Implant related complications in patients operated on with expandable pedicle screws and technical solutions for revision surgery

BackgroundIt is reported that expandable pedicle screws are effective and a safer alternative to pedicle screws with cement augmentation application in patients with poor bone quality.AimsTo study implant related complications associated with expandable pedicle screws application and to propose revision options in case of implant failure.Methods A retrospective analysis of a heterogeneous cohort of patients operated on because of traumatic injuries and degenerative diseases of the lumbar spine and thoracolumbar junction was performed. 42 patients with osteopeny or osteoporosis were enrolled, the duration of the follow-up accounted for 18 months. Cases with implant failure (loosening and screw breakage) were registered and revision pedicle screws fixation was performed.Results Out of 42 enrolled patients 3 were presented with implant failure (a screw loosening in one case and a screw rupture and loosening in 2 cases). The attempts to remove retained fractured fragments were unsuccessful, therefore, alternative bypass creation and a direct screw placement into a retained fractured fragment were carried out and suggested as an alternative strategy to osteotomy with a fractured screw fragment removal.ConclusionIn case of rupture, expandable screws have a poor feasibility for a revision pedicle screw fixation because of fractured fragments strong anchorage in bone. The alternative bypass for a revision screw without fractured fragment removal or tapping and direct screw placement into retained expanded fragment of a screw are less invasive alternatives to osteotomy that can help overcome the discussed issue

Augmentation of pedicle screws using bone grafting in patients with spinal osteoporosis

The aim of the study was to develop a new method of vertebral augmentation based on autologous and allogeneic bone chips to be used in pedicle screw fixation and to compare this method with the technique based on polymethyl methacrylate (PMMA). Materials and Methods. This prospective non-randomized study included 164 patients with degenerative pathologies or traumatic injuries of the lumbar spine and transitional thoracolumbar segments; 153 of the operated patients were followed up for 18 months. In these patients, radiodensity of the cancellous bone tissue was below 110 HU by the Hounsfield scale. Patients with degenerative spinal disorders underwent pedicle screw fixation using transforaminal interbody fusion; patients with traumatic spinal injuries underwent intermediate pedicle screw fixation, and those with a loss of vertebral body height by \u3e50% underwent anterior fusion. The patients were divided into three groups: in group 1 (n=39), bone tissue augmentation was performed using PMMA; in group 2 (n=21), augmentation was done with bone chips; in group 3 (n=93), no augmentation was performed (control group). The follow-up period was 12 months; cases with fixator breakage or loosening were recorded. Results. After augmentation with PMMA, 11 cases (28.2%) of fixator destabilization were detected. With bone chips, fixator instability developed in 2 patients (9.5%) only, whereas in patients operated without augmentation, the instability was observed in 43 cases (46.2%). With PMMA augmentation, the incidence rate of fixator destabilization did not significantly differ from that in the control group (p=0.0801), while the use of bone chips resulted in a statistically significant decrease of this index compared to the control group (p=0.0023). A logistic regression analysis confirmed the superiority of the developed method over the PMMA-based vertebral augmentation. Conclusion. The use of bone chips for vertebral augmentation provides a statistically significant decrease in the incidence of pedicle screw fixator destabilization in the post-operative period. By reducing the risk of proximal loosening and eliminating the risk of bone cement drainage into the spinal canal and vascular bed, the proposed method may become especially effective in patients with impaired bone density

Прогностическая значимость костной плотности, определенной при компьютерной томографии, в отношении низкоэнергетических переломов позвоночника

