Segmental Fixation Research Articles

Posterior Short Segment Fixation with Index Level Screw for the Unstable Thoracolumbar Burst Fracture

Background: Thoracolumbar fracture is nearly 90% of all the spine injuries which treated by spine surgeons. The choice of the stabilization type is still the subject of controversy. In long segment fixation, the problem is that more motion segment loss is concerned. The number of motion segments involved in fusion of spine fracture is minimized by posterior short segment fixation with index level screw. Objective: The purpose of the study is to assess the ability of short segment fixation with index level screw at fracture level to correct deformity, maintain correction and prevent failure. Method: 15 patients who were operated between March 2018 and January 2021 were taken for the retrospective analysis. All patients were surgically treated with short segment fixation using a posterior surgical approach with transpedicular instrumentation. Pedicle screws were placed at one level above and below the fracture site. Additionally, pedicle screws were also inserted at the index level of the fracture. All the patients were followed up at 3 months, 6 months and 12 months postoperatively. Results: The Mean pre-operative kyphosis was 14° (range 6° to 24°). Average post-operative kyphosis was 0° (range 6° to −18°). Average follow-up kyphosis of all cases was 10° (range 0.85° to 35.00°). Excluding failures, average follow-up kyphosis was 8° (range 0.85° to 25.00°). The height of the vertebral body was maintained upto 95% in 6 patients, 80% in 6 patients, and 70% in 3 patients. At initial one-month follow-up, average Oswestry disability score was severe at 52.63% (range 16% to 84%). At most recent follow-up, average Oswestry disability score was minimal at 5.5% (range 0% to 16%). One patient was lost to long-term follow- up. Mean difference from one-month follow-up to most recent follow-up (excluding failures) was 47.27% (P < 0.0001). Conclusion: The short same-segment fixation reduces the implantation failure rate and reoperation rate in our study. Long-term correction of kyp

3D printed clamps for fixation of spinal segments in biomechanical testing

3D printed clamps provide multiple advantages compared to potting for the fixation of spinal specimens and in a recent study, superior fixation stability was reported. The aim of this study was to evaluate the fixation efficacy of 3D printed vertebra clamps during routine application and to present and evaluate a novel clamp for sacrum fixation. Further, public access to the template files is provided. 98 human single-level cadaveric specimens were biomechanically tested in flexion–extension (FE), lateral bending (LB), axial rotation (AR), anteroposterior shear (AS), lateral shear (LS) and axial compression-decompression (AC). Loading amplitudes were +/-7.5 Nm for FE, LB and AR, +/- 150 N for AS and LS and + 400/-100 N for AC. The novel sacrum clamp was used in 8 specimens. The median relative motion between clamps and specimens was 0.6° in FE, 0.7° in LB, 0.3° in AR, 0.5 mm in AS, 0.5 mm in LS and 0.1 mm in AC. With sacrum clamps, the median relative motion was 0.3° in FE, 0.1° in LB, 0.08° in AR, 0.8 mm in AS, 0.7 mm in LS and 0.2 mm in AC. The vertebra clamps used during routine testing provided better stability compared to the values in the literature in all six loading directions (p < 0.05). The sacrum clamp showed superior anchoring stability in three loading directions compared to the caudal vertebra clamps (p < 0.05), while inferior stability was measured in AS (p < 0.001). We conclude that 3D printed vertebra clamps and 3D printed sacrum clamps represent reliable methods for specimen fixation during routine biomechanical testing.

