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.

The Influence of Thread Tap Mismatch on Pedicle Screw Pullout Strength / A influência da incompatibilidade do macho de rosca na resistência à extração do parafuso pedicular

Abstract Objective We aimed to study the "in vitro" pullout strength of SpineGuard/Zavation Dynamic Surgical Guidance Z-Direct Screw (DSG Screw, SpineGuard Inc, Boulder, Colorado, USA), a screw designed to be inserted using a direct insertion technique. Methods Dynamic Surgical Guidance Screws of 5.5 and 6.5 mm were introduced into polyurethane blocks with a density of 10 PCF (0,16g/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 with lineto-line tapping. Conclusion Dynamic Surgical Guidance Screw showed the highest pullout strength after its insertion without pilot hole and tapping.

Resumo Objetivo Nosso objetivo foi estudar a resistência à extração "in vitro" do parafuso SpineGuard/Zavation Dynamic Surgical Guidance Z-Direct (Parafuso DSG Guia Cirúrgico Dinâmico, SpineGuard Inc, Boulder, Colorado, USA), um parafuso projetado para ser inserido utilizando a técnica de inserção direta. Métodos Os parafusos DSG de 5,5 e 6,5 mm foram introduzidos em blocos de poliuretano com densidade de 10 PCF (0,16g/cm3). De acordo com o grupo experimental, os parafusos foram inseridos sem um orifício piloto, com um orifício piloto sem o macheamento, com macheamento e com macheamento linha a linha. Os testes de extração do parafuso foram realizados em uma máquina de teste universal, após a inserção do parafuso em blocos de poliuretano. Resultados Os parafusos inseridos diretamente nos blocos de poliuretano sem o orifício piloto e o macheamento mostraram uma resistência à extração estatisticamente maior. A inserção do parafuso sem o macheamento ou com o macho de menor diâmetro aumenta a resistência à extração do parafuso em comparação com o macheamento linha a linha. Conclusão O parafuso DSG apresentou a maior resistência à extração após a inserção sem o orifício piloto e o macheamento.

Efficacy observation of long-segment pedicle screw reduction and internal fixation combined with kyphoplasty in the treatment of stage Ⅲ reducible Kummell disease / 中华外科杂志

Objective: To investigate the clinical efficacy of long-segment pedicle screw reduction and internal fixation combined with kyphoplasty in the treatment of stage Ⅲ reducible Kummell disease. Methods: The clinical data of 32 patients with stage Ⅲ reducible Kummell disease treated at the Department of Orthopedics, Sir Run Run Shaw Hospital, Zhejiang University College of Medicine from January 2012 to March 2017 were analyzed retrospectively.There were 7 males and 25 females,aged (71.8±6.7)years(range:61 to 86 years).The injured segment was T10 in 1 patient,T11 in 8 patients,T12 in 13 patients,L1 in 7 patients,L2 in 2 patients and L3 in 1 patient.Preoperative American spinal injury association(ASIA) classification of patients all showed grade D.Bone mineral density (BMD),spinal X-ray,CT and MRI were examined before operation.All patients were treated with postural reduction, long-segment pedicle screw reduction and internal fixation combined with kyphoplasty.The operation time,intraoperative blood loss,length of stay and postoperative complications were recorded.The visual analogue scale (VAS) and Oswestry dysfunction index (ODI) as well as the BMD of hip were collected before and after operation.The Cobb angle of involved segment kyphosis and the height of anterior edge of diseased vertebrae were measured before operation,3 days and 12 months after operation.CT-related parameters were measured before and 3 days after operation,including sagittal anterior and posterior diameter of spinal canal,cross-sectional anterior and posterior diameter of spinal canal and cross-sectional spinal canal area.Paired sample t test and repeated measures were used to compare the data before and after operation. Results: All patients received the operation successfully.The operation time was (131.3±16.9) minutes (range:95 to 180 minutes),the blood loss was (82.5±27.1) ml (range:50 to 150 ml),and the length of stay was (8.3±2.4) days (range:5 to 14 days).All patients were followed up for more than 12 months.The VAS decreased gradually at 3 days,3 months,6 months and 12 months after operation,and the differences were statistically significant compared with the VAS before surgery (all P<0.01).ODI at 3,6 and 12 months after surgery was significantly improved compared with that before surgery(All P<0.01).The CT-related parameters at 3 days after operation were significantly higher than those before operation (All P<0.05).At 12 months after surgery,the Cobb angle decreased from (35.2±7.6) ° preoperatively to (4.3±1.7) ° (t=22.630,P<0.01),the height of anterior edge of diseased vertebrae increased from (4.3±1.0) mm preoperatively to (16.9±2.5) mm(t=-25.845,P<0.01),the bone mineral density of hip increased from -(2.2±0.6) preoperatively to -(2.8±0.6)(t=-0.040,P<0.01).Up to the last follow-up,2 patients had distal pedicle screw loosening, 1 patient had proximal junctional kyphosis,and there was no new vertebral fracture. Conclusions: Based on postural reduction,long-segment pedicle screw reduction and internal fixation combined with kyphoplasty is a safe and effective treatment method for stage Ⅲ reducible Kummell disease,which can reconstruct the stability of the diseased vertebrae.Postoperative standard anti-osteoporosis treatment is the basis to ensure the efficacy.

