Attitudes Toward Neurosurgery Education for the Nonneurosurgeon: A Survey Study and Critical Analysis of U.S. Military Training Techniques and Future Prospects.

BACKGROUND: The U.S. military requires medical readiness to support forward-deployed combat operations. Because time and distance to neurosurgical capabilities vary within the deployed trauma system, nonneurosurgeons are required to perform emergent cranial procedures in select cases. It is unclear whether these surgeons have sufficient training in these procedures. METHODS: This quality-improvement study involved a voluntary, anonymized specialty-specific survey of active-duty surgeons about their experience and attitudes toward U.S. military emergency neurosurgical training. RESULTS: Survey responses were received from 104 general surgeons and 26 neurosurgeons. Among general surgeons, 81% have deployed and 53% received training in emergency neurosurgical procedures before deployment. Only 16% of general surgeons reported participating in craniotomy/craniectomy procedures in the last year. Nine general surgeons reported performing an emergency neurosurgical procedure while on deployment/humanitarian mission, and 87% of respondents expressed interest in further predeployment emergency neurosurgery training. Among neurosurgeons, 81% had participated in training nonneurosurgeons and 73% believe that more comprehensive training for nonneurosurgeons before deployment is needed. General surgeons proposed lower procedure minimums for competency for external ventricular drain placement and craniotomy/craniectomy than did neurosurgeons. Only 37% of general surgeons had used mixed/augmented reality in any capacity previously; for combat procedures, most (90%) would prefer using synchronous supervision via high-fidelity video teleconferencing over mixed reality. CONCLUSIONS: These survey results show a gap in readiness for neurosurgical procedures for forward-deployed general surgeons. Capitalizing on capabilities such as mixed/augmented reality would be a force multiplier and a potential means of improving neurosurgical capabilities in the forward-deployed environments.

The challenges of nursing information systems: a narrative review of the literature. / Os desafios dos sistemas de informação em enfermagem: uma revisão narrativa da literatura.

Nursing information systems, where quality indicators are integrated, focus on the standardization of health records and the consequent visibility of the provided care. Despite the acknowledged importance of the contributions of information systems, their implementation has been characterized by several challenges, so we propose to reflect on them. To identify the evidence available in the literature on these same challenges, a narrative review of the literature was developed, with the analysis of relevant articles and reports on this issue. It is clear in the literature the importance of information systems for obtaining quality indicators that are sensitive to nursing care, with a positive impact on the quality of care, allowing for measurable quality in interventions, as well as facilitating inter and intra-institutional comparability, in real-time or in a retrospective analysis. The challenges encountered and which urgently needs to be resolved in clinical practice are related to the difficulty for professionals to perceive the impact of computer records, the visibility of nursing indicators and the time that is allocated in the context of providing care to carry out these records.

Os sistemas de informação em enfermagem, onde se integram os indicadores de qualidade, têm como foco a uniformização dos registos em saúde e a consequente visibilidade dos cuidados prestados. Apesar da reconhecida importância dos contributos dos sistemas de informação, a sua implementação tem-se pautado por vários desafios pelo que nos propomos assim a refletir sobre estes. Com o objetivo de identificar a evidência disponível na literatura sobre estes mesmos desafios, foi desenvolvida uma revisão narrativa da literatura com análise de artigos e relatórios pertinentes acerca desta questão. Está patente na literatura a importância dos sistemas de informação para a obtenção de indicadores de qualidade sensíveis aos cuidados de enfermagem, existindo efetivamente um impacto positivo na qualidade dos cuidados, permitindo a mensurabilidade da qualidade nas intervenções, bem como facilitando a comparabilidade intra e interinstitucional, em tempo real ou em análise retrospetiva. Os desafios encontrados e que urge resolver na prática clínica, relacionam-se com a dificuldade de os profissionais percecionarem o impacto dos registos informáticos, a visibilidade dos indicadores em enfermagem e o tempo que é alocado em contexto de prestação de cuidados para realizar estes registos.

Os desafios dos sistemas de informação em enfermagem: uma revisão narrativa da literatura / The challenges of nursing information systems: a narrative review of the literature

Resumo Os sistemas de informação em enfermagem, onde se integram os indicadores de qualidade, têm como foco a uniformização dos registos em saúde e a consequente visibilidade dos cuidados prestados. Apesar da reconhecida importância dos contributos dos sistemas de informação, a sua implementação tem-se pautado por vários desafios pelo que nos propomos assim a refletir sobre estes. Com o objetivo de identificar a evidência disponível na literatura sobre estes mesmos desafios, foi desenvolvida uma revisão narrativa da literatura com análise de artigos e relatórios pertinentes acerca desta questão. Está patente na literatura a importância dos sistemas de informação para a obtenção de indicadores de qualidade sensíveis aos cuidados de enfermagem, existindo efetivamente um impacto positivo na qualidade dos cuidados, permitindo a mensurabilidade da qualidade nas intervenções, bem como facilitando a comparabilidade intra e interinstitucional, em tempo real ou em análise retrospetiva. Os desafios encontrados e que urge resolver na prática clínica, relacionam-se com a dificuldade de os profissionais percecionarem o impacto dos registos informáticos, a visibilidade dos indicadores em enfermagem e o tempo que é alocado em contexto de prestação de cuidados para realizar estes registos.

