Treatment of thoracolumbar fractures by closed reduction via a percutaneous solid pedicle screw / Tratamento de fraturas toracolombares por redução fechada com parafuso de pedículo percutâneo

ABSTRACT Objectives: Investigate the effect of closed reduction and per- cutaneous pedicle screw fixation in treating thoracolumbar fractures. Methods: This retrospective study analyzed 12 cases of single-segment thoracolumbar spine fractures without spinal cord and nerve injury at our department from March 2016 to September 2017. Patients were treated with closed reduction, percutaneous reduction, and internal fixation with solid pedicle screws. The operation time, intraoperative blood loss, anterior vertebral body height ratio (AVHR), Cobb angle (CA) of sagittal kyphosis, and VAS of back pain were determined and statistically compared. Results: The average operation time was 147.2 ± 45.6 min, and the average intraoperative bleeding was 67.8 ± 34.2 mL. All fractured vertebrae were completely reduced, their height was restored, and kyphosis was corrected. The average follow-up period was 10.6 ± 2.7 months, with significant improvements seen in the AVHR, CA of sagittal kyphosis, and VAS score (P < 0.01). One case had a broken rod after three months, and another had a postoperative infection. All the patients achieved bony healing. Conclusion: The treatment of thoracolumbar fractures by closed reduction and internal fixation with a percutaneous solid pedicle screw is simple, effective, and economical. Level of Evidence VI; Therapeutic Study, Case Series.

RESUMO Objetivo: Investigar o efeito da redução incruenta e da fixação com parafuso de pedículo percutâneo no tratamento das fraturas toraco- lombares. Métodos: Este estudo retrospectivo analisou 12 casos de fraturas toracolombares com segmento único sem lesão medular ou neural, encontrados no departamento dentro do período de março de 2016 a setembro de 2017. Os pacientes foram tratados com redução fechada e fixação interna com parafusos de pedículo percutâneo. O tempo de operação, a perda sanguínea intra-operatória, a relação da altura do corpo vertebral anterior (AVHR), o ângulo de Cobb (CA) da cifose sagital e a EVA relativa à dor nas costas foram determinados e comparados estatisticamente. Resultados: O tempo médio da operação foi de 147,2±45,6 min, com sangramento intraoperatório médio de 67,8±34,2 mL. Todas as vértebras fraturadas foram com- pletamente reduzidas, suas alturas foram restauradas e a cifose foi corrigida. O período médio de acompanhamento foi de 10,6±2,7 meses, apresentando melhorias significativas observadas no AVHR, CA da cifose sagital e pontuação VAS (P <0,01). Um caso teve uma haste quebrada após 3 meses, e outro paciente apresentou uma infecção pós-operatória. Todos os pacientes alcançaram a recuperação óssea. Conclusão: O tratamento das fraturas toracolombares por redução fechada com fixação interna pelo parafuso de pedículo percutâneo é simples, eficaz e econômico. Nível de Evidência IV; Estudos Terapêuticos, Série de Casos

Lumbar arthrodesis in lateral single position: concepts, rational and clinical-functional results of 100 consecutive cases / Artrodese lombar em decúbito lateral único: conceitos, justificativas e resultados clínico-funcionais de 100 casos consecutivos / Artrodesis lumbar en posición lateral única: conceptos, justificaciones y resultados clínico-funcionales de 100 casos consecutivos

ABSTRACT Objective: Arthrodesis techniques such as anterior lumbar interbody fusion (ALIF) and lateral lumbar interbody fusion (LLIF) aim to reestablish physiological lordosis and minimize tissue damage to the paravertebral musculature. Supplementation with percutaneous pedicle screws is indicated in most cases, therefore, intraoperative changes in decubitus are necessary, generating costs and risks for the patient. This study aims to present concepts and results of a series of 100 cases of patients undergoing 360° fusion in lateral single position surgery (LSPS). Methods: retrospective analysis of databases collected between 2016 and 2021. Patients who underwent 360° fusion of the lumbar spine in single lateral decubitus to treat degenerative and infectious diseases were included. Cases with arthrodesis greater than 3 levels were excluded. Data collected include demographics, body mass index (BMI) and scores such as visual analog scale (VAS), EuroQOL 5D (EQ5D) and Oswestry disability index (ODI). Results: 100 patients were included in the study, submitted to LLIF and/or ALIF associated with percutaneous pedicle fixation. The lumbar VAS improved from 6.75 to 2.1 after 12 months, while the sciatica VAS started from 4.55 and reached 0.81 after one year. The EQ5D improved from 66.1 to 81.6 after the first year, while the ODI ranged from 28.54 to 14.18 in the same period. Conclusions: the clinical-functional results of the LSPS procedures are favorable and place the LSPS as an option to be studied, developed and practiced by spine surgery teams. Level of evidence: IV. Case series.

Resumo: Objetivo: Técnicas de artrodese como anterior lumbar interbody fusion (ALIF) e lateral lumbar interbody fusion (LLIF) tem como objetivos o reestabelecimento da lordose fisiológica e a mínima lesão tecidual da musculatura paravertebral. A suplementação com parafusos pediculares por via percutânea é indicada na maioria dos casos, sendo, portanto, necessárias mudanças de decúbito intraoperatórias, gerando custos e riscos para o paciente. Este estudo tem como objetivo apresentar conceitos e resultados de uma série de 100 casos de pacientes submetidos a fusão 360° em lateral single position surgery (LSPS). Métodos: análise retrospectiva de banco de dados coletados entre 2016 e 2021. Foram incluídos pacientes submetidos a fusão 360° da coluna lombar em decúbito lateral único para tratamento doenças degenerativas e infecciosas. Foram excluídos casos com artrodeses maiores que 3 níveis. Os dados coletados incluem demografia, índice de massa corpórea (IMC) e scores como visual analog scale (VAS), EuroQOL 5D (EQ5D) e Oswestry disability index (ODI). Resultados: 100 pacientes foram incluídos no estudo, submetidos a LLIF e/ ou ALIF associados a fixação pedicular percutânea. O VAS lombar apresentou melhora de 6,75 para 2,1 após 12 meses, já o VAS ciatalgia partiu de 4,55 e atingiu 0,81 após um ano. O EQ5D apresentou melhora de 66,1 para 81,6 após o primeiro ano, enquanto o ODI variou de 28,54 para 14,18 no mesmo período. Conclusões: os resultados clínico-funcionais dos procedimentos em LSPS se mostram favoráveis e a colocam o LSPS como uma opção a ser estudada, desenvolvida e praticada pelas equipes de cirurgia de coluna. Nível de evidência: IV. Série de casos.

Resumen: Objetivo: Las técnicas de artrodesis como la fusión intersomática lumbar anterior (ALIF) y la fusión intersomática lumbar lateral (LLIF) tienen como objetivo restablecer la lordosis fisiológica. La suplementación con tornillos pediculares percutáneos está indicada en la mayoría de los casos, por lo que son necesarios cambios en decúbito intraoperatorios, generando costos y riesgos para el paciente. Este estudio tiene como objetivo presentar conceptos y resultados de una serie de 100 casos de pacientes sometidos a fusión de 360° en cirugía de posición única lateral (LSPS). Métodos: análisis retrospectivo de bases de datos recolectadas entre 2016 y 2021. Se incluyeron pacientes que se sometieron a fusión de columna lumbar 360° en decúbito lateral y se excluyeron los casos con artrodesis mayores de 3 niveles. Los datos recopilados incluyen datos demográficos, índice de masa corporal (IMC) y puntajes como la escala analógica visual (VAS), EuroQOL 5D (EQ5D) y el índice de discapacidad de Oswestry (ODI). Resultados: 100 pacientes fueron incluidos en el estudio, sometidos a LLIF y/o ALIF asociados a fijación pedicular percutánea. La EVA lumbar mejoró de 6,75 a 2,1 a los 12 meses, mientras que la EVA de ciática partió de 4,55 y llegó a 0,81 al año. El EQ5D mejoró 66,1 a 81,6 después del primer año, mientras que el ODI varió 28,54 a 14,18 en el mismo período. Conclusiones: los resultados clínico-funcionales de los procedimientos de LSPS son favorables y a sitúan como una opción a ser estudiada, desarrollada y practicada por los equipos de cirugía de columna. Nivel de evidencia: IV. Series de casos.