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.

Efficacy of percutaneous short segment fixation in the treatment of Magerl A3 thoracolumbar fractures with low bone mineral density:a retrospective study / 中国骨伤

OBJECTIVE@#To explore the clinical efficacy of percutaneous pedicle screw short segment internal fixation with or without the intermediate screw in the treatment of Magerl A3 thoracolumbar fractures with low bone mineral density.@*METHODS@#Patients with Magerl A3 thoracolumbar fracture underwent percutaneous pedicle screw short segment internal fixation from January 2017 to July 2020 were retrospectively analyzed, 93 cases met the diagnosis and inclusion criteria, 9 cases were excluded according to the exclusion criteria, and the remaining 84 cases obtained complete imaging follow-up data. There were 38 males and 46 females, the age ranged from 56 to 73 years old with an average of (64.78±7.12) years old, bone mineral density (BMD) ranged from 0.61 to 0.89 g/cm3 with an average of (0.73±0.14) g/cm3, the follow-up time was 11 to 25 months with an average of (17.58±6.12) months. There were 45 cases in group A with intermediate screw and 39 cases in group B without intermediate screw. The operation time and intraoperative blood loss were recorded, Oswestry Disability Index (ODI) and visual analogue scale (VAS) were used for clinical evaluation. The Cobb angle, vertebral wedge angle (VWA) and anterior vertebral body height (AVBH) were measured by X-ray after the operation. The corrected loss of the above parameters was calculated.@*RESULTS@#There were 5 cases of screw loosening in 84 patients (2 cases in group A and 3 cases in group B, P>0.05). There were significant differences in operation time and intraoperative blood loss between two groups(P<0.01). Clinical effects of two groups were good, postoperative VAS and ODI after operation obviously improved, there was no significant difference between two groups during all follow-up periods (3 days, 1 month after operation and the final follow-up) (P>0.05). Three days after the operation, the image evaluations (Cobb angle, VWA and AVBH) were significantly improved (P<0.05), but significant reduction loss was observed in both groups at 1 month after the operation and at the final follow-up (P<0.05). At the final follow-up, the loss of Cobb angle, VWA and AVBH in group A were (5.26±4.18) °, (4.63±3.80) ° and (9.54±8.71)%, respectively;group B was (6.01±4.34) °, (6.55±6.21) ° and (11.67± 9.95)%, respectively;however, there was no significant difference in reduction loss between the two groups(P>0.05).@*CONCLUSION@#Although the curative effect of the patients is satisfactory, the stability of the patients can not be improved by increasing the middle injured vertebra screw placement, the two groups of percutaneous short segment internal fixation can not resist the reduction loss of Magerl-A3 thoracolumbar fracture with low bone mineral density. Because the injured vertebra screw increases the operation time and intraoperative blood loss, it is not significant to use the intermediate screw for the elderly Magerl A3 thoracolumbar fractures with low bone mineral density.

