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BACKGROUND CONTEXT: Surgical site infection following spine surgery is associated with increased morbidity and mortality. Perioperative antibiotic prophylaxis is a key factor in lowering the risk of acquiring an infection. Previous studies have assessed perioperative cefuroxime concentrations in the anterior column of the cervical spine with an anterior surgical approach. However, the majority of surgeries are performed in the posterior column and many surgeries involve the lumbar spine.PURPOSE: The objective of this study was to compare the perioperative tissue concentrations of cefuroxime in the anterior and posterior column during lumbar spine surgery with a posterior surgical approach.STUDY DESIGN: In vivo experimental pharmacokinetics study of cefuroxime concentrations in an acute preclinical porcine model.METHODS: The lumbar vertebral column was exposed from L1 to L5 in 8 female pigs. Microdialysis catheters were placed for sampling in the anterior column (vertebral body) and posterior column (posterior arch) within the same vertebra (L5). Cefuroxime (1.5 g) was administered intravenously. Microdialysates and plasma samples were continuously obtained over 8 hours. Cefuroxime concentrations were quantified by Ultra High Performance Liquid Chromatography Tandem Mass Spectrometry. The primary endpoint was the time above cefuroxime clinical breakpoint minimal inhibitory concentration (T>MIC) for Staphylococcus aureus of 4 µg/mL. The secondary endpoint was tissue penetration (AUCtissue/AUCplasma).RESULTS: Mean T>MIC 4 µg/mL (95% confidence interval) was 123 min (105-141) in plasma, 97 min (79-115) in the anterior column and 93 min (75-111) in the posterior column. Tissue penetration (95% confidence interval) was incomplete for both the anterior column 0.48 (0.40-0.56) and posterior column 0.40 (0.33-0.48).CONCLUSIONS: T>MIC was comparable between the anterior and posterior column. Mean cefuroxime concentrations decreased below the clinical breakpoint minimal inhibitory concentration for S. aureus of 4 µg/mL after 123 min (plasma), 97 min (anterior column) and 93 min (posterior column). This is shorter than the duration of most lumbar spine surgeries, and therefore alternative dosing regimens should be considered in posterior open lumbar spine surgeries lasting more than 1.5 hours.CLINICAL SIGNIFICANCE: Open lumbar spine surgery often involves extensive soft tissue dissection, stripping and retraction of the paraspinal muscles which may impair the local blood flow exposing the lumbar vertebra to postoperative infections. A single intravenous administration of 1.5 g cefuroxime only provided sufficient prophylactic target tissue concentrations in the vertebrae of the lumber spine for up to 1.5 hours.

Optimal restoration of the L5-S1 disc angle (DA) is an important surgical goal in spinal reconstructive surgery. Anterior approach is beneficial for L5-S1 DA reconstruction and fusion. However, factors associated with a greater DA restoration in oblique lateral interbody fusion (OLIF) at L5-S1 have not been studied.This study aimed to identify factors that aid in achieving a greater DA in OLIF at L5-S1.A retrospective analysis.This study involved 61 consecutive patients who underwent OLIF at L5-S1 for lumbar degenerative disease and were followed for more than 1 year. Patients with incomplete data or posterior column osteotomy at L5-S1 were excluded.The L5-S1 DA was measured preoperatively, postoperatively, and at the last follow-up on standing lateral lumbar radiographs. The associations between demographics and/or surgical and/or radiological factors and the L5-S1 DA at the last follow-up were analyzed using multiple regression analysis.Demographics and surgical factors were reviewed from the medical records with respect to age, sex, body mass index, bone mineral density, diagnosis, surgery level, cage parameters (cage lordotic angle and height), laminectomy performed and/or not performed, estimated blood loss, operative time, configuration of the left common iliac vein. Radiological factors were measured with respect to sagittal parameters, the L5-S1 disc parameters, and the postoperative cage parameters.The mean preoperative DA at L5-S1 was 5.4±5.0°, which increased to 18.9±5.6° postoperatively (p.001) and was maintained as 16.5±5.9° at the last follow-up (p.001). The preoperative DA, end plate lesions, anterior spur, facet joint osteoarthritis, or cage position at L5-S1 did not affect the DA at the last follow-up (all p.05). Multiple regression analysis showed four independent variables, including increased age, increased cage lordotic angle, laminectomy performed, and absence of cage subsidence as the factors associated with the greater DA at L5-S1.OLIF at L5-S1 showed favorable DA restoration regardless of the preoperative conditions. To achieve a greater DA, surgeons should try to distract the anterior disc space for insertion of a larger lordotic cage. Laminectomy during posterior fixation is recommended for achieving additional DA restoration.

We report the case of a 58-year-old woman who presented with rapidly destructive osteoarthritis (RDO) of the hip that had been causing her severe pain and disability. By the time of presentation to our institution, she had a significant leg length discrepancy resulting from extensive destruction of the posterior acetabular wall, posterior column, and femoral head with a superiorly migrated femoral shaft. She underwent structural acetabular allograft augmentation of the pelvis re-enforced with a locking plate, concomitant total hip replacement with dual mobility implants, and extensive soft tissue releases to restore length to the extremity.