Axial instrument strategy for atlantoaxial dislocation with complex artery variation / 中华骨科杂志

Objective:To evaluate the axial instrument strategy for atlantoaxial dislocation with complex vertebral artery variation.Methods:A total of 55 patients with atlantoaxial dislocation who underwent surgical treatment from January 2019 to December 2021 were retrospectively analyzed, including 14 males and 41 females, aged 54.0±12.8 years (range, 22-78 years). Among these patients, 10 patients with unilateral vertebral artery high ride with contralateral vertebral artery occlusion, 30 patients with bilateral vertebral artery high ride with single dominant vertebral artery, 15 patients with bilateral vertebral artery high ride. All patients underwent posterior reduction and internal fixation. Visual analogue scale (VAS) and Japanese Orthopaedic Association (JOA) score were used to evaluate the postoperative efficacy.Results:All patients completed the surgery successfully with a follow-up time of 14.6±5.5 months (range, 6-24 months). C 2 pedicle screw fixation was performed on the non-dominant side of unilateral vertebral artery high ride and the non-dominant side of bilateral vertebral artery high ride with one dominant vertebral artery (40 vertebraes). The dominant side of unilateral high vertebral artery and bilateral high vertebral artery with one dominant vertebral artery was fixed with C 2 medial "in-out-in" screw (10 vertebraes), C 2 isthmus screw (21 vertebraes), C 2 without screw (9 vertebraes) only extended the fixed segment. For bilateral vertebral artery high ride patients, one side was used C 2 "in-out-in" pedicle screws (right 10 vertebraes, left 5 vertebraes), and the other side was fixed with C 2 medial "in-out-in" screw (8 vertebraes), C 2 isthmus screw (5 vertebraes), C 2 without screw only extended the fixed segment (2 vertebraes). The JOA scores were 8.5±1.8, 13.9±1.3, and 14.4±1.1 preoperatively, 6 months postoperatively, and at the final follow-up, respectively, with statistically significant differences ( F=279.40, P<0.001). JOA at 6 months postoperatively and at the final follow-up was greater than preoperatively, and the differences were statistically significant ( P<0.05), whereas the differences in JOA scores at 6 months postoperatively and at the final follow-up was not statistically significant ( P>0.05). Preoperative, 6 months postoperatively and final follow-up cervical VAS scores were 3.7±1.9, 2.1±0.9 and 1.6±1.0, respectively, with statistically significant differences ( F=39.53, P<0.001). The cervical VAS at 6 months postoperatively and at the last follow-up was less than that before surgery, and the differences were statistically significant ( P<0.05). Cervical VAS scores at 6 months postoperatively were greater than at the last follow-up, with a statistically significant difference ( P<0.05). Conclusion:For patients with atlantoaxial dislocation with complex vertebral artery variation, C 2 lateral "in-out-in" screw, C 2 medial "in-out-in" screw, isthmus screw fixation or C 2 without screw only extended the fixed segment can obtain good clinical efficacy.

A clinical study of a novel manual screw placement based on anatomical study of the 7th cervical vertebra / 中华创伤骨科杂志

Objective:To evaluate the feasibility, accuracy, effectiveness and safety of a novel manual placement of cervical 7 pedicle screws via the posterior approach of cervicothoracic junction.Methods:A retrospective case series study was conducted to analyze the 35 patients with injury to the lower cervical spine or cervicothoracic junction who had been treated by a novel manual placement of cervical 7 pedicle screws at Department of Orthopedics, The First Affiliated Hospital of Zhengzhou University from March 2015 to July 2021. There were 16 males and 19 females, with an age of (52.7±13.2) years. The core of this placement was to determine the entry point of cervical 7 pedicle screws. After the intersection of the upper edge of the cervical 7 lamina and the medial edge of the superior articular process was recorded as point A while the intersection of the lateral edge of the inferior articular process and the lower edge of the transverse process as point B, the intersection of the outer and middle 1/3 of the AB line was taken as the screw entry point, with the screw placement angle perpendicular to the lamina line or slightly inclined from 30° to 40° to the head side and outward. The length, diameter and placement angle of the cervical 7 pedicle screws were recorded and compared postoperatively between the left and right sides to explore the feasibility of this novel manual placement. According to the Rampersaud method, the screw positions were graded 1 week and 6 months after operation to evaluate the accuracy of this manual placement. The visual analogue scale (VAS) and the Japanese Orthopaedic Association (JOA) score were compared between preoperation, 1 week and 6 months after operation to evaluate the effectiveness of this placement. The postoperative complications were counted to evaluate the safety of this method. Loosening, displacement and breakage of the screws were observed by CT scanning at 6 months after operation.Results:This case series was followed up for (9.8±1.7) months. There was no significant difference in the length, diameter or placement angle of the screws between the left and right sides ( P>0.05). A total of 66 cervical 7 pedicle screws were placed. There was no change in the screw position grading at 1 week or 6 months after surgery. Grade A was achieved in 64 screws, Grade B in 2 screws, and Grade C or D in none. The VAS scores before operation, 1 week and 6 months after operation were respectively 4.4±1.7, 3.8±1.0 and 1.1±1.1, and the JOA scores respectively 6.7±2.2, 13.2±1.5 and 15.3±1.2. The VAS and JOA scores at 1 week and 6 months after operation were significantly improved compared with the preoperative values ( P<0.05). The improvement rates in JOA at 1 week and 6 months after operation were 62.7%±13.3 % and 83.9%±11.6%, respectively. There were no complications related to the placement of cervical 7 pedicle screws; there was no wound hematoma or infection. No loosening, displacement or breakage of the screws was observed by the 6-month follow-up. Conclusion:The novel manual placement of cervical 7 pedicle screws via the posterior approach of cervicothoracic junction is feasible, accurate, effective and safe.

Efficacy of O-arm combined with CT three-dimensional navigation system assisted versus manual screw placement in the treatment of lower cervical fracture and dislocation / 中华创伤杂志

