Sagittal Alignment Concepts and Spinopelvic Parameters / Conceitos de alinhamento sagital e parâmetros espinopélvicos

Abstract Spinal surgery continues to expand its horizons to care for disabled patients presenting pain and deformities. Over the past decade, our knowledge of spinal alignment, from the skull to the pelvis, has increased considerably. Such knowledge must expand to reach general orthopedists and improve the care required for so many people. Global spinal alignment is a critical concept in understanding the impact of pathological conditions (degenerative diseases, traumas, deformities) and their treatment, including spinal instrumentation and arthrodesis. Therefore, the treatment of any spinal disease must include the knowledge of the complexity of the spinopelvic alignment. At first, all parameters seem like pure mathematics, hardly applicable to the everyday life of the inattentive reader. However, it gradually becomes clear that, like everything else in orthopedics, biomechanics is an essential part of the knowledge of the musculoskeletal system, revealing the logic behind the physiology of movements. The knowledge of the sagittal alignment concepts and spinopelvic parameteres provide a better comprehension of the axial and appendicular skeletons, increasing the understanding of the physiological and adaptive spinal processes in the face of the degenerative process that increases throughout life.

Resumo A cirurgia da coluna continua a expandir seus horizontes para cuidar dos pacientes incapacitados com dor e deformidades. Desde a última década, nosso conhecimento sobre o alinhamento espinal, do crânio à pelve, aumentou consideravelmente. Portanto, faz-se necessária a expansão de tal conhecimento para o ortopedista geral, para que possamos proporcionar melhores cuidados para essa população. O alinhamento espinal global é um conceito crítico no entendimento do impacto ocasionado pela condição patológica (doença degenerativa, trauma, deformidade) e mesmo do seu tratamento, como na instrumentação e artrodese da coluna. O tratamento de qualquer doença na coluna deve incluir o entendimento da complexidade do alinhamento espinopélvico. A princípio, todos os parâmetros parecem puramente matemáticos e pouco aplicáveis à realidade do leitor mais desatento. Mas, aos poucos, fica claro que, como tudo em ortopedia, a biomecânica faz parte essencial do conhecimento do sistema musculoesquelético, tornando mais claras as lógicas da fisiologia do movimento. O conhecimento dos conceitos de alinhamento sagital e dos parâmetros espinopélvicos proporcionam uma melhor compreensão dos esqueletos axial e apendicular, além de um melhor entendimento dos processos fisiológicos e adaptativos da coluna frente ao processo degenerativo crescente que ocorre ao longo da vida.

Blood Loss Control in Patients with Idiopathic Scoliosis Undergoing Spinal Fusion: Prospective Evaluation of a Cohort / Controle de sangramento em pacientes com escoliose idiopática submetidos a artrodese da coluna: Avaliação prospectiva de uma coorte de pacientes

Abstract Objective This study aimed to identify risk factors for increased perioperative bleeding in scoliosis surgery. Methods This is a prospective cohort study including 30 patients with idiopathic scoliosis undergoing posterior instrumentation using the pedicle screw system at a university hospital. Results Intraoperative blood losses totaled 798.6 ± 340 mL (24.8% of blood volume). Nine subjects presented massive blood loss. On average, hemoglobin dropped by 3.7g/dL, and each patient received 1.4 blood bags. Postoperative blood loss was 693.4±331.1 mL, and the total number of days using a drain was 2.7±0.7. Intraoperatively, the following variables showed significant correlations (p<0.05) with increased bleeding: age, time from diagnosis to treatment, preoperative Cobb angle, amount of curve correction, number of instrumented and fixated levels, total number of screws, and the number of transfused bags. Postoperatively, the following variables had significant correlations (p < 0.05): age, preoperative Cobb angle, length of hospital stay, number of blood bags transfused, and number of levels fixated with screws. Conclusion The variables most contributing to blood loss were age, preoperative Cobb angle, number of blood bags transfused, and number of levels fixated with a screw. Therefore, patients may benefit from surgical treatment while younger and

Resumo Objetivo O objetivo deste estudo é identificar os fatores de risco para o aumento de sangramento perioperatório em cirurgias para tratamento de escoliose. Métodos Estudo de coorte prospectivo incluindo 30 pacientes com escoliose idiopática submetidos à instrumentação posterior com o uso do sistema de parafusos pediculares em um hospital universitário. Resultados As perdas sanguíneas intraoperatórias totalizaram 798,6 ml ±340 ml (24,8% do volume sanguíneo). Houve perda maciça de sangue em 9 pacientes. Em média, a hemoglobina caiu 3,7 g/dl e foram transfundidas 1,4 bolsas de sangue por paciente. A perda sanguínea pós-operatória foi de 693,4 ml ± 331,1ml, e o total de dias utilizando dreno foi 2,7 ± 0,7. No intraoperatório, as seguintes variáveis apresentaram correlações significativas (p < 0,05) com o aumento do sangramento: idade, intervalo entre diagnóstico e tratamento, Cobb pré-operatório, quantidade de correção da curva, número de níveis instrumentados e fixados, número total de parafusos e o número de bolsas transfundidas. No pós-operatório, as seguintes variáveis apresentaram relação (p<0,05): idade, Cobb pré-operatório, tempo de internação, quantidade de bolsas de sangue transfundidas e o número de níveis fixados com parafuso. Conclusão As variáveis que mais contribuíram para a perda sanguínea foram idade, Cobb pré-operatório, quantidade de bolsas de sangue transfundidas e número de níveis fixados com parafuso. Portanto, os pacientes podem se beneficiar do tratamento cirúrgico

Posterior reduction for treatment of acute severe traumatic lumbar spondylolisthesis / 中华创伤骨科杂志

Objective:To evaluate the clinical effects of posterior reduction in the treatment of acute severe traumatic lumbar spondylolisthesis.Methods:A retrospective study was conducted to analyze the clinical data of 12 patients with acute severe traumatic lumbar spondylolisthesis who had been treated by posterior reduction at Department of Spinal Surgery, Zhengzhou Orthopaedic Hospital from June 2010 to December 2018. There were 7 males and 5 females with an age of (25.7±1.8) years. The spondylolisthesis was at L4 in 4 cases and at L5 in 8 cases, and grade Ⅲ in 7 cases, grade Ⅳ in 4 cases and grade Ⅴ in 1 case according to the Meyerding classification. By the American Spinal Injury Association (ASIA) grading, the preoperative neurological function was at level B in 6 cases, at level C in 4 cases, and at level D in 2 cases. All the 12 patients underwent posterior reduction and internal fixation with pedicle screws, as well as intervertebral bone graft fusion. Operation time and intraoperative blood loss were recorded. Clinical efficacy was evaluated by visual analogue scale (VAS) and Oswestry disability index (ODI) before and after surgery, and neurological function was evaluated by ASIA grading. X-ray, CT plain scan and reconstruction were used to observe internal fixation and bone grafting.Results:All patients were followed up for (18.5±2.1) months. The operation time was (165.7±42.3) min and the blood loss (497.7±75.3) mL. The VAS pain scores [(2.7±0.3) points and (1.8±0.2) points] and ODIs (18.2%±2.3% and 14.5%±2.6%) at 2 weeks after operation and at the last follow-up were significantly lower than the preoperational values [(8.5±0.6) points and 72.3%±12.3%] ( P<0.05), but there was no statistically significant difference between 2 weeks after operation and the last follow-up ( P>0.05). At the last follow-up, X-rays and CT scans showed good fixation and adequate bone grafting; the spondylolisthesis was grade 0 in 10 cases and grade I in 2 cases; the ASIA level of neurological function was C in 2 cases, D in 3 cases, and E in 7 cases. Healing of surgical incision was delayed in 2 patients but responded to symptomatic treatment. Follow-ups observed no such complications as loosening or pulling out of internal fixation. Conclusion:In the treatment of acute severe traumatic lumbar spondylolisthesis, posterior reduction can effectively restore the spondylolisthesis sequence and restore spinal stability, leading to satisfactory curative outcomes.