Objectives Open reduction and internal fixation of both columns is considered the treatment of choice for displaced anterior column with posterior hemitransverse (ACPHT) fractures in non-geriatric patients. Plate fixation of one column combined with lag screw fixation of the other column allows to decrease operative time and approach-related morbidity compared to conventional both column plating. The aim of this biomechanical study was to evaluate whether single column plate plus other column lag screw fixation confers similar stability to both column plate fixation. Physiological loads were simulated using both the single-leg stance (SLS) as well as the sit-to-stand (STS) loading protocols. Methods A clinically relevant ACPHT fracture model was created using fourth-generation composite hemipelves. Fractures were stabilized with three different fixation constructs: (1) anterior column plate plus posterior column screw fixation (AP+PCS), posterior column plate plus anterior column screw fixation (PP+ACS) and anterior column plate plus posterior column plate fixation (AP+PP). Specimens were loaded from 50 to 750 N with a ramp of 100 N/s. Fracture gap motion (FGM) and relative interfragmentary rotation (RIFR) between the three main fracture fragments were assessed under loads of 750 N using an optical 3D measurement system. Results STS loading generally resulted in higher mean FGM and RIFR than STS loading in the AP+PCS and AP+PP groups, while no significant differences were found in the PP+ACS group. Compared to conventional both column plate fixation (AP+PP), PP+ACS displayed significantly higher FGM and RIFR between the iliac wing and the posterior column during SLS loading. No significant differences in FGM and RIFR were identified between the AP+PCS and the AP+PP group. Conclusion Overall, single column plate plus other column lag screw fixation conferred similar stability to conventional both column plate fixation. From a clinical point of view, AP+PCS appears to be the most attractive alternative to conventional AP+PP for internal fixation of ACPHT fractures.

We report a case series of 2 patients with unilateral acetabular insufficiency fractures who received allogeneic peripheral blood stem cell transplantation for hematologic malignancies complicated by chronic graft vs host disease. These were managed with uncemented cup and cage total hip arthroplasty and stabilization of posterior column with plating. Osteonecrosis of the acetabulum is an uncommon musculoskeletal complication of chronic graft vs host disease. The orthopedic impact of this disease should not be overlooked. Surgical intervention with this construct can provide necessary stability to improve patient function.

Background Acetabular fractures in childhood are rare and the literature is scarce to describe a standard protocol in surgical management of these injuries. As the patient is still growing, it warrants a detailed assessment with a sound surgical plan if operative intervention is deemed necessary to prevent late complications. Throughout literature, most fixation rely on using pins, screws, plates or combination of the three which require large surgical exposure and risk of secondary physeal injury, hence we come up with a method of using the Titanium Elastic Nail System (TENS) to overcome this issue. We describe a novel technique in managing acetabular fractures in this group of patients using the TENS. Method An 8 year old girl with a diagnosis of right anterior column posterior hemitransverse acetabular fracture was fixed with 3 TENS for supra-acetabular, anterior column and posterior column fragments. Surgery was performed in a minimally invasive manner. No drilling was performed during the surgery and implant insertion is done manually. Results Advantages of this procedure include minimally invasive surgery with smaller wounds, minimal intraoperative bleeding and theoretically reduces the risk of premature fusion of the triradiate cartilage. Patient is allowed early rehabilitation with this method. Conclusion This novel method provides an alternative to traditional usage of wires, pins, plates and screws as is described in most literature. However, it requires the surgeon to appreciate that the safe corridors for the implant are much narrower than adults. We recommend this technique for fractures that are deemed suitable for intramedullary fixation and further research in the future will be needed.

Objective in elderly patients reduction and fixation of acetabular fractures showed poor outcomes in fracture patterns where cartilage comminution/impaction and/or femoral head dislocation are present; acute arthroplasty with standard uncemented hemispherical cups and posterior plating has been recently proposed, we report on its safety and effectiveness. Methods we used this technique to manage 67 displaced acetabular fracture but both column in patients older than 65 years old. Results fractures of posterior column and/or wall with severe cartilage involvement may be treated safely with acute THA. Conclusions Good results in complex fracture patterns may also be achieved.

Pedicle subtraction osteotomy (PSO) is highly effective as a sagittal correction approach in patients with adult spinal deformity, but relevant issues such as surgical complexity and long-term complications limit its applicability. Recently, minimally invasive techniques have been reported to be useful for surgical treatment of adult spinal deformity; however, few reports have directly compared these techniques with PSO.The purpose of this study was to evaluate the radiological and clinical efficacies of oblique lateral interbody fusion (OLIF) with posterior column osteotomy (PCO) using stiff rods (6.35-mm cobalt chrome [CoCr]).Retrospective comparative study.One-hundred six patients (average age 71.3 years) diagnosed with adult spinal deformity presenting with sagittal imbalance for whom follow-up of over 2 years after sagittal correction (between 2013 and 2017) was available.Description and analysis of X-ray, computed tomography scans, operative time, estimated blood loss, and clinical outcomes (Oswestry Disability Index [ODI] and Visual Analog Scale [VAS]).A comparative analysis was performed evaluating spinopelvic parameters and clinical outcomes including the ODI, VAS, and complications in patients who underwent PSO (PSO group; n=65) or multilevel prepsoas OLIF combined with PCO and open posterior spinal fusion using 6.35-mm CoCr rods (OLIF group; n=41). The authors have no conflicts of interest to disclose.There were no differences in preoperative spinopelvic parameters between the PSO and OLIF groups. Although no differences were observed between the two groups in terms of postoperative SVA (-12.66 mm vs. -16.44 mm), postoperative lumbar lordosis (-71.46° vs. -72.55°), lumbar lordosis correction (77.96° vs. 73.54°), or postoperative pelvic tilt (9.35° vs. 7.17°), the estimated blood loss was significantly lower in the OLIF group (2824 mL vs. 1736 mL, p.05). No differences were observed in clinical outcomes (ODI, VAS, and clinical complications), proximal junctional kyphosis, and spinopelvic parameters between the two groups 2 years after surgery. However, pseudarthrosis during the follow-up period, including rod fracture, occurred less frequently in the OLIF group compared with that in the PSO group (p.05). OLIF was performed from the T12-L1 to L5-S1 regions (124 segments), with an average of three segments per patient. The computed tomography scans immediately after surgery showed an average segmental correction of -18° and 12.9% (16 segments) of 124 segments showed a correction angle of30°.Multilevel OLIF with PCO using a stiff rod to treat severe sagittal imbalance resulted in similar levels of sagittal balance and lordosis correction as obtained by PSO. Multilevel OLIF with PCO using a stiff rod can be an effective alternative to PSO for patients with severe sagittal imbalance.