Objective:To compare the clinical efficacies of O-arm combined with CT three-dimensional navigation system assisted screw placement versus manual screw placement in treating lower cervical fracture and dislocation.Methods:A retrospective cohort study was used to analyze the clinical data of 41 patients with lower cervical fracture and dislocation, who were treated in Honghui Hospital, Xi′an Jiaotong University from May 2021 to February 2022. The patients included 26 males and 15 females, aged 31.5-48.6 years [(41.5±15.0)years]. The injured segments were C 3 in 3 patients, C 4 in 12, C 5 in 13, C 6 in 10 and C 7 in 3. Nineteen patients were treated with cervical pedicle screws by O-shaped arm combined with CT three-dimensional navigation system (navigation group, 76 screws) and 22 by bare hands (traditional group, 88 screws). The total operation time, effective operation time, single nail placement time, single screw correction times, screw distance from anterior cortex, intraoperative blood loss, intraoperative fluoroscopic radiation dose, incision length and length of hospital stay were compared between the two groups, and the height of intervertebral space, Cobb angle, interbody slip distance and American Spinal injury Association (ASIA) grade were compared before operation and at 3 days after operation. Visual analogue score (VAS), Japanese Orthopedic Association (JOA) score, and neck dysfunction index (NDI) were evaluated before operation, at 3 days, 3 months after operation and at the last follow-up. Accuracy of screw placement and incidence of complications (adjacent facet joint invasion, infection, screw loosening) were detected as well. Results:All the patients were followed up for 11.1-13.9 months [(12.5±1.4)months]. The total operation time, intraoperative blood loss, intraoperative fluoroscopic radiation dose and incision length in the navigation group were more or longer than those in the traditional group (all P<0.05). The effective operation time, single nail placement time, single nail correction times and screw distance from anterior cortex in the navigation group were markedly less or smaller than those in the traditional group (all P<0.05). There was no significant difference in the length of hospital stay between the two groups ( P>0.05). There were significant improvements in the height of intervertebral space, Cobb angle and interbody slip distance between the two groups at 3 days after operation (all P<0.05). There was no significant difference in the height of intervertebral space, Cobb angle, interbody slip distance or ASIA grade between the two groups before operation or at 3 days after operation (all P>0.05). Compared with pre-operation, the VAS, JOA score and NDI were significantly improved in both groups at 3 days, 3 months after operation and at the last follow-up (all P<0.05), with further improvement with time. There was no significant difference in VAS between the two groups before operation or at 3 months after operation (all P>0.05), but it was markedly lower in the navigation group compared with the traditional group at 3 days after operation and at the last follow-up (all P<0.05). There were no significant differences in JOA score or NDI between the two groups before operation or at 3 days and 3 months after operation (all P>0.05), but both were lower in the navigation group compared with the traditional group at the last follow-up (all P<0.05). The accuracies of placement of grade 0 and grade 0+1 screws were 92.0% (70/76) and 96.6% (73/76) in the navigation group, respectively, which were markedly higher than 88.7% (78/88) and 93.5% (82/88) in the traditional group (all P<0.05). The rates of adjacent facet joint invasion of A, B, and C degrees were 71.2% (54/76), 28.8% (22/76) and 0% (0/76) in the navigation group, respectively, while the invasion rates were 60.5% (53/88), 32.3% (28/88) and 7.3% (7/88) in the traditional group ( P<0.05). No screw loosening was noted in the navigation group, but the screw loosening rate was 9.1% (8/88) in the traditional group ( P<0.01). Conclusion:Compared with manual screw placement, O-arm combined with CT three-dimensional navigation system assisted screw placement for lower cervical fracture and dislocation has the advantages of shorter effective operation time, quicker screw placement, stronger screw holding force, better cervical stability, slighter postoperative pain, higher screw placement accuracy, and lower facet joint invasion and screw loosening rates.

Anatomical analysis of C 7 pedicle screw implantation based on three-dimensional CT reconstruction model / 中华创伤杂志

Objective:To analyze the ideal entry parameters and entry points for C 7 pedicle screws based on three-dimensional CT reconstruction model. Methods:A retrospective case series study was used to analyze the cervical spine CT image data of 50 adult volunteers collected from April 2021 to March 2022 at Taizhou People′s Hospital Affiliated to Nanjing Medical University, including 25 males and 25 females; aged 20-67 years [(43.8±13.5)years]. No significant structural abnormalities were seen in the cervicothorax of all volunteers. First, the 50 CT images were imported into the medical engineering software Mimics 17.0 to reconstruct the three-dimensional C 7 model, and the C 7 pedicle screw diameter (PSD), pedicle screw length (PSL), sagittal angle (SA) and lateral angle (LA) were measured. Then, the anatomical markers, namely the lateral notch and the midpoint of the inferior edge of the C 6 articular process, were used to measure the horizontal distance between the midpoint of the inferior edge of the C 6 articular process and the ideal entry point (line segment A), and the horizontal and vertical distances between the lateral notch and the ideal entry point (line segments B and C). Finally, the lateral notch and the midpoint of the inferior edge of the C 6 articular process were used as markers to observe the distribution of entry points. The values of the above measured parameters were recorded and compared with each other to analyze the differences between different sides and genders. Intra-group correlation coefficients (ICC) were also used to assess intra- and inter-observer agreement. Results:All 100 pedicles from 50 C 7 models were accessed, with the PSD being (6.5±0.7)mm, PSL being (31.8±4.5)mm, SA being (89.8±8.8)°, LA being (31.0±6.7)°, line segment A being 0.9(-0.4, 2.1) mm, line segment B being (5.8±1.7)mm, and line segment C being (3.6±1.5)mm. All ideal entry points were located medial above the lateral notch; moreover, with the midpoint of the inferior edge of the C 6 articular process as a reference, 71 (71%) of the entry points were located laterally and 29 (29%) were located medially. The 12 mm area around the midpoint of the inferior edge of the C 6 articular process was divided into 6 sections, with 47% of the entry points being located within 2 mm lateral to the midpoint, 25% within 2 mm medial to the midpoint, 19% within 2-4 mm lateral to the midpoint, and only 9% within 50% lateral to the midpoint. The measured parameters were not significantly different between the left and right sides (all P>0.05). The PSD, SA, and line segment B in males were (6.8±0.7)mm, (92.0±8.2)°, and (6.3±1.6)mm, which were significantly greater than those in females [(6.2±0.6)mm, (87.5±8.0)°, and (5.3±1.6)mm] (all P<0.01). The remaining parameters were similar between two genders (all P>0.05). All measured parameters had high intra- and inter-observer agreement (ICC: 0.84-0.91), except for line segment A that had moderate intra- and inter-observer agreement (ICC: 0.46-0.63). Conclusions:For C 7 pedicle screw implantation, when the surface of the lateral mass is used as the reference plane, SA is approximately 90°; with reference to the lateral notch, all the ideal entry points are located medially above it; with reference to the midpoint of the inferior edge of the C 6 articular process, approximately 70% of the entry points are located laterally. There are no significant differences in the parameters between the different sides of screw implantation on pedicles. The measured parameters show high intra- and inter-observer agreement, except for line segment A.

Efficacy comparison of robot-assisted and free-hand long segment screw fixation combined with wedge osteotomy in the treatment of type IV chronic symptomatic osteoporotic thoracolumbar fractures / 中华创伤杂志

Objective:To compare the clinical efficacies of robot-assisted and free-hand long segment screw fixation combined with wedge osteotomy in the treatment of type IV chronic symptomatic osteoporotic thoracolumbar fractures (CSOVCFs).Methods:A retrospective cohort study was conducted to analyze the clinical data of 72 patients with type IV CSOVCFs who were admitted to Honghui Hospital of Xi′an Jiaotong University from May 2019 to December 2021, including 22 males and 46 females; aged 61-82 years [(71.2±12.3)years]. Fracture segments were located at T 11-T 12 in 37 patients and at L 1-L 2 in 31. A total of 32 patients were treated with robot-assisted long segment screw fixation combined with wedge osteotomy (robot group) and 36 with free-hand long segment screw fixation combined with wedge osteotomy (free-hand group). The operation time, intraoperative bleeding volume, dosage of radiation exposure, intraoperative needle adjustment, time of single pedicle screw placement and accuracy of pedicle screw placement were compared between the two groups. The kyphotic Cobb angle, sagittal vertical axis (SVA), thoracic kyphosis (TK), lumbar kyphosis (LL), visual analogue scale (VAS) and Oswestry disability index (ODI) were measured preoperatively, at 3 days postoperatively and at the last follow-up. The incidences of facet joint violation, deviation in guide needle placement, cerebrospinal leak and proximal junctional kyphosis (PJK) were observed. Results:All patients were followed up for 12-26 months [(18.2±5.1)months]. The operation time and time of single pedicle screw placement showed no significant differences between the two groups (all P>0.05). The intraoperative bleeding volume was (502.5±58.3)ml in the robot group, less than that in the free-hand group [(690.2±45.9)ml]. The dosage of radiation exposure was (32.6±10.8)μSv in the robot group, lower than that in the free-hand group [(48.6±15.2)μSv]. The intraoperative needle adjustment was (2.1±0.3)times in the robot group, higher than that in the free-hand group [(20.7±5.8)times], and the accuracy of pedicle screw placement was 99.7% in the robot group, less than that in the free-hand group (91.8%) (all P<0.01). Compared with pre-operation, the kyphotic Cobb angle, SVA, TK and LL were significantly improved in both groups at postoperative 3 days and at the last follow-up (all P<0.05). Compared with postoperative 3 days, the kyphotic Cobb angle, SVA and TK were increased at the last follow-up within the two groups, but with no significant differences (all P>0.05). Compared with postoperative 3 days, the LL was decreased within the two groups at the last follow-up, but with no significant differences (all P>0.05). The VAS and ODI in the two groups were significantly lower at postoperative 3 days and at the last follow-up when compared with those before operation (all P<0.05), and both values were significantly lower at the last follow-up than those at postoperative 3 days (all P<0.05). There were no significant differences in the VAS or ODI at all time points between the two groups (all P>0.05). The incidence of facet joint violation in the robot group was 1.6%, markedly lower than that in the free-hand group (9.6%) ( P<0.01). The incidences of deviation in guide needle placement, cerebrospinal leak and PJK showed no differences between the two groups (all P>0.05). Conclusion:For type IV CSOVCFs, the robot-assisted long segment screw fixation combined with wedge osteotomy can better reduce intraoperative blood loss, decrease radiation exposure, improve accuracy of pedicle screw placement, and reduce facet joint violation when compared with free-hand long segment screw fixation combined with wedge osteotomy.