Сравнительный анализ одноуровневого переднего и заднего спондилодеза при дегенеративных заболеваниях пояснично-крестцового отдела позвоночника

Transpedicular fixation (TPF) as a method of posterior fusion is currently the most common, reliable and economically justified option of spinal fusion in various diseases and injuries of the lumbar spine, having more than half a century of history. As a result of the search for less invasive and more effective methods of fixation of the spinal segments to improve the results of surgical treatment, shorten the hospitalization, and reduce the number of perioperative complications, an approach involving fusion with rigid implant from the anterior (ALIF) was developed. Objective. To analyze the immediate and long-term results of treatment of single-level herniated discs by total removal of the intervertebral disc using anterior access with a rigid spondylodesis (ALIF) and the method of posterior discectomy, spondylodesis and transpedicular fixation (TPF). Materials and methods. A prospective cohort study was conducted. The study included patients after total intervertebral disc removal by the ALIF method and patients after discectomy and TPF. The achieved result was evaluated using radiological tests, as well as using standardized questionnaires and surveys. Results. After the surgery, patients in both groups showed a significant reduction in pain on the NRS scale. Patients from the first group had 4 to 0 for back and 8 to 0 for leg, patients from the second group had 6 to 4 for back and 8 to 0 for leg. The quality-of-life assessment by ODI scale also showed a positive trend from 36 to 4 in the first group and from 22 to 12 in the second group. Clinically, the result of surgical treatment was rated as excellent 5 in the ALIF group and as good in the TPF group 4 on the modified subjective assessment scale Macnab. Conclusion. The ALIF method as a decompression-stabilizing surgical aid is less traumatic. The less invasive nature of the technique was confirmed by significantly shorter surgical intervention time, smaller volume of intraoperative blood loss, and a shorter period of hospitalization. In the long-term period, statistically significant differences were obtained indicating that the ALIF method is more effective than TPF.

Upper and lower adjacent segment range of motion after fixation of different lumbar spine segments in the goat: an in vitro experiment.

ObjectivesThe purpose of this study was to examine the biomechanical effects of fixation on range of motion (ROM) in the upper and lower adjacent segments of different lumbar spine segments in a goat spine model.MethodsFifteen goat spine specimens (vertebrae T12–S1) were randomly divided into three groups: A (single-segment fixation), B (double-segment fixation), and C (triple-segment fixation). Motion in different directions was tested using a spinal motion simulation test system with five external loading forces. Transverse, forward–backward, and vertical displacement of the upper and lower adjacent segments were measured.ResultsAs the external load increased, the upper and lower adjacent segment ROM increased. A significantly greater ROM in group C compared with group A was found when the applied external force was greater than 75 N. The upper adjacent segment showed a significantly greater ROM than the lower adjacent segment ROM within each group.ConclusionsAdjacent segment ROM increased with an increasing number of fixed lumbar segments. The upper adjacent segment ROM was greater than that of the lower adjacent segments. Adjacent segment stability after lumbar internal fixation worsened with an increasing number of fixed segments.

Comparative study of long segment versus short segment posterior fixation of thoracolumbar fractures with pedicle screws

Choice of long or short segment fixation for thoracolumbar fractures, benefits of either of these techniques has been a topic for analysis and assessment. Kyphotic angles in twenty patients diagnosed to have thoracolumbar vertebral fractures between December 2019 to December 2020 in Bapuji hospital and Chigateri general hospital, Davanagere, Karnataka, India were measured pre operatively, post operatively and at one year follow up and assessed. No statistical difference between the degrees of correction of initial kyphotic angle between long segment fixation and short segment posterior fixation in our study was found (p&lt;0.6). Method of fixation of the thoracolumbar vertebral fracture did not correlate with initial degree of kyphosis (p=0.4). Amount of correction loss at one year follow up was found to be statistically significant in short segment fixation (p&lt;0.05). Loss of kyphotic angle at one year follow up was higher in case of short segment fixation than long segment fixation and found to be statistically significant (p&lt;0.005). Our study showed that long segment fixation helps in better correction of the kyphosis angle with lesser chance of loss of correction and can be opted when pedicles aren’t intact at the fracture level, as in cases of burst fractures. Short segment fixation provides better rigid fixation at the site of fracture with increased range of motion at the thoracolumbar segment and can be treatment of choice when the pedicles at the fractured level are intact, as in cases of compression fractures, having benefits of shorter duration of surgery and reduced risks.

The Anatomical Basis for Plate Fixation in BSSO to Minimize Condylar Torquing: A Comparative CT Study of Mandibular Advancement and Setback.