Abstract Nursing information systems, where quality indicators are integrated, focus on the standardization of health records and the consequent visibility of the provided care. Despite the acknowledged importance of the contributions of information systems, their implementation has been characterized by several challenges, so we propose to reflect on them. To identify the evidence available in the literature on these same challenges, a narrative review of the literature was developed, with the analysis of relevant articles and reports on this issue. It is clear in the literature the importance of information systems for obtaining quality indicators that are sensitive to nursing care, with a positive impact on the quality of care, allowing for measurable quality in interventions, as well as facilitating inter and intra-institutional comparability, in real-time or in a retrospective analysis. The challenges encountered and which urgently needs to be resolved in clinical practice are related to the difficulty for professionals to perceive the impact of computer records, the visibility of nursing indicators and the time that is allocated in the context of providing care to carry out these records.

Aprender prática baseada na evidência pelo envolvimento em atividades de investigação - autopercepção dos estudantes / Aprendizaje de prácticas basadas en evidencia por medio del involvimiento en actividades investigativas - la autopercepción de estudiantes / Learning evidence based practice through involvement in investigation activities - the self-perception of students

RESUMO Objetivo: compreender como os estudantes percepcionam o seu envolvimento em atividades de investigação e o contributo para o desenvolvimento de uma prática baseada na evidência. Método: estudo qualitativo, transversal, descritivo e exploratório, realizado em Portugal, em agosto de 2019, que recorreu ao grupo focal, com oito participantes, para responder à questão: "Quais as vantagens da participação dos estudantes de enfermagem em atividades de investigação para o desenvolvimento de conhecimentos, atitudes e competências de utilização da evidência?". A análise de conteúdo foi realizada com o software NVivo. Resultados: da análise qualitativa dos achados, emergiram cinco categorias e subcategorias: autoaprendizagem, integração teórico-prática, trabalho interdisciplinar, tomada de decisão baseada na evidência e literácia científica. Conclusão: a criação de uma experiência eficaz de aprendizagem ajuda na construção do conhecimento e potencialmente contribui para a saúde da comunidade, os resultados de aprendizagem do estágio e o desenvolvimento de competências essenciais para uma Prática Baseada na Evidência.

RESUMEN Objetivo: comprender como estudiantes perciben su envolvimiento con actividades investigativas y su contribución para desarrollar una práctica basada en evidencias. Método: estudio cualitativo, trasversal, descriptivo y exploratorio, hecho en Portugal en agosto de 2019, utilizando un grupo focal con ocho participantes para responder a la cuestión: "Cuales las ventajas de la participación de los estudiantes de enfermería en actividades de investigación para desarrollar conocimientos, actitudes y competencias de utilización de la evidencia?" Se hizo al análisis de contenido con el software NVivo. Resultados: el análisis cuantitativo de los datos generó cinco categorías y subcategorías: autoaprendizaje, integración teórico-práctica, interdisciplinariedad, tomada de decisiones basadas en evidencia, y alfabetización científica. Conclusión: la creación de una experiencia eficaz de aprendizaje ayuda en la construcción del conocimiento y potencialmente contribuye para la salud de la comunidad, para los resultados del aprendizaje en la pasantía y para el desarrollo de competencias esenciales para una Práctica Basada en Evidencias.

ABSTRACT Objective: to understand how students perceive their involvement in investigation activities and how they contribute for the development of evidence-based practices. Method: qualitative, cross-sectional, descriptive, and exploratory study, carried out in Portugal, in August 2019. A focus group of eight participants was formed to answer the question: "What are the advantages of the participation of nursing students in investigations for the development of knowledge, attitudes, and performance in the use of evidence?" The software NVivo was used for a content analysis. Results: five categories and subcategories emerged from the qualitative analysis of findings: self-learning, integration of theory and practice, interdisciplinary work, evidence-based decision making, and scientific literacy. Conclusion: creating an effective learning experience helps building knowledge and can contribute for the health of the community, for improved educational results during the internship, and for the development of the abilities necessary for Evidence Based Practice.

Analysis of student biomechanics in videos of delivery simulation practice. / Prática simulada: análise de filmes sobre a biomecânica dos estudantes na realização do parto.

OBJECTIVE: Analyze the posture of students from the master's degree program in Maternal Health and Obstetrical Nursing; understand how intervention during delivery influences posture; and identify strategies for the prevention of work-related musculoskeletal injuries. METHOD: Qualitative descriptive study, which recorded and analyzed videos in a learning situation using high-fidelity simulation practice. RESULTS: Thirteen students participated in the study. The results show the adopted body movement does not take into account coordination of the musculoskeletal system to keep body balance, posture and alignment when changing the delivery position. CONCLUSION: Obstetric nurses have a high prevalence of musculoskeletal injuries, and the specificity of professional activity makes it difficult to assess and prevent risks. Training favors the acquisition of knowledge and reflection of behaviors. Investments should be made in training to students and professionals in work contexts.