Efficacy of pedicle screws combined with vertebroplasty or intermediate screws for the treatment of osteoporotic thoracolumbar fracture: a Meta-analysis / 中华创伤杂志

Objective:To evaluate the efficacy between pedicle screws combined with vertebroplasty (PSV) and pedicle screws combined with intermediate screws (PSIS) for the treatment of osteoporotic thoracolumbar fracture (OTLF).Methods:PubMed, Cochrane Library, Web of Science, CNKI, VIP and Wanfang database were searched for all randomized controlled trial (RCT) or case-control trial (CCT) studies that comparing PSV and PSIS for the treatment of OTLF. Two reviewers independently screened the studies in the light of the inclusion and exclusion criteria, extracted data and evaluated the quality of the included studies. The Meta-analysis was performed using the RevMan 5.4 software. The subjects were divided into PSV group and PSIS group according to different treatment methods. Operation time, intraoperative blood loss, postoperative incision infection rate, postoperative short-, mid- and long-term visual analogue scale (VAS) score, postoperative short- and mid-term Oswestry disability index (ODI), hospitalization time, postoperative short-, mid- and long-term Cobb angle, postoperative short-, mid- and long-term anterior vertebral height ratio (VBH) and implant failure rate were compared between the two groups.Results:A total of 12 studies were enrolled for review, involving 870 subjects (433 in PSV group and 437 in PSIS group). The results showed insignificant difference between the two groups in operation time ( WMD=7.07, 95% CI -4.00, 18.13, P>0.05), intraoperative blood loss ( WMD=0.62, 95% CI -7.19, 8.43, P>0.05), postoperative incision infection rate ( OR=0.65, 95% CI 0.10, 4.08, P>0.05), postoperative short-term Cobb angle ( WMD=-0.19, 95% CI -0.43, 0.05, P>0.05) and postoperative short-term VBH ( WMD=0.91, 95% CI -1.30, 3.13, P>0.05). However, there was significant difference between the two groups in postoperative short-term VAS score ( WMD=-0.59, 95% CI -1.02, -0.15, P<0.05), mid-term VAS score ( WMD=-0.41, 95% CI -0.65, -0.16, P<0.05), long-term VAS score ( WMD=-0.51, 95% CI -0.59, -0.43, P<0.05), postoperative short-term ODI ( WMD=-6.26, 95% CI -9.65, -2.87, P<0.05), postoperative mid-term ODI ( WMD=-2.44, 95% CI -3.43, -1.45, P<0.05), hospitalization time ( WMD=-2.65, 95% CI -4.61, -0.68, P<0.05), postoperative mid-term Cobb angle ( WMD=-1.40, 95% CI -2.41, -0.39, P<0.05), postoperative long-term Cobb angle ( WMD=-1.06, 95% CI -1.59, -0.52, P<0.05), postoperative mid-term VBH ( WMD=3.06, 95% CI 1.31, 4.81, P<0.05), postoperative long-term VBH ( WMD=4.11, 95% CI 2.44, 5.77, P<0.05) and implant failure rate ( OR=2.06, 95% CI 0.11, 0.59, P<0.05). Conclusion:Compared with PSIS, PSV can not reduce the operation time, intraoperative blood loss and incision infection in the treatment of OTLF, but it can significantly relieve pain, improve function, decrease reduce hospitalization time, help to maintain Cobb angle and anterior vertebral height after operation, and reduce implant failure rate.

Research progress in screw-rod fixation system in the treatment of unstable sacral fracture / 中华创伤杂志

Unstable sacral fracture is usually caused by high-energy trauma. Unstable sacral fracture often results in damage to the mechano-conductive structures of the spine and pelvis and thereby affects walking dysfunction. Treatment of sacral fracture has been a challenge due to the complex local anatomy, unique biomechanics and poor bone quality of the sacrum. The screw-rod fixation system has always played an important role in the treatment of variant sacral fracture and more severe sacral fracture. With the introduction of new technology, the screw-rod fixation system has evolved into a variety of structural types. According to whether the fixation range extends to the spine, it can be divided into two categories including spine-pelvic stabilization techniques and pelvic stabilization techniques. The authors review the progress of the screw-rod fixation system in the treatment of sacral fracture from aspects of biomechanical properties and clinical efficacy, so as to provide a reference for the selection of clinical internal fixation.

Comparison of curative effect of forceful reduction percutaneous pedicle screw and ordinary percutaneous pedicle screw in the treatment of osteoporotic thoracolumbar burst fracture with kyphosis / 中华创伤杂志

Objective:To compare the efficacy of forceful reduction percutaneous pedicle screw and ordinary percutaneous pedicle screw in the treatment of osteoporotic thoracolumbar burst fracture with kyphosis.Methods:A retrospective cohort study was conducted to analyze the clinical data of 566 patients with osteoporotic thoracolumbar burst fracture with kyphosis admitted to Honghui Hospital, Xi ′an Jiaotong University from January 2015 to December 2018, including 191 males and 375 females, with age range of 48-79 years [(61.7±10.7)years]. Fracture segments were located at T 11 in 134 patients, T 12 in 154, L 1 in 160, and L 2 in 118. All fractures were type IIIA according to the acute symptomatic osteoporotic thoracolumbar fracture classification (ASOTLF). The thoracolumbar osteoporotic fracture severity score assessment system (TLOFSAS) score was ≥5 points. A total of 275 patients underwent forceful reduction and percutaneous pedicle screw internal fixation (forceful reduction screw group), and 291 patients underwent common percutaneous pedicle screw internal fixation (common screw group). The operation time, intraoperative blood loss, times of X-ray exposure on patients and measures documented before operation, at 3 days after operation and at 2 years after operation including anterior height ratio of the injured vertebrae, sagittal Cobb angle of the injured vertebrae, Japanese Orthopaedic Association (JOA) score and visual analog scale (VAS) were compared between the two groups. Moreover, degree of correction of Cobb angle at 3 days after operation, loss of correction of Cobb angle at 2 years after operation and postoperative complications were observed. Results:All patients were followed up for 25-34 months [(29.9±3.4)months]. The operation time, intraoperative blood loss and times of X-ray exposure on patients in forceful reduction screw group were (69.4±10.2)minutes, (60.3±13.1)ml and (26.8±3.7)times, less than (80.6±11.9)minutes, (80.7±15.4)ml and (30.4±3.4)times in common screw group (all P<0.01). There was no significant difference in anterior height ratio of the injured vertebrae between the two groups before operation and at 3 days after operation (all P>0.05). The anterior height ratio of the injured vertebrae in forceful reduction screw group was (95.5±2.3)% at 2 years after operation, significantly higher than (85.4±1.7)% in common screw group ( P<0.01). There was no significant difference in sagittal Cobb angle of the injured vertebrae between the two groups before operation ( P>0.05). The sagittal Cobb of the injured vertebrae in forceful reduction screw group at 3 days and 2 years after operation were (7.9±1.6)° and (8.8±1.5)°, lower than (10.6±1.1)° and (12.3±1.2)° in common screw group ( P<0.05 or 0.01). There were no significant difference in JOA score and VAS between the two groups before operation, at 3 days and at 2 years after operation (all P>0.05). The degree of correction of Cobb angle in forceful reduction screw group was (19.4±2.5)°, higher than (17.3±2.6)° in common screw group ( P<0.05). The loss of correction of Cobb angle in forceful reduction group was less than that in common screw group at 2 years after operation, but the difference was not statistically significant ( P>0.05). The incidence of postoperative complications in forceful reduction screw group was 12.4% (34/275), compared to 14.1% (41/291) in common screw group ( P>0.05). There were no complications such as iatrogenic nerve injury, fracture or loosening of internal fixator or leakage of bone cement in the spinal canal in both groups. Conclusions:For osteoporotic thoracolumbar burst fracture with kyphosis, forceful reduction and percutaneous pedicle screw internal fixation can significantly shorten operation time, reduce intraoperative blood loss and times of X-ray exposure on patients, restore height of the injured vertebrae, correct kyphosis and maintain reduction height of the injured vertebrae in contrast with conventional percutaneous pedicle screw internal fixation.