Condylar displacement after bilateral sagittal-split osteotomy (BSSO) occur in the sagittal plane as clockwise/counter-clockwise rotation of the ramus, in the coronal plane as medial/lateral inclination, or in the axial plane as medial/lateral condylar torquing. The purpose of this prospective CT study was to evaluate the role of plate fixation in minimizing condylar torquing or rotational changes in the axial plane. This prospective study was carried out on 26 patients, 13 of whom underwent advancement BSSO and 13 setback BSSO, without maxillary LeFort I osteotomies. All mandibular movements were symmetrical. Fixation of the osteotomized segments was achieved with a single 4-hole plate and monocortical screws. In case of mandibular setbacks, a straight plate was used, whereas an inset-bent plate was used for advancements. Computed tomography scans were obtained preoperatively and postoperatively to measure condylar rotation or torqueing in the axial plane. An increase in condylar angle on axial slices was considered as lateral condylar torquing, whereas a decrease was considered as medial condylar torquing. A mean medial condylar torquing of 0.2° was noted postoperatively in case of setbacks (p > 0.05 not significant). This suggested minimal condylar torquing, indicating that the proximal and distal segments maintained contact at the anterior vertical osteotomy fixed with a straight plate. In case of advancements, a mean lateral condylar torquing of 2.2° was noted postoperatively (p < 0.005, highly significant). This suggested that the proximal segment flare at the anterior vertical osteotomy site was maintained by inset-bent plate fixation. The gaps between the proximal and distal segments created by mandibular advancement and setback should be maintained. An attempt to close these gaps, especially in mandibular advancement, will result in an unfavourable axial condylar torque. Consequently, the areas of bony contact between the proximal and distal osteotomy sites created by mandibular advancement and setback should be maintained as well.

Open reduction of thoraco-lumbar fractures and sagittal balance correction using Schanz screws

IntroductionThe correction of thoracic and lumbar spine fractures with a short instrumentation using Schanz screws, is an effective method for stabilization and sagittal balance restoration. Materials and methodsBidirectional observational study, included patients undergoing arthrodesis with Schanz screws to manage thoracic and lumbar fractures, the general characteristics, type, and location of the fracture, besides the gain in height of the vertebral body and segmental angle were analyzed before and after surgery. Clinical and imaging control was performed postoperatively and 1 month after this. p-value<.05 was statistically significant. ResultsOf 35 patients undergoing arthrodesis, 13 were excluded due to the absence of images and follow-up. There was a higher proportion of men, the main location of the fracture and AO spine classification was in T12 and type A4/B1 respectively, there was no intraoperative complication, no transfusion was required, and a short hospital stay. A mild complication was presented in the follow-up. The average pre and postoperative change was 12 degrees in the Cobb angle and 5.2mm vertebral body height in the fractured vertebra, these changes were statistically significant. ConclusionThoracolumbar and lumbar spine fracture correction with short segment fixation using Schanz screws, is an effective, safe and fast, showing significantly vertebral height gain and segmental angle correction, as a consequence, a correction of the balance and alignment of the spine.

A study of design and digital simulation of a anterior internal fixation system

At present, anterior cervical discectomy and fusion often use internal fixation system to assist fixation of surgical segments, and the design of internal fixation system profile has an important influence on postoperative complications such as vertebral injury. In this study, a triangular anterior internal fixation system was designed to reduce the risk of postoperative complications. In this study, a intact C1-C7 segment finite element model was established and verified. Based on this model, a quadrilateral fixation system (QFS) and a triangle fixation system (TFS) implanted model were established. The stress distribution and peak value of the screw holes were compared during the postoperative flexion, lateral bending, rotation and extension motion patterns. Compared with the QFS, the stress ratio of the bone-screw interface of TFS is 40% smaller on average. After TFS implantation, in addition, because of the TFS screw hole beard less stress, it has certain advantages of screw loosening and reducing the risk of vertebra damage at the screw hole.

