RESUMO
AIM: Laparoscopic ventral rectopexy (LVR) is a non-resectional technique for selected patients with full-thickness rectal prolapse and obstructed defaecation syndrome. Despite its challenges, LVR can be performed with relatively minimal patient trauma thus creating the potential for same-day discharge. Our aim was to assess the safety of day-case LVR and identify factors associated with same-day discharge. METHOD: Data were prospectively collected on all patients (n = 120) from June 2008 to October 2011. Variables included demographics, perioperative details and postoperative course. Primary outcome was length of stay and secondary outcome was symptom improvement at the latest outpatient follow-up. Patients discharged the same day after LVR were compared with those who stayed overnight or longer. RESULTS: Indications included rectocele and internal prolapse (47%), full-thickness rectal prolapse (44%) and other (9%). Mean operative time was 97 min, same-day discharge occurred with 23% (n = 27) and 67% (n = 80) were discharged on postoperative day 1. In terms of complications, 89% had none, 8% minor and 3% major, including one 24-h readmission for pain. Logistic regression identified younger age (P = 0.054) and private insurance status (P < 0.001) as being significantly associated with same-day discharge. Although surgical indication (P < 0.001), no prior hysterectomy (P = 0.012) and use of biological mesh (P = 0.012) had significant association they were probably confounded by age. CONCLUSION: In selected patients with rectal prolapse or obstructed defaecation, same-day discharge after LVR is feasible and safe. Our analysis identified quicker discharge in the private system with younger patients. Nevertheless, in unselected patients 90% were discharged by the first operative day.
Assuntos
Procedimentos Cirúrgicos Ambulatórios/estatística & dados numéricos , Procedimentos Cirúrgicos do Sistema Digestório/estatística & dados numéricos , Laparoscopia/estatística & dados numéricos , Tempo de Internação/estatística & dados numéricos , Prolapso Retal/cirurgia , Reto/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Procedimentos Cirúrgicos Ambulatórios/métodos , Estudos de Coortes , Constipação Intestinal/etiologia , Constipação Intestinal/cirurgia , Procedimentos Cirúrgicos do Sistema Digestório/métodos , Estudos de Viabilidade , Incontinência Fecal/etiologia , Incontinência Fecal/cirurgia , Feminino , Humanos , Laparoscopia/métodos , Pessoa de Meia-Idade , Readmissão do Paciente/estatística & dados numéricos , Seleção de Pacientes , Complicações Pós-Operatórias , Estudos Prospectivos , Prolapso Retal/complicações , Telas Cirúrgicas , Resultado do TratamentoRESUMO
BACKGROUND: The aim was to measure female sexual function after total proctocolectomy with ileal pouch-anal anastomosis for ulcerative colitis using a validated scoring system and to determine the impact of pouch function on sexual function. METHODS: A cross-sectional survey was performed using a modified version of the Female Sexual Function Index (FSFI-m). Measures of pouch function, including the Faecal Incontinence Severity Index, were also evaluated. RESULTS: Of 166 women eligible for inclusion, 90 responded to the questionnaires and 83 of these reported sexual activity. The mean age of the 83 women was 38.4 years and the mean time since pouch formation was 6.2 years. Thirty-nine women (47.0 per cent) had an FSFI-m score of 26 or less, indicating sexual dysfunction. The association between sexual dysfunction and stool leakage interfering with the ability to enjoy sexual activity tended toward significance (P = 0.071), but other measures of pouch function were not associated with sexual dysfunction. Some 55-80 per cent of respondents perceived no change or improved performance in the six domains of sexual function. CONCLUSION: Almost half of the respondents reported having sexual dysfunction. Although poor pouch function was not identified as an important predictor of sexual dysfunction in this series, larger studies may be required to identify associated prognostic factors clearly.
