Currently, there are no standards in surgical treatment of dumbbell-shaped tumors of lumbo-foraminal region.
OBJECTIVE: To evaluate the effectiveness and long-term results of minimally invasive resection of dumbbell-shaped lumbar schwannomas Eden type 2 and 3 combined with transforaminal lumbar interbody fusion and transpedicular stabilization.
METHODS: A retrospective study included 13 patients (8 men and 5 women) with lumbar dumbbell tumors Eden type 2 and 3 who underwent minimally invasive facetectomy through posterolateral anatomical corridor, microsurgical tumor resection and MI TLIF. We analyzed intraoperative parameters, neurological functions (ASIA scale), clinical characteristics (ODI, SF-36), and complications. Resection quality and area of the multifidus muscle were assessed according to MRI data. All patients were followed-up throughout at least 3-year.
RESULTS: Surgery time was 147 min, blood loss - 118 ml, hospital-stay - 7 days. Clinical parameters significantly improved in the follow-up period: ODI score decreased from 72 to 12 (p=0.004), SF-36 PCS increased from 26.24 to 48.51 (p=0.006) and MCS score increased from 29.13 to 53.68 (p=0.002). According to MRI data, no tumor recurrences and severe muscle atrophy (>30%) were observed after 3 years in all cases. Superficial wound infection occurred in 1 (7.7%) case. There were normal neurological functions (ASIA type E) in all patients.
CONCLUSIONS: Minimally invasive facetectomy through posterolateral approach with MI TLIF technology can be used for safe and effective resection of dumbbell-shaped schwannomas Eden type 2 and 3.
В настоящее время отсутствуют стандарты в выборе способа оперативного лечения гантелеообразных опухолей, расположенных в пояснично-фораминальной области.
UNASSIGNED: Оценка эффективности и отдаленных результатов минимально инвазивного удаления гантелеобразных шванном поясничного отдела 2-го и 3-го типов по классификации Eden в сочетании с трансфораминальным поясничным спондилодезом и транспедикулярной стабилизацией (MI TLIF).
UNASSIGNED: В ретроспективное исследование включены 13 пациентов (8 мужчин и 5 женщин) с гантелеобразными опухолями поясничной локализации 2-го и 3-го типов по классификации Eden, которым осуществлялись минимально инвазивная фасетэктомия через заднебоковой анатомический коридор, микрохирургическое удаление опухоли и MI TLIF. Изучались операционные параметры, неврологические функции по шкале ASIA, клинические характеристики (ODI, SF-36), наличие осложнений. По результатам магнитно-резонансной томографии (МРТ) оценивали степень радикальности удаления опухоли и изменения площади многораздельной мышцы. Все пациенты находились под минимальным 3-летним наблюдением.
UNASSIGNED: Средние значения периоперационных данных составили: продолжительность операции 147 мин, объем кровопотери 118 мл, длительность госпитализации 7 дней. В катамнезе установлено значимое улучшение клинических параметров в среднем: функционального состояния по ODI c 72 до 12 (p=0,004), SF-36 PCS с 26,24 до 48,51 (p=0,006) и MCS с 29,13 до 53,68 (p=0,002). По данным МРТ, через 3 года после операции во всех случаях не выявлено рецидивов опухоли, а также выраженной мышечной атрофии (>30%). В 1 (7,7%) случае зарегистрирована поверхностная раневая инфекция. У всех пациентов сохранены нормальные неврологические функции (тип E по шкале ASIA).
UNASSIGNED: Для безопасного, эффективного и радикального удаления гантелеобразных шванном 2-го и 3-го типов по классификации Eden может быть использована минимально инвазивная фасетэктомия из заднебокового доступа с технологией MI TLIF.

UNASSIGNED: To prospectively evaluate the feasibility and safety of a polyetheretherketone (PEEK) polymer transpedicular vertebral system to treat vertebral compression fracture (VCF).
UNASSIGNED: Nine consecutive patients (4 men and 5 women; median age 59 [interquartile range: 58-64 years]) were included. The procedure duration, length of hospital stay, and complications were reported. Visual analog scale (VAS) and the Oswestry disability index (ODI) for pain and disability were assessed before and at 2, 6, and 12-month after the procedure.
UNASSIGNED: The procedure was technically feasible in all patients. The median procedural time was 64 minutes [45-94]. Only minor adverse events were reported (5 clinically asymptomatic cement leakages) but no severe complications. No post procedural adjacent fracture was reported during follow-up (median: 193 days [147-279]). The median VAS score decreased from 55 mm [50-70] before the procedure to 25 mm [5-30] at 2-month (P = .0003) and 30 mm [15-40] at 6-month follow-up (P = .14). The median ODI decreased from 23% [19-26] before the procedure to 12% [10-14] at 2-month (P = .03) and 12% [9-20] at 6-month follow-up (P = .47).
UNASSIGNED: Percutaneous transpedicular fixation of VCF by PEEK implants appears feasible and safe.