Feasibility of Imaging-Based 3-Dimensional Models to Design Patient-Specific Osteosynthesis Plates and Drilling Guides

In acetabular fracture surgery, achieving an optimal reconstruction of the articular surface decreases the risk of osteoarthritis and the subsequent need for total hip arthroplasty. However, no one-size-fits-all osteosynthesis plate is available owing to differences in fracture patterns and variations in pelvic anatomy. Currently, osteosynthesis plates need to be manually contoured intraoperatively, often resulting in inadequate reduction and fixation of the fractured segments. To determine the feasibility and accuracy of a novel concept of fast-track 3-dimensional (3-D) virtual surgical planning and patient-specific osteosynthesis for complex acetabular fracture surgery. This case series study examines the use of patient-specific osteosynthesis plates for patients needing operative treatment for displaced associated-type acetabular fractures at a tertiary university-affiliated referral center and level 1 trauma center between January 1, 2017, and December 31, 2018. Models were created in 3-D based on computed tomography (CT) data, fractures were virtually reduced, and implant positions were discussed in a multidisciplinary team of clinicians and engineers. Patient-specific osteosynthesis plates with drilling guides were designed, produced, sterilized and clinically applied within 4 days. Data were analyzed at the 1-year follow-up. Development and clinical implementation of personalized fracture surgery. The primary outcome was the quality of the reduction as determined by the postoperative CT scan. The secondary outcomes were accuracy of the screw placement and clinical outcome using patient-reported outcome measures. Ten patients with a median (range) age of 63 (46-79) years with an acetabular fracture were included. The median (interquartile range [IQR]) preoperative gap was 20 (15-22) mm, and the median (IQR) step-off was 5 (3-11) mm. Postoperatively, the median (IQR) gap was reduced to 3 (2-5) mm (P = .005), and the median (IQR) step-off was reduced to 0 (0-2) mm (P = .01), indicating good fracture reduction, indicating good fracture reduction. The mean difference between the preoperative and postoperative gap was 14.6 (95% CI, 10-19) mm, and the mean difference in step-off was 5.7 (95% CI, 2-9) mm. The median (IQR) difference in screw direction between the planning and actual surgery was only 7.1° (7°-8°). All patients retained their native hip and reported good physical functioning at follow-up. These findings suggest that 3-D virtual surgical planning, manufacturing, and clinical application of patient-specific osteosynthesis plates and drilling guides was feasible and yielded good clinical outcomes. Fast-track personalized surgical treatment could open a new era for the treatment of complex injuries.

Patient-specific plate for navigation and fixation of the distal radius: a case series

PurposeCorrective osteotomy of a malunited distal radius conventionally relies on 2D imaging techniques for alignment planning and evaluation. However, this approach results in suboptimal bone repositioning, which is associated with poor patient outcomes. In this case series, we evaluate the use of novel patient-specific plates (PSPs), which feature navigation and fixation of bone segments as preoperatively planned in 3D.MethodsTen participants with distal radius malunion underwent CT scans for preoperative alignment planning. Patient-specific guides and plates were designed, 3D-printed, and sterilized for use in corrective surgery of the distal radius. Pre- and postoperative results were compared in regard to clinical, functional, and radiographic outcomes.ResultsThe application of a PSP was successful in 7 of the 10 cases. After treatment, the residual alignment error was reduced by approximately 50% compared with conventional treatment. The use of PSPs reduced pain significantly. Pre- and postoperative results were pooled and demonstrated significant correlations between: (1) pain and malpositioning, (2) the range of pro- and supination motion, the MHOQ score, the EQ-5D-5L score and dorsovolar angulation, and (3) MHOQ score and proximodistal translation.ConclusionThe correlation between malalignment and MHOQ score, EQ-5D-5L score, pain, and range of motion shows that alignment should be restored as well as possible. Compared to the conventional approach, which relies on 2D imaging techniques, corrective osteotomy based on 3D preoperative planning and intraoperative fixation with a PSP has been shown to improve bone alignment and reduce pain.Level of evidenceIV.