Assuntos
Colite Ulcerativa/cirurgia , Bolsas Cólicas/efeitos adversos , Proctocolectomia Restauradora/psicologia , Disfunções Sexuais Psicogênicas/etiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Nível de Alerta , Colite Ulcerativa/psicologia , Bolsas Cólicas/fisiologia , Estudos Transversais , Feminino , Humanos , Pessoa de Meia-Idade , OrgasmoRESUMO
Rabbit muscle phosphofructokinase (E.C. 2.7.1.11; ATP: D-fructose-6-phosphate 1-phosphotransferase) consists of four protomers of 80 000 molecular weight, each of which contains 15--16 sulfhydryl groups. Specific cyanylation of the most reactive sulfhydryl group in each protomer with 2-nitro-5-thio-[14C]cyanobenzoic acid and cleavage of the S-cyanylated protomer yields two fragments--a 14C-labeled fragment of 72 500 molecular weight and an unlabeled fragment of 5400 molecular weight--indicating that the position of the cysteine residue bearing the most reactive sulfhydryl group is approx. 5400 daltons from the amino-terminal end of each protomer. The phosphofructokinase protomer also contains 5--6 sulfhydryl groups that are reactive in the denatured protomer but unreactive in the native protomer. The cleavage fragments, obtained from protomers specifically cyanylated at sulfhydryl groups reactive only in the denatured protomer, indicate that three of the cysteine residues bearing this class of sulfhydryl group occupy positions approx. 5000, 11 500, and 58 000 daltons from the carboxyl-terminal end of each protomer.
Assuntos
Fosfofrutoquinase-1 , Animais , Sítios de Ligação , Fenômenos Químicos , Química , Cisteína , Peso Molecular , Fragmentos de Peptídeos , Conformação Proteica , Desnaturação Proteica , Coelhos , TiocianatosRESUMO
Tris buffer was observed to produce an apparent inhibition of the homoserine dehydrogenase (EC 1.1.1.3)-catalyzed reduction of aspartic beta-semialdehyde and an apparent inhibition of the glyceraldehyde phosphate dehydrogenase (EC 1.2.1.9)-catalyzed oxidation of glyceraldehyde 3-phosphate. In each case, the apparent inhibition was found to be due to a lowering of the substrate concentration as a result of a reversible reaction between the free base form of Tris and the substrate, an aldehyde. The product of the reaction was tentatively identified as an imine on the basis of its spectral properties. The inhibition of these two enzymatic reactions by Tris was employed to investigate the kinetics of the reaction of Tris with their substrates. Assuming that these aldehydes exist entirely as the free aldehyde in aqueous solution, equilibrium constants of 369 +/- 12M-1 and 68 +/- 1.5M-1 were determined at 25 degrees C for the reaction of the free base form of Tris with glyceraldehyde 3-phosphate and asparitic beta-semialdehyde, respectively. Correcting for the existence of the hydrated form of glyceraldehyde 3-phosphate in aqueous solution, an equilibrium constant of 1.1-10(4) M-1 was obtained for the reaction of this aldehyde with the free base form of Tris. Forward and reverse direction rate constants for the reaction of Tris with glyceraldehyde 3-phosphate were determined at pH 7.45 and pH 8.5, and both were found to be pH-dependent.
Assuntos
Oxirredutases do Álcool/metabolismo , Gliceraldeído-3-Fosfato Desidrogenases/metabolismo , Homosserina Desidrogenase/metabolismo , Trometamina/farmacologia , Sítios de Ligação , Gliceraldeído , Cinética , Matemática , Compostos Organofosforados , Ligação Proteica , Espectrofotometria , Espectrofotometria UltravioletaRESUMO
Human tissues that express the angiotensin II (Ang II) type 1 receptor (hAT(1)R) can synthesize four distinct alternatively spliced hAT(1)R mRNA transcripts. In this study, we show that the relative abundance of these mRNA transcripts varies widely in human tissues, suggesting that each splice variant is functionally distinct. Here we demonstrate, for the first time, that the hAT(1)R-B mRNA splice variant encodes a novel long hAT(1)R isoform in vivo that has significantly diminished affinity for Ang II (i.e. >3-fold) when compared with the short hAT(1)R isoform (encoded by hAT(1)R-A mRNA splice variant). This reduced agonist affinity caused a significant shift to the right in the dose-response curve for Ang II-induced inositol trisphosphate production and Ca(2+) mobilization of the long hAT(1)R when compared with that of the short hAT(1)R. The functional differences between these isoforms allows Ang II responsiveness to be fine-tuned by regulating the relative abundance of the long and short hAT(1)R isoform expressed in a given human tissue.