OBJECTIVE: Computer-assisted surgical planning methods help to reduce the risks and costs in transpedicular fixation surgeries. However, most methods do not consider the speed and versatility of the planning as factors that improve its overall performance. In this work, we propose a method able to generate surgical plans in minimal time, within the required safety margins and accounting for the surgeon\'s personal preferences.
METHODS: The proposed planning module takes as input a CT image of the patient, initial-guess insertion trajectories provided by the surgeon and a reduced set of parameters, delivering optimal screw sizes and trajectories in a very reduced time frame.
RESULTS: The planning results were validated with quantitative metrics and feedback from surgeons. The whole planning pipeline can be executed at an estimated time of less than 1 min per vertebra. The surgeons remarked that the proposed trajectories remained in the safe area of the vertebra, and a Gertzbein-Robbins ranking of A or B was obtained for 95 % of them.
CONCLUSIONS: The planning algorithm is safe and fast enough to perform in both pre-operative and intra-operative scenarios. Future steps will include the improvement of the preprocessing efficiency, as well as consideration of the spine\'s biomechanics and intervertebral rod constraints to improve the performance of the optimisation algorithm.

BACKGROUND: Many studies have been conducted to compare traditional trajectory (TT) and cortical bone trajectory (CBT) screws; however, how screw parameters affect the biomechanical properties of TT and CBT screws, and so their efficacy remains to be investigated.
METHODS: A finite element model was used to simulate screws with different trajectories, diameters, and lengths. Responses for implant and tissues at the adjacent and fixed segments were used as the comparison indices. The contact lengths and spanning areas of the inserted screws were defined and compared across the varieties.
RESULTS: The trajectory and diameter had a greater impact on the responses from the implant and tissues than the length. The CBT has shorter length than the TT; however, the contact length and supporting area of the CBT within the cortical bone were 19.6%. and 14.5% higher than those of the TT, respectively. Overall, the TT and CBT were equally effective at stabilizing the instrumented segment, except for bending and rotation. The CBT experienced less adjacent segment compensations than the TT. With the same diameter and length, the TT was considerably less stressed than the CBT, especially for flexion and extension.
CONCLUSIONS: The CBT may provide less stress at adjacent segments compared with the TT. The CBT may provide more stiffer in osteoporotic segments than the TT due to greater contact with cortical bone and a wider supporting base between the paired screws. However, both entry point and insertion trajectory of the CBT should be carefully executed to avoid vertebral breach and ensure a stable cone-screw purchase.

The aim of the study was to assess the efficacy and safety of direct posterior transpedicular osteosynthesis in traumatic spondylolisthesis of C2 vertebra.
The present study is an observational retrospective analysis of the results of surgical treatment of 19 patients operated on in 2014-2020 using the posterior transpedicular osteosynthesis technique with Herbert\'s compression screws for a Hangman\'s fracture type II according to Levine-Edwards classification. After the operation, the follow-up period lasted for 22 [10; 36] months.
The study group of patients (n=19) made 2.48% of all patients operated on for traumatic injury of the cervical spine (n=766) in the period from 2014 to 2020. In all cases, the surgical treatment was successful; there were no intraoperative complications in the form of damage to the vascular and nerve structures. The average duration of surgery was 70.8±24.5 min, and intraoperative blood loss was 92.9±41.8 ml. The length of hospitalization stay was 7 [5; 17] days. On the postoperative CT scans, no significant screw malposition (>2 mm) was found.
Transpedicular osteosynthesis with compression screws in C2 traumatic spondylolisthesis is a safe and sparing operation with a short duration and insignificant blood loss. Thorough preoperative planning and knowledge of the anatomic landmarks make it possible to perform this operation effectively under the C-arm X-ray system control without any navigation system.

The major management technique for lumbar burst fractures is transpedicular fixation (TPF). However, in relation to fractures of the L5 vertebra, this tactic often has no advantages over conservative treatment, and, therefore, it is expected to be supplemented with anterior decompression and reconstruction of the anterior column of the L5 vertebra. The aim of the study was to determine the most optimal treatment tactics for patients with isolated burst fractures of the fifth lumbar vertebra.
We performed a retrospective study of 58 patients treated for isolated burst L5 fractures. 12 patients refused to undergo surgery and received conservative outpatient treatment. TPF was performed in 27 patients; circular spondylosynthesis (TPF + anterior column support with a Mesh implant) - in 19 patients. The effectiveness of the treatment was assessed by clinical and introscopic research methods.
The radiological and functional outcomes of surgery with conventional TPF for isolated L5 burst fractures are generally comparable with the outcomes of conservative treatment. In 26% of the patients, the instability of the metal construction developed within 12 months after surgical intervention. Supplementing the transpedicular system with wedging anterior column support with a Mesh implant ensures preservation in 21%, and improves the parameters of the sagittal profile of the lumbosacral transition in 79% of cases.