Risk factors for adjacent vertebral compression fracture after fusion surgery of lumbar canal stenosis in the elderly / 中华创伤杂志

Objective:To evaluate the risk factors for adjacent vertebral compression fracture (AVCF) after fusion surgery of lumbar canal stenosis in the elderly.Methods:A retrospective cohort study was designed for 297 patients with lumbar canal stenosis who underwent fusion surgery in Hubei Provincial Hospital of Integrated Chinese and Western Medicine from January 2017 to December 2020. There were 42 males and 255 females, aged 68-85 years [(76.3±7.2)years]. The patients were divided into AVCF group ( n=67) and non-AVCF group ( n=230) according to with or without the occurrence of AVCF. The indicators recorded were the gender, age, body mass index, education level, number of combined basic diseases, course of the disease, preoperative bone mineral density, intraoperative bleeding volume, number of level fused during operation, postoperative blood transfusion volume, postoperative observation in the ICU, types of postoperative external fixation and time of external fixation. Univariate analysis was conducted to analyze the correlation between above risk factors and AVCF after fusion surgery of lumbar canal stenosis in the elderly. Multivariate Logistic regression analysis was used to determine the independent risk factors for the occurrence of AVCF in these patients. Results:In the univariate analysis, age, education level, preoperative bone mineral density, intraoperative bleeding volume, postoperative blood transfusion volume and postoperative observation in the ICU were correlated with AVCF after fusion surgery of lumbar canal stenosis in the elderly ( P<0.05 or 0.01), while there was no correlation of AVCF with gender, body mass index, number of combined basic diseases, course of the disease, number of level fused during operation, types of postoperative external fixation and time of external fixation (all P>0.05). Multivariate Logistic regression analysis showed that gender ( OR=4.02, 95% CI 1.35, 12.00, P<0.05), preoperative bone mineral density≤-2.5 SD ( OR=2.01, 95% CI 1.47, 2.75, P<0.01), intraoperative bleeding volume≥475 ml ( OR=1.01, 95% CI 1.00, 1.01, P<0.01) and postoperative blood transfusion volume≥434 ml ( OR=0.99, 95% CI 0.98, 1.00, P<0.01) were significantly associated with AVCF after fusion surgery of lumbar canal stenosis in the elderly. Conclusion:The female, bone mineral density≤-2.5 SD, intraoperative bleeding volume≥476 ml and postoperative blood transfusion volume≥434 ml are independent risk factors for AVCF after fusion surgery of lumbar canal stenosis in the elderly.

Clinical efficacy analysis of DELTA endoscopic lumbar interbody fusion for the treatment of lumbar spondylolisthesis / 中国医师杂志

Objective:To explore the clinical efficacy of DELTA endoscopic lumbar interbody fusion for the treatment of mild to moderate, single segment lumbar spondylolisthesis.Methods:A retrospective analysis was conducted on the clinical data of 48 surgical cases of grade Ⅰ to Ⅱ lumbar spondylolisthesis admitted to the First Affiliated Hospital of Hunan University of Traditional Chinese Medicine from February 2020 to March 2022. Among them, 24 cases treated with DELTA endoscopic lumbar interbody fusion surgery were classified as the DELTA group, and 24 cases treated with traditional minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) surgery were classified as the MIS-TLIF group. Two groups of patients were compared in terms of perioperative indicators (surgical time, postoperative drainage volume, incision length, hospital stay), clinical efficacy [Visual Analogue Scale (VAS) score for low back and leg pain, lumbar Japanese Orthopaedic Association Scores (JOA), improved MacNab standard excellence rate], and lumbar fusion rate (Bridwell intervertebral fusion grade).Results:The DELTA group had longer surgical time than the MIS-TLIF group, and the postoperative drainage volume, incision length, and hospital stay were all lower than the MIS-TLIF group, with statistically significant differences (all P<0.05). The VAS score of lower back and leg pain and lumbar JOA score of the two groups of patients at 1 week, 3 months, and the last follow-up were significantly improved compared to those before surgery (all P<0.01), and the DELTA group had better VAS score of lower back and leg pain and lumbar JOA score at all time points after surgery than the MIS-TLIF group, with statistically significant differences (all P<0.05). The improved MacNab standard was used to evaluate the efficacy of the two groups of patients at the last follow-up after surgery, and there was no statistically significant difference in the excellent and good rates ( P>0.05); There was no statistically significant difference ( P>0.05) in the fusion rate between the two groups. Conclusions:DELTA endoscopic lumbar interbody fusion has a significant therapeutic effect on lumbar spondylolisthesis, with the advantages of small surgical incision and fast recovery; After crossing the DELTA endoscopic learning curve and optimizing surgical procedures, this technology can become an alternative to MIS-TLIF technology.

The effect of reduction and in situ fusion on postoperative imaging parameters of degenerative lumbar spondylolisthesis / 中华骨科杂志