Assuntos
Processamento Alternativo , RNA Mensageiro/análise , Receptores de Angiotensina/genética , Receptores de Angiotensina/fisiologia , Neoplasias do Córtex Suprarrenal/metabolismo , Sequência de Aminoácidos , Angiotensina II/farmacologia , Animais , Sequência de Bases , Células CHO , Cricetinae , Éxons , Citometria de Fluxo , Expressão Gênica , Glicosilação , Humanos , Fosfatos de Inositol/biossíntese , Cinética , Dados de Sequência Molecular , RNA Mensageiro/biossíntese , Receptor Tipo 1 de Angiotensina , Receptor Tipo 2 de Angiotensina , Receptores de Angiotensina/química , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Relação Estrutura-Atividade , Distribuição Tecidual , Transfecção , Células Tumorais CultivadasRESUMO
Transport properties of active enzyme species can be studied effectively by layering a small band of enzyme-containing sample on a gel chromatographic column previously saturated with substrate. The column is optically scanned at successive time intervals to yield profiles representing the appearance of chromophoric product or disappearnce of chromophoric substrate. These profiles permit determination of the specific activity and rate of transport of the active species. Initial studies on mechanic of the technique establish the feasibility of accurately determining transport properties of active enzyme species chromatographed on gel columns. Illustrative results are presented for L-glutamate dehydrogenase and for homoserine dehydrogenase studied in both forward and reverse reactions. It is shown that the partititon cross sections derived from the rates of motion of catalytic activity are the same as those determined by equilibrium saturation experiments which directly measure the degree of partitioning by the protein. These results establish the validity of the technique for a variety of future studies. Active enzyme gel chromatography appears comparable in precision to the active enzyme sedimentation technique at current stages of development.
Assuntos
Oxirredutases do Álcool/isolamento & purificação , Cromatografia em Gel/métodos , Glutamato Desidrogenase/isolamento & purificação , Homosserina Desidrogenase/isolamento & purificação , Glutamato Desidrogenase/metabolismo , Homosserina Desidrogenase/metabolismo , Matemática , NADPRESUMO
Sixty-one patients were followed for an average of thirty months (range, twenty-four to thirty-five months) after arthrodesis of the lumbar or lumbosacral spine with pedicle screw-plate fixation for painful degenerative arthritis, spondylolisthesis, or pseudarthrosis. The patients rated the clinical result according to an analog scale. Most patients reported a marked decrease in pain and an increase in function, and two-thirds were able to work full time. The result of the operation was regarded as a clinical failure if the patient considered it so, if an additional operation had been done, or if the functional and pain scores were not good (that is, if the patient was not able to work full time and the rating for pain was more than 5 of 10 points). Seventeen (28 per cent) of the patients were considered to have a clinical failure, with the lowest rate (20 per cent) for patients who had painful degenerative arthritis and the highest rate (47 per cent) for patients who had had a pseudarthrosis before the operation. The rate of fusion was 90 per cent in patients who had painful degenerative disease, 93 per cent in patients who had spondylolisthesis, and 65 per cent in patients who had had a pseudarthrosis preoperatively.
