Variations in surgical treatment of cervical facet dislocations

Journal ArticleObjective. To explore surgeon preference in the choice of surgical approach in the treatment of traumatic cervical facet dislocations. Summary of Background Data. The choice of surgical approach in the treatment of traumatic cervical dislocations is highly variable and maybe influenced by a variety of factors. The purpose of this study was to examine inter-rater reliability in choice of surgical approach. Methods. Twenty-five members of the Spine Trauma Study Group evaluated 10 cases of traumatic cervical dislocations. Evaluation of the case as a unilateral or bilateral injury and surgeon interpretation of the presence of a disc herniation as well as preferred surgical approach were assessed. Results. Only slight agreement was observed among surgeons in the choice of surgical approach (Kappa < 0.1). This improved slightly when patients were assumed to have a complete spinal cord injury (Kappa - 0.15). Surgeons used more anterior approaches either alone or as the first stage in a combined approach when a disc herniation was present regardless of neurologic status of the patient. When a patient was neurologically intact, an anterior approach was more common than a posterior approach even when a disc herniation was not present. Combined approaches were preferred for the treatment of bilateral facet dislocations. Conclusion. The poor agreement on the treatment of these injuries likely reflects a combination of factors including surgeon training and experience. Treatment decisions are likely to be affected by the neurologic status of the patient, interpretation of a disc herniation, and the classification of the injury as a unilateral or bilateral injury

Corporate environmental disclosure in Libya : evidence and environmental determinism theory

There is no doubt that in recent years Corporate Environmental Disclosure (CED) by corporations has received much attention among accounting academic researchers. However, reviewing previous studies has identified the following existing gaps which have given an impetus for this study and need to be bridged namely: (1) the need for a new approach of analysis namely, a three-dimensional analysis that includes the intra-country (external) factors, inter-organisational (internal) factors and content analysis; (2) the requirement for investigating other available means of CED such as internal reports and stand alone environmental reports; and (3) the call for examining CED practice in Libya where there was no previous attention given to this country. This study aims to examine the various aspects of CED in Libya with a view to testing the applicability of Environmental Determinism Theory. It did this initially by providing the first detailed and longitudinal description of the extent of practices of CED which were made by the all the largest industrial companies quoted on the Libyan Industrial Production Administration for the years 1998-2001. It then endeavoured to explain and understand this evidence of CED practice (or non-practice) by utilising (1) the perspectives of a sample of corporate managers of such companies regarding the nature of corporate environmental responsibility and CED; and (2) the political, economic and social contexts in which the CED is being made. To achieve this, three methods (triangulation approach) were utilised in this study, namely, content analysis, questionnaire and historiography. The results of content analysis showed that CED has yet to develop in Libya. There is no evidence of environmental disclosure either in terms of its quantity or quality, especially if the health and safety category is excluded. Libyan companies provide some statements in their annual reports, and, in some cases, other external reports (specific forms) or internal reports related to only one category of CED namely health and safety information. Apart from health and safety disclosed, the companies studied have disclosed no other environmental information. They still have a long way to go in order to reach the level reached by their counterparts in developed countries. An interesting point was that Libyan companies, by contrast with their counterparts even in developing countries, have given more attention to negative news. The perceptions of managers were investigated by using a questionnaire survey. Fifty three questionnaires were used with a rate of response of 62%. The results suggest that the vast majority of them accept that Libyan companies should recognise their environmental responsibility and provide environmental disclosure to the central authorities. However, most managers felt that a scarcity of legal and professional standards and guidelines, along with their lack of expertise, qualification and training in the field of CED have prevented them from engaging in CED. Therefore CED has not been put in the agenda of many Libyan companies. The analysis of the environmental influence on CED practice in Libya indicates that the social context including religion seems to be having to some extent an influence upon CED practice in Libya. However, the country's unique political and economic contexts along with the managers' attitudes and qualifications were the fundamental CED disclosure determinants. Therefore, this study has concluded that CED practices in Libya are shaped not only by one single factor but by the external and internal factors. The impact of the political, economic and social (external) factors reflects the indirect influence on the disclosure environment. Whereas, the internal factors (perception and cognition) reflect the direct impact of those involved in the disclosure process, namely the managers, as they are the ones who decide what information to be disclosed.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Corporate Environmental Disclosure in Libya: Evidence and Environmental Determinism Theory.