Biomechanical stability of transverse connectors in the setting of a thoracic pedicle subtraction osteotomy.

BACKGROUND CONTEXT: Transverse connectors (TCs) are often used to improve the rigidity of posterior spinal instrumentation as previous investigations have suggested that TCs enhance torsional rigidity in long-segment thoracic constructs. Posterior osteotomies, such as pedicle subtraction osteotomy (PSO), are used in severe thoracic deformities and provide a significant amount of correction; as a consequence, however, PSOs also induce three-column spinal instability. In theory, augmentation of longitudinal constructs with TC after a thoracic PSO may provide additional rigidity, but the concept has not been previously evaluated. PURPOSE: To evaluate the biomechanical contribution of TC to the rigidity of a long-segment pedicle screw-rod construct after a thoracic PSO. STUDY DESIGN: An in vitro fresh-frozen human cadaveric biomechanical analysis. METHODS: Seven human cadaveric thoracic spines were prepared and instrumented from T4-T10 with bilateral pedicle screws/rods and a PSO was performed at T7. Intact range of motion (ROM) testing was performed with nondestructive loading and analyzed by loading modality (axial rotation [AR], flexion/extension [FE], and lateral bending [LB]). Range of motion analysis was performed in the unaugmented construct, the construct augmented with one TC, and the construct augmented with two TCs. RESULTS: After PSO and an unaugmented longitudinal pedicle screw-rod construct, T4-T10 (overall construct) and T6-T8 (PSO site) ROMs were significantly reduced in all planes of motion compared with intact condition (AR: 11.8° vs. 31.7°; FE: 2.4° vs. 12.3°; 3.4° vs. 17.9°, respectively, p<.05). Augmentation of longitudinal construct with either one or two TCs did not significantly increase construct rigidity in FE or LB compared with the unaugmented construct (p>.05). In contrast, during AR, global ROM was significantly reduced by 43% and 48% at T6-T8 (1.7° and 1.2° vs. 2.38°, respectively) after addition of one and two TCs (p<.05), respectively. One TC did not significantly reduce torsional ROM from the intact state. CONCLUSIONS: Two TCs significantly improved torsional rigidity of the entire construct and at the PSO site, with no differences in rigidity for FE and LB or with the addition of only one TC. In the setting of a PSO and long-segment pedicle screw-rod construct, augmentation with at least two TCs should be considered to improve torsional rigidity.

Do stand-alone interbody spacers with integrated screws provide adequate segmental stability for multilevel cervical arthrodesis?

BACKGROUND CONTEXT: Some postoperative complications after anterior cervical fusions have been attributed to anterior cervical plate (ACP) profiles and the necessary wide operative exposure for their insertion. Consequently, low-profile stand-alone interbody spacers with integrated screws (SIS) have been developed. Although SIS constructs have demonstrated similar biomechanical stability to the ACP in single-level fusions, their role as a stand-alone device in multilevel reconstructions has not been thoroughly evaluated. PURPOSE: To evaluate the acute segmental stability afforded by an SIS device compared with the traditional ACP in the setting of a multilevel cervical arthrodesis. STUDY DESIGN: In vitro human cadaveric biomechanical analysis. METHODS: Thirteen human cadaveric cervical spines (C2-T1) were nondestructively tested with a custom 6 df spine simulator under axial rotation, flexion-extension, and lateral bending loading. After intact analysis, eight single-levels (C4-C5/C6-C7) from four specimens were instrumented and tested with ACP and SIS. Nine specimens were tested with C5-C7 SIS, C5-C7 ACP, C4-C7 ACP, C4-C7 ACP+posterior fixation, C4-C7 SIS, and C4-C7 SIS+posterior fixation. Testing order was randomized with each additional level instrumented. Full range of motion (ROM) data were obtained and analyzed by each loading modality, using mean comparisons with repeated measures analysis of variance. Paired t tests were used for post hoc analysis with Sidak correction for multiple comparisons. RESULTS: No significant difference in ROM was noted between the ACP and SIS for single-level fixation (p>.05). For multisegment reconstructions (two and three levels), the ACP proved superior to SIS and intact condition, with significantly lower ROM in all planes (p<.05). When either the three-level SIS or ACP constructs were supplemented with posterior lateral mass fixation, there was a greater than 80% reduction in ROM under all testing modalities (p<.05), with no significant difference between the ACP and SIS constructs (p>.05). CONCLUSIONS: The SIS device may be a reasonable option as a stand-alone device for single-level fixation. However, SIS devices should be used with careful consideration in the setting of multilevel cervical fusion. However, when supplemented with posterior fixation, SIS devices are a sound biomechanical alternative to ACP for multilevel fusion constructs.

Cervical hybrid arthroplasty with 2 unique fusion techniques.