Assuntos
Placas Ósseas , Parafusos Ósseos , Fusão Vertebral/métodos , Adulto , Comportamento do Consumidor , Feminino , Seguimentos , Humanos , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/cirurgia , Masculino , Pessoa de Meia-Idade , Osteoartrite/cirurgia , Dor , Pseudoartrose/cirurgia , Radiografia , Estudos Retrospectivos , Sacro/diagnóstico por imagem , Sacro/cirurgia , Doenças da Coluna Vertebral/cirurgia , Fusão Vertebral/instrumentação , Espondilolistese/cirurgiaRESUMO
Sixty-three first, second, or third-time repairs of one or more pseudarthroses were done in fifty-one patients who had had an arthrodesis for idiopathic scoliosis. Forty-five of the patients were female and six were male. The average age was 30.2 years. The indications for the sixty-three repairs were pain (twenty-five repairs), progression of the curve (sixteen), both pain and progression of the curve (twelve), and radiographic changes only (ten). Failure of the implant was identified before 27 per cent of the sixty-three procedures. The pseudarthroses were diagnosed an average of 2.8 years after the initial arthrodeses. Sixty-eight per cent of the defects were visible on plain radiographs preoperatively and 32 per cent were identified at operation. During the time between the original arthrodeses and the repairs of the pseudarthroses, the scolioses increased by a mean of 7 degrees and the kyphoses, by a mean of 10 degrees. Harrington distraction was the most commonly used instrumentation (twenty-six [41 per cent] of the sixty-three procedures), and autogenous iliac bone was the most commonly used material for the graft (thirty-three [52 per cent] of the procedures).
Assuntos
Vértebras Lombares/cirurgia , Pseudoartrose/cirurgia , Escoliose/cirurgia , Fusão Vertebral/efeitos adversos , Vértebras Torácicas/cirurgia , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Criança , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Dor/fisiopatologia , Pseudoartrose/diagnóstico por imagem , Pseudoartrose/etiologia , Radiografia , Estudos Retrospectivos , Escoliose/diagnóstico por imagem , Fusão Vertebral/instrumentação , Fusão Vertebral/métodosRESUMO
Fifty-five patients who had loss of lumbar lordosis after spinal fusion and subsequently had corrective osteotomies were studied. When they were first seen, fifty-two patients (95 per cent) were unable to stand erect and forty-nine (89 per cent) had back pain. The previous use of distraction instrumentation with a hook placed at the level of the lower lumbar spine or the sacrum was the factor that was most frequently identified as leading to the development of the flatback syndrome. Sixty-six extension osteotomies were performed in these fifty-five patients. Nineteen patients (35 per cent) had an associated anterior spinal fusion. Thirty-three patients (60 per cent) had one or more complications, including pseudarthrosis, a dural tear, failure of hardware, neurapraxia, and urinary tract infection. The results of the operation were evaluated at follow-up by review of clinical records, radiographs, and questionnaires. At an average follow-up of six years (range, two to fourteen years), most patients felt that they had benefited from the corrective osteotomies. However, twenty-six patients (47 per cent) continued to lean forward and twenty patients (36 per cent) continued to have moderate or severe back pain. The failure to restore sagittal plane balance led to a higher rate of pseudarthrosis, which was associated with recurrent deformity. Anterior spinal fusion combined with posterior osteotomy resulted in greater maintenance of correction. The prevention of flatback syndrome is important, since its treatment is difficult. When a spinal fusion must be extended to the level of the lower lumbar spine or the sacrum, the use of distraction instrumentation should be avoided in order to prevent this deformity.
Assuntos
Complicações Pós-Operatórias/cirurgia , Doenças da Coluna Vertebral/cirurgia , Fusão Vertebral/métodos , Adolescente , Adulto , Idoso , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Dispositivos de Fixação Ortopédica , Osteotomia/métodos , Radiografia , Reoperação , Escoliose/cirurgia , Doenças da Coluna Vertebral/diagnóstico por imagemRESUMO
Facet forces, longitudinal ligament loads, and vertebral body motion were experimentally measured in five fresh human lumbar spine segments, L1-L2. Strain gages on the bone surface were used to quantify facet loads. Buckle transducers were used to measure anterior and posterior longitudinal ligament loads. The three-dimensional motion of the motion segment was measured with an instrumented spatial linkage. The facets were found to carry no load in flexion, large loads during extension (205 N at a 10 Nm moment and a 190 N axial load), torsion (65 N at a 10 Nm moment and a 150 N axial load), and lateral bending (78 N at a 3 Nm moment and a 160 N axial load). The facet contact site on the inferior articular process of L1 was found to move inferiorly to a position of tip impingement near the lamina as extension moments increased. Impingement occurred in the range of 4-6 Nm extension. The posterior and anterior longitudinal ligaments were predominantly loaded in flexion and extension, respectively. No ligament loads occurred in lateral bending and torsion. A 1 cm strip of the anterior longitudinal ligament carried loads up to 130 N at the largest extension moment of 11.4 Nm. The posterior longitudinal ligament had a 60 N load at the largest flexion moment of 7.1 Nm. There was no pre-load in the ligament detectable with the buckle transducers (> 4 N). The facets and ligaments began carrying load immediately with applied load, without a lax region. The experimental technique developed and used provides a good tool for obtaining simultaneous facet joint loads, ligament loads, and vertebral body motion without altering the motion segment.