There is no doubt that in recent years Corporate Environmental Disclosure (CED) by corporations has received much attention among accounting academic researchers. However, reviewing previous studies has identified the following existing gaps which have given an impetus for this study and need to be bridged namely: (1) the need for a new approach of analysis namely, a three-dimensional analysis that includes the intra-country (external) factors,inter-organisational (internal) factors and content analysis; (2) the requirement for investigating other available means of CED such as internal reports and stand alone environmental reports; and (3) the call for examining CED practice in Libya where there was no previous attention given to this country.This study aims to examine the various aspects of CED in Libya with a view to testing the applicability of Environmental Determinism Theory. It did this initially by providing the firstdetailed and longitudinal description of the extent of practices of CED which were made by the all the largest industrial companies quoted on the Libyan Industrial Production Administration for the years 1998-2001. It then endeavoured to explain and understand this evidence of CEDpractice (or non-practice) by utilising (1) the perspectives of a sample of corporate managers of such companies regarding the nature of corporate environmental responsibility and CED; and (2) the political, economic and social contexts in which the CED is being made. To achieve this, three methods (triangulation approach) were utilised in this study, namely, content analysis, questionnaire and historiography.The results of content analysis showed that CED has yet to develop in Libya. There is no evidence of environmental disclosure either in terms of its quantity or quality, especially if the health and safety category is excluded. Libyan companies provide some statements in their annual reports, and, in some cases, other external reports (specific forms) or internal reports related to only one category of CED namely health and safety information. Apart from healthand safety disclosed, the companies studied have disclosed no other environmental information. They still have a long way to go in order to reach the level reached by their counterparts in developed countries. An interesting point was that Libyan companies, by contrast with their counterparts even in developing countries, have given more attention to negative news. The perceptions of managers were investigated by using a questionnaire survey. Fifty three questionnaires were used with a rate of response of 62%. The results suggest that the vast majority of them accept that Libyan companies should recognise their environmental responsibility and provide environmental disclosure to the central authorities. However, most managers felt that a scarcity of legal and professional standards and guidelines, along with theirlack of expertise, qualification and training in the field of CED have prevented them from engaging in CED. Therefore CED has not been put in the agenda of many Libyan companies.The analysis of the environmental influence on CED practice in Libya indicates that the social context including religion seems to be having to some extent an influence upon CED practice in Libya. However, the country's unique political and economic contexts along with the managers' attitudes and qualifications were the fundamental CED disclosure determinants. Therefore, this study has concluded that CED practices in Libya are shaped not only by one single factor but by the external and internal factors. The impact of the political, economic and social (external) factors reflects the indirect influence on the disclosure environment. Whereas, the internal factors (perception and cognition) reflect the direct impact of those involved in the disclosureprocess, namely the managers, as they are the ones who decide what information to be disclosed

The Pecking Order Theory and Start-up Financing of Small and Medium Enterprises: Insight into Available Literature in the Libyan Context

The Pecking Order Theory states that internal financing is preferred when available; and, if external financing is required, debt is preferred over equity. Thus, this paper aims to test the application of The Pecking Order Theory as an exploitation of start-up financing of Small and Medium Enterprises in Libya

Iatrogenic Spinal Cord Injury Resulting From Cervical Spine Surgery.