OBJECTIVE: Multilevel cervical arthroplasty achieved using the Prestige ST disc can be challenging and often unworkable. An alternative to this system is a hybrid technique composed of alternating total disc replacements (TDRs) and fusions. In the present study, the authors review the safety and radiological outcomes of cervical hybrid arthroplasty in which the Prestige ST disc is used in conjunction with 2 unique fusion techniques. METHODS: After obtaining institutional review board approval, the authors completed a retrospective review of all hybrid cervical constructs in which the Prestige ST disc was used between August 2007 and November 2009 at the Walter Reed Army Medical Center. A Prestige ST total disc replacement was performed in 119 patients. Thirty-one patients received a hybrid construct defined as a TDR and fusion (TDR-anterior cervical decompression and fusion [ACDF]) or as 2 TDRs separated by a fusion (TDR-ACDF-TDR). A resorbable plate and graft system (Mystique) or stand-alone interbody spacer (Prevail) was implanted at the fusion levels. Plain radiographs were compared and evaluated for cervical lordosis, range of motion, implant complications, development of adjacent-level disease, and pseudarthrosis. In addition, charts were reviewed for clinical complications related to the index surgery. RESULTS: Thirty-one patients (18 men and 13 women; mean age 50 years, range 32-74 years) received a hybrid construct. All patients were diagnosed with radiculopathy and/or myelopathy. Twenty-four patients received a 2-level and 7 a 3-level hybrid construct. In 2 patients in whom a 2-level hybrid construct was implanted, a noncontiguous TDR was also performed. The mean clinical and radiological follow-up duration was 18 months. There was no significant difference in preoperative (19.3° ± 13.3°) and postoperative (19.7° ± 10.5°) cervical lordosis (p = 0.48), but there was a significant decrease in range in motion (from 50.0° ± 11.8° to 38.9° ± 12.7°) (p = 0.003). There were no instances of screw backout, implant dislodgement, progressive kyphosis, formation of heterotopic bone, pseudarthrosis, or symptomatic adjacent-level disease. Seven patients had dysphasia and 1 patient had vocal cord paralysis at 6 weeks. By 3 months, both the dysphasia and the vocal cord paralysis were resolved in all patients. CONCLUSIONS: Hybrid cervical arthroplasty involving the placement of a Prestige ST disc and either the Mystique resorbable plate or Prevail stand-alone interbody device is a safe and effective alternative to multilevel fusion for the management of cervical radiculopathy and myelopathy.

Approach-related complications after decompression for cervical ossification of the posterior longitudinal ligament.

The surgical management of compressive cervical ossification of the posterior longitudinal ligament (OPLL) can be challenging. Traditionally, approach indications for decompression of cervical spondylotic myelopathy have been used. However, the postoperative complication profile after cervical OPLL decompression is unique and may require an alternative approach paradigm. The authors review the literature on approach-related OPLL complications and suggest a management strategy for patients with single- or multiple-segment OPLL with or without greater than 50% canal stenosis.

Structures at risk from pedicle screws in the proximal thoracic spine: computed tomography evaluation.

BACKGROUND CONTEXT: Pedicle screw placement in the proximal thoracic spine may result in unwanted bicortical breach. An understanding of the potential structures at risk is paramount to safe screw placement. PURPOSE: To assess the anatomic location of structures at risk with the placement of bicortical pedicle screw fixation in the proximal thoracic spine. STUDY DESIGN: Retrospective radiographic review. PATIENT SAMPLE: Twenty patients with dedicated computed tomography (CT) scans of the thoracic spine. OUTCOME MEASURES: Radiographic parameters on CT. METHODS AND MATERIALS: Computed tomography was performed on 20 patients and analyzed from T1 to T4 for proximity of major structures at risk with breach of the anterior vertebral body cortex from pedicle screw placement. Descriptive statistics, analyses of variance and post hoc paired t tests were used to analyze screw position relative to the esophagus, trachea, aortic arch, carotid, and vertebral arteries. RESULTS: One hundred sixty potential anterior cortical violation positions were analyzed. Left-sided pedicle screws posed a significantly higher risk (p<.05) to the esophagus at T1-T3; in particular, the left T2 screw was significantly closer (p<.05). Right-sided pedicle screws posed a significantly higher risk to the trachea at T2-T4 (p<.05). The right T3 and T4 screws posed the greatest risk to the trachea and right main bronchus, respectively (p<.05). The carotid and vertebral arteries were not at risk for injury. The aortic arch was present at T4 in 70% of patients and was not at risk. CONCLUSIONS: Careful preoperative evaluation with CT is warranted to determine anatomic structures at risk when placing proximal thoracic pedicle screws. Left-sided screws pose the greatest risk to the esophagus; right-sided screws pose the greatest risk to the trachea. The carotid and vertebral arteries, along with the aortic arch are at minimal risk for injury.

Does catastrophic midline failure of upper thoracic lamina screws violate the spinal canal? A cadaveric biomechanical analysis using two lamina screw techniques.