Application of spinal surgical robots in minimally invasive surgery for thoracolumbar fracture / 中国骨伤

OBJECTIVE@#To evaluate the safety and accuracy of Renaissance robot navigation system in minimally invasive surgery for thoracolumbar fracture.@*METHODS@#The clinical data of patients with thoracolumbar fracture who underwent posterior minimally invasive pedicle screw internal fixation from July 2016 to July 2019 was retrospectively analyzed. And the patients were divided into robot group and artificial group. Robot navigation assisted screw placement was used in robot group, and traditional unarmed screw placement was used in artificial group. There were 20 patients in robot group, including 13 males and 7 females, aged from 23 to 69 years old with an average of(45.05±11.81)years old, one case was T11 fracture, 2 cases were T12, 10 cases were L1, 6 cases were L2 and 1 case was L3. There were 20 patients in artificial group, including 11 males and 9 females, aged from 26 to 65 years old with an average of(43.40±11.22)years old, 2 cases were T11 fractures, 7 cases were T12, 10 cases were L1, and 1 case was L3. The numbers of fluoroscopy, operation time and intraoperative blood loss were observed. The screw position was evaluated by Neo method.@*RESULTS@#A total of 126 screws were implanted in robot group and 124 screws were implanted in artificial group. The operation time, fluoroscopy times, intraoperative blood loss were(115.75±14.26) min, (7.95±0.89) times and (132.50±29.36) ml in robot group and (129.50±10.50) min, (14.40±2.56) times and(182.50±23.14) ml in artificial group, respectively, there was significant difference between the groups(P<0.05). According to Neo classification method, there were 122 screws at grade 0, 4 screws at grade 1 in robot group, and there were 108 screws at grade 0, 9 screws at grade 1 and 7 screws at grade 2 in artificial group. The accuracy of the robot group was better than that of artificial group(P<0.05).@*CONCLUSION@#Compared with free hand screw placement, Renaissance robot navigation system can effectively improve the accuracy of pedicle screw placement, reduce the number of fluoroscopy times and intraoperative blood loss, thereby improving the safety of operation.

Treatment of ankylosing spondylitis with thoracolumbar fractures by robot-assisted internal fixation in lateral decubitus position / 中国骨伤

OBJECTIVE@#To explore the effect of robot-assisted internal fixation in lateral decubitus position for the treatment of ankylosing spondylitis (AS) complicated with thoracolumbar fractures.@*METHODS@#The clinical data of 26 patients with ankylosing spondylitis complicated with thoracolumbar fractures treated from January 2018 to June 2020 was retrospectively analyzed. According to different surgical methods, these patients were divided into observation group and control group. There were 8 patients in observation group, which were treated with robot-assisted percutaneous screw fixation in lateral decubitus position, including 4 males and 4 females, aged form 55 to 85 years old with an mean of (66.25±9.42) years, the course of disease was (4.00±0.76) days on average, 2 cases were T11 fracture, 2 cases were T12, 3 cases were L1 and 1 case was L2. And there were 18 patients in control group, which were treated with conventional percutaneous screw fixation in prone position, including 6 males and 12 females, aged from 48 to 81 years old with a mean of (61.22±9.53) years, the course of disease was (4.11±0.83) days on average, 2 cases were T10 injury, 3 cases were T11, 4 cases were T12, 7 cases were L1, and 2 cases were L2. The intraoperative blood loss, operation time, position time and postoperative neurological complications were compared between two groups. Postoperative visual analogue scale (VAS) at 1d and 3 months, and Oswestry Disability Index (ODI) before and 3 months after operation were observed. According to Gertzbein-Robbins standard to evaluate the accuracy of pedicle screw placement.@*RESULTS@#There was no nerve injury due to pedicle screw placement in both groups. The intraoperative blood loss in observation group and control group was (34.13±4.61) ml and (78.17±22.02) ml, operation time was(92.13±9.82) min and (106.22±11.55) min, position time was(10.00±2.14) min and (15.17±2.66) min, the differences was statistically significant(P<0.05);VAS of the two groups were (2.38±0.52) points and (4.56±0.98) points one day after surgery, respectively, with statistically significant differences (P<0.05), while VAS and ODI three months after surgery showed no statistically significant differences (P>0.05). The screw accuracy was 96.88%(62/64) in observation group and 81.48%(88/108) in control group, the difference was statistically significant(P<0.05).@*CONCLUSION@#Robot-assisted internal fixation in lateral decubitus position for the treatment of ankylosing spondylitis complicated with thoracolumbar fractures can shorten the position time and operation time, significantly improve the accuracy of internal fixation screw placement, relieve the early postoperative pain, reduce intraoperative blood loss and postoperative complications, and facilitate the fast track rehabilitation of patients.

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.

