of epidural fibrosis. The laminectomy model was an effective model for epidural fibrosis formation. Rats that underwent laminectomy demonstrated significant fibrosis compared to control animals (p<0.001). However, there was no significant difference in histological grade of fibrosis between normal saline and alanyl-glutamine treatment groups (p=0.83). Based on this study, alanyl-glutamine does not appear to have an effect in reducing epidural fibrosis at a histological level. It is possible that alanyl-glutamine may have an effect that is not detectable using this model, in which case further studies with a more sensitive model may be indicated. Resources may be better used elucidating the mechanism by which glutamine acts to reduce adhesions in the peritoneal model and further studies exploiting those mechanisms can be designed.

Cervical spondylotic myelopathy is the most common spinal cord disorder in persons over 55 years of age in North America and perhaps in the world. Surgical options are broadly classified into two categories namely, anterior and posterior approaches. This study focuses on the posterior based approach (i.e. laminectomy or laminoplasty) which is considered when multiple levels of the spine have to be decompressed or when most of the cord compression results from posterior pathological conditions. The external and internal behavior of the spine after laminoplasty and laminectomy has been evaluated using both experimental and computational methods. Computationally, a validated intact 3D finite element model of the cervical spine (C2-T1) was modified to simulate laminectomy and laminoplasty (open door (ODL) and double door (DDL)) at levels C3-C6. During flexion, after ODL the adjacent levels C2-C3 and C6-C7 showed a 39% and 20% increase in the motion respectively; while no substantial changes were observed at the surgically altered levels. The percent increase in motion after DDL varied from 4.3% to 34.6%. The inclination towards increased motion during flexion after double door laminoplasty explains the role of the lamina-ligamentum flavum complex in the stability of spine. Compared to the intact model, laminectomy at C3-C6 led to a profound increase (37.5% to 79.6%) in motion across the levels C2-C3 to C6-C7. Furthermore, the changes in the von Mises stresses of the intervertebral disc observed after laminoplasty and laminectomy during flexion can be correlated to the changes in the intersegmental motions. An in-vitro biomechanical study was conducted to address the effects of laminoplasty (two-level and four-level) and four-level laminectomy on the flexibility of the cervical spine. Both two-level and four-level laminoplasty resulted in minimal changes in C2-T1 range of motion. For flexion/extension, two-level and multi-level laminoplasty showed an approximate 20% decrease (p>0.05) in the range of motion at C4-C5 and C2-C3 respectively due to the encroachment of the spinous process into the opened lamina. The decrease was mostly observed in older specimens and specimens with adjacent laminae close to each other; thus leading to the encroachment of the spinous process into the opened lamina. Laminectomy resulted in a statistically significant (p<0.05) increase in the range of motion compared to the intact condition during the three loading modes. These results correspond well with the finite element predictions, where a four-level ODL and laminectomy resulted in a minimal 5.4% and a substantial 57.5% increase in C2-T1 motion respectively during flexion. Adaptive bone remodeling theory was applied to the open door laminoplasty model to understand the effect of the surgical procedure on the internal architecture of bone. Bone remodeling was implemented at the C5 vertebra by quantifying the changes in apparent bone density in terms of the mechanical stimulus (i.e. SED/density). After laminoplasty, the increased load distribution through the bony hinge region led to the increased bone density during extension. This increased bone density could eventually lead to bone formation in those regions through external remodeling. The current study proved laminoplasty to be a motion preservation technique wherein the plates and spacer provided additional stability via reconstruction of the laminar arch while laminectomy can cause instability of spine especially during flexion. In the future, patient-specific finite element models that incorporate geometry-related differences could be developed to optimize the number of operated levels and to further explain the effect of surgical procedure on the unaltered levels.

Tez (Tıpta Uzmanlık) - Süleyman Demirel Üniversitesi, Tıp Fakültesi, Nöroşirürji Anabilim Dalı, 2007. / Bibliyografya var.

Thesis (M.S.)--University of Michigan, 1988.