BACKGROUND CONTEXT: Lamina screws have been reported to be a biomechanically sound alternative to pedicle screws in the proximal thoracic spine. However, concerns have been raised that midline failure may result in a spinal canal breach. PURPOSE: To evaluate the catastrophic failure of proximal thoracic lamina screws using two techniques for lamina screw purchase. STUDY DESIGN: Biomechanical study with human cadaveric vertebrae. PATIENT SAMPLE: Not applicable. OUTCOME MEASURES: Not applicable. METHODS: Nineteen fresh-frozen T1-T2 vertebrae were Dual energy X-ray absorptiometry scanned for bone mineral density. Caliper measurements of lamina thickness and lateral mass width for bicortical purchase were obtained. Ten specimens had right-to-left 26-mm lamina screws inserted entirely within the length of the lamina (unicortical). Nine specimens had right-to-left 42-mm lamina screws inserted as to extend the length of the lamina and breach the cortex behind the first and second ribs (bicortical). All screws were placed by experienced spine surgeons under fluoroscopic visualization using 4.5-mm cervicothoracic screws. Insertional torque was recorded while placing all implants and reported in "in-lbs." Tensile loading to failure was performed with the force oriented in the parasagittal plane along the vertebral midline. Pullout loading was applied at a rate of 0.25 mm/s using an MTS 858 MiniBionix II System (MTS Systems, Inc., Minneapolis, MN, USA) with the maximum pullout strength (POS) recorded in Newtons. Video fluoroscopy was performed during midline pullout to evaluate screw failure and ascertain spinal canal breach. After testing, all specimens were visually inspected for spinal canal breach. RESULTS: Neither the unicortical nor the bicortical lamina screws violated the spinal canal during catastrophic midline failure. The ventral lamina cortex remained intact for both the lamina screw techniques. All of the unicortical lamina screws resulted in dorsal avulsion of the spinous process and lamina. All nine bicortical lamina screws separated the dorsal lamina from the ventral but were able to maintain lateral mass purchase. The peak insertional torque for both lamina screw techniques was not significantly different (p = .20). However, bicortical lamina screw POS (584.8 ± 150.2 N) was significantly greater than unicortical lamina screw POS (455.6 ± 100.2 N) (p = .04). Bone mineral density showed a moderate correlation with unicortical (r = 0.67) and bicortical (r = 0.47) lamina screw POS. CONCLUSION: Our results suggest that catastrophic midline failure of lamina screws does not violate the spinal canal. Of the two techniques tested, bicortical lamina screws have a biomechanical advantage. Lamina screws present a viable option for instrumenting the proximal thoracic spine.

Multilevel cervical arthroplasty with artificial disc replacement.

OBJECT: In this study, the authors review the technique for inserting the Prestige ST in a contiguous multilevel cervical disc arthroplasty in patients with radiculopathy and myelopathy. They describe the preoperative planning, surgical technique, and their experience with 10 patients receiving a contiguous Prestige ST implant. They present contiguous multilevel cervical arthroplasty as an alternative to multilevel arthrodesis. METHODS: After institutional board review approval was obtained, the authors performed a retrospective review of all contiguous multilevel cervical disc arthroplasties with the Prestige ST artificial disc between August 2007 and November 2009 at a single institution by a single surgeon. Clinical criteria included patients who had undergone a multilevel cervical disc arthroplasty performed for radiculopathy and myelopathy without the presence of a previous cervical fusion. Between August 2007 and November 2009, 119 patients underwent cervical arthroplasty. Of the 119 patients, 31 received a Hybrid construct (total disc resection [TDR]-anterior cervical decompression and fusion [ACDF] or TDR-ACDF-TDR) and 24 received a multilevel cervical arthroplasty. The multilevel cervical arthroplasty group consisted of 14 noncontiguous and 10 contiguous implants. This paper examines patients who received contiguous Prestige ST implants. RESULTS: Ten men with an average age of 45 years (range 25-61 years) were treated. Five patients presented with myelopathy, 3 presented with radiculopathy, and 2 presented with myeloradiculopathy. Twenty-two 6 x 16-mm Prestige ST TDRs were implanted. Six patients received 2-level Prestige ST implants. Five patients received TDRs at C5-6 and C6-7, and 1 patient received TDRs at C3-4 and C4-5. One patient received a TDR at C3-4, C5-6, and C6-7 where C4-5 was a congenital block vertebra. Three patients (2 with 3-level disease and 1 with 4-level disease) received contiguous Prestige ST implants as well as a Prevail ACDF as part of their constructs. The mean clinical and radiographic follow-up was 12 months. There has been no case of screw backout, implant dislodgment, progressive kyphosis, formation of heterotopic bone, evidence of pseudarthrosis at the Prevail levels, or development of symptomatic adjacent level disease. CONCLUSIONS: Multilevel cervical arthroplasty with the Prestige ST is a safe and effective alternative to fusion for the management of cervical radiculopathy and myelopathy.

Does the Wilson frame assist with optimizing surgical exposure for minimally invasive lumbar fusions?