Assuntos
Ligamentos/fisiologia , Vértebras Lombares/fisiologia , Adulto , Idoso , Fenômenos Biomecânicos , Calibragem , Feminino , Humanos , Ligamentos/anatomia & histologia , Vértebras Lombares/anatomia & histologia , Masculino , Pessoa de Meia-Idade , Movimento , Rotação , Processamento de Sinais Assistido por Computador , Estresse Mecânico , TransdutoresRESUMO
The parameters in adolescent idiopathic scoliosis correction (longitudinal height gain, coronal and sagittal plane changes) that correlate most closely with an increase in thoracic volume are reported. With pre- and postoperative radiographs of matched patients having straight Harrington distraction rods and contoured Luque rods, coordinates were digitized and the change in thoracic volume was calculated in ten subjects undergoing surgery for right thoracic curves. An increase in volume (7% increase in Harrington rod and 16% among Luque rod patients) was most closely correlated with a change in thoracic kyphosis toward physiologic ranges.
Assuntos
Cifose/etiologia , Radiografia Torácica , Escoliose/cirurgia , Adolescente , Criança , Feminino , Humanos , Cifose/diagnóstico por imagem , Masculino , Escoliose/complicações , Escoliose/diagnóstico por imagem , Fusão VertebralRESUMO
Increased lumbar lordosis places increased stress on the pars interarticularis. Fatigue fractures of the pars can result in spondylolysis. There was a 50% incidence of asymptomatic spondylolysis in 18 patients who had Scheuermann's kyphosis and an increased lumbar lordosis. This significant increase further confirms the pathogenesis of spondylolysis. Patients with Scheuermann's disease with low-back pain should be evaluated with oblique radiographs of the lumbar spine to rule out spondylolysis.
Assuntos
Doença de Scheuermann , Espondilolistese , Espondilólise , Adolescente , Feminino , Humanos , Masculino , Radiografia , Doença de Scheuermann/complicações , Doença de Scheuermann/diagnóstico por imagem , Fatores Sexuais , Espondilolistese/diagnóstico por imagem , Espondilolistese/etiologia , Espondilólise/diagnóstico por imagem , Espondilólise/etiologiaRESUMO
Harrington distraction rods with either sublaminar wires or convexity compression rods and transverse loading wires were used to treat idiopathic scoliotic patients. Laboratory measurement of transverse forces and orthographic projection of the apical vertebra enabled calculation of x- and y- plane forces in addition to torque. The construct utilizing sublaminar wires generated more favorable corrective vectors. Both devices tended to further rotate the scoliotic spine. Use of the compression apparatus should be limited to spines where reduction of kyphosis is desirable.
Assuntos
Dispositivos de Fixação Ortopédica , Escoliose/terapia , Adolescente , Fenômenos Biomecânicos , HumanosRESUMO
In this study, 124 consecutive cases of posterior spinal fusion with variable screw plate fixation were reviewed. In 33 patients (27%), 41 complications were identified. Urinary tract infection without sequelae developed in 13 patients. Dural tear occurred in seven patients and wound hematoma in five. Wound infection developed in three patients; one was subfascial requiring instrument and graft removal. Neurologic deficit developed in seven patients (6%), in five of whom the deficit was due to manipulation and reduction of neural elements. Two of the seven deficits were believed to be caused by misplaced pedicle screws. Variable screw plate fixation is a formidable procedure with a significant complications rate.
