Variations in Practice Patterns among Neurosurgeons and Orthopaedic Surgeons in the Management of Spinal Disorders

Study design: This is a case series.Purpose: We wanted to identify variations in the practice patterns among neurosurgeons and orthopedic surgeons for the management of spinal disorders.Overview of literature: Spinal disorders are common in the clinical practice of both neurosurgeons and orthopedic surgeons. It has been observed that despite the availability of various guidelines, there is lack of consensus among surgeons about the management of various disorders.Methods: A questionnaire was distributed, either directly or via e-mail, to the both the neurosurgeons and orthopedic surgeons who worked at 5 tertiary care centers within a single region of Korea. The surgeons were working either in private practice or in academic institutions. The details of the questionnaire included demographic details and the specialty (orthopedic/neurosurgeon). The surgeons were classified according to the level of experience as up to 5 years, 6-10 years and \u3e 10 years. Questions were asked about the approach to lumbar discectomy (fragmentectomy or aggressive disc removal), using steroids for treating discitis, the fusion preference for spondylolisthesis, the role of an orthosis after fusion, the preferred surgical approach for spinal stenosis, the operative approach for spinal trauma (early within 72 hours or late \u3e 72 hours) and the role of surgery in complete spinal cord injury. The data was analyzed using SPSS ver 16. p-values \u3c 0.05 were considered to be significant.Results: Of the 30 surgeons who completed the questionnaire, 20 were neurosurgeons and 10 were orthopedic surgeons. Statistically significant differences were observed for the management of spinal stenosis, spondylolisthesis, using an orthosis after fusion, the type of lumbar discectomy and the value of surgical intervention after complete spinal cord injury.Conclusions: Our results suggest that there continues to exist a statistically significant lack of consensus among neurosurgeons and orthopedic spine surgeons when considering using an orthosis after fusion, the type of discectomy and the value of intervention after complete spinal injury

Fractal nature in fat crystal networks

The determination of the mechanical and rheological characteristics of several plastic fats requires a detailed understanding of the microstructure of the fat crystal network aggregates. The fractal approach is useful for the characterization of this microstructure. This review begins with information on fractality and statistical self-similar structure. Estimations for fractal dimension by means of equations relating the volume fraction of solid fat to shear elastic modulus G’ in linear region are described. The influence of interesterification on fractal dimension decrease (from 2,46 to 2,15) for butterfat-canola oil blends is notable. This influence is not significant for fat blends without butterfat. The need for an increase in research concerning the relationship between fractality and rheology in plastic fats is emphasized.La determinación de las características mecánicas y reológicas de ciertas grasas plásticas requiere conocimientos detallados sobre las microestructuras de los agregados que forman la red de cristales grasos. El estudio de la naturaleza fractal de estas microestructuras resulta útil para su carac­terización. Este artículo de información se inicia con descripciones de la dimensión fractal y de la "autosimilitud estadística". A continuación se describe el cálculo de la dimensión fractal mediante ecuaciones que relacionan la fracción en volumen de grasa sólida con el módulo de recuperación (G') dentro de un comportamiento viscoelástico lineal. Se destaca la influencia que la interesterificación ejerce sobre la dimensión fractal de una mezcla de grasa láctea y aceite de canola (que pasa de 2,64 a 2,15). Esta influencia no se presenta en mezclas sin grasa láctea. Se insiste sobre la necesidad de incrementar las investi­gaciones sobre la relación entre reología y estructura fractal en grasas plásticas.Peer reviewe

Risk Factors Associated with the Halo Phenomenon after Lumbar Fusion Surgery and its Clinical Significance

STUDY DESIGN: Retrospective study. PURPOSE: First, to examine the association between bone mineral density (BMD) and the halo phenomenon, and second, to investigate risk factors predisposing to the halo phenomenon and its correlation with clinical outcomes. OVERVIEW OF LITERATURE: The few in vivo studies regarding the relationship between pedicle screw stability and BMD have shown conflicting results. METHODS: Forty-four female patients who underwent spine fusion surgery due to spinal stenosis were included in this study. The halo phenomenon and fusion state were evaluated through plain radiographs performed immediately after surgery and through the final outpatient follow-up examination. BMD, osteoarthritis grade in the hip and knee joints, and surgical outcome were also evaluated. RESULTS: BMD was not related to the halo phenomenon, but age, absence of osteoarthritis in the knee, and non-union state were found to be significant risk factors for the halo phenomenon. However, the radiological halo phenomenon did not correlate with clinical outcome (visual analogue scale for back pain and leg pain). CONCLUSIONS: The halo phenomenon is a simple phenomenon that can develop during follow-up after pedicle screw fixation. It does not influence clinical outcomes, and thus it is thought that hydroxyapatite coating screws, expandable screws, cement augmentation, and additional surgeries are not required, if their purpose is to prevent the halo phenomenon.ope

Diagnosing Cervical Fusion: A Comprehensive Literature Review

STUDY DESIGN: Comprehensive literature review. PURPOSE: To document the criteria for fusion utilized in these studies to determine if a consensus on the definition of a solid fusion exists. OVERVIEW OF LITERATURE: Numerous studies have reported on fusion rates following anterior cervical arthrodesis. There is a wide discrepancy in the fusion rates in these studies. While factors such as graft type, Instrumentation, and technique play a factor in fusion rate, another reason for the difference may be a result of differences in the definition of fusion following anterior cervical spine surgery. METHODS: A comprehensive English Medline literature review from 1966 to 2004 using the key words anterior, cervical, and fusion was performed. We divided these into two groups: newer studies done between 2000 and 2004, and earlier studies done between 1966 and 2000. These articles were then analyzed for the number of patients, follow-up period, graft type, and levels fused. Moreover, all of the articles were examined for their definition of fusion along with their fusion rate. RESULTS: In the earlier studies from 1966 to 2000, there was no consensus for what constituted a solid fusion. Only fifteen percent of these studies employed the most stringent definition of a solid fusion which was the presence of bridging bone and the absence of motion on flexion and extension radiographs. On the other hand, the later studies (2000 to 2004) used such a definition a majority (63%) of the time, suggesting that a consensus opinion for the definition of fusion is beginning to form. CONCLUSIONS: Our study suggests that over the past several years, a consensus definition of fusion is beginning to form. However, a large percentage of studies are still being published without using stringent fusion criteria. To that end, we recommend that all studies reporting on fusion rates use the most stringent criteria for solid fusion following anterior cervical spine surgery: the absence of motion on flexion/extension views and presence of bridging trabeculae on lateral x-rays. We believe that a universal adoption of such uniform criteria will help to standardize such studies and make it more possible to compare one study with another

Experimental evaluation of an adaptive Joule--Thomson cooling system including silicon-microfabricated heat exchanger and microvalve components

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98726/1/JVA021005.pd

Successful outcome of six-level cervicothoracic corpectomy and circumferential reconstruction: case report and review of literature on multilevel cervicothoracic corpectomy

The authors report the successful outcome of a six-level corpectomy across the cervico-thoracic spine with circumferential reconstruction in a patient with extensive osteomyelitis of the cervical and upper thoracic spine. To the authors’ knowledge, this is the first report of a corpectomy extending across six levels of the cervico-thoracic spine. Clinical relevance: the authors recommend anterior cage and plate-assisted reconstruction and additional posterior instrumentation using modern spinal surgical techniques and implants