OBJECTIVE: To evaluate the feasibility and safety of percutaneous transpedicular fixation by PEEK polymer implants and cementoplasty for vertebral compression fracture (VCF).
METHODS: From February 2019 to December 2019, 6 consecutive patients (3 men and 3 women; mean age 55 ± 8 years; range 40-64 years) who had percutaneous transpedicular fixation with cementoplasty for the treatment of VCF (5 tumor lesions, 1 traumatic) were included. The procedure duration, length of hospital stay, and complications were reported. Visual analog scale (VAS) and the Oswestry disability index (ODI) for pain and disability were assessed before and 2 months after the procedure.
RESULTS: The mean procedure duration was 74 ± 47 min (range 20-140 min). The median length of hospital stay was 3 days (range 2-63) after the procedure. Only minor adverse events were reported (4 asymptomatic cement leakages) but no severe complications. No cases of procedural site fracture during follow-up were noted (median 198 days; range 78-238 days). The mean VAS score decreased from 6.2 ± 1.8 mm (median 6 mm; range 4-9 mm) before the procedure to 1.7 ± 2.1 mm (median 1; range 0-5 mm) after the procedure. The ODI decreased from 36 ± 14% (range 18-54%) before the procedure to 23 ± 10% (range 11-30%) at 2-months follow-up.
CONCLUSIONS: Percutaneous transpedicular fixation of VCF by PEEK implants with cementoplasty appears feasible and safe.

OBJECTIVE: To compare an effectiveness of different methods of rigid transpedicular fixation and decompression in patients with degenerative lumbar stenosis.
METHODS: A prospective study included 160 patients with degenerative lumbar spine stenosis. In the first group (n=37), patients underwent laminectomy and transpedicular fixation, in the second group (n=60) - laminectomy, transpedicular fixation and implantation of interbody fusion cage. In the third group (n=30), interlaminar decompression and transpedicular fixation were carried oud, in the fourth group (n=33) - interlaminar decompression, transpedicular fixation and implantation of interbody fusion cage. Surgeries were performed in three clinics in Moscow. Outcomes were assessed using a visual analogue scale (VAS) and Oswestry questionnaire in 1 and 2 years after surgery. Between-group comparison of the outcomes was performed. In patients with unfavorable outcome, we analyzed the cause of unsatisfactory result and risk factors.
RESULTS: Satisfactory result was noted in 103 patients (64%) in 2 years after surgery. Outcomes were comparable in all groups. More significant regression of back pain was noted in group II (laminectomy, transpedicular fixation, interbody cage) compared to other groups. Preoperative risk factors of adverse outcome were resting leg pain VAS score > 4 and age over 71 years. Incidence of pseudoarthrosis and back pain was higher among patients without interbody cage. Incidence of adjacent level lesion was higher among patients with interbody cages.
CONCLUSIONS: Decompression type and implantation of interbody cage do not significantly change postoperative outcomes in most patients with degenerative lumbar stenosis undergoing transpedicular fixation. However, interbody cage implantation during transpedicular fixation is advisable in patients with severe back pain (VAS score > 5-6).
В настоящее время окончательно не определена тактика в плане выбора способа ригидной транспедикулярной фиксации и декомпресии у больных с дегенеративным поясничным стенозом. Результаты различных исследований противоречивы.
UNASSIGNED: Сравнить эффективность различных способов ригидной транспедикулярной фиксации и декомпрессии у больных с дегенеративным поясничным стенозом.
UNASSIGNED: Проведено проспективное исследование с включением 160 больных с симптомным дегенеративным стенозом позвоночного канала на поясничном уровне. Больным группы I (n=37) выполнили ляминэктомию и транспедикулярную фиксацию, больным группы II (n=60) — ляминэктомию, транспедикулярную фиксацию и имплантацию межтелового кейджа, больным группы III (n=30) — интерламинарную декомпрессию и транспедикулярную фиксацию, больным группы IV (n=33) — интерламинарную декомпрессию, транспедикулярную фиксацию и имплантацию межтелового кейджа. Операции проводили в трех клиниках г. Москвы. Исходы оценивали по регрессу боли по визуально-аналоговой шкале (ВАШ) и по опроснику Освестри через 1 и 2 года после операции. Исходы у больных разных групп сравнивали между собой. У пациентов с неудовлетворительным результатом определяли причину неудовлетворительного исхода и факторы риска его развития.
UNASSIGNED: Через 2 года после операции удовлетворительный результат отметили у 103 (64%) пациентов. Исходы у пациентов всех четырех групп оказались сопоставимы друг с другом. У пациентов группы II (ляминэктомия, транспедикулярная фиксация, межтеловой кейдж) отмечен более выраженный регресс болевого синдрома в поясничной области по сравнению с пациентами других групп. Дооперационными факторами риска неблагоприятного исхода оказались уровень боли в ноге в покое более 4 баллов по ВАШ и возраст пациентов более 71 года. Частота псевдоартроза и боли в области транспедикулярной системы оказалась выше у пациентов без использования межтелового кейджа. Частота поражения смежного уровня была выше у пациентов с межтеловыми кейджами.
UNASSIGNED: При выполнении транспедикулярной фиксации у большинства пациентов с дегенеративным поясничным стенозом тип декомпрессии и установка межтелового кейджа существенно не меняют результат хирургического лечения. Однако если у пациента на уровне стеноза отмечается выраженная поясничная боль (более 5—6 баллов по визуально-аналоговой шкале), то транспедикулярную фиксацию целесообразно дополнять установкой межтелового кейджа.