Effect of posterior short-segment fixation plus percutaneous kyphoplasty via the outer upper edge of the base of the fractured vertebral pedicle in the treatment of osteoporotic thoracolumbar burst fracture / 中华创伤杂志

Objective:To investigate the safety and efficacy of short-segment fixation covering the fractured vertebrae via posterior intermuscular approach plus percutaneous kyphoplasty (PKP) through the outer upper edge of the base of the fractured vertebral pedicle in the treatment of osteoporotic thoracolumbar burst fracture.Methods:A retrospective case series study was used to analyze the clinical data of 56 patients with osteoporotic thoracolumbar burst fracture admitted to Ningbo No.6 Hospital from January 2018 to February 2021, including 24 males and 32 females; aged 56-72 years [(63.5±4.6)years]. All patients underwent short-segment fixation covering the fractured vertebrae via posterior intermuscular approach combined with PKP through the outer upper edge of the base of the fractured vertebral pedicle. The operation time, intraoperative blood loss, hospitalization day and surgery-related complications were recorded. The visual analogue score (VAS) of back pain, ratios of the anterior, middle and posterior height of the fractured vertebrae and kyphotic Cobb angle were compared before operation, at postoperative 2 days and at the final follow-up.Results:All patients were followed up for 12-28 months [(14.5±2.2)months]. The operation time was 55-85 minutes [(62.0±12.1)minutes], intraoperative blood loss was 80-150 ml [(94.0±18.5)ml], and hospitalization day was 5-9 days [(7.4±1.1)days]. Based on CT examination at postoperative 2 days, there were 2 patients with paravertebral cement leakage, 2 with intervertebral space leakage and 1 with intracanal leakage, but none reported associated clinical symptoms. No implant failure or fractures of adjacent segments was detected during the follow-up period. The VAS was significantly decreased from preoperative (7.5±1.2)points to (3.2±0.8)points at postoperative 2 days ( P<0.01), and the score was further lowered to (2.2±0.8)points at the final follow-up when compared with that at postoperative 2 days ( P<0.01). The ratios of the anterior, middle and posterior height of the fractured vertebrae and kyphotic Cobb angle were significantly improved at postoperative 2 days [(89.5±13.2)%, (85.8±7.9)%, (89.5±9.0)% and (5.6±3.2)°] when compared with those before operation [(48.9±11.8)%, (61.9±11.9)%, (79.9±9.8)% and (26.3±5.6)°] (all P<0.01). Slight losses were observed in the ratios of the anterior, middle and posterior height of the fractured vertebrae and kyphotic Cobb angle at the final follow-up [(87.0±12.7)%, (82.1±7.8)%, (88.6±10.0)% and (5.4±3.2)°], but not significantly different from those at postoperative 2 days (all P>0.05). Conclusion:Short-segment fixation covering the fractured vertebrae via posterior intermuscular approach plus PKP through the outer upper edge of the base of the fractured vertebral pedicle can safely and effectively treat osteoporotic thoracolumbar burst fracture, for it can significantly improve back pain, restore the height of the fractured vertebrae and correct the kyphotic deformity.

Low-cost 3D modeling software for generating patient-specific drill guide templates for cervical pedicle screw insertion: An in vitro study

BACKGROUND@#Instrumented posterior cervical spine surgery (IPCSS) can be conducted using screws inserted through the pedicles of the vertebra. A safe IPCSS method uses 3D-printing to produce templates that will serve as drill guides for screw placement.@*OBJECTIVES@#This study describes the generation of 3D-printed drill guides using low-cost general purpose 3D modeling software and the comparison of screw insertion accuracy scores against the traditional landmark method and guides created using commercial grade software.@*METHODS@#Twenty-five (25) subaxial pedicles of five cadaveric spines were selected and scanned using computed tomography (CT). A digital reconstruction of the five cadaveric spines were created based on the CT DICOM data. A low-cost 3D modeling software, Rhinoceros 3D, was utilized for trajectory planning and generation of a patientspecific drill template using the digital reconstruction. The templates were then fabricated in ABS plastic using a fused deposition modeling (FDM) 3D printer. Insertion of cervical pedicle screws on the cadaveric spines was done by an orthopedic resident using the 3D printed guides. Postoperative CT scans were obtained, and placement accuracy of the screws were scored by two assessors utilizing a four-point rating system. Screws in correct placement were scored Grade 0 while misplaced screws with neurovascular damage were given a score of Grade 3.@*RESULTS@#Accuracy scores for the 3D-printed drill guides were 52% for assessor 1 and 44% for assessor 2. For assessor 1, screw placement in C3, C6, and C7 received the highest scores. For assessor 2, the highest scores were achieved in C3 and C7. The hybrid method of Bundoc et al. achieved scores of 94% while 3D printed guides utilizing commercial software like Materialise Mimics, Geomagic Freeform, or UG Imageware achieved scores of 80-100%. The traditional landmark method had scores ranging from 12% to 94% depending on the skill of the surgeon.@*CONCLUSION@#Commercial medical 3D image-based engineering software has high acquisition costs that might be beyond the reach of most institutions. A sub-$1000 general purpose 3D modeling software can be used to create drill templates. Several factors were identified in the design and fabrication of the template that can be addressed to increase accuracy. Trajectory planning can also be improved by automating the process. The researchers recommend further studies in these areas specially in the context of developing 3D printing as a support service for surgical operations in the Philippines.