Objective:To compare the efficacy of reduction and in situ intervertebral fusion fixation in the treatment of degenerative lumbar spondylolisthesis.Methods:A total of 182 patients (92 males and 90 females) with L 4 degenerative lumbar spondylolisthesis of Meyerding's classification of grade I and grade II, aged (62.6±6.8) years (range, 57-73 years), who underwent posterior L 4, 5 internal fixation and interbody fusion in the Department of Spinal Surgery, the Second Hospital of Shanxi Medical University, were retrospectively analyzed from January 2019 to December 2022. There were 105 cases of I-degree spondylolisthesis and 77 cases of II-degree spondylolisthesis. According to the operation method, the patients were divided into reduction intervertebral fusion fixation (reduction group) and in situ intervertebral fusion fixation group (in situ group). Imaging parameters such as lumber lordosis (LL), pelvic incidence (PI)-LL, L 3, 4 intervertebral space heights, fusion segment angle, and sagittal vertical axis (SVA) were measured on the pre- and post-surgical lumbar spine lateral radiographs. The visual analogue scale (VAS) and Oswestry Disability Index (ODI) of low back pain were recorded before and after surgery. The differences in clinical and imaging parameters were compared between reduction and in situ fusion group. Results:All 182 patients successfully completed the surgery and were followed up for 12.0±2.4 months (range, 9-15 months). The LL of the reduction group before surgery, immediately after surgery, and at the last follow-up were 46.9°±7.1°, 57.2°±5.9°, 55.6°±5.5°, respectively, with statistically significant differences ( F=87.61, P<0.001), with immediate and final follow-up being smaller than those in the in situ fixation group. The LL of the in situ fixation group before surgery, immediately after surgery, and at the last follow-up were 47.8°±7.2°, 50.5°±7.0°, and 48.7°± 6.4°, respectively, with no statistically significant difference ( F=2.83, P=0.062). The immediate and final follow-up of LL in the reduction group was lower than those in the in situ fixation group ( P<0.05). The fusion segment angles of the reduction group before surgery, immediately after surgery, and at the last follow-up were 14.2°±5.1°, 23.2°±4.7°, 23.2°±4.7°, respectively, with statistically significant differences ( F=152.87, P<0.001), with immediate and final follow-up after surgery being greater than before surgery. The fusion segment angles of the in situ fixation group before surgery, immediately after surgery, and at the last follow-up were 15.4°±5.9°, 18.2°±5.5°, and 17.4°±5.1°, respectively, with statistically significant differences ( F=4.69, P=0.009), with immediate and final follow-up being greater than before surgery. The fusion segment angulation in the reduction group was greater than that in the in situ fixation group at both the immediate and final follow-up ( P<0.05). The SVA of the reduction group before surgery, immediately after surgery, and at the last follow-up were 16.9±18.2 mm, 9.5±12.0 mm, and 8.7±11.3 mm, respectively, with statistically significant differences ( F=11.32, P<0.001), with immediate and final follow-up being smaller than before surgery. The SVA of immediately after surgery and at the last follow-up were both smaller than before surgery. The SVA of the in situ fixation group before surgery, immediately after surgery, and at the last follow-up were 16.4±17.2 mm, 14.3±15.5 mm, and 13.8±15.0 mm, respectively, with no statistically significant difference ( F=0.57, P=0.576). The SVA of the reduction group at immediate and final follow-up was lower than that of the in situ fixation group ( P<0.05). Conclusion:Both reduction and in situ intervertebral fusion fixation can effectively relieve the clinical symptoms of patients. Fusion fixation after reduction can improve the angulation of fusion segments to form segmental kyphosis, which is more conducive to improving SVA.

Lateral lumbar interbody fusion for severe lumbar spinal stenosis: a randomized controlled trial with 1-year follow-up / 中华骨科杂志

Objective:To investigate the clinical outcomes of minimally invasive lateral lumbar interbody fusion (LLIF) and the necessity to perform LLIF plus posterior direct decompression in the treatment of severe degenerative lumbar spinal stenosis (DLSS).Methods:In this prospective randomized, controlled trial, we assigned 71 patients, who were 50 to 80 years old, and diagnosed with severe DLSS (Schizas Classification grade C on magnetic resonance imaging), in a 1∶1 ratio to undergo either one-stage LLIF plus posterior internal fixation (treatment group) or CLIF plus posterior internal fixation with laminectomy (control group). Demographic and perioperative data were collected and compared. The clinical outcome measures included Oswestry Disability Index (ODI), Zurich Claudication Questionnaire (ZCQ) score as well as visual analogue scale (VAS). Patients were followed up for at least 1 year.Results:The treatment group included 36 patients with 46 surgical levels, while the control group included 35 patients with 46 surgical levels. The baseline demographic data of the 2 groups were equivalent in preoperative central canal areas, spinal canal anteroposterior diameter, disc height, ODI, ZCQ score for symptom severity and physical function, as well as VAS scores for back and leg pain. The mean operative time, blood loss, drainage volume and hospital stay of the treatment group are significantly less than the control group (157.2±29.1 min vs. 180.6±26.8 min, 75.6±39.1 ml vs. 108.6±43.3 ml, 136.9±73.9 ml vs. 220.5±121.3 ml, 5.3±1.1 d vs. 6.6±2.3 d). There were 2 cases with dura tear and 1 case with wound infection in control group. Thus, the surgical trauma and complications of the control group were more than the treatment group. At 1-year follow-up, the mean ODI score of treatment group improved from 42.24%±10.70% preoperatively to 18.21%±11.49%, the mean ZCQ symptom severity from 2.89±0.38 to 1.61±0.41, the mean ZCQ physical function from 2.31±0.45 to 1.50±0.37, the mean VAS for back from 5.56±1.19 to 1.97±1.13 and the mean VAS for leg from 4.44±1.81 to 0.94±1.26. At 1-year follow-up, the mean ODI score of the control group improved from 43.65%±14.93% preoperatively to 17.36%±12.15%, the mean ZCQ symptom severity from 2.92±0.52 to 1.65±0.39, the mean ZCQ physical function from 2.37±0.52 to 1.55±0.39, the mean VAS for back from 5.63±1.40 to 2.34±1.47, and the mean VAS for leg from 4.37±2.14 to 0.83±1.20. The ZCQ satisfactory score of both groups were not significant different (1.25±0.45 vs. 1.26±0.43, t=0.07, P=0.944). The mean improvement rate of both groups for ODI, ZCQ symptom severity, ZCQ physical function, VAS back and VAS leg at 1-year follow-up were not significant different (55.43%±27.74% vs. 58.36%±25.06%, 43.07%±17.22% vs. 42.66%±12.95%, 32.25%±23.65% vs. 31.71%±23.24%, 62.65%±21.25% vs. 58.37%±22.44%, 78.94%±26.41% vs. 85.45%±20.53%). One adjacent segment disease was found in each group at 1 year follow-up. Conclusion:CLIF+ posterior internal fixation in the treatment of Schizas Grade C DLSS has satisfactory clinical outcome at 1-year follow-up. Laminectomy increases surgical trauma, but does not significantly improve the clinical outcome at 1-year follow-up.