STUDY DESIGN: Retrospective cohort study of prospectively collected data. OBJECTIVE: To examine the incidence of iatrogenic spinal cord injury following elective cervical spine surgery. METHODS: A retrospective multicenter case series study involving 21 high-volume surgical centers from the AOSpine North America Clinical Research Network was conducted. Medical records for 17 625 patients who received cervical spine surgery (levels from C2 to C7) between January 1, 2005, and December 31, 2011, were reviewed to identify occurrence of iatrogenic spinal cord injury. RESULTS: In total, 3 cases of iatrogenic spinal cord injury following cervical spine surgery were identified. Institutional incidence rates ranged from 0.0% to 0.24%. Of the 3 patients with quadriplegia, one underwent anterior-only surgery with 2-level cervical corpectomy, one underwent anterior surgery with corpectomy in addition to posterior surgery, and one underwent posterior decompression and fusion surgery alone. One patient had complete neurologic recovery, one partially recovered, and one did not recover motor function. CONCLUSION: Iatrogenic spinal cord injury following cervical spine surgery is a rare and devastating adverse event. No standard protocol exists that can guarantee prevention of this complication, and there is a lack of consensus regarding evaluation and treatment when it does occur. Emergent imaging with magnetic resonance imaging or computed tomography myelography to evaluate for compressive etiology or malpositioned instrumentation and avoidance of hypotension should be performed in cases of intraoperative and postoperative spinal cord injury

Incidence and Outcomes of Acute Implant Extrusion Following Anterior Cervical Spine Surgery.

STUDY DESIGN: Multi-institutional retrospective case series of 8887 patients who underwent anterior cervical spine surgery. OBJECTIVE: Anterior decompression from discectomy or corpectomy is not without risk. Surgical morbidity ranges from 9% to 20% and is likely underreported. Little is known of the incidence and effects of rare complications on functional outcomes following anterior spinal surgery. In this retrospective review, we examined implant extrusions (IEs) following anterior cervical fusion. METHODS: A retrospective multicenter case series study involving 21 high-volume surgical centers from the AOSpine North America Clinical Research Network. Medical records for 17 625 patients who received cervical spine surgery (levels from C2 to C7) between January 1, 2005, and December 31, 2011, were reviewed to identify occurrence of 21 predefined treatment complications. RESULTS: Following anterior cervical fusion, the incidence of IE ranged from 0.0% to 0.8% across 21 institutions with 11 cases reported. All surgeries involved multiple levels, and 7/11 (64%) involved either multilevel corpectomies or hybrid constructs with at least one adjacent discectomy to a corpectomy. In 7/11 (64%) patients, constructs ended with reconstruction or stabilization at C7. Nine patients required surgery for repair and stabilization following IE. Average length of hospital stay after IE was 5.2 days. Only 2 (18%) had residual deficits after reoperation. CONCLUSIONS: IE is a very rare complication after anterior cervical spine surgery often requiring revision. Constructs requiring multilevel reconstruction, especially at the cervicothoracic junction, have a higher risk for failure, and surgeons should proceed with caution in using an anterior-only approach in these demanding cases. Surgeons can expect most patients to regain function after reoperation

Misplaced Cervical Screws Requiring Reoperation.

STUDY DESIGN: A multicenter, retrospective case series. OBJECTIVE: In the past several years, screw fixation of the cervical spine has become commonplace. For the most part, this is a safe, low-risk procedure. While rare, screw backout or misplaced screws can lead to morbidity and increased costs. We report our experiences with this uncommon complication. METHODS: A multicenter, retrospective case series was undertaken at 23 institutions in the United States. Patients were included who underwent cervical spine surgery from January 1, 2005, to December 31, 2011, and had misplacement of screws requiring reoperation. Institutional review board approval was obtained at all participating institutions, and detailed records were sent to a central data center. RESULTS: A total of 12 903 patients met the inclusion criteria and were analyzed. There were 11 instances of screw backout requiring reoperation, for an incidence of 0.085%. There were 7 posterior procedures. Importantly, there were no changes in the health-related quality-of-life metrics due to this complication. There were no new neurologic deficits; a patient most often presented with pain, and misplacement was diagnosed on plain X-ray or computed tomography scan. The most common location for screw backout was C6 (36%). CONCLUSIONS: This study represents the largest series to tabulate the incidence of misplacement of screws following cervical spine surgery, which led to revision procedures. The data suggest this is a rare event, despite the widespread use of cervical fixation. Patients suffering this complication can require revision, but do not usually suffer neurologic sequelae. These patients have increased cost of care. Meticulous technique and thorough knowledge of the relevant anatomy are the best means of preventing this complication

Epidemiology and Outcomes of Vertebral Artery Injury in 16 582 Cervical Spine Surgery Patients: An AOSpine North America Multicenter Study.