To investigate the clinical and imaging outcomes of posterior unilateral vertebral lamina fenestration debridement and bone grafting fusion combined with laminar reconstruction and instrumentation compared with the traditional posterior-only method for treating monosegment spinal tuberculosis.Fifty-four patients underwent posterior unilateral vertebral lamina fenestration debridement and bone grafting fusion combined with laminar reconstruction and internal fixation (group A), and 60 patients underwent 1-stage posterior debridement, laminectomy decompression, bone grafting fusion and instrumentation (group B). The clinical and radiographic outcomes of these groups were analyzed and compared.Group A had less intraoperative blood loss, shorter hospitalization, and a shorter fusion time than did group B (P0.05). At 3 months postoperatively, group A had a lower mean Oswestry Disability Index than did group B (P0.05). At the final follow-up, group A had a lower mean visual analog scale pain score and a lower mean ODI than did group B (P0.05). Group A had a smaller kyphotic angle loss (1.2° ± 0.6°) and loss rate (4.8% ± 2.5%) than did group B (P0.05).The procedure of posterior unilateral vertebral lamina fenestration debridement and bone grafting fusion combined with laminar reconstruction and internal fixation is safe and effective in treating monosegment spinal tuberculosis. Compared with the conventional posterior-only approach, this method maximizes the retention and reconstruction of the posterior column and is minimally invasive, achieving faster postoperative recovery with fewer complications.

The use of peripheral nerve blockade for hip surgeries has proved to be beneficial. The PEricapsular Nerve Group block is a new technique described for hip fracture and hip arthroplasty that has shown to provide better analgesia compared to other peripheral blocks commonly performed for this type of surgery. This technique blocks the obturator nerve and the articular branches of the femoral nerve and the accessory obturator nerve. There are few reports describing continuous analgesia using catheters inserted in the pericapsular nerve group area. We describe a case of continuous nerve block for preoperative analgesia that lasted up to 120hours in an adult patient with a fracture of the posterior column and wall of the acetabulum. We found that by increasing the infusion rate, analgesia reached the distal femoral area. Unlike the original technique, a high-frequency linear probe was used in this case.

Background Tibial plateau fractures involving two or more columns were routinely assessed by two-dimensional radiography in the past. This often misled surgeons and attention was given only to the medial and lateral column without consideration of the posterior column, especially the postero-medial corner. Luo in 2010 introduced the new three-column classification system based on multiplanar computed tomography images. This study was conducted to assess the outcome after internal fixation of tibial plateau fractures involving two or more columns in our centre based on the column specific approach. Materials and Methods This was a prospective study conducted at our institute, between 2011 and 2016. Total of 183 patients with tibial plateau fractures involving two or more columns were admitted during this study period of which 123 patients were satisfied our inclusion criteria. 8 patients were lost to follow up. Hence 115 patients with tibial plateau fractures involving two or more columns were classified based on the new three column classification system. Dual column fixation (Anterolateral +Anteromedial) was done in 76 patients, (Anterolateral+Posteromedial) fixation in 25 patients and triple column fixation (Anterolateral + Anteromedial + Posteromedial) in 14 patients. Post operatively patients were assessed by Modified Rasmussen functional and radiological scoring system. Results Based on Modified Rasmussen functional scoring system, 73 patients (63.5%) had excellent results, 37 patients (32.2%) had good results and 5 patients (4.3%) had fair results. Based on Modified Rasmussen radiological scoring system, 71 patients (61.7%) had excellent results, 38 patients (33.1%) had good results, 6 patients (5.2%) had fair results. 3 patients had deep infections. Conclusion Based on our study, we like to conclude that we had good outcomes utilizing this modern column specific approach to the treatment of these two or more column tibial plateau fracture injuries, which includes assessment of three columns.

Highlights • Schwannomatosis is defined as multiple schwannomas without presence of neurofibromatosis and this is a relatively rare pathology. • In vast majority of cases the schwannomas grew from different nerve roots. • We present the case of a patient with six schwannomas of the cauda equina that grew from a single spinal root as well as discuss the treatment strategy. • Multiple spinal cord schwannomas that are growing along the same part of the vertebral column can be safely removed by one side hemilaminectomy using a high-speed diamond drill with preservation of the integrity of the muscles and ligaments on the opposite side and thus maintain spinal stability. • Neuromonitoring is mandatory for the surgical procedure to allow successful results and to prevent any neurological damage. • The 30 degree endoscope can be a good tool for visual exploration of the spinal canal., Introduction Schwannomatosis is defined as multiple schwannomas without presence of neurofibromatosis and is a rare pathology. In vast majority of cases the schwannomas grow from different nerve roots or peripheral nerves. Presentation of case A 52-year-old woman presented with multiple intradural schwannomas arranged in a chain along the spinal canal causing significant compression. The lesions were successfully removed using a left side en-bloc hemilaminectomy technique in order to preserve maximal stability of the posterior column. Back and leg pain resolved completely. Tendon reflexes returned to normal shortly. There was decreased pain sensation in the distribution of the left L3 spinal root. Discussion The traditional surgical strategy for posterior approach by laminectomy or laminotomy is sometimes complicated with instability or deformation of the vertebral column that requires surgical stabilization. We performed a one side en-bloc hemilaminectomy thus maintaining the integrity of the muscles and ligaments on the opposite side and preserving maximal stability of the vertebral column. Densely adherent tumors required careful sharp dissection and separation under neurosurgical monitoring and stimulation for recognition and preservation of spinal roots. An additional tumor was discovered by exploration of the spinal canal using an endoscope. Conclusion Multiple spinal cord schwannomas that are growing along the same part of the vertebral column can be safely removed by one-sided hemilaminectomy with preservation of the integrity of the muscles and ligaments on the opposite side and thus maintain spinal stability. The 30° endoscope can be a good tool for visual exploration of the spinal canal.