BACKGROUND: Surgical correction of adolescent idiopathic scoliosis is inevitably accompanied by blood loss. About 37-85% of patients undergo allogeneic transfusions associated with a risk of serious complications. Prediction of the expected blood loss volume remains a topical problem. In this regard, there is a need to clarify predictors of increased blood loss.
OBJECTIVE: To assess the effect of vertebrectomy on the intraoperative blood loss volume during surgical correction of adolescent idiopathic scoliosis.
METHODS: A retrospective study included 511 adolescents who underwent posterior correction of spinal deformity. Two groups were allocated: Group I consisted of 303 patients who underwent multilevel transpedicular fixation; Group II included 208 patients who underwent multilevel transpedicular fixation combined with Smith-Peterson osteotomy.
RESULTS: Intergroup comparisons revealed significant differences in the number of transpedicular fixation levels and the volume of blood loss, which were higher in Group II. After aligning the groups by the number of transpedicular fixation levels using the Propensity Score Matching method, no statistically significant difference was observed. We derived formulas for calculating the expected blood loss volume in Groups I and II. Comparison of the formulas revealed that the formula for Group II predicted a significantly lower volume of blood loss, by 2.51%, while the formula for Group I predicted a significantly higher volume of blood loss, by 3.27%. In our opinion, application of the formula that overestimates expected intraoperative blood loss is most reasonable due to a possibility of the worst case scenario during surgery; therefore, the formula for Group I approaches a universal model for use.
CONCLUSIONS: Smith-Peterson osteotomy did not affect the amount of blood loss during surgical correction of adolescent idiopathic scoliosis, considering the number of transpedicular fixation levels.

A high-riding vertebral artery (HRVA) has been defined as a C2 isthmus height of ≤5 mm and/or internal height of ≤2 mm measured 3 mm lateral to the border of the spinal canal. Its reported prevalence has varied widely. If overlooked during the approach for craniocervical fusion, injury to the vertebral arteries can occur, affecting the outcome. The present meta-analysis aimed to provide the pooled prevalence of HRVAs.
A comprehensive database search was conducted by 3 of us. Peer-reviewed studies that had followed the strict definition for HRVAs and had reported its prevalence were included. The risk of bias was assessed using the anatomical quality assessment tool. The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were followed. The pooled prevalence was calculated using a random effects model.
The data from 20 studies with 3126 subjects (7496 sides) were analyzed. The overall pooled prevalence of ≥1 HRVA was 25.3% (95% confidence interval [CI], 19.6%-31.5%). The prevalence in those without the most important confounding factor, rheumatoid arthritis (RA), was 20.9% (95% CI, 16.5%-25.8%). Patients with RA had a prevalence of 42.9% (95% CI, 23.8%-63.1%). The difference between the non-RA and RA groups was statistically significant (P < 0.001, test of homogeneity, χ2). No geographical differences were noted (P = 0.20, test of homogeneity, χ2). Among those with HRVA, unilateral HRVA was present in 70.3% (95% CI, 65.2%-75.2%) and bilateral in 29.7% (95% CI, 24.8%-34.8%). No left or right side predilection was found (left, 50.8%; 95% CI, 33.8%-67.6%; right, 49.2%; 95% CI, 32.4%-66.2%).
Craniocervical fusion should be preceded by examination of the vertebral arteries at the level of C2 because the presence of HRVAs is common and might preclude the safe insertion of transarticular or transpedicular screws.