STUDY DESIGN: A multicenter retrospective case series was compiled involving 21 medical institutions. Inclusion criteria included patients who underwent cervical spine surgery between 2005 and 2011 and who sustained a vertebral artery injury (VAI). OBJECTIVE: To report the frequency, risk factors, outcomes, and management goals of VAI in patients who have undergone cervical spine surgery. METHODS: Patients were evaluated on the basis of condition-specific functional status using the Neck Disability Index (NDI), modified Japanese Orthopaedic Association (mJOA) score, the Nurick scale, and the 36-Item Short-Form Health Survey (SF-36). RESULTS: VAIs were identified in a total of 14 of 16 582 patients screened (8.4 per 10 000). The mean age of patients with VAI was 59 years (±10) with a female predominance (78.6%). Patient diagnoses included myelopathy, radiculopathy, cervical instability, and metastatic disease. VAI was associated with substantial blood loss (770 mL), although only 3 cases required transfusion. Of the 14 cases, 7 occurred with an anterior-only approach, 3 cases with posterior-only approach, and 4 during circumferential approach. Fifty percent of cases of VAI with available preoperative imaging revealed anomalous vessel anatomy during postoperative review. Average length of hospital stay was 10 days (±8). Notably, 13 of the 14 (92.86%) cases resolved without residual deficits. Compared to preoperative baseline NDI, Nurick, mJOA, and SF-36 scores for these patients, there were no observed changes after surgery (P = .20-.94). CONCLUSIONS: Vertebral artery injuries are potentially catastrophic complications that can be sustained from anterior or posterior cervical spine approaches. The data from this study suggest that with proper steps to ensure hemostasis, patients recover function at a high rate and do not exhibit residual deficits

An Ovariectomy-Induced Rabbit Osteoporotic Model: A New Perspective

Study DesignExperimental Animal Model.PurposeThe aim of our study was to validate a pure bilateral ovariectomy (OVX) female New Zealand white rabbit model of postmenopausal osteoporosis utilizing animal-sparing in vivo techniques for evaluating bone mineral density (BMD). We also sought to demonstrate that bilateral OVX in female New Zealand white rabbits can produce diminished BMD in the spinal column and simulate osteoporosis, without the need for adjuvant chemotherapeutic agents (i.e., no additional glucocorticosteroids or other drugs were used for stimulating accelerated BMD loss), which can be assessed by in vivo BMD testing.Overview of LiteratureMultiple animal models of postmenopausal osteoporosis have been described. Rat ovariectomy models have been successful, but are limited by rats' inability to achieve true skeletal maturity and a slight morphology that limits surgical instrumentation. Rabbit models have been described which do not have these limitations, but previous models have relied on adjunctive steroid therapy to achieve osteoporosis and have required animal sacrifice for bone mineral density assessment.MethodsThirty-six skeletally mature female rabbits underwent bilateral OVX. BMD was measured using dual-energy X-ray absorptiometry on the metaphysis of the proximal tibia and distal femur, at baseline and 17 weeks postoperatively.ResultsMean BMD values were significantly reduced by 21.9% (p<0.05) in the proximal tibia and 11.9% (p<0.001) in the distal femur at 17 weeks.ConclusionsThis study is the first to demonstrate a significant bone loss within four months of pure OVX in rabbits using animal-sparing validation techniques. We believe that this OVX model is safe, reproducible, and can be employed to longitudinally evaluate the effect of anti-osteoporosis therapeutics and surgical interventions