Computed tomography (CT) can be used to accurately determine bone density in Hounsfield units (HU), the use of CT as a predictive tool has not been conclusively demonstrated in relation to low energy vertebra compression fracture (VCF). The objective: to define the prognostic value of bone density measured during CT investigation in relation to VCF. Materials and methods. One hundred consecutive patients undergoing CT scans were enrolled in this study. Bone density measurements were obtained at the level LII or LIII from the cancellous portion of the vertebral body in the mid-sagittal, mid-coronal and axial planes. The presence of a single-level or multi-level VCF was identified by CT. Multilevel degenerative changes were characterized and recorded. Logistic regression was utilized to assess the relationship between the variables of bone density in HU, single - or multi-level VCF and the presence of degenerative changes. Results. HU were found to have a strong correlation to the risk of VCF. HU of less than 101 were associated with a significant increase in the rate of VCF, whereas HU of less than 82 were associated with a significant increase in the rate of multi-level VCF. Hypertrophic degenerative changes were found to be associated with a decreased rate of VCF. Conclusion. CT data can accurately define the risk of VCF and therefore presents a useful clinical tool to support the need for prophylactic medical therapies for osteoporosis or to provide information useful in counseling patients at risk for VCF.При выполнении рентгеновской КТ может быть определена костная плотность в единицах Хаунсфилда (ед.Н), но прогностическая значимость этого параметра в отношении низкоэнергетических переломов позвонков до настоящего времени недостаточно исследована. Цель исследования: определить прогностическую значимость костной плотности, определенной при КТ-исследовании, в отношении риска низкоэнергетических патологических переломов. Материал и методы. Проведена оценка результатов КТ 100 пациентов. На уровне LII или LIII определяли плотность губчатой кости в ед.Н в сагиттальной, фронтальной плоскостях и на аксиальных срезах, после чего вычисляли среднее значение. Регистрировали наблюдения с одно- и многоуровневыми патологическими переломами, а также наблюдения с многоуровневыми дегенеративными изменениями. Исследовали прогностическую значимость указанных параметров в отношении патологических компрессионных переломов позвонков, для этого применяли логистический регрессионный анализ. Результаты. Выявлено, что имеется связь плотности позвонков, определенной в ед.Н, с частотой патологических переломов: снижение костной плотности ниже 101 ед.Н сопряжено с нарастанием частоты патологических переломов, в то время как снижение костной плотности ниже 82 ед.Н ассоциируется с увеличением частоты многоуровневых патологических переломов. Наличие многоуровневых дегенеративных изменений ассоциируются со снижением частоты патологических переломов позвонков. Заключение. КТ-данные могут быть использованы для оценки риска патологических компрессионных переломов позвонков и служить основанием для назначения профилактических мер или дальнейшего обследования

Effect of surgical experience and spine subspecialty on the reliability of the {AO} Spine Upper Cervical Injury Classification System

OBJECTIVE The objective of this paper was to determine the interobserver reliability and intraobserver reproducibility of the AO Spine Upper Cervical Injury Classification System based on surgeon experience (< 5 years, 5–10 years, 10–20 years, and > 20 years) and surgical subspecialty (orthopedic spine surgery, neurosurgery, and "other" surgery). METHODS A total of 11,601 assessments of upper cervical spine injuries were evaluated based on the AO Spine Upper Cervical Injury Classification System. Reliability and reproducibility scores were obtained twice, with a 3-week time interval. Descriptive statistics were utilized to examine the percentage of accurately classified injuries, and Pearson’s chi-square or Fisher’s exact test was used to screen for potentially relevant differences between study participants. Kappa coefficients (κ) determined the interobserver reliability and intraobserver reproducibility. RESULTS The intraobserver reproducibility was substantial for surgeon experience level (< 5 years: 0.74 vs 5–10 years: 0.69 vs 10–20 years: 0.69 vs > 20 years: 0.70) and surgical subspecialty (orthopedic spine: 0.71 vs neurosurgery: 0.69 vs other: 0.68). Furthermore, the interobserver reliability was substantial for all surgical experience groups on assessment 1 (< 5 years: 0.67 vs 5–10 years: 0.62 vs 10–20 years: 0.61 vs > 20 years: 0.62), and only surgeons with > 20 years of experience did not have substantial reliability on assessment 2 (< 5 years: 0.62 vs 5–10 years: 0.61 vs 10–20 years: 0.61 vs > 20 years: 0.59). Orthopedic spine surgeons and neurosurgeons had substantial intraobserver reproducibility on both assessment 1 (0.64 vs 0.63) and assessment 2 (0.62 vs 0.63), while other surgeons had moderate reliability on assessment 1 (0.43) and fair reliability on assessment 2 (0.36). CONCLUSIONS The international reliability and reproducibility scores for the AO Spine Upper Cervical Injury Classification System demonstrated substantial intraobserver reproducibility and interobserver reliability regardless of surgical experience and spine subspecialty. These results support the global application of this classification system