Thesis (M.S.)--University of Michigan, 1988.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The purpose of this study was to isolate the adjacent epaxial musculature from exposed spinal cord by modified dorsal laminectomy in dogs with aluminum implant and whether the muscles contribute to form fibrosis epidural and influence of neurological signs. Ten dogs were submitted to modified dorsal laminectomy, five dogs just surgery technical (GI) and other five dogs the aluminum implant was placed between the musculature and defect (GII). Daily neurological examination until 180 days, myelography at 15, 30 and 60 days postoperatively and macroscopic evaluation of the implant at six months were performed. There was no difference at the neurological examination. Two qualified persons evaluated latero-laterally, ventro-dorsally, right and left oblique myelography incidences. There was statistics difference in degree of compression only 15 day postoperatively. During the implant of macroscopic evaluated was observed the musculature was not in contact with epidural fibrosis, differently the control group. The implant was removed easily with some degree of deformity. The results showed the adjacent musculature of the spinal cord submitted a modified dorsal laminectomy in dogs is isolated by aluminum implant, without contact with epidural fibrosis and influence in neurological signs. / O objetivo deste experimento foi isolar a musculatura epaxial da medula espinhal de cães submetidos à laminectomia dorsal modificada e averiguar se os músculos influenciaram na formação da fibrose epidural, na compressão medular e no aparecimento dos sinais neurológicos. Para isso, foram utilizados dez cães hígidos, sem raça definida, pesando entre 10 e 20 quilos e submetidos à laminectomia dorsal modificada entre as vértebras T13 e L1. Após, foram distribuídos aleatoriamente em dois grupos de igual número denominados de I (controle) onde a medula espinhal permaneceu exposta sem a presença de implante e II (tratado), onde foi colocado um implante a base de alumínio entre a musculatura epaxial adjacente e a medula espinhal exposta pela laminectomia. Foram realizados exames clínicos e neurológicos diários até os 60 dias de pós-operatório (PO) e observações gerais até 180 dias de PO. Decorridos 15, 30 e 60 dias de PO, os cães foram submetidos à mielografia para avaliar o grau de compressão medular e após seis meses, por avaliação macroscópica mediante a reintervenção cirúrgica. Aos 15 dias de pós-operatório, foi verificado, na mielografia, que o grau de compressão da linha de contraste foi maior no grupo tratado (P<0,05) quando comparado ao grupo controle, não havendo diferença dos demais tempos estudados. Na avaliação macroscópica, pode-se observar que no grupo II, a musculatura epaxial adjacente à medula espinhal não estava em contato com a fibrose epidural, diferentemente do grupo controle. O implante pôde ser removido facilmente e apresentava discreto grau de deformidade crânio-dorsal. Com exceção de um cão do grupo II, não foi verificada deficiências neurológicas até os 60 dias de PO. Pode-se concluir que a musculatura epaxial adjacente é isolada da medula espinhal pelo implante à base de alumínio em cães submetidos à laminectomia dorsal modificada, e esta não influencia na formação da fibrose epidural, compressão medular e no aparecimento dos sinais neurológicos.

Propósito: Analizar si la adición de un espaciador interespinoso o la fusión intersomática ofrece ventajas en relación con la microdiscetomía aislada en el tratamiento de la hernia discal lumbar. Métodos: Pacientes con hernia de disco lumbar que iban a someterse a cirugía fueron elegidos para participar. En este estudio de cohorte los pacientes se dividieron en 3 grupos; Microdiscectomía sola (MD), microdiscectomía más espaciador interespinoso (IS) y fusión intersomática lumbar posterior (PLIF). La medida de resultado primaria fue la eficacia clínica mediante el índice de discapacidad de Oswestry (ODI). También evaluamos varios otros parámetros de resultado, entre los que se incluyeron: escala analógica visual para el dolor (EVA) de espalda y piernas, duración de la estancia, coste desde el ingreso hasta el alta hospitalaria, tasa de complicaciones de 90 días y tasa de reoperación tras 1 año. Resultados: Se incluyeron un total de 103 pacientes cuya edad media fue de 39,1 (± 8,5) años. En los 3 grupos se detectó una mejora significativa de la puntuación inicial del dolor de espalda y piernas con ODI y EVA. Las puntuaciones del ODI cambiaron de 62.66 a 13.77 en el grupo MD, 62.93 a 13.50 en el grupo IS, y 59.62 a 17.62 en el grupo PLIF (p <0.001). Después de 1 año, no se encontraron diferencias significativas en el ODI, ni en la EVA de espalda y piernas entre los 3 grupos. Hubo un aumento del 169% en el coste hospitalario en el grupo IS y del 287% en el grupo PLIF, en relación con la MD (p <0,001). La duración de la estancia fue un 86% mayor en el grupo IS y un 384% más en el grupo PLIF en comparación con MD (p <0,001). Las tasas de reoperación a 1 año fueron de 5,6%, 10% y 16,2% (p = 0,33) en los grupos MD, IS y PLIF respectivamente. Conclusión: La mejoría clínica parece deberse a la microdiscectomía, sin que el implante (interespinoso o fusión) agregue ningún beneficio. La adición de espaciador interespinoso o fusión no protegió contra la reoperación, y aumentó la duración de la estancia hospitalaria y los gastos quirúrgicos.