Surgical safety of cervical pedicle screw placement with orthopaedic surgery robot system / 中华骨科杂志

Objective:To evaluate the accuracy and safety of cervical pedicle screw (CPS) placement under orthopaedic robot navigation system guidance.Methods:From March 2019 to February 2021, the data of 33 patients (19 males and 14 females, aged from 26 to 75 years, with an average age of 50.5 years) treated with pedicle screw fixation with the assistance of orthopaedic surgery robot through the posterior cervical spine were retrospectively analyzed. In clinical diagnosis, there was upper cervical fracture with instability in 14 patients (fracture nonunion in 2 patients), upper & subaxial cervical fracture in 1 patient, cervical spinal cord injury with spinal stenosis in 2 patients, cervical spinal stenosis in 9 patients, occipitocervical deformity in 2 patients, post-operative revision of cervical spondylosis in 2 patients, cervical intraspinal tumor in 3 patients. A total of 151 CPSs were inserted in C 1-C 7 using robot navigation system based on intraoperative three-dimensional C-arm fluoroscopy to assist in screw placement in posterior cervical surgery. Among them, 74 screws were implanted into upper cervical spine; 77 screws were implanted in the lower cervical spine. CT was used to obtain image data within 7 days after operation, and Neo classification was used to evaluate the accuracy of cervical pedicle screw placement. The patients were followed up for 2 weeks to observe the clinical symptoms and signs, and to determine whether there were surgical complications such as nerve and blood vessel injury and incision infection. Results:According to Neo classification, 91.4% (138/151) screws were completely contained in the pedicle without breaking through the pedicle cortex (grade 0). Among them, the accuracy of C 1 screws was 97.1% (34/35), C 2 screws was 92.3% (36/39), C 3 screws was 88.2% (15/17), C 4 screws was 71.4% (10/14), C 5 screws was 85.7% (12/14), C 6 screws was 93.3% (14/15), C 7 screws was 100.0% (17/17). The screw accuracy was highest in C 7, the lowest in C 4. The Kruskal-Wallis H test was performed on the accuracy of screw placement in different cervical level, and the results showed that there was no statistical difference (χ 2=1.31, P=0.971). However, a total of 13 screws were found to perforate the cortex of pedicle, although any neural or vascular complications associated with CPS placement were not encountered. Among them, 9 screws were found to perforate laterally, and 4 screws were found to perforate medially. No postoperative incision infection occurred in all cases. Conclusion:The safety of CPS placement can be effectively guaranteed with the assistance of the orthopaedic robot system.

Development and clinical application of a new transverse process retractor based on computer-aided design and 3D printing technology / 中国骨伤

OBJECTIVE@#To manufacture a new type of transverse process retractor by using computer-aided design(CAD) combined with 3D printing technology and investigate its clinical application effect.@*METHODS@#A new type of transverse protrusion retractor was developed by CAD combined with 3D printing technology. From September 2018 to September 2019, the new transverse process retractor was applied in clinic. Sixty patients with lumbar single segment lesions who needed treatment by pedicle screw fixation, bone grafting and interbody fusion were divided into new transverse process retractor group and control group, with 30 cases in each group. There were 14 males and 16 females in new type transverse process retractor group, the age was (68.0±4.3) years old on average; lesion segment of 8 cases were L3,4, 9 cases were L4,5, 13 cases were L5S1;5 cases of lumbar disc herniation, 20 cases of lumbar spinal stenosis, 5 cases of degenerative lumbar spondylolisthesis;new transverse process retractor was used to pedicle screw placement. While there were 15 males and 15 females in control group, with an average age of (69.2±4.5) years old;lesion segment of 8 cases were L3,4, 10 cases were L4,5, 12 cases were L5S1;5 cases of lumbar disc herniation, 21 cases of lumbar spinal stenosis, 4 cases of degenerative lumbar spondylolisthesis;the traditional lamina retractor was used for soft tissue pulling and finished pedicle screw placement by freehand. The length of surgical incision, the time required for inserting a single screw, fluoroscopy times, the times of adjusting the positioning needle or screw in insertion process, and the visual analogue scale (VAS) of surgical incision 72 hours after operation were compared between two groups.@*RESULTS@#Using CAD and 3D printing technology, a new type of transverse protrusion retractor was developed quickly. The length of surgical incision, the time required for inserting a single screw, fluoroscopy time, and the times of adjusting the positioning needle or screw in insertion process in new transverse process retractor group were less than those in control group(P<0.05). There was no significant difference in VAS of lumbar incision pain at 72 hours after operation between two groups(P>0.05).@*CONCLUSION@#Using CAD combined with 3D printing technology to develop a new transverse protrusion retractor has the advantages of convenient design, short development cycle and low cost. It provides a new idea for the research and development of new medical devices. The new transverse process retractor has the advantages of easy operation, reliable fixation, less damage to paravertebral muscle, convenient pedicle screw placement, reducing fluoroscopy time and so on.

Accuracy and safety of robot assisted pedicle screw placement / 中国骨伤

OBJECTIVE@#To investigate the accuracy and safety of pedicle screw placement assisted by orthopedic robot and C-arm fluoroscopy.@*METHODS@#The clinical data of 36 patients with spinal diseases underwent surgical treatment from January 2019 to August 2020 was retrospectively analyzed. Among them, 18 cases were implanted pedicle screws assisted by orthopaedic robot(observation group), including 12 males and 6 females, aged from 16 to 61 years with an average of (38.44±3.60) years;there were 1 case of adolescent scoliosis, 1 case of spinal tuberculosis, 7 cases of lumbar spondylolisthesis, 4 cases of thoracic fracture and 5 cases of lumbar fracture. Another 18 cases were implanted pedicle screws assisted by C-arm fluoroscopy(control group), including 10 males and 8 females, aged from 18 to 58 years with an average of (43.22±2.53) years;there were 1 case of adolescent scoliosis, 6 cases of lumbar spondylolisthesis, 6 cases of thoracic fracture and 5 cases of lumbar fracture. The intraoperative fluoroscopy times, nail placement time and postoperative complications were recorded in two groups. CT scan was performed after operation. The Gertzbein-Robbins standard was used to evaluate the accuracy of pedicle screw placement which was calculated.@*RESULTS@#The number of intraoperative fluoroscopy in observation group was(6.89±0.20) times, which was significantly higher than that in control group(14.00±0.18)times(P<0.05). The placement time of each screw in observation group was(2.56±0.12) min, which was significantly different from that in control group(4.22±0.17) min (P<0.05). One case of incision infection occurred in control group after operation, and recovered after active dressing change. During the follow-up period, no serious complications such as screw loosening and fracture occurred in two groups, and there was no significant difference in complications between two groups(P>0.05). A total of 107 screws were placed in observation group, including 101 screws in class A, 4 in class B, 2 in class C, 0 in class D and 0 in class E, the accuracy rate of pedicle screw placement=[(number of screws in class A+B) / the number of all screws placed in the group] ×100%=98.1%(105/107); and a total of 104 screws were placed in control group, including 90 screws in class A, 4 in class B, 5 in class C, 5 in class D and 0 in class E, the accuracy rate of pedicle screw implantation=[(number of screws in class A+B/the number of all screws placed in the group]×100%=90.3% (94/104); there was significant difference between two groups (P<0.05).@*CONCLUSION@#Orthopaedic robot assisted pedicle screw placement has the advantages of less fluoroscopy times, shorter screw placement time and higher accuracy, which can further improve the surgical safety and has a broad application prospect in the orthopaedic.

Morphometric description of thoracic vertebral pedicles in adult Malawian cadavers and implications for transpedicula spine fixation / Descripción morfometrica de los pedículos vertebrales torácicos en cadáveres de Malawi adultos e implicaciones para la fijación transpedicular de la columna

SUMMARY: Thoracic pedicles are important during the surgical repair of the thoracic spine deformities. Individuals show considerable differences in the asymmetric dimensions of the thoracic pedicles across populations. The purpose of this study was to determine the thoracic pedicle size and angle in adult Malawian cadavers and to suggest the clinical implications associated particularly the transpedicular fixation of spinal deformities. Adult thoracic vertebra from undetermined sex specimens (n=227) from the skeletal collection in the Anatomy Division, Biomedical Sciences Department, College of Medicine, University of Malawi were measured to assess the pedicle width, pedicle height, chord length, transverse diameter, interpedicular distance, transverse and sagittal pedicle angles. The mean pedicle width was 4.71 ± 1.83 mm (left side) and 4.82 ± 1.77 mm (right side) and the mean pedicle height was 12.63 ± 2.61 mm (left side) and 12.60 ± 2.54 mm (right side). The mean transverse pedicle angle was 12.22 ± 2.30 degrees (left side) and 12.46 ± 2.34 degrees (right side). The mean sagittal pedicle angle was 9.24 ± 2.67 degrees (left side) and 9.40 ± 2.76 degrees (right side). The mean interpedicular distance was 16.67 ± 2.23 mm. Our sample population generally showed smaller thoracic pedicle dimensions than those reported in other populations. Prior knowledge of the variations regarding the thoracic pedicle dimensions is vital for the determination of the pedicle screw size and design. Most importantly the information helps surgeons during preoperative planning of the transpedicular thoracic spine fixation and radiological interpretation.