Survey on worldwide trauma team activation requirement

PURPOSE : trauma team activation (TTA) is thought to be essential for advanced and specialized care of very severely injured patients. However, non-specific TTA criteria may result in overtriage that consumes valuable resources or endanger patients in need of TTA secondary to undertriage. Consequently, criterion standard definitions to calculate the accuracy of the various TTA protocols are required for research and quality assurance purposes. Recently, several groups suggested a list of conditions when a trauma team is considered to be essential in the initial care in the emergency room. The objective of the survey was to post hoc identify trauma-related conditions that are thought to require a specialized trauma team that may be widely accepted, independent from the country’s income level. METHODS : A set of questions was developed, centered around the level of agreement with the proposed post hoc criteria to define adequate trauma team activation. The participants gave feedback before they answered the survey to improve the quality of the questions. The finalized survey was conducted using an online tool and a word form. The income per capita of a country was rated according to the World Bank Country and Lending groups. RESULTS : The return rate was 76% with a total of 37 countries participating. The agreement with the proposed criteria to define post hoc correct requirements for trauma team activation was more than 75% for 12 of the 20 criteria. The rate of disagreement was low and varied between zero and 13%. The level of agreement was independent from the country’s level of income. CONCLUSIONS : The agreement on criteria to post hoc define correct requirements for trauma team activation appears high and it may be concluded that the proposed criteria could be useful for most countries, independent from their level of income. Nevertheless, more discussions on an international level appear to be warranted to achieve a full consensus to define a universal set of criteria that will allow for quality assessment of over- and undertriage of trauma team activation as well as for the validation of field triage criteria for the most severely injured patients worldwide.http://link.springer.com/journal/68am2022Surger

Implant related complications in patients operated on with expandable pedicle screws and technical solutions for revision surgery

Background It is reported that expandable pedicle screws are effective and a safer alternative to pedicle screws with cement augmentation application in patients with poor bone quality. Aims To study implant related complications associated with expandable pedicle screws application and to propose revision options in case of implant failure. Methods A retrospective analysis of a heterogeneous cohort of patients operated on because of traumatic injuries and degenerative diseases of the lumbar spine and thoracolumbar junction was performed. 42 patients with osteopeny or osteoporosis were enrolled, the duration of the follow-up accounted for 18 months. Cases with implant failure (loosening and screw breakage) were registered and revision pedicle screws fixation was performed. Results Out of 42 enrolled patients 3 were presented with implant failure (a screw loosening in one case and a screw rupture and loosening in 2 cases). The attempts to remove retained fractured fragments were unsuccessful, therefore, alternative bypass creation and a direct screw placement into a retained fractured fragment were carried out and suggested as an alternative strategy to osteotomy with a fractured screw fragment removal. Conclusion In case of rupture, expandable screws have a poor feasibility for a revision pedicle screw fixation because of fractured fragments strong anchorage in bone. The alternative bypass for a revision screw without fractured fragment removal or tapping and direct screw placement into retained expanded fragment of a screw are less invasive alternatives to osteotomy that can help overcome the discussed issue

The relationship between Computed Tomography and DXA results: A potential bias in Bone Mineral Density assessment