Background Indication for surgical treatment of posterior tibial plateau fractures (TPFs) remains up for debate. Three-dimensional computed tomography (3D-CT) reconstruction can provide insight into fracture morphology and could improve treatment strategy and surgical planning. In this study, we investigated the value of 3D-CT reconstruction in the treatment of posterior TPF and evaluated the influence on surgical decision-making. Methods CT images of 34 cases with a TPF involving the posterior column were included and digitally presented to a panel of five international observers at two intervals. At the first evaluation, only coronal, axial and sagittal images were shown. After an interval of at least three weeks, 3D-CT reconstruction images were added. During both surveys, observers were asked to classify the TPF according to the revised three-column classification (rTCC), as well as to define operative strategy. Results When using 2D images, overall multirated kappa value was 0.48, with an average pairwise agreement of 68%. After adding 3D images, overall multirated kappa value was 0.43, with average pairwise agreement of 67%. Hierarchical logistic regression of decision to operate on image condition (3D vs. 2D) shows an odds ratio of 2.01 (95% confidence interval, 1.11–3.67), P = .022. Increase in operative indication was seen mainly in posterolateral fractures. Conclusion This study investigated the value of 3D classification in the treatment of posterior column TPF. Contrary to expectations, the addition of 3D images to the assessment did not reduce but rather appeared to increase operative indications, especially in fractures involving the posterolateral region.

BACKGROUND: Modern treatment principles for posterior wall fractures have become widespread in the last decade in many countries by means of international or local courses. The purpose of this study was to compare the clinical and radiologic outcomes of acetabulum posterior wall fractures using unconventional methods of fixation, including plates placed in unusual directions, or, in the case of reoperation, only interfragmentary screws. In addition, we examined acetabulum posterior wall fractures treated by open reduction and internal fixation with standard undercountered plates from ischion to iliac bone in latter cases. METHODS: Twenty-one patients who had open reduction and internal fixation of an unstable unilateral fracture of the posterior wall of the acetabulum between 2009 and 2013 were included. Group 1 was composed of 10 former patients who were treated with unconventional methods that included a compression technique with a direct plate or solely screw fixation. Group 2 was composed of latter 11 patients who were treated with standard surgery that included undercountered plates oriented from the ischial tuberosity to the iliac bone proximally and reconstruction of marginal impaction if necessary. The functional outcome was evaluated with the use of the clinical grading system adopted by Merle d'Aubigné and Postel. The Kellgren–Lawrence radiologic criteria were used for the radiologic assessments. The reduction of the fracture, posterior dislocation, marginal impaction, mean fracture particle amount, trochanteric osteotomy and avascular necrosis were compared between the two groups and examined with the Mann–Whitney U test. RESULTS: In Groups 1 and 2, the median score of the modified Merle d'Aubigné and Postel clinical scoring system was 16 (8–18) and 18 (14–18), respectively. The clinical scores between the two groups were statistically significant (p

Sagittal imbalance is most commonly seen in patients with multilevel degenerative disc disease, inflammatory arthropathies, severe osteoporosis, and untreated idiopathic scoliosis. The degree of imbalance is closely correlated with clinical symptoms. Sagittal deformity can occur from a variety of causes in both young and elderly patients, however it has been found to most likely be multifactorial. Other causes include Scheuermann's Kyphosis, iatrogenic flat-back, post-traumatic, neuromuscular, and congenital disorders such Klippel–Feil and infantile scoliosis. Clinical evaluation includes a thorough health history and physical examination, as well as more advanced methods such as surface topography and 3D postural analysis. The determination to utilize an osteotomy during deformity surgery is based on many factors including the patient's global sagittal alignment and radiographic assessment, the amount of correction needed to restore proper alignment, the relative rigidity of the deformity, and any focal areas of severe angulation. The three most commonly utilized osteotomies are discussed below including the posterior column Smith–Peterson/Ponte osteotomy, as well as the three-column pedicle subtraction osteotomy and vertebral column resection. The goal of a corrective osteotomy is to normalize the local segment's curve in order to correct the overall global spinal alignment and improve patient function. Complication rates as high as 25–40 percent have been reported in literature.

Cervical spine finite element models reported in biomechanical literature usually represent a static morphology. Not considering morphology as a model parameter limits the predictive capabilities for applications in personalized medicine, a growing trend in modern clinical practice. The objective of the study was to investigate the influence of variations in spinal morphology on the flexion-extension responses, utilizing mesh-morphing-based parametrization and metamodel-based sensitivity analysis. A C5-C6 segment was used as the baseline model. Variations of intervertebral disc height, facet joint slope, facet joint articular processes height, vertebral body anterior-posterior depth, and segment size were parametrized. In addition, material property variations of ligaments were considered for sensitivity analysis. The influence of these variations on vertebral rotation and forces in the ligaments were analyzed. The disc height, segmental size, and body depth were found to be the most influential (in the cited order) morphology variations; while among the ligament material property variations, capsular ligament and ligamentum flavum influenced vertebral rotation the most. Changes in disc height influenced forces in the posterior ligaments, indicating that changes in the anterior load-bearing column of the spine could have consequences on the posterior column. A method to identify influential morphology variations is presented in this work, which will help automation efforts in modeling to focus on variations that matter. This study underscores the importance of incorporating influential morphology parameters, easily obtained through computed tomography/magnetic resonance images, to better predict subject-specific biomechanical responses for applications in personalized medicine.