No description available.

Approximately one in five adults in the United States experiences chronic pain. Over the last 50 years, spinal cord stimulation has become increasingly recognized as a minimally invasive, efficacious treatment modality for the management of chronic pain. The authors report a case study of a 46-year-old female in the first documented spinal cord stimulation simultaneously targeting intractable neuropathic and visceral pain caused by post-laminectomy syndrome and chronic pancreatitis, respectively. This case study demonstrates near-total relief of the patient's neuropathic low back/leg pain and visceral epigastric pain, showing evidence of potential clinical usefulness for spinal cord stimulation as a treatment option in patients who present with a combination of visceral and somatic pain symptoms.

Stenosis is one of the most common causes for spinal surgery. Laminectomy decompression and fusion are surgical procedures prescribed for this condition. The intention of this work was to investigate the effects of a laminectomy decompression, followed by fusion, on a lumbar functional spinal unit (FSU) through in vitro dynamic (±8Nm at 0.125Hz) and quasi-static (±7.5Nm at 0.1Hz) biomechanical tests, for flexion, extension, bending and rotation motions. Six FSUs where disarticulated from four human cadaveric lumbar spines (63 ± 12 years) and were tested under the following sequence: (1) intact, (2) laminectomy decompression, and (3) Pedicle Screw System (PSS), using a load-displacement controlled system. Dynamic neutral zone (NZ), dynamic neutral zone stiffness (NZS) and the range of motion (ROM) were the parameters evaluated. Since only 6 FSUs from different spinal levels were used, any effect related to the spinal level could not be evaluated. This limitation enforced to consider normalized data (with respect to intact) as an alternative analysis, but large standard deviations after transforming the data forced us to contemplate this "a pilot study". Dynamic testing revealed that there were no significant differences in the neutral zone magnitude for any motion after a laminectomy decompression, while its magnitude for flexion-extension was significantly affected by PSS treatment (p<0.004). The change in dynamic NZ (normalized data) was significantly different (p<0.03) after both treatments for flexion-extension motion. The reduction in stiffness (normalized data) for extension after a laminectomy, and the increase in stiffness (normalized data) for flexion and extension after PSS treatment, were both significant (p<0.03 and p<0.05, respectively). The ROM were not statistically significant for the three treatments, but normalized data showed significant differences (p<0.05) for all motions, except for right bending after laminectomy and right rotation after PSS. Non-normalized data from quasi-static testing didn't show any statistically significant difference between the treatments for any motion. Normalized data suggested significant differences for the change in ROM for all motions at multiple load conditions, especially for flexion and extension. This pilot study suggests there may be a considerable effect of a laminectomy on the stability of a lumbar FSU. Dynamic data suggested the changes in neutral zone stiffness triggered by a laminectomy procedure may be significant for extension. PSS treatment increased segment's NZ stiffness by more than double. The changes in ROM from quasi-static loading caused by a laminectomy decompression may be significant as well, especially for flexion (20%) and extension (greater than 10%). It is suggested that further studies involving spine biomechanics should consider and report, but not be limited to the following variables: exposure time of the specimen to room temperature, preservation and testing conditions, ligaments and joints conditions, testing protocol, and loading history.