Oblique lumbar interbody fusion combined with percutaneous endoscopic decompression and posterior fixation for the treatment of lumbar spondylolisthesis accompanied with lumbar spinal stenosis / 中华骨科杂志

Objective:To investigate the efficacy of oblique lumbar interbody fusion (OLIF) combined with percutaneous transforaminal endoscopic decompression (PTED) and posterior pedicle fixation through Wiltse approach in the treatment of lumbar spondylolisthesis accompanied with lumbar spinal stenosis.Methods:From June 2017 to February 2022, 103 patients (50 males and 53 females) of lumbar spondylolisthesis accompanied with lumbar spinal stenosis were performed with OLIF combined with PTED and posterior pedicle fixation. The mean age was 64.1±5.2 years (range, 42-87 years). All involved cases were single-segment and included 83 cases of L 4, 5, 17 cases of L 3, 4, and 3 cases of L 2, 3. Among them, 94 cases were performed for the first time, and other 9 were revision surgery treated by posterior lumbar laminectomy previously. The visual analog scale (VAS) was used to evaluate the low back pain and leg pain, and the Oswestry disability index (ODI) was used to evaluate the lumbar function. The VAS and ODI scores were recorded respectively before the operation, at discharge, 1, 3, 6 months after the operation and at the last follow-up. Macnab criteria was used to evaluate the clinical efficacy at the last follow-up. At the same time, imaging measurements were conducted, including the anterior and posterior disc height, segmental lordotic angle, percentage of slip on lateral X-ray film and the vertebral canal area on axial MRI before and after surgery. Results:All of 103 patients were successfully operated in one stage with an average operation time of 177.7±21.5 min (range, 155-220 min), and an average intraoperative blood loss of 55.9±18.3 ml (range, 30-150 ml). The mean follow-up time were 15.1±2.6 months (range, 6-36 months). There were significant differences in both VAS scores of back and leg and ODI scores at each postoperative time point when compared with preoperative ( F=508.25, F=1524.82, F=1148.68, P<0.001). Macnab criteria of the last follow-up was evaluated as follow: excellent in 85 cases, good in 14, fair in 4, and the excellent and good rate was 96.1%. The radiographic results showed the mean immediate postoperative anterior disc height, posterior disc height, segmental lordotic angle, percentage of slip and axial area of the vertebral canal were 15.23±2.97 mm, 9.32±2.31 mm, 14.36°±4.18°, 3.89%±3.11%, 113.37±47.27 mm 2, and thus all of those increased significantly compared to the mean preoperative 11.93±3.17 mm, 7.21±2.03 mm, 6.15°±3.99°, 23.66%±7.79%, 57.63±28.91 mm 2, respectively ( t=7.84, t=7.07, t=14.91, t=27.62, t=9.68, P<0.001). All cases achieved bony fusion during 6-12 months after operation. The incidence of surgery-related complications was 10.7% (11/103). There were 3 cases of end plate fracture and 2 cases of dural injury, which had no complaint after operation. There was 1 case of pedicle screw entering into the spinal canal by mistake, and the symptoms of nerve damage appeared after operation. After 1 year it basically returned to normal. There were 2 cases of thigh numbness and 1 case of psoas major weakness after operation, all of which relieved after 4 weeks. There was 1 case continuous pain of abdominal incision after surgery. There was 1 case of cage subsidence at the last follow-up. Conclusion:OLIF combined with PTED and posterior pedicle fixation through Wiltse approach is a minimally invasive surgical method for the treatment of lumbar spondylolisthesis accompanied with lumbar spinal stenosis. With the combined minimally invasive techniques, the decompression, fusion and fixation of the lumbar spine can be fulfilled perfectly. It has the advantages of minimally invasive, good clical outcome, few complications and rapid rehabilitation.

Diagnosis and treatment of atlantoaxial dislocation / 中华骨科杂志

Atlantoaxial dislocation is a pathological anatomical condition caused by the loss of stability between the atlantoaxial joints, which is a serious disabling disease in spine surgery, and may even endanger the patient's life. The causes of atlantoaxial dislocation include traumatic, congenital, inflammatory, degenerative, tumor, and other factors. Since the symptoms and signs are not specific in clinic, imaging examination is particularly important. Atlantoaxial dislocation is mainly classified according to the etiology, the relative position of atlas and axis, and the difficulty of reduction. Accurate classification is of great significance for the selection of treatment options. There is no popular guideline for surgical indications of atlantoaxial dislocation. Patients presenting with related symptoms or spinal cord dysfunction are generally recognized surgical indications in clinical practice. With the continuous improvement and optimization of atlantoaxial screw placement, reduction and fusion technology, supplemented by new equipment in spine surgery, the surgery-related risks and complications have been greatly reduced, and the surgical treatment of atlantoaxial dislocation can obtain good reduction and fusion results. This tutorial summariz the etiology, diagnosis, classification, treatment, complications, and prognosis of atlantoaxial dislocation, in order to provide a more complete and refined reference for clinical diagnosis and treatment.

Postoperative bracing on clinical outcomes following posterior lumbar fusion for degenerative lumbar diseases: a meta-analysis / 中华骨科杂志

Objective:To systematically evaluate whether the early use of bracing after posterior lumbar fusion has advantages in terms of the improvement of clinical outcomes such as pain, functional disability, fusion rate, and complication rate in patients with lumbar degenerative diseases.Methods:All randomized controlled trials of bracing performed after posterior lumbar fusion in patients with lumbar degenerative diseases were searched in Pubmed, Web of Science, Embase, China national knowledge infrastructure (CNKI) and Wanfang database from January 1990 to May 2022. The data extracted were authors, year of publication, nationality, subject characteristics, sample size, surgical protocol, type and time of bracing, follow-up duration, preoperative and postoperative Oswestry disability index (ODI) and visual analogue scale (VAS), postoperative fusion rate and complication rate. The Cochrane Risk of Bias tool was used to evaluate the risk of bias. The use of fix- or random-effect models was depended on the magnitude of heterogeneity. Data analysis was performed using Stata 17.0 statistical software for meta analysis.Results:A total of five randomized controlled trials were included, all in English, with a total of 362 patients (male 144, female 218). The results of meta-analysis showed that there was no statistically significant difference in the improvement of ODI scores [ MD=1.25, 95% CI(-2.39, 4.88), P=0.501]and VAS scores[ MD=0.21, 95% CI(-0.22, 0.63), P=0.340]between the brace group and the control group after operation. In terms of fusion rate, there was no significant difference between the brace group and the control group[ OR=0.59, 95% CI(0.25, 1.38), P=0.224]. In addition, there was also no significant difference in the incidence of postoperative complications between two groups[ OR=1.12, 95% CI(0.58, 2.15), P=0.735]. Conclusion:The early use of bracing after lumbar fusion has no significant advantages in improving symptoms and functional recovery, fusion rate and surgical complications. The necessity of postoperative bracing after posterior lumbar fusion requires further high-quality research to prove.