A case-control study of minimally invasive transforaminal interbody fusion with the assistance of robot and traditional fluoroscopy in the treatment of single-space lumbar disc herniation / 中国骨伤

OBJECTIVE@#To compare the safety and nail placement accuracy of fluoroscopy-assisted and robot-assisted minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) in the treatment of single-space lumbar disc herniation.@*METHODS@#The clinical data of 52 patients with single-space lumbar disc herniation treated by MIS-TLIF from March 2019 to February 2020 were retrospectively analyzed. Among them, 24 patients were treated by robot-assisted MIS-TLIF(group A) and 28 patients were treated by fluoroscopy-assisted MIS-TLIF (group B). The intraoperative blood loss, operation time, intraoperative fluoroscopy times, preoperative and postoperative visual analogue scale(VAS), Japanese Orthopaedic Association(JOA) scores and operation-related complications were recorded in two groups. Gertzbein-Robbins grade according to CT scan was used to evaluate the nail placement after operation. Grade A and B were evaluated as satisfactory nail placement, and grade C, D, and E were evaluated as error placement. Babu's method was used to evaluate the screw's invasion to the superior articular process.@*RESULTS@#The operation time, intraoperative blood loss and intraoperative fluoroscopy times in group A were less than those in group B(P<0.05).VAS and JOA scores of all patients at the final follow-up were significantly improved compared with those before operation(P<0.05), but there was no statistically significant difference between the groups(P>0.05). There were 96 and 112 screws in group A and group B, respectively. Three days after operation, according to the Gertzbein-Robbins grade to evaluate the nail placement accuracy, there were 90 screws of grade A, 5 of grade B, 1 of grade C, no grade D and E in group A;there were 84 screws of grade A, 16 of grade B, 8 of grade C, 4 of grade D, no grade E in group B;the difference between two groups was statistically significant(Z=-3.709, P=0.000). The satisfactory rate of screw placement in group A was 98.96% (95/96), and that of group B was 89.29% (100/112), the difference between two groups was statistically significant (χ2=8.254, P=0.004). Three days after operation, the invasion of superior facet joints by pedicle screws was evaluated according to Babu's method, including 90 screws in grade 0, 4 in grade 1, 2 in grade 2, and 0 in grade 3 in group A;86 in grade 0, 12 in grade 1, 10 in grade 2 and 4 in grade 3 in group B, and the difference was statistically significant(Z=-3.433, P=0.001). There were no serious spinal cord, nerve and vascular injuries and other operation-related complications caused by screw implantation failure in both groups. All patients were followed up from 6 to 12(9.06±1.60) months. The neurological symptoms improved well after operation. During the follow-up period, there was no recurrence of symptoms, loosening or breakage of the internal fixation.@*CONCLUSION@#Compared with the traditional fluoroscopy-assisted MIS-TLIF, the spinal robot-assisted MIS-TLIF not only has more minimally invasive and safer, but also has higher accuracy in nail placement, lower incidence of upper articular process invasion, and more accurate decompression targets, which can be used for minimally invasive treatment of single-space lumbar disc herniation.

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.

Biomechanical study of different approach for lumbar interbody fusion surgeries under vibration load / 生物医学工程学杂志

The human spine injury and various lumbar spine diseases caused by vibration have attracted extensive attention at home and abroad. To explore the biomechanical characteristics of different approaches for lumbar interbody fusion surgery combined with an interspinous internal fixator, device for intervertebral assisted motion (DIAM), finite element models of anterior lumbar interbody fusion (ALIF), transforaminal lumbar interbody fusion (TLIF) and lateral lumbar interbody fusion (LLIF) are created by simulating clinical operation based on a three-dimensional finite element model of normal human whole lumbar spine. The fusion level is at L4-L5, and the DIAM is implanted between spinous process of L4 and L5. Transient dynamic analysis is conducted on the ALIF, TLIF and LLIF models, respectively, to compute and compare their stress responses to an axial cyclic load. The results show that compared with those in ALIF and TILF models, contact forces between endplate and cage are higher in LLIF model, where the von-Mises stress in endplate and DIAM is lower. This implies that the LLIF have a better biomechanical performance under vibration. After bony fusion between vertebrae, the endplate and DIAM stresses for all the three surgical models are decreased. It is expected that this study can provide references for selection of surgical approaches in the fusion surgery and vibration protection for the postsurgical lumbar spine.