Functional Outcomes of Nerve Root Sparing Posterior Corpectomy in Lumbar Vertebral Burst Fractures

Study Design:Retrospective observational.Objectives:This study aimed to document the safety and efficacy of lumbar corpectomy with reconstruction of anterior column through posterior-only approach in complete burst fractures.Methods:In this retrospective study, we analyzed complete lumbar burst fractures treated with corpectomy through posterior only approach between 2014 and 2018. Clinical and intraoperative data including pre and post-operative neurology as per the ISNCSCI grade, VAS score, operative time, blood loss and radiological parameters, including pre and post-surgery kyphosis, height loss and canal compromise was assessed.Results:A total of 45 patients, with a mean age of 38.89 and a TLICS score 5 or more were analyzed. Preoperative VAS was 7-10. Mean operating time was 219.56 ± 30.15 minutes. Mean blood loss was 1280 ± 224.21 ml. 23 patients underwent short segment fixation and 22 underwent long segment fixation. There was no deterioration in post-operative neurological status in any patient. At follow-up, the VAS score was in the range of 1-3. The difference in preoperative kyphosis and immediate post-operative deformity correction, preoperative loss of height in vertebra and immediate post-operative correction in height were significant (p < 0.05).Conclusion:The posterior-only approach is safe, efficient, and provides rigid posterior stabilization, 360° neural decompression, and anterior reconstruction without the need for the anterior approach and its possible approach-related morbidity. We achieved good results with an all posterior approach in 45 patients of lumbar burst fracture (LBF) which is the largest series of this nature.

Cage-screw and anterior plating combination reduces the risk of micromotion and subsidence in multilevel anterior cervical discectomy and fusion—a finite element study

BACKGROUND CONTEXTAnterior cervical discectomy and fusion (ACDF) is widely used to treat patients with spinal disorders, where the cage is a critical component to achieve satisfactory fusion results. However, it is still not clear whether a cage with screws or without screws will be the best choice for long-term fusion as the micromotion (sliding distance) and subsidence (penetration) of the cage still take place repeatedly. PURPOSEThis study aims to examine the effect of cage-screws on the biomechanical characteristics of the human spine, implanted cage, and associate hardware by comparing the micromotion and subsidence. STUDY DESIGNA finite element (FE) analysis study. METHODSA FE model of a C3-C5 cervical spine with ACDF was developed. The spinal segment was modeled with the removal of the anterior longitudinal ligament (ALL), posterior longitudinal ligament (PLL), and discectomy was then implanted with a cage-screw system. Three models were analyzed: the first was the original spine (S1 model), the second, S2, was implanted with cages and anterior plating, and the third, S3, was implanted with a cage-screw system in addition to the anterior plate. All investigations were under 1 N•m in flexion, extension, lateral bending, and axial rotation situations. RESULTSFinite element analysis (FEA) demonstrated that range of motion (ROM) at C3-C4 in the S2 model was significantly reduced more than that in the S3 model, while the ROM at both C4-C5 in the S3 model was reduced more than that in the S2 model in all simulations. The ROM at C3-C5 in the S1 model was reduced by over 5° in the S2 and S3 models in all loading conditions. The micromotion and subsidence at all contacts of C3-C5 in the S3 model were lower than that in the S2 model in all flexion, extension, bending, and axial simulations. The subsidence and micromotion could be seen in the barrier area of the S2 model, while they occurred near the edge of the screw in the S3 model. CONCLUSIONSThese results showed that the cage-screw and anterior plating combination has promising potential to reduce the risk of micromotion and subsidence of implanted cages in two or more level ACDFs. CLINICAL SIGNIFICANCEThe use of double segmental fixation with cage-screw anterior plating combination constructs may increase the stiffness of the construct and reduce the incidence of clinical and radiographic pseudarthrosis following multilevel ACDF, which in turn, could decrease the need for revision surgeries or supplemental posterior fixation.