The clinical characteristics and treatment of "sandwich" atlantoaxial dislocation / 中华骨科杂志

Objective:To evaluate the specialty of the clinical features, treatment procedure, clinical outcome, and prognosis in the patients with "sandwich" atlantoaxial dislocation (AAD).Methods:From 2008 to 2018, 160 cases with "sandwich" AAD were retrospectively selected from the case series of AAD in Peking University Third Hospital. The case series had 80 males and 80 females. The mean age at the initial visit was 35.5±14.6 years (range, 5-77). The clinical courses, treatment methodology and prognosis were reviewed. And the surgical approach, posterior fixation segment and the recovery of neurological function were mainly summarized. The atlantodental interval (ADI), the distance by which the odontoid exceeded the Chamberlain line and the cervical-medullary angle were analyzed.Results:The most common symptoms included weakness or numbness of the limbs (67.5%, 108/160), unstable gait (30%, 48/160) and vertigo (20%, 32/160). Among all, 130 cases (81.3%, 130/160) had myelopathy, with the Japanese Orthopaedic Association (JOA) scores from 4 to 16 (mean JOA scores 13.5±2.5). Cranial neuropathy was involved in 20 cases (12.5%). Radiological findings showed brainstem and/or cervical-medullar in 130 cases (81.3%), syringomyelia in 37 cases (23.1%) and Chiari malformation in 30 cases (18.8%). Computed tomography angiography (CTA) was performed in 90 cases, which showed vertebral artery anomalies in 55 cases (61.0%) and excessive medialized internal carotid artery in 5 cases (5.6%). All cases had no spinal cord or vertebral artery injury. The surgery included posterior occipito-cervical fusion (reducible dislocation, 145 cases), and transoral release followed by posterior fusion (irreducible dislocation, 15 cases). Fifty-seven cases were treated using alternative fixation technique. The average follow-up time was 50.5±22.4 months (range, 24 to 120 months). All of 152 cases (95.0%) achieved solid atlantoaxial fusion; there was no obvious osseous fusion formation on postoperative images in 6 cases (3.8%), but no atlantoaxial instability was found on dynamic radiographs; screw loosening happened in 2 patients (1.2%). Nine patients (5.6%) suffered complications, including 4 cases with recurrent dislocation, 2 screw loosening, 2 cases with bulbar paralysis and 1 wound infection. The mean postoperative JOA was 15.1±1.8 (range, 5-17), and the mean neurological improvement rate was 42.9%±33.3% in the patients with myelopathy.Conclusion:"Sandwich" AAD, a subgroup of AAD, has unique clinical features: earlier onset age and more severe myelopathy. The incidence of bone and vascular malformation is higher. So alternative surgical plan and hybrid fixation should be prepared for this subgroup of AAD.

An analysis on the optimal match between thoracolumbar kyphosis and lower lumbar lordosis in adult spinal deformity after long-fusion surgery / 中华骨科杂志

Objective:To explore the optimal match degree between thoracolumbar kyphosis (TLK) and lower lumbar lordosis (LLL) in adult spinal deformity (ASD) after correction surgery.Methods:Data of 119 ASD patients (male: 28, female: 91), belonging to the Affiliated Hospital of Jining Medical University (19 cases), the Affiliated Hospital of Shandong University of Traditional Chinese Medicine (11 cases), and the First Medical Center of Chinese PLA General Hospital (89 cases) were reviewed and documented from March 2019 to March 2020. All patients (age, 64.48±8.88 years; range, 45-79 years) underwent the surgical procedure of thoracolumbar fusion with instrumentations were followed up over 24 months (51.68±15.60 months; range, 24-87 months) after surgery. Postoperative proximal interface failure, Oswestry disability index (ODI) score and Scoliosis Research Society-22 (SRS-22) score were recorded for all patients. The immediate match of TLK to LLL postoperatively was calculated as follows: TLM=TLK/LLL. The data of those individuals with excellent improvements in the ODI (>50%) at the final follow-up were recorded and analyzed. Then the mean value and the 95% CI of TLM in those individuals were calculated. All participants were subdivided into three groups according to the 95% CI value of TLM. After the receiver operating characteristic curve (ROC) analyzing, the area under the ROC curve (AUC) was the best cutoff value of TLM. The association of proximal junctional failure (PJF) developing with the abnormal TLM postoperatively was analyzed with logistic regression, and the odds ratio (OR) was calculated. Results:62 patients had significant improvements in ODI (>50%) at the final follow-up, and the mean TLM in those individuals was 0.41 [95% CI (0.2, 0.5)]. All patients were divided into three groups: TLM<0.2 (35 cases), 0.2≤TLM≤0.5 (48 cases) and TLM>0.5 (36 cases). The preoperative TLK (13.87°±16.61°) and T 1 pelvic angle (19.69°±10.55°) in the those patients with TLM<0.2 were the smallest, and those were the largest in those with TLM>0.5 (30.59°±16.68°, 28.30°±14.46°). The individuals with TLM<0.2 still had the smallest TLK (2.89°±1.78°), however, those with TLM>0.5 had the largest TLK (17.13°±12.13°) and the smallest LLL (-26.16°±11.02°) accordingly. Additionally, the ODI and SRS-22 for those with 0.2≤TLM≤0.5 at the final follow-up were the best ( P<0.05). ROC curve analysis results showed that the best cutoff value of TLM was 0.4 (sensitivity=78.9%, specificity=76.2%; AUC=0.802, 95% CI (0.708, 0.896) , P<0.001). During the follow-up after orthopedic surgery, there were 19 patients with postoperative proximal junction failure, including 16 patients in the mismatched group (6 patients in the TLM<0.2 group, 10 patients in the TLM>0.5 group) and 3 patients in the matched group (0.2≤TLM≤0.5 group), with the incidence of 23% (16/71) and 6% (3/48), respectively. The difference was statistically significant (χ 2=5.66, P=0.017). Thoracolumbar mismatch was significantly associated with proximal borderline failure after orthosis [ OR=4.35, 95% CI (1.196, 15.924)]. Conclusion:The abnormal correction in thoracolumbar kyphosis and lower lumbar lordosis may result in mismatch between thoracolumbar segments, which would undermine the quality of life, and increase the incidence of proximal junctional failure developing in those ASD patients underwent long-fusion surgeries. The match between TLK and LLL should be 0.2 to 0.5.

Analgesic effect of buccal acupuncture on patients after lumbar spinal fusion: a randomized controlled trial / 中国针灸

OBJECTIVE@#To observe the effect of buccal acupuncture on pain after lumbar spinal fusion.@*METHODS@#Sixty patients undergoing lumbar spinal fusion were randomly divided into an observation group (30 cases, 1 case dropped off) and a control group (30 cases, 1 case was eliminated). The patients in the control group were treated with routine anesthesia. On the basis of the control group, the patients in the observation group were treated with buccal acupuncture at bilateral back point, waist point, and sacral point for 30 min per treatment. The first acupuncture was given before anesthesia induction, and then once a day postoperation for two days, totally 3 treatments. The dosage of sufentanil, the number of remedial analgesia, and the incidence of nausea and vomiting within 48 h after surgery were compared between the two groups; rest and motion visual analogue scale (VAS) scores at 2 (T1), 8 (T2), 12 (T3), 24 (T4), and 48 (T5) h after surgery were observed; the quality of recovery-15 scale (QoR-15) at 24 and 48 h after surgery were evaluated.@*RESULTS@#The dosage of sufentanil and the number of remedial analgesia within 48 h after surgery in the observation group were lower than those in the control group (P<0.01). There was no significant statistically difference in rest and motion VAS scores between the two groups in T1, T2, T3, T4 and T5 (P>0.05). The QoR-15 scores in the observation group at 24 and 48 h after surgery were higher than those in the control group (P<0.01). The incidence of nausea in the observation group was lower than that in the control group (P<0.05).@*CONCLUSION@#Buccal acupuncture could reduce the amount of postoperative analgesic drugs of patients after lumbar spinal fusion, and promote early postoperative recovery.