Background Context: One of the characteristics of reported observations in adolescent idiopathic scoliosis (AIS) is that the thoracic spine is longer anteriorly than posteriorly, more pronounced around the apex than the transitional zones. This reversal of the normal kyphotic anatomy of the thoracic spine is related to questions of etiopathogenesis of AIS. The changes in the anatomy of the anterior column have been described rather in detail; however, the role of the posterior spinal column and the laminae has so far not been elucidated. If the posterior column exhibits a longitudinal growth disturbance, it could act as a tether, leading to a more or less normal anterior column with a deformed and shorter posterior aspect of the spine. So far, it has remained unclear whether this anterior-posterior length discrepancy is the result of relative anterior lengthening or relative posterior shortening, and which tissues (bone, disc, intervertebral soft tissue) are involved. Purpose: The present study aimed to compare the discrepancy of the anterior-posterior length of the spinal column in the “true” midsagittal plane of each vertebra in patients with idiopathic scoliosis versus controls, using three-dimensional computed tomography (CT) scans. Study Design/Setting: This is a cross-sectional study. Patient Sample: The sample consisted of computed tomography scans of 80 patients with moderate to severe AIS (Cobb angle: 46°–109°) before scoliosis navigation surgery and 30 non-scoliotic age-matched controls. Outcome Measures: The height of the osseous and non-osseous structures from anterior to posterior in the “true” midsagittal plane has been determined: the anterior side of the vertebral body and disc, the posterior side of the vertebral body and disc, the lamina and interlaminar space and the spinous process and interspinous space, as well as the height ratios between the anterior column and posterior structures of the primary thoracic and lumbar AIS curves and corresponding levels in non-scoliotic controls. Methods: Semiautomatic software was used to reconstruct and measure the parameters in the true midsagittal plane of each vertebra and intervertebral structure that are rotated and tilted in a different way. Results: In AIS, the anterior height of the thoracic curve was 3.6±2.8% longer than the posterior height, 2.0±6.1% longer than the length along the laminae, and 8.7±7.1% longer than the length along the spinous processes, and this differed significantly from controls (−2.7±2.4%, −7.4±5.2%, and +0.7±7.8%; p

We aimed to determine the changes in cervical canal diameters and spinal cord compression at each level from C2-3 to C7-T1 in flexion and extension positions and to study the use of flexion-extension magnetic resonance imaging (MRI). We also aimed to assess the changes in the length of the spinal cord in flexion and extension positions of the cervical spine.Flexion-extension MRI scans were performed consecutively on sixty-six patients with neck pain with/without neurogenic symptoms of the cervical spine. All patients were treated conservatively. We investigated the length of the cervical spinal cord (LSC), length of the cervical spinal anterior column (LAC), length of the cervical spinal posterior column (LPC), spinal canal diameter, and severity of cord compression in flexion, neutral, and extension positions.At each intervertebral level (from C2-3 to C7-T1), the average spinal canal diameter showed significant decrease from flexion to extension positions (P 0.05). The average LSC, LAC, and LPC were decreased on extension of the neck compared with flexion (P 0.05). Higher stages were found in extension position than in flexion position with statistically significant differences (P 0.05).The use of flexion-extension MRI may demonstrate true pathology that contributes in the pathogenesis of cervical degenerative disease (CDD). Higher stages in spinal cord compression were found in extension position than in flexion position. However, higher stages in spinal cord compression in extension position did not necessarily cause severe myelopathy. This finding is an important evidence for conservative therapy on patient neck position education.

Introduction: Operative treatments of T-type acetabular fractures are challenging surgical procedures. Open reduction and internal fixation is the standard method for the operative management of these fractures, however this is associated with high blood loss, long hospital stay and longer rehabilitation. Anterior subcutaneous pelvic fixation (internal fixation = INFIX) and retrograde pubic screw fixation have shown promising results in minimally invasive treatment of pelvic ring fractures. For T-type acetabular fractures, however, minimally invasive treatment concepts are still rare. Therefore we performed a mechanical in vitro study to: - investigate the potential favorability of minimally invasive treatment options over the already established open anterior locking plate osteosynthesis of acetabular T-fractures regarding biomechanical stability and post-surgical stiffness;- explore the biomechanical feasibility of the INFIX;- assess its potential ability to reduce the anterior acetabular column. Hypothesis: A minimally invasive treatment of acetabular T-type fractures is biomechanically equivalent to an open anterior plate osteosynthesis. Methods: Twenty-four synthetic hemipelvis specimens with a T-type acetabular fracture were divided in four groups. A posterior column screw was placed in every pelvis of every group. The anterior column was fixed with: - anterior column screw;- anterior column screw incl. INFIX;- INFIX alone;- 14-hole angular stable locking plate (standard fixation method). Displacement of the anterior column was reduced in group 2 +3 using the INFIX. All specimens were cyclically loaded with 200 N until a maximum of 600 N. Movement/displacement of the fracture fragments were detected with a 3D-ultrasound measuring system. Displacement (mm) and Stiffness (N/mm) of the construction were analyzed. Results: Statistical assessment showed no significant differences between the four fixation types (p > 0.05). The 14-whole locking plate (group 4) displayed the overall highest stability with a displacement of 1.3 +/- 0.04 mm and stiffness of 76.3 +/- 2.4 N/mm. Anterior screw fixation (group 1) proved to be the minimally invasive fixation method with the least displacement and highest stiffness (1.5 +/- 0.2 mm, 68.3 +/- 6.8 N/mm). The combination of an INFIX and an anterior column screw (group 2), showed a mean stiffness of 62.1 +/- 6.0 N/mm and a mean displacement of 1.7 +/- 0.2 mm. INFIX only (group 3) presented a displacement of 1.6 +/- 0.1 mm and a stiffness of 64.5 +/- 4.5 N/mm. Discussion: Minimally invasive fixation techniques for T-type acetabular fractures show promising biomechanical stability in non- or slightly displaced fractures. Furthermore, INFIX could be a feasible tool for the reduction of the anterior acetabular column.