RESUMEN: Los pedículos de las vértebras torácicas son importantes durante la reparación quirúrgica de las deformidades de la columna torácica. Los individuos muestran diferencias considerables en las dimensiones asimétricas de las vértebras torácicas entre poblaciones. El propósito de este estudio fue determinar el tamaño y el ángulo los pedículos de las vértebras torácicas en cadáveres de Malawi adultos y sugerir las implicaciones clínicas asociadas a la fijación transpedicular de las deformidades espinales. Se midieron 227 vértebras torácicas de muestras de individuos de sexo indeterminado de la colección esquelética en la División de Anatomía, Departamento de Ciencias Biomédicas, Facultad de Medicina, Universidad de Malawi para evaluar el ancho del pedículo, la altura del pedículo, la longitud, el diámetro transversal, distancia interpedicular y ángulos pediculares transversales y sagitales. El ancho medio del pedículo fue de 4,71 ± 1,83 mm (lado izquierdo) y 4,82 ± 1,77 mm (lado derecho) y la altura media del pedículo fue de 12,63 ± 2,61 mm (lado izquierdo) y 12,60 ± 2,54 mm (lado derecho). El ángulo pedicular transverso medio fue de 12,22 ± 2,3 grados (lado izquierdo) y 12,46 ± 2,34 grados (lado derecho). El ángulo pedicular sagital medio fue de 9,24 ± 2,67 grados (lado izquierdo) y 9,40 ± 2,76 grados (lado derecho). La distancia interpedicular media fue de 16,67 ± 2,23 mm. La población de esta muestra mostró dimensiones de los pedículos de las vértebras torácicas generalmente más pequeñas que las informadas en otras poblaciones. El conocimiento previo de las variaciones con respecto a las dimensiones de los pedículos de las vértebras torácicas es vital para la determinación del tamaño y diseño del tornillo pedicular. Lo más importante es que la información ayuda a los cirujanos durante la planificación preoperatoria para la fijación transpedicular de la columna torácica y su interpretación radiológica.

Direct pedicle screw insertion pullout strength / Resistência ao arrancamento do parafuso pedicular de inserção direta

ABSTRACT Objective: Study the in vitro pullout strength of SpineGuard/Zavation Dynamic Surgical Guidance Z-Direct Screw (DSG Screw), a screw pedicle designed to be inserted using a direct insertion technique. Methods: DSG Screws of 5.5 mm and 6.5 mm were introduced into polyurethane blocks with a density of 10 PCF (0,16 g/cm3). According to the experimental group, screws were inserted without pilot hole, with pilot without tapping, undertapping and line-to-line tapping. Screw pullout tests were performed using a universal test machine after screw insertion into polyurethane blocks. Results: Screws inserted directly into the polyurethane blocks without pilot hole and tapping showed a statistically higher pullout strength. Insertion of the screw without tapping or with undertapping increases the pullout screw strength compared to line-to-line tapping. Conclusion: DSG Screw showed the highest pullout strength after its insertion without pilot hole and tapping. Level of Evidence V, Expert Opinion.

RESUMO Objetivo: Estudar a resistência ao arrancamento in vitro do parafuso de inserção direta da SpineGuard/Zavation (parafuso DSG), um parafuso pedicular projetado para ser inserido usando a técnica de inserção direta. Métodos: Parafusos DSG de 5,5 mm e 6,5 mm foram introduzidos em blocos de poliuretano com densidade de 10 PCF (0,16 g/cm3). De acordo com o grupo experimental, os parafusos foram inseridos sem orifício piloto, com orifício e sem macheamento e macheamento diâmetro inferior com mesma geometria. Os testes de resistência dos parafusos foram realizados usando uma máquina de teste universal após a inserção dos parafusos nos blocos de poliuretano. Resultados: Os parafusos inseridos diretamente nos blocos de poliuretano sem orifício piloto e sem macheamento apresentaram uma resistência de arrancamento com significância estatística maior. A inserção do parafuso sem macheamento ou com macheamento com diâmetro inferior apresenta maior resistência ao arrancamento em comparação com o macheamento do mesmo diâmetro. Conclusão: O parafuso DSG apresentou a maior resistência ao arrancamento após sua inserção sem orifício piloto e sem macheamento. Nível de Evidência V, Opinião do Especialista.

Minimally invasive lumbar arthrodesis and percutaneous pedicle screws: a systematic review / Artrodese lombar minimamente invasiva e parafusos pediculares percutâneos: revisão sistemática / Artrodesis lumbar mínimamente invasiva y tornillos pediculares percutáneos: revisión sistemática

ABSTRACT A systematic review of the literature was performed in order to organize, evaluate, and select evidences available about the safety and efficacy of minimally invasive percutaneous arthrodesis with percutaneous pedicle screws in the treatment of patients with degenerative disc disease (and other spinal pathologies) as compared to conventional arthrodesis. PubMed, EMBASE and Cochrane Library databases were consulted to locate clinical trials and case reports/case series published in English between 2014 and 2019. After selection according to the inclusion/exclusion criteria, 21 of the 197 articles identified were chosen for a complete reading and used for the present review. Although the level of evidence of most of the studies included made the demonstration of efficacy and superiority among the surgical techniques reviewed difficult, the findings related to the minimally invasive procedure indicate a safe and reliable approach for the treatment of lumbar diseases. Level of evidence II; Systematic review of literature.

RESUMO A revisão sistemática da literatura foi realizada com o objetivo de organizar, avaliar e selecionar evidências a respeito da segurança e eficácia da artrodese percutânea minimamente invasiva com parafusos pediculares percutâneos no tratamento de pacientes com doença degenerativa de disco (e outras patologias da coluna), em comparação com a artrodese convencional. Foram consultadas as bases de dados PubMed, EMBASE e Biblioteca Cochrane para localizar ensaios clínicos e relatos/séries de casos publicados em inglês entre 2014 e 2019. Dentre 197 estudos identificados, depois de seleção usando critérios de inclusão/exclusão, 21 artigos foram escolhidos para leitura na íntegra e usados na presente revisão. Apesar do nível de evidência da maioria dos estudos incluídos dificultar a demonstração de eficácia e superioridade entre as técnicas cirúrgicas revisadas, os achados referentes ao procedimento minimamente invasivo apontam para uma abordagem segura e confiável para o tratamento de doenças lombares. Nível de evidência II; Revisão sistemática da literatura.

RESUMEN La revisión sistemática de la literatura fue realizada con el objetivo de organizar, evaluar y seleccionar evidencias al respecto de la seguridad y eficacia de la artrodesis percutánea mínimamente invasiva con tornillos pediculares en el tratamiento de pacientes con enfermedad degenerativa de disco (y otras patologías de la columna) en comparación con la artrodesis convencional. Fueron consultadas las bases de datos PubMed, EMBASE y Biblioteca Cochrane para localizar ensayos clínicos y relatos/series de casos publicados en inglés entre 2014 y 2019. Entre 197 estudios identificados, después de selección usando criterios de inclusión/exclusión, fueron escogidos 21 artículos para lectura integral y usados en la presente revisión. A pesar de que el nivel de evidencia de la mayoría de los estudios incluidos dificulte la demostración de eficacia y superioridad entre las técnicas quirúrgicas revisadas, los hallazgos referentes al procedimiento mínimamente invasivo apuntan hacia un abordaje seguro y confiable para el tratamiento de enfermedades lumbares. Nivel de evidencia II; Revisión sistemática de la literatura.