Short-segment pedicle screw fixation combined with vertebroplasty for the treatment of Kümmell disease with kyphosis / 中国骨伤

OBJECTIVE@#To explore the clinical effects of posterior short-segment pedicle screw internal fixation combined with vertebroplasty for the treatment of Kümmell disease with kyphosis.@*METHODS@#Twenty-four patients with Kümmell disease complicated with kyphosis treated by posterior short-segment pedicle screw internal fixation combined with vertebroplasty from January 2016 to December 2018 were retrospectively analyzed, including 6 males and 18 females, aged 63 to 85 (73.1±6.5) years old. The clinical effect was evaluate by visual analogue scale (VAS), Oswestry Disability Index (ODI), the anterior height of injured vertebral body, and the sagittal Cobb angle of the affected segment beforeoperation, at 3 days and final follow up after operation. And the surgical complications were observed.@*RESULTS@#All 24 patients were followed up from 12 to 24 months with an average of (15.5±3.2) months. The VAS score was decreased from 5.21±1.06 preoperatively to 2.38±0.58 at 3 days postoperatively and 1.71±0.75 at final follow-up;ODI was decreased from (50.4±13.5)% preoperatively to (20.9±8.0)% at 3 days postoperatively and (16.7±9.6)% at final follow-up;the anterior height of injured vertebral body was restored from (8.0±4.2) mm before surgery to (18.1±5.0) mm at 3 days after surgery and (16.8±5.1) mm at final follow up;the sagittal Cobb angle of affected segment was decreased from (19.5±6.3)° preoperatively to (7.6±2.1)° at 3 days after surgery and(8.4±1.7)° at final follow-up. VAS, ODI, anterior height of injured vertebral body, and sagittal Cobb angle of affected segment were significantly improved at 3 days after operation and at final follow-up (@*CONCLUSION@#Posterior short-segment pedicle screw internal fixation combined with vertebroplasty for the treatment of Kümmell disease with kyphosis has relatively small surgical trauma, excellent clinical results, good vertebral height recovery, satisfactory correction of kyphotic angle, and fewer complications, etc. It is a safe and effective surgical method to treat Kümmell disease with kyphosis.

Imageology study of correlation loss and its related factors after short-segment pedicle screw reduction and fixation for lumbar fractures / 中国骨伤

OBJECTIVE@#To analyze the correction loss after posterior segmental fixation for lumbar spine fractures and explore the related image factors.@*METHODS@#Posterior short-segment fixation was received in 48 patients with L@*RESULTS@#The average follow-up was 12 to 18 (16.13±5.39) months. LKA, AVH and VWA at 1 week postoperative and those at the final follow up, were significantly improved compared with those preoperative (@*CONCLUSION@#The angle of adjacent intervertebral discs and anterior height of injured vertebrae were lost statistically after posterior short-segment pedicle screw treatment for lumbar fractures, and multivariate analysis showed that all of them were correlated with load-sharing score.

Channel-assisted fixation and interbody fusion in treating recurrent lumbar disc herniation by muscle-splitting approach / 中国骨伤

OBJECTIVE@#To explore the clinical value and safety of unilateral pedicle screw fixation combined with contralateral translaminar facet screw fixation and interbody fusion by muscle-splitting approach treatment of recurrent lumbar disc herniation.@*METHODS@#The clinical data of 51 patients with recurrent lumbar disc herniation treated from June 2012 to December 2017 were retrospectively analyzed. There were 32 males and 19 females, aged 34 to 64 years with an average of (51.11± 7.28) years. Lesions invoved L@*RESULTS@#There was no statistical difference in operation time between two groups (@*CONCLUSION@#Muscle-splitting approach is feasible for thetreatment of recurrent lumbar disc herniation with pedicle screw fixation combined with contralateral translaminar facet screw fixation and interbody fusion. Compared with the median incision approach, the muscle-splitting approach has the advantages of small incision, less trauma, less bleeding, rapid recovery. Also it can protect multifidus and do not increase the incidence of serious complications. Thus, it can be used as a choice for fixation and fusion of recurrent lumbar disc herniation.