Background It is often difficult to achieve stable fixation in Tile type C1 pelvic fractures and there is no standard fixation technique for these types of injuries. Hypothesis Iliac screw fixation can be used for treating Type C1 pelvic fractures. Patients and methods A retrospective review was performed on 47 patients who underwent iliac screw fixation in posterior column of ilium (PCI) for Tile type C1 pelvic fractures from July 2007 to December 2014. All patients were treated with fracture reduction, sacral nerve root decompression (if needed), internal fixation by iliac screw and connecting rod. The data on surgical time, intraoperative bleeding volume, postoperative neurologic functions and postoperative complications were analyzed. Patients were follow-up for at least 12 months. Results The mean surgical time was 148 minutes, and the mean intraoperative bleeding volume was 763 ml. Patients were encouraged in-bed activities immediately after surgery. The postoperative Majeed functional score was 48–100 points (mean 80.2), corresponding to an excellent and good recovery of 91.5%. Postoperative X-radiographs and CT scans indicated satisfactory fracture reduction. Discussion Iliac screw fixation combined with sacral nerve canal decompression could effectively restore pelvic alignment and improve neurological functions for complex pelvic trauma.

Purpose The authors have identified a subset of unicondylar tibial plateau depression fracture patterns caused by a flexion-valgus force. The purpose of this study was to describe this fracture pattern and suggest a modified lateral approach that may allow for improved reduction and stabilization. Methods The preoperative radiographs and CT scans of 102 patients who sustained unicondylar tibial plateau fractures (OTA 41B) were reviewed. Twenty-six fracture patients had posterolateral (PL) tibial plateau depression fractures. By medical record review and telephone follow-up, the injury mechanism of the 22 unicondylar tibial plateau fractures was confirmed as a flexion-valgus force. The radiographic features of those cases were analyzed and measured. To address this specific fracture pattern, a modified approach combined with a novel intra-articular osteotomy was applied. Results According to the morphological characteristics, this tibial plateau fracture pattern could be divided into two subtypes: type A was a confined, basin-like articular surface depression fracture located in the PL quadrant, and type B was a cancellous fracture involving the PL tibial plateau resulting in a decrease in the posterior slope. One radiographic hallmark of this fracture pattern is an anatomically or a mechanically intact posterior column wall. The novel approach was applied to both types. The postoperative radiographic measurements revealed excellent reduction quality. On axial scans, the distance between the most posterior rafting screw and the tangent line of the tibial plateau rim was 3.0 ± 2.07 mm (from −1.9 to 4.3), and the angulation between them was 8.9 ± 3.02° (from −7.3 to 15.6). These results indicated excellent PL quadrant coverage from the rafting screws. Conclusion Flexion-valgus force-induced unicondylar tibial plateau depression fracture is a unique injury pattern. We suggest a novel surgical approach to address this injury’s key features, which may facilitate exposure and enhance fixation strength.

Background Vertebroplasty represents an established treatment option for osteoporotic vertebral compression fracture (OVCF), but its radiographic and clinical outcomes have not been clearly described in patients with intra-vertebral cleft (IVC). The aim of this study was to assess vertebral height restoration, recollapse and change of back pain in OVCF patients with or without IVC. Methods The records of 108 patients with IVC (group I) and 233 patients without IVC (group II) were included in our analysis between March 2001 and February 2014. The heights of the anterior, middle, and posterior columns, as well as the wedge angle (WA) of the fractured vertebral body were measured. For each vertebral column, the mean height of the superior and inferior vertebral body served as reference. Pre-operative, postoperative, and final compression rates (CR), as well as restoration and recollapse rates were calculated for each column. Subjective back pain was assessed as the numeric rating scale (NRS) score. Results The overall incidence of IVC in OVCF patients who underwent vertebroplasty was 20.8% (127/611 patients). Group I showed significantly higher CR over the entire follow-up period, with the exception of CR for the anterior column at final follow-up, and CR for the posterior column throughout the follow-up. The mean restoration rates at the anterior and middle column immediately after vertebroplasty were also significantly larger in group I. Recollapse rate in all columns was similar for groups I and II. The mean wedge angle was significantly larger in group I over the entire follow-up period. The groups did not differ in terms of NRS score at final follow-up. Conclusions Vertebroplasty restores vertebral body heights and WA more effectively in OVCF patients with IVC, and provides satisfactory radiographic and clinical outcomes regardless of the presence of IVC.

Scheuermann's disease is a rigid kyphotic deformity due to anterior wedging of at least three thoracic vertebrae that occurs in the growing spine. The aetiology, pathogenesis and natural history are not completely understood and this leads to significant debate about the treatment options. Patients present with a cosmetic deformity and thoracic pain but symptoms tend to settle at skeletal maturity. For most patients, observation and physiotherapy alone are required during spinal growth. In moderate deformities bracing may stop or slow down kyphosis progression whilst the spine grows but deformity tends to recur once the brace is removed. Surgical correction is indicated for adolescents with progressive deformities greater than 70° that are associated with thoracic pain and have not responded to nonoperative treatment. There is no consensus over optimal surgical technique for correction but options include posterior only or anteroposterior correction and spinal fusion, with or without posterior osteotomies to shorten the posterior column during correction. The risk of complications is significant and should be discussed in detail with the patient and their family prior to any treatment decision.