Reducción abierta de fracturas toracolumbares y corrección del balance sagital usando tornillos Schanz

IntroductionThe correction of thoracic and lumbar spine fractures with a short instrumentation using Schanz screws, is an effective method for stabilization and sagittal balance restoration. Materials and methodsBidirectional observational study, included patients undergoing arthrodesis with Schanz screws to manage thoracic and lumbar fractures, the general characteristics, type, and location of the fracture, besides the gain in height of the vertebral body and segmental angle were analyzed. before and after surgery. Clinical and imaging control was performed postoperatively and 1 month after this. p-value < .05 was statistically significant. ResultsOf 35 patients undergoing arthrodesis, 13 were excluded due to the absence of images and follow-up. There was a higher proportion of men, the main location of the fracture and AO spine classification was in T12 and type A4/B1 respectively, there was no intraoperative complication, no transfusion was required, and a short hospital stay. A mild complication was presented in the follow-up. The average pre and postoperative change was 12 degrees in the Cobb angle and 5.2 mm vertebral body height in the fractured vertebra, these changes were statistically significant. ConclusionThoracolumbar and lumbar spine fracture correction with short segment fixation using Schanz screws, is an effective, safe and fast, showing significantly vertebral height gain and segmental angle correction, as a consequence, a correction of the balance and alignment of the spine.

Thoracolumbar Spine Fracture-Dislocation without Neurological Deficit: A Case Report and Review of the Literature

Background: Thoracolumbar spine fracture-dislocations are very unstable and usually secondary to high energy trauma. Due to disruption of the entire vertebrae columns, the absence of neurological deficit is exceptional. Aim: The purpose of this work is to report our experience in the management of this entity in a context of limited resources and to make a review of the literature. Case presentation: A 30-year-old man was admitted with a severe low back pain after a traffic accident. Neurological functions were intact after examination. Radiological assessments revealed a complete L3-L4 fracture-dislocation. The patient underwent an open posterior reduction and internal long segment fixation. The post-operative was marked by a surgical site infection treated with surgical debridement and targeted antibiotic therapy. The neurological functions were preserved. Conclusion: Fracture-dislocations of the thoracolumbar spine are caused by high energy trauma and are remarkably unstable lesions. When they are associated with intact neurorological functions, reduction and stabilization of these fractures are a challenge.

Surgical Management of High Energy Dorsolumbar Fractures

Background: The management of dorsolumbar fractures has been the subject of much controversy. There are different criteria for the choice of management based on the severity of the kyphotic deformity, canal compromise, vertebral height loss, and neurologic status. Objective:To evaluate the results of surgical management of high energy dorsolumbar fractures in the Trauma Unit at Assiut, and at Al-Azhar University Hospitals. Patients and Methods: From October 2017 to October 2019, 40 patients with thoracolumbar spine (TLS) fractures, all of them were treated by posterior instrumentation with pedicle screws and rod system. 23 petients (57.5%) underwent long-segment fixation and 17 patients (42.5%) underwent short-segment fixation. They were operated upon at the Trauma Unit of Assiut University Hospital and Al-Azhar University Hospital. Results:The clinical outcome according to modified Macnab criteria; in long segment group it was excellent in 8 patients (34.7%), good in 11 patients (47.8%), fair in 3 patients (13% ) and poor in 1 patient (4.3%), while in short segment group; it was excellent in 3 (17.6%), good in 10 (58.8%), fair in 3 (17.6%)andpoor in 1 (5.9%). The kyphosis correction (%), in long segment group was ≥70 in 16 patients (70%), <70 in 7 patients (30%), while in short segment group, it was ≥70 in 10 patients (59%) and <70 in 7 patients (41%). Conclusion: Short segment fixation using pedicle screw at the level of fracture, inhigh energy thoracolumbar fractures; provides comparable correction to long segment fixation and the amount of correction loss can be minimized by proper selection of cases suitable for short segment fixation.