Minimally invasive direct lateral approach debridement, interbody bone grafting, and interbody fusion combined with posterior percutaneous pedicle screw fixation for lumbar spinal tuberculosis / 中国骨伤

OBJECTIVE@#To investigate the clinical efficacy and superiority of direct lateral interbody fusion combined with posterior percutaneous screw fixation in the treatment of lumbar tuberculosis.@*METHODS@#From June 2013 to August 2016, the clinical data of 83 patients with lumbar tuberculosis were retrospectively analyzed, including 55 males and 28 females, aged from 27 to 72 (49.5±13.5) years. These 83 patients were divided into two groups according to different operation methods, 35 cases in group A were treated with direct lateral interbody fusion combined with posterior percutaneous screw fixation;48 cases in group B were treated with anterior traditional extraperitoneal debridement combined with posterior internal fixation. After operation, regular quadruple antituberculosis drugs were continued for 18 months. The operation time, intraoperative blood loss, hospital stay, bone graft fusion time and complications were compared between the two groups. Visual analogue score (VAS) of lumbar pain, Oswestry Disability Index (ODI), sagittal Cobb angle, erythrocyte sedimentation rate (ESR) and C-reactive protein(CRP) values before and after operation were analyzed.@*RESULTS@#The operation was successfully completed in both groups, and the operation mode was not changed during operation. The operation time, intraoperative blood loss and hospital stay were (149.4±13.3) min, (354.3±69.0) ml, (9.4±1.6) d in group A and(116.8±10.0) min, (721.9±172.3) ml, (11.8±1.7) d in group B, respectively, with significant difference between the two groups (@*CONCLUSION@#The two kinds of operation can obtain satisfactory clinical effect. Direct lateral interbody fusion combined with posterior percutaneous screw fixation can reduce intraoperative blood loss and hospital stay, which is conducive to early rehabilitation of patients.

Comparative study between 3D guide plate assisted and free-hand insertion of anterior cervical transpedicular screw / 中国骨伤

OBJECTIVE@#To compare accuracy of anterior cervical pedicle screws between assist of rapid prototyping 3D guide plate and free-hand insertion, and evaluate the safety of two methods.@*METHODS@#Eight adult cervical cadaver specimens after formaldehyde immersion, including 4 males and 4 females, aged 32 to 65(40.3±5.6) years old. After X-ray examination to exclude bone damage and deformity, 4 of them (3D guide plate group) randomly selected were for CT scan to obtain DICOM format data, and the data was imported into Mimics software for model, designed the ideal entry point and nail path for anterior cervicaltranspedicular screw (ATPS). After obtaining the personalized guide plate of the nail channel, it was exported as STL data, and the individual guide plate was printed by rapid prototyping and 3D printing technology. In turn, with the assistance of 3D guide plates, one-to-one personalized ATPS screws were placed on the four lower cervical cadaver specimens. Another 4 (free-hand group) lower cervical cadaver specimens were implanted with ATPS screws using free-hand technique. All specimens were performed CT thin-layer scanning and three-dimensional reconstruction after operation. The Tomasino method was used to evaluate the safety of the screws on the CT cross-sectional and sagittal images, to determine whether there was a cortical puncture of the lower and inner edges of the pedicle. According to the CT rating results, gradeⅠandⅡwere safe, and grade Ⅲ- Ⅴ were dangerous.And the accuracy of screws was recorded and analyzed between two groups.@*RESULTS@#Two screws were inserted in each segment from C@*CONCLUSION@#The 3D printing rapid prototyping guide plate assisted insertion of the anterior cervical pedicle screw can significantly improve the accuracy and safety, and provide a theoretical basis for further clinical application.

Cement augmented pedicle screw combined with vertebroplasty for the treatment of Kümmell's disease with type Ⅲ / 中国骨伤

OBJECTIVE@#To explore clinical effect of cement-augmented pedicle screw combined with vertebroplasty in treating Kümmell disease with type Ⅲ.@*METHODS@#From January 2015 to December 2018, 37 patients with type Ⅲ Kümmell disease were retrospectively analyzed, including 11 males and 26 females, aged from 61 to 84 years old with an average of (68.6±4.2) years old, and the courses of disease ranged from 2 to 10 months with an average of(6.5±2.3) months. Nine patients were grade C, 20 patients were grade D and 8 patients were grade E according to Frankle grading. All patients were treated by cement-augmented pedicle screw combined with vertebroplasty. Operation time, blood loss, postoperative drainage, hospital stay and complicationswere observed after oeprtaion. Visual analogue scale(VAS), Oswestry Disability Index(ODI), height of anterior vertebral body, Cobb angle before and after operation were compared.@*RESULTS@#All patients were followed up from 12 to 60 months with an average of (22.4±10.9) months. Operation time was (240.9±77.4) min, blood loss was (315.0±149.2) ml, postoperative drainage was (220.8±72.0) ml, hospital stay was (12.6±4.7) days. One patient occurred incision redness and 1 patient occurred infection after opertaion. No loosening of bone cement occurred. Postopertaive VAS and ODI were lower than that of before opertaion(@*CONCLUSION@#Cement-augmented pedicle screw combined with vertebroplasty is a safe and effective method for the tretament of Kümmell disease with type Ⅲ.