Introduction and importance Anterior column plate combined with posterior column screws have been effectively used for treatment of displaced transverse acetabular fractures. This article presents the use of 3D-printed technology for customising a guide template to appropriately place posterior column screw. Case presentation A 50-year-old female suffered displaced juxtatectal fracture of the right acetabulum. A personalised guide for antegrade posterior column screw placement was designed based on the data of her pelvic CT-scan. This guide and a prototype of her right acetabulum - created by mirroring the intact left acetabulum - were 3D-printed for preoperative evaluation and pre-contouring of reconstruction plate. Modified Stoppa approach and additional lateral window were used for direct reduction, anterior column plate and posterior column lag screw fixation. Post-operative CT-scan showed good reduction and nearly ideal screw position. Clinical discussion Anterior column plate and antegrade posterior column screw could provide joint stability and early mobilisation for displaced transverse acetabular fractures. However, determination of optimal entry point, direction and length for screw insertion is still technically demanding. The 3-D reconstruction images of hemipelvic specimen allowed us to identify the safe bone corridor, design a drill guide to put the proper guide pin and conduct preoperative trial. All those resulted in appropriate real screw fixation with reduction of soft tissue damage, X-ray exposure and time of operation. Conclusion The use of 3D-printed personalised guide for posterior column screw fixation is a promising alternative option for treatment of displaced transverse acetabular fracture where 3D-navigation system is not available., Highlights • 3D-printed personalised drill guide is a potential tool for minimally invasive techniques. • Anatomical reduction is required to optimise the precision of 3D-printed personalised guide. • Iliac tubercle can be used as a landmark for defining the entry point of posterior column lag screw. • Intraoperative fluoroscopic control is still needed to confirm the screw placement.

BACKGROUND CONTEXT Pseudarthrosis with distal mechanical failure is a common complication after long constructs in adult spinal deformity (ASD). Multiple strategies have been proposed to improve fusion rates and reduce the rate of rod fracture, including the use of interbody fusion (IBF) and multi-rod (≥3) techniques. Whether rod fracture rates are lower with the utilization of IBF versus multi-rod constructs remains unknown. PURPOSE To assess for any difference in rod fracture rate between constructs with IBF and multiple rods up to 2 years postoperatively. STUDY DESIGN/SETTING Retrospective Cohort. PATIENT SAMPLE ASD patients undergoing fusion of ≥6 levels to ilium and a minimum follow-up of 24 months. OUTCOME MEASURES Rate of postoperative rod fracture. METHODS ASD patients undergoing fusion of ≥6 levels to ilium and a minimum follow-up of 24 months were included. Patients with a history of prior fusion to L4 or below, and those with neuromuscular disease, inflammatory arthritis, or skeletal dysplasia were excluded. Patients were grouped by construct types: 2 rods w/ IBF (IBF) and w/o IBF (2R) and ≥3 rods w/o IBF (3R). Demographics, perioperative and radiographic data, and evidence of rod fracture were collected. ANOVA, chi-square and Fisher exact tests were used to compare across construct types. RESULTS Seventy-one patients were included, with mean age 65.0 years (±8.5) and BMI 26.7 kg/m2 (±5.4). In total, 20 patients had 2R constructs, 12 had IBF, and 39 had 3R. There were no significant differences in sagittal or coronal parameters at baseline or 2 years, or in OR time, EBL, or number of levels fused across groups. There were 76.1% of patients with posterior column osteotomy (2R 75.0%, IBF 50.0%, 3R 84.6%; p=0.063) and 9.9% had 3 column osteotomy. There were 12 total rod fractures (15.2%) with no significant difference between groups (2R 25.0%, IBF 16.7%, 3R 12.8%; p=0.423) and no differences in revision rate for rod fracture. CONCLUSIONS Compared to multi-rod techniques, the addition of IBF does not reduce the rate of rod fracture at two years after long constructs for ASD. These findings suggest that increasing the rigidity of the construct with the addition of a third rod may be sufficient to prevent rod fractures while IBF may provide no additional benefit at 2 years follow-up. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Surgical removal of lateral or ventrolateral spinal intramedullary gliomas remains a challenge. For lateral or ventrolateral tumors, the dorsal root entry zone (DREZ) myelotomy (equivalent to dorsolateral sulcus approach) and the posterior midline myelotomy would require dissection of the posterolateral tract or posterior column tracts and cause neurologic dysfunction. In Video 1, we introduce a novel approach in which myelotomy was performed anterior to DREZ. The spinal cord was entered between the DREZ and dorsal spinocerebellar tracts, and the surgical path was posterior to the lateral corticospinal tract. Thus no important spinal cord tracts were damaged. The patients with intramedullary glioma depicted in this video had no new neurologic dysfunction postoperatively. This approach has also been reported in treating intramedullary cavernous malformations.1 Compared with the DREZ approach, myelotomy anterior to the DREZ has 2 advantages. First, the blood vessels anterior to DREZ are always sparser than the posterolateral sulcus. Second, the injury of the somatosensory tract and posterior horn of the spinal cord caused by the dorsolateral sulcus approach can be avoided. Special technique details for this approach are as follows: 1) Myelotomy anterior to DREZ can be optional for selective cases of lateral or ventrolateral intramedullary tumor. 2) It is difficult for cervical intramedullary tumors because the cervical dorsal roots always cover the area of the anterior DREZ. 3) It is useful for a multisegment tumor to cut the dentate ligament. 4) Hemilaminectomy can be used in selective cases for this approach.

Correction of adult spinal deformity is associated with substantial improvements in patient quality of life. However, traditional open osteotomy techniques are associated with notably high rates of morbidity particularly when utilizing larger, more powerful, 3-column osteotomies. Data exists that support the use of minimally invasive posterior column osteotomies in the context of transforaminal lumbar interbody fusion, but further research is warranted to confirm the clinical utility of mini-open 3-column osteotomies.