Assuntos
Placas Ósseas , Parafusos Ósseos , Doenças do Sistema Nervoso/epidemiologia , Fusão Vertebral/efeitos adversos , Infecção da Ferida Cirúrgica/epidemiologia , Infecções Urinárias/epidemiologia , Adulto , Humanos , Deslocamento do Disco Intervertebral/cirurgia , Estudos Retrospectivos , Espondilolistese/cirurgiaRESUMO
OBJECTIVES: The authors evaluated the reduction of rib prominence in patients who underwent thoracoplasty versus matched control patients who underwent fusion without thoracoplasty. SUMMARY OF BACKGROUND DATA: Correction in rib prominence with thoracoplasty is not well quantified in the literature. The role of rib bone graft as an alternative to iliac crest is unknown. METHODS: Fifty patients who underwent thoracoplasty were reviewed and compared with 26 patients who underwent fusion without thoracoplasty. Rib prominence, clinical data, and patient outcome were evaluated. RESULTS: The mean reduction in rib prominence was 71% in the thoracoplasty group and 17% in the control group. There was no difference in estimated blood loss, operative time, and length of hospitalization. Satisfaction with thoracoplasty was high. CONCLUSIONS: Thoracoplasty is more effective than fusion alone for reduction of rib prominence in thoracic scoliosis; it provides ample, effective bone graft for fusion.
Assuntos
Costelas/cirurgia , Escoliose/cirurgia , Fusão Vertebral , Vértebras Torácicas/cirurgia , Toracoplastia/métodos , Adulto , Perda Sanguínea Cirúrgica , Volume Sanguíneo , Transplante Ósseo/métodos , Feminino , Seguimentos , Humanos , Fixadores Internos , Tempo de Internação/estatística & dados numéricos , Masculino , Costelas/anatomia & histologia , Costelas/transplante , Fatores de TempoRESUMO
STUDY DESIGN: A retrospective review of late pelvic ring fractures after long spine fusions to the lumbosacral spine. OBJECTIVES: To review the clinical course and predisposing features of late fractures of the pelvic ring, usually atraumatic, in patients with long fusions to the lumbosacral spine. SUMMARY OF BACKGROUND DATA: Fractures of the pelvic ring after long fusions to the lumbosacral spine is a heretofore rarely reported complication. METHODS: Records from the authors' institution from 1985 to 1994 were reviewed retrospectively. Two hundred sixty-eight patients with long fusions to the lumbosacrum were identified. RESULTS: Between 1985-1994, five patients suffered late atraumatic fractures of the pelvic ring after long instrumented fusions to L5 or the sacrum. All fractures were on the left side of the pelvic ring, primarily the public rami. All patients were women, and at the time of fracture, all were aged 50 years or older. Fractures occurred from 4 months to 7 years after the last surgery (mean, 28 months). All were treated with protected weightbearing until comfortable. At average 27 months' follow-up evaluation, four patients reported no pain; the fifth had become pain-free at 31 months, but 2 months later, the patient spontaneously fractured the contralateral public rami. CONCLUSION: Stress-type fractures of the pelvic ring are a potential source of late pain after long fusions to the lumbosacral spine. Orthopedic surgeons should be aware of this possibility, especially in older, potentially osteoporotic women. Early treatment with simple protected weightbearing appears satisfactory and can prevent significant morbidity.
Assuntos
Fraturas Ósseas/etiologia , Pelve/lesões , Complicações Pós-Operatórias , Fusão Vertebral , Adulto , Idoso , Feminino , Fraturas Ósseas/diagnóstico por imagem , Humanos , Pessoa de Meia-Idade , Estudos Retrospectivos , Tomografia Computadorizada por Raios XRESUMO
Ten consecutive patients with adolescent idiopathic scoliosis and King-Moe curve Types II and III, scheduled consecutively for Cotrel-Dubousset instrumentation, underwent pre- and postoperative computed tomography scans with axial slices through each vertebra, and including the pelvis. Vertebral rotation was measured and referenced to the pelvis. Average derotation of the thoracic apex after surgery was 9%. King-Moe Type II curves tended to derotate more successfully (average 26% improvement), while Type III curves derotated very little, if at all (average 1.3% worsening of the rotational deformity). Type II curves often showed segmental rotational changes outside the levels of instrumentation, while Type III curves did not; more frequently the spinal-pelvic axis rotated en bloc. It appears, therefore, that Cotrel-Dubousset instrumentation does not consistently or predictably derotate the thoracic apex relative to the pelvis, and coronal plane correction may only be apparent, due to transmitted torque and rotation of the entire spinal-pelvic axis.