OBJECT: Minimally invasive lumbar spine surgery has dramatically evolved over the last decade. Minimally invasive techniques and transforaminal lumbar interbody fusion (TLIF) often require a steep learning curve. Surgical techniques require pre-positioning the patient in maximal kyphosis to optimize visualization of the disc space and prevent unnecessary retraction of neural structures. The authors describe their experience in validating the surgical technique recommendation of Wilson frame-induced kyphosis. METHODS: Over the past 6 months, data obtained in 20 consecutive patients (40 total levels) undergoing minimally invasive TLIF were reviewed. In each patient, preincision intraoperative radiographs were reviewed at L4-5 and L5-S1 with the patient on a Wilson frame in maximal lordosis and then in maximal kyphosis. The change in disc space angle at L4-5 and L5-S1 after changing from maximal lordosis to maximal kyphosis was reviewed. Descriptive statistics were calculated for sagittal plane angular measures at L4-5 and L5-S1 in lordosis and kyphosis, including absolute differences and percentage of change between positions. Inferential statistics were calculated using paired t-tests with alpha= 0.05. RESULTS: Twenty patients underwent single- or multilevel minimally invasive TLIF. Inducing kyphosis with the Wilson frame aided in optimizing exposure and decreasing the need for neural structure retraction. Both L4-5 and L5-S1 showed statistically significant (p < 0.001) and clinically meaningful changes with increased segmental flexion in the kyphotic position. At L4-5 the mean increase in flexion was 4.5 degrees (95% CI 2.9-6.0 degrees), representing an average 47% change. The mean increase in flexion at L5-S1 was 3.2 degrees (95% CI 2.3-4.2 degrees), representing an average 20.8% change. In lordosis the mean angle at L4-5 was 10.6 +/- 4.4 degrees and at L5-S1 was 17 +/- 7.0 degrees. In kyphosis the mean angle at L4-5 was 6.1 +/- 4.5 degrees and at L5-S1 was 13.8 +/- 6.5 degrees. Additionally, there was a statistically significant difference (p < 0.05) in percentage of change between the 2 levels, with L4-5 showing a greater change (27% more flexion) between positions, but the absolute mean difference between the levels was small (1.3 degrees). CONCLUSIONS: Minimally invasive TLIF is challenging and requires a significant learning curve. The recommended surgical technique of inducing kyphosis with the Wilson frame prior to incision significantly optimizes exposure. The authors' experience demonstrates that this technique is essential when performing minimally invasive lumbar spinal fusions.

Effect of teriparatide [rhPTH(1,34)] and calcitonin on intertransverse process fusion in a rabbit model.

STUDY DESIGN: Randomized, double-blinded, placebo controlled animal study. OBJECTIVE: To evaluate the effect of teriparatide and calcitonin after an intertransverse process spinal fusion in a rabbit model. SUMMARY OF BACKGROUND DATA: It is widely recognized that some osteoporosis medications, including bisphosphonates, can interfere with bone healing. Although prescribed frequently in the treatment of osteoporosis, the effect of teriparatide and calcitonin on spinal fusion has not been fully elucidated. We hypothesized that teriparatide, being the only anabolic medication for osteoporosis treatment, would have a beneficial effect on spine fusion. METHODS: Fifty-one New Zealand white rabbits underwent a posterolateral L5-L6 intertransverse process arthrodesis using autogenous iliac crest bone graft. The rabbits were randomly divided into 3 groups. All animals received daily subcutaneous injections of group I (n = 17) 1 mL of saline placebo; group II (n = 17) 10 microg/kg/day of teriparatide; group III (n = 17) 14 IU/animal of calcitonin during the 8-week postoperative period. Postmortem analyses included manual palpation, radiographic, biomechanical, and histologic assessment. Three random 10x fields were examined/graded within the cephalad, middle, and caudal regions of each section (810 fields). Fusion quality was graded using the Emery histologic scale (0-7 based on fibrous/bone content of the fusion mass). RESULTS: Histologic fusion rates for teriparatide averaged 86.7% and was significantly greater than the autograft control group (50%) (P = 0.033). Radiographically, there was a strong trend towards teriparatide being superior to the calcitonin group (85.7% vs. 56.3%, respectively; P = 0.07). The average Emery grading score was 5.99 +/- 1.46 SD for the autologous group and 6.26 +/- 0.93 SD for the teriparatide group (P = 0.031). Although not significant, the teriparatide group showed less motion in flexion/extension, lateral bending, and axial rotation. CONCLUSION: Our results suggest that teriparatide enhances spinal fusion while calcitonin has a neutral effect. The teriparatide group had the best histologic fusion rate and Emery scores, while the calcitonin group was similar to the saline controls. Although not significant, the teriparatide group had a strong trend towards superior radiographic fusion over the calcitonin group.

Neurosurgical management of spinal dysraphism and neurogenic scoliosis.