Pedicle Screws and Facet Violation - The importance of the Angle between the Facet and the Screw / Parafusos pediculares e violação facetária - A importância do ângulo entre a faceta e o parafuso

Abstract Objective To verify whether, regardless of the screw placement technique, there is a safe distance or angle in relation to the facets that can prevent violation of the facet joint when the screws are placed. Methods Retrospective, single, comparative, non-randomized center. We evaluated by axial computed tomography: the angle of the screw/rod in relation to the midline, the angle of the center of the facets in relation to the midline, the distance between the head of the screw/rod to the midline, and the distance from the center of the facets to the midline; the violation of the facet joint will be evaluated in a gradation of 0 to 2. Also will be measured the difference between the angle os the facets and the angle of the screws (Δ Angle) and, the difference between the facet distance and the screw distance (Δ Distance). Results A total of 212 patients and 397 facets were analyzed (196 on the left and 201 on the right). Of these, 303 were not violated (grade 0), corresponding to 76,32%, and 94 suffered some type of violation (grade 1 and 2), corresponding to 23,68%. The mean of Δ angle was 9.87° +/− 4.66° (grade 0), and of 3.77° +/− 4.93° in facets (grade 1 and 2) (p< 0.001), and the Δ mean distance in cases in which there was no violation was 0.94 arbitrary units (a.u.) +/− 0.39 a.u., while the Δ distance in G1 and G2 cases was 0.56 a.u. +/− 0.25 a.u. (p< 0.001). Conclusion The measurements of angle and distance between facet and screw can help in the placement of screws. These parameters can be used as safety measures with the most frequent use of surgical navigation techniques.

Resumo Objetivo Verificar se, independente da técnica de colocação do parafuso, há uma distância ou angulação segura em relação as facetas para que os parafusos sejam colocados de modo a evitar a violação da articulação facetária. Métodos Estudo retrospectivo, comparativo, não randomizado, em centro único. Foram avaliados em tomografia computadorizada axial: o ângulo do parafuso/barra em relação a linha média, o ângulo do centro das facetas em relação a linha média, a distância entre a cabeça do parafuso/barra até a linha média, e a distância do centro das facetas até a linha média; a violação da articulação facetária será avaliada em uma gradação de 0 a 2. Serão também calculados a diferença entre o ângulo do parafuso e ângulo da faceta (Δ Ångulo) e também a diferença entre a distância da faceta e a distância do parafuso (Δ Distância). Resultados Um total de 212 pacientes e 397 facetas foram analisados (196 do lado esquerdo e 201 do lado direito). Destes, 303 foram não violados (grau 0), correspondendo a 76,32%, e 94 sofreram algum tipo de violação (grau 1 e 2), correspondendo a 23,68%. A média do Δ ângulo foi de 9,87° +/− 4,66° (grau 0) e de 3,77° +/− 4,93° em facetas (grau 1 e 2) (p< 0.001), e o Δ distância médio nos casos em que não houve violação foi de 0,94 unidades aleatórias (u.a.) +/− 0,39 u.a., enquanto o Δ distância de casos G1 e G2 foi de 0,56 u.a. +/− 0,25 u.a. (p< 0.001). Conclusão As medidas de ângulo e distância entre faceta e parafuso, podem auxiliar na colocação de parafusos. Esses parâmetros podem ser utilizados como medidas de segurança com o uso mais frequentes das técnicas de navegação cirúrgica.

Pedicle morphology in scoliosis: classification agreement for pre-operative evaluation / Morfologia do pedículo na escoliose: concordância na classificação para avaliação pré-operatória / Morfología del pedículo en la escoliosis: concordancia de clasificación para evaluación prequirúrgica

ABSTRACT Objectives Although Watanabe morphological classification is well known, there is no consensus of its use among spine surgeons. We propose an analysis of the Watanabe classification by three observers, one senior and two recently graduated orthopedic spine surgeons, and its applicability in pre-operative evaluation. Methods An intraobserver and interobserver analysis of the classifications of 937 thoracic pedicles among 55 scoliosis patients treated surgically in two institutions. The average age at time of surgery was 16.3 years (10- 50 years). The etiologies of the scoliosis were: idiopathic (n= 47), congenital (n=4), syndromic (n= 3) and neuromuscular (n=1). The mean Cobb angle was 67 degrees (41- 120º). The evaluation of the thoracic pedicle was performed using pre-operative CT images. Results A total of 937 pedicles were classified by three observers with percentages of 47.5% type A, 28.6% type B, 17.1% type C and 6.9% type D for the total pedicles, convex and concave. Intraobserver agreement was fair to almost perfect (kappa 0.34 to 0.92) and interobserver agreement was fair to moderate (kappa 0.33 to 0.59) with statistical significance of p<0.001. Conclusion Watanabe classification remains a good method for predicting intraoperative difficulties, and has better agreement as the surgeon becomes more experienced. Level of evidence II; Prognostic Studies.

RESUMO Objetivo A classificação morfológica dos pedículos descrita por Watanabe, apesar de bem conhecida, não é consenso entre os cirurgiões de coluna. Propomos uma análise da classificação por três observadores, um sênior e dois cirurgiões de coluna recém-graduados, e sua aplicabilidade na avaliação pré-operatória. Métodos Foi realizada uma análise intraobservador e interobservador das classificações de Watanabe de 937 pedículos em 55 pacientes com escoliose, tratados cirurgicamente em duas instituições. A média de idade no momento da cirurgia foi de 16,3 anos (10 a 50 anos). As etiologias da escoliose foram: idiopática (n = 47), congênita (n = 4), sindrômica (n = 3) e neuromuscular (n = 1). O ângulo médio de Cobb foi de 67 graus (41º a 120º). A avaliação dos pedículos torácicos foi realizada com imagens pré-operatórias de tomografia computadorizada. Resultados Três observadores classificaram 937 pedículos côncavos e convexos, evidenciando 47,5% do tipo A; 28,6% do tipo B; 17,1% do tipo C e 6.9% do tipo D. A concordância intraobservador foi de razoável a quase perfeita (kappa 0,34 a 0,92) e concordância interobservador foi de razoável a moderada (kappa 0,33 a 0,59), com significância estatística de p < 0,001. Conclusões A classificação de Watanabe pode ser considerada um bom método para prever dificuldades intraoperatórias e apresenta melhor concordância à medida que o cirurgião se torna mais experiente. Nível de Evidência II; Estudos Prognósticos.

RESUMEN Objetivo La clasificación morfológica de los pedículos descrita por Watanabe, a pesar de ser bien conocida, no es consenso entre los cirujanos de columna. Proponemos un análisis de la clasificación por 3 observadores, un sénior y dos cirujanos de columna recién graduados, y su aplicabilidad en la evaluación prequirúrgica. Método Fue realizado un análisis intraobservador e interobservador de las clasificaciones de Watanabe de 937 pedículos en 55 pacientes con escoliosis, tratados quirúrgicamente en dos instituciones. El promedio de edad en el momento de la cirugía fue de 16,3 años (10-50 años). Las etiologías de la escoliosis fueron: idiopática (n=47), congénita (n=4), sindrómica (n=3) y neuromuscular (n=1). El ángulo promedio de Cobb fue de 67 grados (41º a 120º). La evaluación de los pedículos torácicos fue realizada con imágenes prequirúrgicas de tomografía computada. Resultados Tres observadores clasificaron 937 pedículos cóncavos y convexos, evidenciando 47,5% tipo A, 28,6% tipo B, 17,1% tipo C y 6,9% tipo D. La concordancia intraobservador fue de razonable a casi perfecta (kappa 0,34 a 0,92)y la concordancia interobservador fue de razonable a moderada (kappa 0,33 a 0,59) con una significancia estadística de p<0,001. Conclusiones La clasificación de Watanabe puede ser considerada un buen método para prever dificultades intraquirúrgicas y presenta mejor concordancia a medida que el cirujano se vuelve más experimentado. Nivel de Evidencia II; Estudios Pronósticos.