Assuntos
Fixadores Internos , Vértebras Lombares/fisiopatologia , Pelve/fisiopatologia , Rotação , Escoliose/cirurgia , Vértebras Torácicas/fisiopatologia , Adolescente , Fenômenos Biomecânicos , Criança , Feminino , Humanos , Masculino , Escoliose/fisiopatologiaRESUMO
Spinal decompensation after corrective surgery for scoliosis appears to be a significant problem after Cotrel-Dubousset instrumentation (CDI). CDI produces torsional changes in the instrumented and uninstrumented spine that could result in spinal imbalance. Preoperative and postoperative three-dimensional analysis including computed tomography (CT) scans to measure vertebral rotation and segmental rotation were performed to evaluate the importance of torsional changes. Moe/King Type II deformities had a substantially greater risk of imbalance. Deformities instrumented over fewer spinal segments were less likely to decompensate. Specifically, instrumentation excluding the mobile transition segment, determined by maximum segmental rotation and segmental Cobb angle, was likely to decompensate. Derotation and deformity correction excessive in relation to preoperative side bending flexibility and segmental rotation frequently resulted in imbalance. Spinal imbalance after CDI can be reduced by avoiding overcorrection and inclusion of mobile transition segments.
Assuntos
Dispositivos de Fixação Ortopédica , Escoliose/cirurgia , Fusão Vertebral/instrumentação , Vértebras Torácicas/cirurgia , Adolescente , Feminino , Humanos , Masculino , Complicações Pós-Operatórias/diagnóstico por imagem , Complicações Pós-Operatórias/prevenção & controle , Escoliose/diagnóstico por imagem , Fusão Vertebral/efeitos adversos , Vértebras Torácicas/diagnóstico por imagem , Tomografia Computadorizada por Raios XRESUMO
STUDY DESIGN: This laboratory-based experiment correlates fibronectin content of intervertebral disc with a morphologic grade of degeneration. OBJECTIVES: To correlate the fibronectin content of the anulus fibrosus and nucleus pulposus with a gross morphologic grade of disc degeneration, and to determine the molecular size of the extractable fibronectin. SUMMARY OF BACKGROUND DATA: Intervertebral disc degeneration increases with age and can lead to low back pain. Fibronectin helps to organize the extracellular matrix and provides environmental cues by interaction with cell surface integrins. In other tissues, its synthesis is elevated in response to injury. Fibronectin fragments can stimulate cells to produce metalloproteases and cytokines and inhibit matrix synthesis. METHODS: In this study, 17 anuli fibrosis and 18 nuclei pulposus from 11 spines were graded by Thompson's gross morphologic scale. Fibronectin was sequentially extracted with 4 mol/L guanidine hydrochloride and trypsin, and then quantitated by enzyme-linked immunoassay. The size of extractable fibronectin was determined by Western blot analyses. RESULTS: The fibronectin content of the disc increased with grade and was significantly elevated between Grades 3 and 4. The percentage of extractable fibronectin varied widely, but it was more extractable from the nucleus. In both the nucleus and anulus, 30% to 40% of the extractable fibronectin existed as fragments. Many of the fragments contained functional heparin or collagen-binding sites. CONCLUSIONS: Fibronectin is elevated in degenerated discs and frequently present as fragments. Elevated levels of fibronectin suggest that disc cells are responding to the altered environment. Fibronectin fragments resulting from normal or enhanced proteolytic activity could be a mechanism that induces the cell to degrade the matrix further.