Surgery for Vertebral Hemangioma in Resource-Constrained Environment

Background: Vertebral hemangiomas are benign, highly vascular lesions of the vertebra. Asymptomatic hemangiomas are common, but they rarely enlarge in size and present with myelopathy. The aim of this study was to analyze the long-term outcome of patients of vertebral hemangioma presenting with myelopathy who were managed in a resource-constrained environment, the majority of whom were treated by our novel three-pronged strategy of alcohol injection, posterior decompression, and short segment fixation. Methods: All patients of symptomatic vertebral hemangioma with myelopathy treated at our hospital from 2001 to 2015 with follow up till January 2018, with at least 2 year follow up were included. The operative procedure, blood loss and complications were recorded. Clinical outcomes were measured using ASIA score. Results: Out of 60 patients operated, 44 (26 males, 18 females) fulfilled the inclusion criteria. 41 hemangiomas were located in the thoracic spine two in lumbar spine and one in cervical spine. Upper thoracic spine involvement was more common than lower thoracic spine involvement. Mean age was 29.34 years (range 10 - 68 years). Mean follow up was 74.63 months (range 24 - 180 months). All patients had improvement in motor strength postoperatively. Local pain, which was present in two patients resolved, bladder symptoms present in 13 patients also resolved. Conclusions: Our experience in treating symptomatic vertebral hemangiomas, along with the long term follow up data suggests that good postoperative results can be achieved with minimal complications, in carefully selected patients. Funding Statement: None. Declaration of Interests: None. Ethics Approval Statement: Approval for the study was taken from the institutional ethical board.

Risk factors of recurrent kyphosis in thoracolumbar burst fracture patients treated by short segmental pedicle screw fixation

OBJECTIVE To analyze the risk factors of recurrent kyphosis after removal of short segmental pedicle screw fixation in patients with thoracolumbar burst fractures. METHODS Retrospective analysis was conducted of 144 cases of thoracolumbar burst fractures without neurological impairment treated in Peking University Third Hospital from January 2010 to December 2017. There were 74 males and 70 females, with an average age of (39.1±13.2) years. The distribution of the injured vertebrae was T12: 42, L1: 72 and L2: 30, with fracture types of A3: 90, B1: 25 and B2: 29. The patients were divided into two groups: Recurrent kyphosis group (n=92) and non-recurrent kyphosis group (n=52). SPSS 26.0 software was used for univariate analysis and Logistic regression analysis. RESULTS The average follow-up time was 28 (20-113) months. The imaging indexes of pre-operation, 3 days post-operation, 12 months post-operation and the last follow-up were measured and compared. Anterior vertebral body height, segmental kyphosis, vertebral wadge angle and Gardner deformity were significantly improved after operation (P < 0.05), and there were some degrees of loss in the 1-year follow-up; anterior vertebral body height and vertebral wadge angle were no longer changed after the removal of the screws; however, segmental kyphosis and Gardner deformity were still aggravated after the removal of the screws (P < 0.05). There were some degrees of collapse of the height of the upper and lower discs during the follow-up. Univariate analysis showed that there were statistically significant differences (P < 0.05) between the two groups in gender, age (36.9 years vs. 43.0 years), upper disc injury, CT value (174 vs. 160), segmental kyphosis (16.6° vs. 13.3°), vertebral wadge angle (16.7° vs. 13.6°), Gardner deformity (19.1° vs. 15.2°) and ratio of anterior vertebral body height (0.65 vs. 0.71). Logistic regression analysis showed that male (OR: 2.88, 95%CI: 1.196-6.933), upper disc injury (OR: 2.962, 95%CI: 1.062-8.258) and injured vertebral wedge angle were risk factors of recurrent kyphosis after removal of internal fixation for thoracolumbar burst fracture (P < 0.05). CONCLUSION The patients with thoracolumbar burst fracture can obtain satisfactory effect immediately after posterior short segmental pedicle screw fixation, however, there may be some degree of loss during the follow-up. Male, upper disc injury and injured vertebral wedge angle are the risk factors of recurrent kyphosis after removal of internal fixation for thoracolumbar burst fracture.

Treatment of Reducible Atlantoaxial Dislocation and Basilar Invagination Using the Head Frame Reduction Technique and Atlantoaxial Arthrodesis.