Analysis of 5 cases of Waveflex semi-rigid internal fixation in treatment of thoracolumbar fracture / 国际外科学杂志

Objective:To investigate various clinical treatment measures for thoracolumbar fractures and provide new diagnosis and treatment methods.Methods:The case data of 5 patients(3 males, 2 females, and the age ranged from 39 to 59 years with an average of 51 years) with thoracolumbar fractures were treated with Waveflex semi-rigid internaI fixation system from May 2020 to December 2021 were retrospectively analyzed, imaging indexes and clinical effects were followed up, and analyzed and summarized in combination with relevant literatures.Results:The operations of all 5 patients were successfully completed, and the follow-up period was 6 months. At the last follow-up, the internal fixation position was good, the height of the injured vertebra was maintained satisfactorily, and the clinical effect was satisfactory.Conclusion:Waveflex semi-rigid internal fixation system combines the advantages of fusion and non-fusion, providing a new idea for the treatment of thoracolumbar fractures, but its long-term effect still needs further follow-up.

Application of oblique lateral interbody fusion in the treatment of lumbar intervertebral disc degeneration in patients with Modic change and endplate sclerosis / 中国骨伤

OBJECTIVE@#To explore the feasibility and clinical effect of Stand-alone oblique lateral interbody fusion (OLIF) in the treatment of lumbar intervertebral disc degeneration with Modic changes and endplate sclerosis.@*METHODS@#A retrospective analysis was performed on 16 cases with lumbar intervertebral disc degeneration with Modic changes and endplate sclerosis admitted to three medical centers from January 2015 to December 2018. There were 6 males and 10 females, the age ranged from 45 to 67 years old with an average of (55.48±8.07) years old, the medical history ranged from 36 to 240 months with an average of (82.40±47.68) months. The lesion sites included L2,3 in 2 cases, L3,4 in 5 cases, and L4,5 in 9 cases. All patients presented with chronic low back pain with lower limb neurological symptoms in 3 cases. All patients were treated by Stand-alone oblique lateral lumbar interbody fusion. Clinical and radiological findings and complications were observed.@*RESULTS@#There was no vascular injury, endplate injury and vertebral fracture during the operation. The mean incision length, operation time, and intraoperative blood loss were(4.06±0.42) cm, (45.12±5.43) min, (33.40±7.29) ml, respectively. The mean visual analogue scale (VAS) of the incision pain was (1.14±0.47) at 72 hours after operation. There was no incision skin necrosis, poor incision healing or infection in patients. Sympathetic chain injury occurred in 1 case, anterolateral pain and numbness of the left thigh in 2 cases, and weakness of the left iliopsoas muscle in 1 case, all of which were transient injuries with a complication rate of 25%(4/16). All 16 patients were followed up from 12 to 36 months with an average of (20.80±5.46) months. The intervertebral space height was significantly recovered after operation, with slight lost during the follow-up. Coronal and sagittal balance of the lumbar spine showed good improvement at the final follow-up. There was no obvious subsidence or displacement of the cage, and the interbody fusion was obtained. At the final follow-up, Japanese Orthopaedic Association(JOA) score and Oswestry disability index(ODI) were significantly improved.@*CONCLUSION@#As long as the selection of case is strict enough and the preoperative examination is sufficients, the use of Stand-alone OLIF in the treatment of lumbar intervertebral disc degeneration with Modic changes and endplate sclerosis has a good results, with obvious clinical advantages and is a better surgical choice.

Effect of adjacent segmental facet joint degeneration on adjacent segment disease after lumbar fusion and fixation / 中国骨伤

OBJECTIVE@#To explore the effect of facet joint degeneration in adjacent segments on the incidence of adjacent segment disease (ASD) after lumbar fusion and fixation.@*METHODS@#A retrospective analysis was performed on 138 patients who underwent L5S1 posterior lumbar interbody fusion (PLIF) from June 2016 to June 2019. Patients were divided into a degeneration group (68 cases) and a non-degenerative group (70 cases) based on the presence or absence of L4,5 facet joint degeneration before surgery (graded using the Weishaupt standard). Age, gender, body mass index (BMI), follow-up time, and preoperative L4,5 intervertebral disc degeneration (graded using the Pfirrmann standard) were collected for both groups. Clinical outcomes were evaluated using the visual analogue scale (VAS) and Oswestry disability index (ODI) at 1 and 3 months after surgery. The incidence and time of ASD after surgery were analyzed.@*RESULTS@#There were no significant differences between the two groups in age, gender, BMI, follow-up time, or preoperative L4,5 intervertebral disc degeneration. Both groups showed significant improvement in VAS and ODI at 1 and 3 months after surgery (P<0.001), with no significant difference between the groups(P>0.05). However, there was a statistically significant difference in the incidence and timing of ASD between the groups (P<0.05). The degeneration group had 2 cases of ASD in gradeⅠdegeneration, 4 cases of ASD in gradeⅡdegeneration, and 7 cases of ASD in grade Ⅲ degeneration. There was a statistically significant difference between the number of patients with grade Ⅲ degeneration and those with gradesⅠandⅡASD (P<0.0167, Bonferroni correction).@*CONCLUSION@#Preoperative degeneration of adjacent articular processes will increase the risk of ASD after lumbar fusion fixation, whereas gradeⅢ degeneration will further increase the risk.

Comparison of clinical effect and muscle injury imaging between oblique lateral lumbar interbody fusion and transforaminal lumbar interbody fusion in the treatment of single-segment degenerative lumbar spinal stenosis / 中国骨伤