Enxerto pediculado de omento maior como adjuvante no tratamento de osteomielite de tíbia em cão - relato de caso / [Greater omentum pedicle flap as adjunctive treatment of tibial osteomyelitis in a dog - case report]

A osteomielite é um desafio terapêutico em ortopedia, capaz de retardar ou mesmo impedir a consolidação óssea. O omento, há anos, tem sido empregado como alternativa em diferentes procedimentos cirúrgicos, por sua capacidade, entre outras, de angiogênese, sendo aplicado na ortopedia veterinária quando há o risco de não união óssea. Neste caso, um cão Fila Brasileiro foi submetido à realização de enxerto com retalho pediculado de omento maior, após osteomielite resistente presente em osteossíntese de fratura múltipla de tíbia aberta grau II. Durante 16 dias, manteve-se a comunicação do retalho, mas, diante do risco de peritonite, o pedículo foi seccionado. Numa sequência de intervenções cirúrgicas, após 89 dias, houve cicatrização óssea e remissão da osteomielite, mesmo na presença de bactérias multirresistentes. Neste relato, o omento foi efetivo como terapia adjuvante no tratamento da osteomielite e garantiu o retorno da função do membro.(AU)

Osteomyelitis is a therapeutic challenge in orthopedics, capable of delaying or even preventing bone healing. The omentum has been used in different surgical procedures as an alternative for its capacity, among others, of angiogenesis, being applied in veterinary orthopedics, when there is a risk of non-union of bone. In this case, a Brazilian row dog was submitted to grafting with pedicle flap of greater omentum, after resistant osteomyelitis present in open fracture osteosynthesis of open tibia grade II. For 16 days the communication of the flap was maintained, but at the risk of peritonitis, the pedicle was sectioned. In a sequence of surgical interventions, after 89 days, there was bone healing and remission of osteomyelitis, even in the presence of multi-resistant bacteria. In this report, the omentum was effective as adjuvant therapy in the treatment of osteomyelitis and guaranteed the return of limb function.(AU)

The Role of Pedicle Screw Surface on Insertion Torque and Pullout Strength / Influência da superfície dos parafusos pediculares no torque de inserção e resistência ao arrancamento

Abstract Objective Compare by mechanical tests the pullout resistance and the insertion torque of rough and smooth pedicle screws. Methods Pedicle screws with rough surface and smooth surface, with diameters of 4.8; 5.5 and 6.5 mm, were inserted in polyurethane blocks with density of 10 PCF (0.16 g/cm3). Insertion torque and pullout strength were assessed. Results The pullout strength of the rough surface and smooth surface screws did not differ, except in the group of 4.8 mm diameter screws. In this group, the rough surface screws showed greater resistance to pullout. Conclusion Pedicle screws with a rough surface did not show increased pullout resistance in the acute phase of their insertion in polyurethane blocks compared to smooth surface screws. The rough surface screws had a higher insertion torque than the smooth surface screws, depending on the diameter of the screw and the preparation of the pilot hole.

Resumo Objetivo Comparar por testes mecânicos a resistência ao arrancamento e o torque de inserção do parafuso pedicularjateado e liso. Métodos Parafusos pediculares de superfície áspera e de superfície lisa com diâmetros de 4,8; 5,5 e 6,5 mm foram inseridos em blocos de poliuretano com densidade de 10 PCF (0,16 g/cm3). O torque de inserção e a força de arrancamento foram avaliados. Resultados A força de arrancamento dos parafusos de superfície áspera e de superfície lisa não diferiu, exceto no grupo de parafusos com 4,8 mm de diâmetro. Nesse grupo, os parafusos de superfície áspera apresentaram maior resistência ao arrancamento. Conclusão Os parafusos pediculares de superfície áspera não apresentaram aumento da resistência ao arrancamento na fase aguda de sua inserção em blocos de poliuretano em relação aos parafusos de superfície lisa. Os parafusos de superfície áspera apresentaram maior torque de inserção que os parafusos de superfície lisa, dependendo do diâmetro do parafuso e da preparação do furo piloto.

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.