STUDY DESIGN: To review diagnosis and treatment of neurogenic factors implicated in the development of progressive scoliosis. OBJECTIVE: Increased awareness of neurogenic causes as a contributing component of spinal cord tethering has led to enhanced radiographic surveillance for etiologic factors contributing to the genesis of scoliosis. Review of various manifestations of spinal dysraphism offers better definition of clinical indications for surveillance MRI scans and thus may contribute to improving outcomes for affected individuals. SUMMARY OF BACKGROUND DATA: Increasing utilization of surveillance MRI has led to a greater awareness of neurogenic causes as contributing factors in the setting of scoliosis. It is imperative for clinicians treating individuals with scoliosis to be aware of the most common etiologies of neurogenic factors as well as be cognizant of the neurosurgical approaches to treating these conditions in a pre-emptive fashion. This will serve to minimize potential neurological complications and offer improved surgical outcomes after instrumentation. METHODS: Current therapeutic approaches were outlined for various etiologies of neurogenic scoliosis as well as neurosurgical management of the tethered cord, spinal cord tumors in addition to current challenges surrounding Chiari malformations and syringomyelia. RESULTS: Timely recognition of these frequently progressive conditions may not only prevent irreversible neurologic compromise but may also help to ameliorate or stabilize concurrent scoliosis. Tethered cords are best treated by releasing the affected cord and offers the best opportunity to stabilize or improve the scoliosis. Syringomyelia, often associated with a Chiari malformation, is a well-known progenitor of scoliosis, and addressing the underlying cause with a Chiari decompression frequently leads to a reduction or resolution of the syrinx and may result in a concomitant improvement in scoliosis. CONCLUSION: Surveillance MRI should be undertaken for scoliosis when there are clinical indications consistent for a tethered cord, spinal cord tumor, or Chiari malformation and associated syringomyelia.

Using lamina screws as a salvage technique at C-7: computed tomography and biomechanical analysis using cadaveric vertebrae. Laboratory investigation.

OBJECT: Transpedicular instrumentation at C-7 has been well accepted, but salvage techniques are limited. Lamina screws have been shown to be a biomechanically sound salvage technique in the proximal thoracic spine, but have not been evaluated in the lower cervical spine. The following study evaluates the anatomical feasibility of lamina screws at C-7 as well as their bone-screw interface strength as a salvage technique. METHODS: Nine fresh-frozen C-7 cadaveric specimens were scanned for bone mineral density using dual energy x-ray absorptiometry. Prior to testing, all specimens were imaged using CT to obtain 1-mm axial sections. Caliper measurements of both pedicle width and laminar thickness were obtained. On the right side, pedicle screws were first inserted and then pulled out. Salvage intralaminar screws were inserted into the left lamina from the right spinous process/lamina junction and then pulled out. All screws were placed by experienced cervical spine surgeons under direct fluoroscopic visualization. Pedicle and lamina screws were 4.35- and 3.5-mm in diameter, respectively. Screws sizes were chosen based on direct and radiographic measurements of the respective anatomical regions. Insertional torque (IT) was measured in pounds per inch. Tensile loading to failure was performed in-line with the screw axis at a rate of 0.25 mm/sec using a MiniBionix II system with data recorded in Newtons. RESULTS: Using lamina screws as a salvage technique generated mean pullout forces (778.9 +/- 161.4 N) similar to that of the index pedicle screws (805.3 +/- 261.7 N; p = 0.796). However, mean lamina screw peak IT (5.2 +/- 2.0 lbs/in) was significantly lower than mean index pedicle screw peak IT (9.1 +/- 3.6 lbs/in; p = 0.012). Bone mineral density was strongly correlated with pedicle screw pullout strength (r = 0.95) but less with lamina screw pullout strength (r = 0.04). The mean lamina width measured using calipers (5.7 +/- 1.0 mm) was significantly different from the CT-measured mean lamina width (5.1 +/- 0.8 mm; p = 0.003). Similarly, the mean pedicle width recorded with calipers (6.6 +/- 1.1 mm) was significantly different from the CT-measured mean pedicle width (6.2 +/- 1.3 mm; p = 0.014). The mean laminar width measured on CT at the thinnest point ranged from 3.8 to 6.8 mm, allowing a 3.5-mm screw to be placed without difficulty. CONCLUSIONS: These results suggest that using lamina screws as a salvage technique at C-7 provides similar fixation strength as the index pedicle screw. The C-7 lamina appears to have an ideal anatomical width for the insertion of 3.5-mm screws commonly used for cervical fusions. Therefore, if the transpedicular screw fails, using intralaminar screws appear to be a biomechanically sound salvage technique.

810 nm Wavelength light: an effective therapy for transected or contused rat spinal cord.

BACKGROUND AND OBJECTIVES: Light therapy has biomodulatory effects on central and peripheral nervous tissue. Spinal cord injury (SCI) is a severe central nervous system trauma with no effective restorative therapies. The effectiveness of light therapy on SCI caused by different types of trauma was determined. STUDY DESIGN/MATERIALS AND METHODS: Two SCI models were used: a contusion model and a dorsal hemisection model. Light (810 nm) was applied transcutaneously at the lesion site immediately after injury and daily for 14 consecutive days. A laser diode with an output power of 150 mW was used for the treatment. The daily dosage at the surface of the skin overlying the lesion site was 1,589 J/cm(2) (0.3 cm(2) spot area, 2,997 seconds). Mini-ruby was used to label corticospinal tract axons, which were counted and measured from the lesion site distally. Functional recovery was assessed by footprint test for the hemisection model and open-field test for the contusion model. Rats were euthanized 3 weeks after injury. RESULTS: The average length of axonal re-growth in the rats in the light treatment (LT) groups with the hemisection (6.89+/-0.96 mm) and contusion (7.04+/-0.76 mm) injuries was significantly longer than the comparable untreated control groups (3.66+/-0.26 mm, hemisection; 2.89+/-0.84 mm, contusion). The total axon number in the LT groups was significantly higher compared to the untreated groups for both injury models (P<0.05). For the hemisection model, the LT group had a statistically significant lower angle of rotation (P<0.05) compared to the controls. For contusion model, there was a statistically significant functional recovery (P<0.05) in the LT group compared to untreated control. CONCLUSIONS: Light therapy applied non-invasively promotes axonal regeneration and functional recovery in acute SCI caused by different types of trauma. These results suggest that light is a promising therapy for human SCI.