Background It has been reported that the results of the lumbar spine bone mineral density assessment can be strongly biased by degenerative changes. However, the reported data remains controversial and a potential bias has not been assessed. Aims To evaluate the relationships between the results of DXA and CT with the assessment of potential bias related to the influence of different structures. Methods This is a cross-sectional study and 25 patients were enrolled. Using DXA scan, Bone Mineral density (BMD) (g/cm2) was calculated from 100 vertebra from the lumbar spine. Out of all the CT measurements, a mean radiodensity in HU (Hounsfield Units) for cancellous bone and total vertebra body, a mean square and radiodensity of vertebra pedicles and facet were calculated. Results Linear regression analysis demonstrated a strong correlation between BMD measured by DXA and CT data. Multiple correlation coefficient of model accounts for 0.8093, r2=0.6550, p<0.0001. Parameters that have significant relationships with the results of DXA were: a product of facet joints radiodensity and mean square on axial images (B= 0.000003379, p<0.0001) and total vertebral body radiodensity B=0.0016395253, p=0.0201. Beta coefficients for those variables accounted for 0.6729 and 0.3037 respectively. Conclusion The results of the bone mineral density assessment of the lumbar spine using DXA, can be strongly influenced by facet joints condition, especially in cases of degenerative changes. The results of BMD, provided by DXA, are partly relevant to vertebral body bone quality assessment and irrelevant to the characteristics of bone in pedicles. This means that the prognostic value of the DXA measurement results might be limited in relation to predicting low energy vertebra fracture and implant stability

The relationship between Computed Tomography and DXA results: A potential bias in Bone Mineral Density assessment

BackgroundIt has been reported that the results of the lumbar spine bone mineral density assessment can be strongly biased by degenerative changes. However, the reported data remains controversial and a potential bias has not been assessed.Aims To evaluate the relationships between the results of DXA and CT with the assessment of potential bias related to the influence of different structures.Methods This is a cross-sectional study and 25 patients were enrolled. Using DXA scan, Bone Mineral density (BMD) (g/cm2) was calculated from 100 vertebra from the lumbar spine. Out of all the CT measurements, a mean radiodensity in HU (Hounsfield Units) for cancellous bone and total vertebra body, a mean square and radiodensity of vertebra pedicles and facet were calculated. Results Linear regression analysis demonstrated a strong correlation between BMD measured by DXA and CT data. Multiple correlation coefficient of model accounts for 0.8093, r2=0.6550, p < 0.0001. Parameters that have significant relationships with the results of DXA were: a product of facet joints radiodensity and mean square on axial images (B= 0.000003379, p < 0.0001) and total vertebral body radiodensity B=0.0016395253, p=0.0201. Beta coefficients for those variables accounted for 0.6729 and 0.3037 respectively.ConclusionThe results of the bone mineral density assessment of the lumbar spine using DXA, can be strongly influenced by facet joints condition, especially in cases of degenerative changes. The results of BMD, provided by DXA, are partly relevant to vertebral body bone quality assessment and irrelevant to the characteristics of bone in pedicles. This means that the prognostic value of the DXA measurement results might be limited in relation to predicting low energy vertebra fracture and implant stability

Early Management of Cervical Spine Trauma: WFNS Spine Committee Recommendations

Zileli, Mehmet/0000-0002-0448-3121WOS:000604731600006PubMed: 33401852Epidemiology, prevention, early management of cervical spine trauma and it's reduction are the objectives of this review paper. A PubMed and MEDLINE search between 2009 and 2019 were conducted using keywords. Case reports, experimental studies, papers other than English language and and unrelated studies were excluded. Up-to-date information on epidemiology of spine trauma, prevention, early emergency management, transportation, and closed reduction were reviewed and statements were produced to reach a consensus in 2 separate consensus meeting of World Federation of Neurosurgical Societies (WFNS) Spine Committee. The statements were voted and reached a positive or negative consensus using Delphi method. Global incidence of traumatic spinal injury is higher in low- and middle-income countries. The most frequent reasons are road traffic accidents and falls. The incidence from low falls in the elderly are increasing in high-income countries due to ageing populations. Prevention needs legislative, engineering, educational, and social efforts that need common efforts of all society. Emergency care of the trauma patient, transportation, and in-hospital acute management should be planned by implementing detailed protocols to prevent further damage to the spinal cord. This review summarizes the WFNS Spine Committee recommendations on epidemiology, prevention, and early management of cervical spine injuries