Study design:Retrospective case series.Object:To evaluate the outcomes of a head frame reduction and atlantoaxial arthrodesis technique for the treatment of reducible basilar invagination (BI) and atlantoaxial dislocation (AAD).Methods:Seventy-two reducible BI and AAD cases who were treated with the head frame reduction and atlantoaxial arthrodesis technique from June 2015 to December 2018 were retrospectively analyzed. Radiological measurements including the atlantodental interval (ADI), the height of odontoid process above Chamberlain line, Wackenheim line, clivus-canal angle (CCA) and JOA score were evaluated.Results:There was no death in this series. The follow-up period ranged from 6 to 32 months (mean: 21.2 months). Radiological, complete or 90% reduction was attained and complete decompression was demonstrated in all patients. The CCA increased from 123.22 ± 8.36 preoperatively to 143.05 ± 8.79 postoperatively (P < 0.01). There was no patient found postoperative dysphagia. Neurological improvement was observed in all patients, with the JOA scores increasing from 12.53 ± 1.93 preoperatively to 16.13 ± 1.23 postoperatively (P < 0.01). Solid bony fusion was demonstrated in 69 patients at follow-up (95.8%).Conclusion:Head frame reduction technique is a simple and effective treatment which could relief neurologic compression and adjust the CCA in patients with reducible AAD and BI with lower potential risks. Atlantoaxial fixation with short segmental fixation, strong purchase and low shearing force could maintain superior stabilization. The safety and long-term efficacy of such fixation and reduction technique were favorable, which illustrated that it could be a promising treatment algorithm for such kind of disease.

Multistage Hybrid Approach to Management of Significant Sagittal Malalignment: 2-Dimensional Operative Video.

Minimally invasive surgery (MIS) approaches for the correction of adult spinal deformity have gained popularity in the past decade. MIS approaches can result in decreased hospitalization times and decreased morbidity. However, compared to open techniques, MIS approaches are challenging in the setting of fixed sagittal deformity and strategic surgical staging. Combined MIS and miniopen techniques are described as "hybrid" techniques. We report on the surgical approach for a fixed sagittal deformity using both MIS and miniopen techniques, specifically a miniopen pedicle subtraction osteotomy (PSO) and an anterior column release (ACR). The patient gave written informed consent for surgical treatment; institutional review board approval was not required. The patient first underwent the placement of percutaneous modular pedicle screws from T12 to the pelvis as well as a mini-PSO across the previously fused L5 vertebral body, with the placement of a temporary rod. The following day, the patient underwent lateral transpsoas interbody fusion and ACR at L2/3; a percutaneous rod was then passed from T12 to the pelvis for segmental fixation. The patient recovered well and was discharged home without complication 6 d after the initial day of surgery. The combined use of surgical staging and traditional open techniques in a selective, minimalistic fashion and adherence to minimally invasive principles provide for a powerful set of surgical techniques that capitalize on less invasive approaches to deformity management. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.

Functional outcome of lumbar canal stenosis treated by decompression and fixation

Introduction: Low back pain affects every population and is one of foremost debilitating condition and is considered as one of the most unrewarding problems, especially in the age group 40 –75 years, during the stage of instability. Despite an improving understanding of degenerative disc disease, treatment results vary greatly, and we studied the functional outcomes of lumbar canal stenosis treated by Decompression and Pedicle Screw Fixation.Methods: Our study included a total of 30 diagnosed cases of lumbar intervertebral disc prolapse between age group 40-75 years between February 2018 and February 2019 at KIMS Hospital, Bengaluru, unresponsive to conservative management during the period. The patient’s clinical characteristics had been reviewed prospectively including clinical presentations, preoperative medical comorbidities, intraoperative status, and postoperative status. Oswestry disability index (ODI), visual analog scale (VAS) and patient satisfaction were evaluated before surgery and last follow-up period.Results: There was no significant difference in diagnosis with respect to the level of IVDP and number of levels operated. There were improvements in ODI and VAS and functional outcome of patients before and after the operation. During the average follow-up period, 100% of patients had varying degrees of symptomatic relief. The lumbar interbody fusion with pedicle screw technique provided strong spinal segment fixation and a reliable ground for bone arthrodesis. No patient needed any additional modality of treatment or reoperation for recurrence of symptoms.