Does superior-segment facet violation or laminectomy destabilize the adjacent level in lumbar transpedicular fixation? An in vitro human cadaveric assessment.

STUDY DESIGN: This is an in vitro biomechanical study. OBJECTIVE: The current investigation was performed to evaluate adjacent level kinematic change following unilateral and bilateral facet violation and laminectomy following 1-, 2-, and 3-level reconstruction. SUMMARY OF BACKGROUND DATA: The incidence of superior-segment facet violation with lumbar transpedicular fixation has been reported as high as 35%; however, its contribution to biomechanical instability at the supradjacent level is unknown. In addition, superior-segment laminectomy has been implicated as a risk factor for the development of adjacent level disease. The authors assess the acute biomechanical effects of proximal facet violation and subsequent laminectomy in an instrumented posterior fusion model in 10 cadaveric specimens. METHODS: Biomechanical testing was performed on 10 human cadaveric spines under axial rotation (AR), flexion-extension (FE), and lateral bending (LB) loading. After intact analysis, pedicle screws were inserted from L5-S1 and testing repeated with: (1) preserved L4-L5 facets, (2) unilateral facet breach, (3) bilateral breach, and (4) L5 laminectomy. Following biomechanical analysis, instrumentation was extended to L4, then L3 and biomechanical testing repeated. Full range of motion (ROM) at the proximal adjacent levels were recorded and normalized to intact (100%). RESULTS: Supradjacent level ROM was increased for all groups under all loading methods relative to intact (P < 0.05). However, AR testing revealed progressive instability at the adjacent level in groups 3 and 4, relative to group 1, following 1-, 2- and 3-level fixation (P < 0.05). During FE, supradjacent level ROM was significantly increased for group 4 specimens compared with group 1 after L5-S1 fixation (P < 0.05), and was greater than all other groups for L3-S1 constructs (P < 0.05). Interestingly, under lateral bending, facet joint destabilization did not change adjacent segment ROM. CONCLUSION: There were significant changes in proximal level ROM immediately after posterior stabilization. However, an additional increase in supradjacent segment ROM was recorded during AR after bilateral facet breach.Subsequent complete laminectomy at the uppermostfixation level further destabilized the supradjacent segment in FE and AR. Therefore, meticulous preservation of the cephalad-most segment facet joints-is paramount to ensure stability.

Computed tomography and biomechanical evaluation of screw fixation options at the cervicothoracic junction: intralamina versus intrapedicular techniques.

STUDY DESIGN: In vitro cadaveric biomechanical analysis. OBJECTIVE: Define the T1 and T2 anatomic lamina size and evaluate the bone-screw interface strength of various pedicle screw options and intralamina techniques. SUMMARY OF BACKGROUND DATA: Transpedicular instrumentation is well accepted, but salvage techniques in the proximal thoracic spine are limited. Intralamina fixation has been described at C2 with favorable biomechanical characteristics. In addition, this technique has been introduced clinically in the proximal thoracic spine. However, the biomechanical potential has not been evaluated. METHODS: Fourteen fresh-frozen cervicothoracic cadaveric specimens were scanned using dual-energy radiograph absorptiometry for bone mineral density, imaged under computed tomography, and then instrumented in the following configuration: (1) Right-sided pedicle screws in a straight-forward trajectory, (2) "salvage anatomic trajectory pedicle screws, and (3) "salvage" intralamina screws into the contralateral lamina. Insertional torque (IT) was recorded with each revolution and screws were pulled out in-line (POS) with the screw axis to simulate intraoperative failure of fixation. RESULTS: Lamina screws as a salvage technique generated statistically greater peak IT (P = 0.002) and relative POS (P < 0.05) in comparison with straight-forward transpedicular screws as the initial fixation type. Furthermore, lamina screws, when compared to the salvage anatomic trajectory pedicle screws, had a significantly greater peak IT (P = 0.011). The peak IT showed a stronger correlation with POS in lamina screws than straight-forward or anatomic pedicle screws with a similar trend noted in mean IT. Bone mineral density correlated with POS in all methods of fixation. The mean lamina width measured on computed tomography at the thinnest point was 5.9 +/- 0.7 mm (range, 4.9-7.9). CONCLUSION: Our results suggest that lamina screws, used as a salvage technique in the proximal thoracic spine, provide stronger fixation than transpedicular screws when using standard 4.5-mm cervical screws. In-tralamina screws appear to be a biomechanically sound salvage technique in the region, and appear to be a safe, effective technique for instrumenting the proximal thoracic spine.