OBJECTIVE@#To compare the efficacy and muscle injury imaging between oblique lateral lumbar interbody fusion (OLIF) and transforaminal lumbar interbody fusion (TLIF) in the treatment of single-segment degenerative lumbar spinal stenosis.@*METHODS@#The clinical data of 60 patients with single-segment degenerative lumbar spinal stenosis who underwent surgical treatment from January 2018 to October 2019 was retrospectively analyzed. The patients were divided into OLIF groups and TLIF group according to different surgical methods. The 30 patients in the OLIF group were treated with OLIF plus posterior intermuscular screw rod internal fixation. There were 13 males and 17 females, aged from 52 to 74 years old with an average of (62.6±8.3) years old. And 30 patients in the TLIF group were treated with TLIF via the left approach. There were 14 males and 16 females, aged from 50 to 81 years old with an average of (61.7±10.4) years old. General data including operative time, intraoperative blood loss, postoperative drainage volume, and complications were recorded for both groups. Radiologic data including disc height (DH), the left psoas major muscle, multifidus muscle, longissimus muscle area, T2-weighted image hyperintensity changes and interbody fusion or nonfusion were observed. Laboratory parameters including creatine kinase (CK) values on postoperative 1st and 5th days were analyzed. Visual analogue scale(VAS) and Oswestry disability index(ODI) were used to assess clinical efficacy.@*RESULTS@#There was no significant difference in the operative time between two groups(P>0.05). The OLIF group had significantly less intraoperative blood loss and postoperative drainage volume compared to the TLIF group(P<0.01). The OLIF group also had DH better recovery compared to the TLIF group (P<0.05). There were no significant differences in left psoas major muscle area and the hyperintensity degree before and after the operation in the OLIF group (P>0.05). Postoperativly, the area of the left multifidus muscle and longissimus muscle, as well as the mean of the left multifidus muscle and longissimus muscle in the OLIF group, were lower than those in the TLIF group (P<0.05) .On the 1st day and the 5th day after operation, CK level in the OLIF group was lower than that in the TLIF group(P<0.05). On the 3rd day after operation, the VAS of low back pain and leg pain in the OLIF group were lower than those in the TLIF group (P<0.05). There were no significant differences in the ODI of postoperative 12 months, low back and leg pain VAS at 3, 6, 12 months between the two groups(P>0.05). In the OLIF group, 1 case of left lower extremity skin temperature increased after the operation, and the sympathetic chain was considered to be injured during the operation, and 2 cases of left thigh anterior numbness occurred, which was considered to be related to psoas major muscle stretch, resulting in a complication rate of 10% (3/30). In the TLIF group, one patient had limited ankle dorsiflexion, which was related to nerve root traction, two patients had cerebrospinal fluid leakage, and the dural sac was torn during the operation, and one patient had incision fat liquefaction, which was related to paraspinal muscle dissection injury, resulting in a complication rate of 13% (4/30). All patients achieved interbody fusion without cage collapse during the 6- month follow-up.@*CONCLUSION@#Both OLIF and TLIF are effective in the treatment of single-segment degenerative lumbar spinal stenosis. However, OLIF surgery has obviously advantages, including less intraoperative blood loss, less postoperative pain, and good recovery of intervertebral space height. From the changes in laboratory indexes of CK and the comparison of the left psoas major muscle, multifidus muscle, longissimus muscle area, and high signal intensity of T2 image on imaging, it can be seen that the degree of muscle damage and interference of OLIF surgery is lower than that of TLIF.

Clinical and radiologic comparison between oblique lateral interbody fusion and minimally invasive transforaminal lumbar interbody fusion for degenerative lumbar spondylolisthesis / 中国骨伤

OBJECTIVE@#To compare the short-term clinical efficacy and radiologic differences between oblique lateral interbody fusion(OLIF) and minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) for degenerative lumbar spondylolisthesis.@*METHODS@#A retrospective analysis was performed on 58 patients with lumbar spondylolisthesis treated with OLIF or MIS-TLIF from April 2019 to October 2020. Among them, 28 patients were treated with OLIF (OLIF group), including 15 males and 13 females aged 47 to 84 years old with an average age of (63.00±9.38) years. The other 30 patients were treated with MIS-TLIF(MIS-TLIF group), including 17 males and 13 females aged 43 to 78 years old with an average age of (61.13±11.10) years. General conditions, including operation time, intraoperative blood loss, postoperative drainage, complications, lying in bed, and hospitalization time were recorded in both groups. Radiological characteristics, including intervertebral disc height (DH), intervertebral foramen height (FH), and lumbar lordosis angle (LLA), were compared between two groups. The visual analogue scale (VAS) and Oswestry disability index (ODI) were used to evaluate the clinical effect.@*RESULTS@#The operation time, intraoperative blood loss, postoperative drainage, lying in bed, and hospitalization time in OLIF group were significantly less than those in the MIS-TLIF group (P<0.05). The intervertebral disc height and intervertebral foramen height were significantly improved in both groups after the operation (P<0.05). The lumbar lordosis angle in OLIF group was significantly improved compared to before the operation(P<0.05), but there was no significant difference in the MIS-TLIF group before and after operation(P>0.05). Postoperative intervertebral disc height, intervertebral foramen height, and lumbar lordosis were better in the OLIF group than in the MIS-TLIF group (P<0.05). The VAS and ODI of the OLIF group were lower than those of the MIS-TLIF group within 1 week and 1 month after the operation (P<0.05), and there were no significant differences in VAS and ODI at 3 and 6 months after the operation between the two groups(P>0.05). In the OLIF group, 1 case had paresthesia of the left lower extremity with flexion-hip weakness and 1 case had a collapse of the endplate after the operation;in the MIS-TLIF group, 2 cases had radiation pain of lower extremities after decompression.@*CONCLUSION@#Compared with MIS-TLIF, OLIF results in less operative trauma, faster recovery, and better imaging performance after lumbar spine surgery.

Analysis of the causes and clinical results of vertebral fracture during oblique lateral lumbar interbody fusion / 中国骨伤

OBJECTIVE@#To analyze the causes of vertebral fracture during oblique lateral interbody fusion in the treatment of lumbar spondylopathy, summarize the clinical results, and propose preventive measures.@*METHODS@#Retrospective analysis was made on the data of 8 cases of lumbar spondylopathy and vertebral fracture treated by oblique lateral interbody fusion in three medical centers from October 2014 to December 2018. All were female, aged from 50 to 81 years with an average of 66.4 years. Disease types included 1 case of lumbar degenerative disease, 3 cases of lumbar spinal stenosis, 2 cases of lumbar degenerative spondylolisthesis and 2 cases of lumbar degenerative scoliosis. Preoperative dual energy X-ray bone mineral density test showed that 2 cases had T-value >-1 SD, 2 cases had T-value -1 to -2.5 SD, and 4 cases had T-value <-2.5 SD. Single segment fusion was in 5 cases, two segment fusion in 1 case and three segment fusion in 2 cases. Four cases were treated with OLIF Stand-alone and 4 cases were treated with OLIF combined with posterior pedicle screw fixation. Postoperative imaging examination showed vertebral fracture, and all of them were single vertebral fracture. There were 2 cases of right lower edge fracture of upper vertebral body at fusion segment, 6 cases of lower vertebral body fracture at fusion segment, and 6 cases with endplate injury and fusion cage partially embedded in vertebral body. Three cases of OLIF Stand-alone were treated with pedicle screw fixation via posterior intermuscular approach, while one case of OLIF Stand-alone and four cases of OLIF combined with posterior pedicle screw fixation were not treated specially.@*RESULTS@#The 5 cases of initial operation and 3 cases of reoperation did not show wound skin necrosis or wound infection. The follow-up time was from 12 to 48 months with an average of 22.8 months. Visual analogue scale (VAS) of low back pain was preoperative decreased from 4 to 8 points (averagely 6.3 points) and postoperative 1 to 3 points (averagely 1.7 points) at the final follow-up. Oswestry disability index (ODI) was preoperative 39.7% to 52.4% (averagely 40.2%), and postoperative 7.9% to 11.2% (averagely 9.5%) at the final follow-up. During the follow-up, there was no loosening or fracture of the pedicle screw system, and no lateral displacement of the fusion cage;however, the fusion cage at the vertebral fracture segment had obvious subsidence. The intervertebral space height of vertebral fracture segment was preoperaive 6.7 to 9.2 mm (averagely 8.1 mm), and postoperative 10.5 to 12.8 mm (averagely 11.2 mm). The improvement rate after operation was 37.98% compared to preoperative. The intervertebral space height at final follow-up was 8.4 to 10.9 mm (averagely 9.3 mm), and the loss rate was 16.71% compared with that after operation. At the final follow-up, interbody fusion was achieved in all cases except for one that could not be identified.@*CONCLUSION@#The incidence of vertebral fracture during oblique lateral interbody fusion in the treatment of lumbar spondylopathy is lower, and there are many reasons for fracture, including preoperative bone loss or osteoporosis, endplate injury, irregular shape of endplate, excessive selection of fusion cage, and osteophyte hyperplasia at the affected segment. As long as vertebral fracture is found in time and handled properly, the prognosis is well. However, it still needs to strengthen prevention.

Transiliac endoscopic assisted ilif: a cadaveric study / Ilif assistida por endoscopia por via transilíaca: estudo em cadáver / Ilif asistida por endoscopia transilíaca: estudio en cadáver

ABSTRACT Objective: Demonstrate the feasibility of endoscopic assisted L5S1 intraforaminal lumbar interbody fusion (iLIF) through a transiliac approach. Methods: Ten transiliac iLIF and ten supra iliac iLIF were performed bilaterally at L5S1 in five randomly selected fresh-frozen human cadavers. The following measurements were recorded: distances from the transiliac track to the iliac crest, posterior superior iliac spine, and superior gluteal neurovascular bundle; pelvic parameters; approach angles; cage's lateral and AP center point ratio (CPR); percentage of the cage crossing the midline in the AP and lateral views. Endplate integrity was assessed through endoscopic visualization. In addition, the facet joint, sacroiliac joint, iliolumbar ligament, and exiting and traversing nerve roots were checked for integrity through anatomic dissection. Results: In the transiliac technique, the axial and coronal approach angles were significantly decreased by 13.5º (95% CI -15.5; -11.5; p value<0.001) and 13.2º (95% CI -15.3; -11.1; p value<0.001), respectively, the sagittal approach angle was significantly increased by 5.4º (95% CI 1.8,8.9; p-value = 0.008), and the AP CPR was significantly higher (MD 0.16; 95% CI 0.12,0.20; p value<0.001). The percentage of the cage crossing the AP view's midline was increased by 31.6% (95% CI 19.8,43.4; p value<0.001). The integrity of endplates, facet joints, sacroiliac joints, iliolumbar ligament, and exiting and traversing nerve roots was maintained. Conclusion: L5S1 transiliac iLIF is a feasible surgical technique. It allows a more centrally placed interbody cage in the coronal plane without compromising the anterior position in the lateral plane. The integrity of the major anatomic structures at risk was preserved. Evidence Level III: A case-control study.

Resumo: Objetivo: Demonstrar a viabilidade da fusão intersomática lombar assistida por endoscopia (iLIF) em L5S1 através de abordagem transilíaca. Métodos: Dez iLIF por via transilíaca e dez iLIF por via suprailíaca foram realizados bilateralmente em L5S1 em cinco cadáveres selecionados aleatoriamente. Foram registadas as seguintes medidas: Distâncias da via transilíaca até a crista ilíaca, crista ilíaca póstero-superior e feixe neurovascular do glúteo superior; parâmetros pélvicos; ângulos da abordagem; relação do ponto central lateral e AP do cage (CPR); percentagem do cage cruzando a linha média nas incidências AP e perfil. A integridade das placas vertebrais foi avaliada através de visualização endoscópica. Foi verificada através de dissecção anatómica a integridade das articulações facetárias, sacroilíacas, ligamento iliolombar e raízes de L5 e S1. Resultados: Na técnica transilíaca, os ângulos de abordagem axial e coronal foram significativamente menores em 13,5º (CI 95% -15,5;-11,5; p<0,001) e 13,2º (CI 95% -15,3;-11,1; p<0,001 ), respectivamente, o ângulo de abordagem sagital aumentou significativamente em 5,4º (CI 95% 1,8,8,9; p = 0,008), e o AP CPR foi significativamente maior (MD 0,16; CI 95% 0,12,0,20; p <0,001). A percentagem do cage cruzando a linha média em AP foi superior em 31,6% (CI 95% 19,8,43,4; valor p<0,001). A integridade das placas vertebrais, articulações facetadas, articulações sacroilíacas, ligamento iliolombar e raízes de L5 e S1 foi mantida. Conclusão: A realização de iLIF L5S1 por via transilíaca é uma técnica cirúrgica viável. Permite que o cage seja colocado mais centrado no plano coronal sem comprometer a posição anterior no plano sagital. A integridade das principais estruturas anatómicas em risco foi preservada. Nível de Evidencia III: Estudo caso-controle.

Resumen: Objetivo: Demostrar la viabilidad de la fusión intersomática lumbar asistida por endoscopia (iLIF) en L5S1 con un abordaje transilíaco. Métodos: Se registraron las siguientes mediciones: distancias del abordaje transilíaco a la cresta ilíaca, la cresta ilíaca posterosuperior y el haz neurovascular glúteo superior; parámetros pélvicos; ángulos de abordaje; relación del punto medio lateral y AP del cage (CPR); porcentaje del cage que cruza la línea media en las incidencias AP y perfil. Se evaluó la integridad de las placas vertebrales por visualización endoscópica. Se comprobó la integridad de las articulaciones facetarias, las articulaciones sacroilíacas, el ligamento iliolumbar y las raíces de L5 y S1 mediante disección anatómica. Resultados: En la técnica transilíaca, los ángulos de abordaje axial y coronal fueron significativamente menores en 13,5° (IC 95% -15,5;-11,5; p<0,001) y 13,2º (IC 95% -15,3;-11,1); p<0,001 ), respectivamente, el ángulo de aproximación sagital aumentó significativamente en 5,4º (IC 95% 1,8,8,9; p = 0,008), y el AP CPR fue significativamente mayor (MD 0,16; IC 95% 0,12,0,20; p <0,001). El porcentaje del cage que cruzaba la línea media en AP era mayor en un 31,6% (IC 95% 19,8,43,4; valor p <0,001). Se mantuvo la integridad de las placas vertebrales, las articulaciones facetarias, las articulaciones sacroilíacas, el ligamento iliolumbar y las raíces de L5 y S1. Conclusión: La iLIF transilíaca L5S1 es una técnica quirúrgica viable. Permite colocar el cage más centrado en el plano coronal sin comprometer la posición anterior en el plano sagital. Se preservó la integridad de las principales estructuras anatómicas en riesgo. Nivel de evidencia III: Estudio de casos y controles.