Background Lateral interbody fusion (LIF) is traditionally performed with the patient in lateral decubitus, requiring repositioning to prone for adjunctive posterior procedures, or modifying traditional posterior techniques to be done while positioned lateral. The benefits of lateral anterior column access may be achievable with the patient prone, allowing for concomitant posterior techniques in a more familiar single-position setting. Methods Prone transpsoas (PTP) access was outlined and vetted by a group of LIF-experienced spine surgeons. Early clinical experience included prospectively capturing procedural details and perioperative outcomes across a multi-centre cohort of clinicians to assess feasibility and to identify efficiencies and/or challenges. Results Perioperative data was prospectively collected from 120 consecutive cases (176 levels) from 22 surgeons. Lateral exposure was achieved in an average 18 min/level, guided by triggered EMG; and retraction time averaged 25 min/level, with continued plexus monitoring via saphenous SSEP. Fixation was via percutaneous pedicle screws (65%), open pedicle screws (24%), other (11%). No re-positioning was required. Concomitant procedures facilitated by prone position included direct decompression (37%), treatment at L5-S1 (18%), posterior instrumentation revision (7%), and osteotomy/bony releases (9%). PTP procedure time, blood loss, and length of stay were consistent with established LIF experience. Challenges included patient movement with lateral instrument forces, retractor sag, stability of access relative to the patient, and surgeon ergonomics of the working channel. These challenges were overcome later in the experience through development of a specialized positioner and retractor system specific to this approach and a prescribed workflow developed by consensus of the surgeons. Conclusion Initial multi-centre clinical experience suggests that PTP is not only feasible but creates efficiencies by allowing for single-position surgery maximizing both anterior and posterior column access and corrective techniques, with perioperative outcomes consistent with lateral decubitus experience. Learnings included the need for development of procedure-specific technologies and technique refinement.

Background Posterior column osteotomy (PCO) has been used for the correction of various spinal deformities. However, little evidence is available regarding the effects of multilevel PCO in adult spinal deformity (ASD) surgery. This study aimed to show the usefulness of PCO in rigid ASD surgery by assessing radiographic and clinical outcomes. We also aimed to assess the corrective potential of multilevel PCOs compared with a single-level pedicle subtraction osteotomy (PSO). Methods Between 2012 and 2016, the medical records of 70 consecutive patients who underwent a multilevel PCO (35 patients) or a single-level PSO (35 patients) for ASD in a single institute were reviewed. Baseline data, radiographic measurements, and clinical outcomes using the Scoliosis Research Society-22 (SRS-22) questionnaire were compared between groups. Results The following variables were no different between the groups: age at surgery, sex, level fused, preoperative and postoperative radiologic parameters, and bone mineral density T score. However, operation time (380.0 vs. 483.6 minutes), estimated blood loss (1175.7 vs. 1362.6 mL), and the number of complications (8 vs. 20) were significantly reduced in the PCO group compared with the PSO group. A significant improvement in the SRS-22 score was seen in both groups after surgery, although no difference was observed between the groups postoperatively. Conclusions Multilevel PCOs for the correction of rigid ASD were slightly superior to PSO, regarding clinical outcomes. Radiographic outcomes were similar between groups. Thus, multilevel PCOs may be a viable option for the treatment of rigid ASD with a mobile segment.

Background Context Spinal osteoid osteomas are benign primary tumors arising predominantly from the posterior column of the spine. These "osteoblastic" lesions have traditionally been treated with intralesional excision. Purpose The purpose of the present study was to review the treatment and local recurrence rates for symptomatic spinal osteoid osteomas. Study Design/Setting Multicenter ambispective cross-sectional observational cohort study. Patient Sample During the study period, a total of 84 patients (65 males, 19 females) were diagnosed with a spinal osteoid osteoma and received surgical treatment. The mean age at surgery was 21.8 ± 9.0 years (range: 6.7–52.4 years) and the mean follow-up was 2.7 years (13 days–14.5 years). Outcome Measures Local recurrence, perioperative morbidity, and cross-sectional survival. Methods Using the AOSpine Knowledge Forum Tumor multicenter ambispective database, surgically treated osteoid osteoma cases were identified. Patient demographic, clinical and diagnostic, treatment, local recurrence, perioperative morbidity, and cross-sectional survival data were collected and retrieved. Descriptive statistics were summarized using mean/standard deviation or frequency/percentage. Results In our study, most of the tumors were localized in the mobile spine (81 of 84 [96%]); all patients reported pain as a symptom. According to the postoperative assessment, 10 (12%) patients received an en bloc resection with marginal or wide margins, whereas two (2%) patients received en bloc resections with intralesional margins, 69 (82%) patients were treated by piecemeal "intralesional" resection, and three (4%) patients were not assessed. A total of six patients (7%) experienced a local recurrence, all of which occurred in patients who had received an intralesional resection. Conclusions Benign bone-forming tumors of the spine are uncommon. Most patients in our series underwent a piecemeal resection with intralesional margins. This remains safe with a low local recurrence rate. En bloc excision may provide more chance of complete excision of the nidus but is not mandatory. The importance of complete excision of the nidus cannot be overemphasized.

Objective The fluoroscopically-guided procedure of antegrade posterior lag screw in posterior column fixation through anterior approach is technique-dependent and requires an experienced surgeon. The purpose of this study was to establish the safe zone for the antegrade posterior lag screw by using computational analysis. Method The virtual three-dimensional model of 178 hemi-pelvises was created from the CT data (DICOM format) by using Mimics® program, and were used to measure the safe zone of antegrade lag screw fixation on the inner table of the iliac wing, and the largest diameter of cylindrical implant inside safe zone. The central point (point A) of the cylinder was assessed and was compared with the intersection point (point B) between the linea terminalis and the anterior border of the sacroiliac articulation. Results The safe zone was triangular with an average area of 670.4 mm2 (range, 374.8–1084.5 mm2). The largest diameter of the cylinder was a mean 7.4 mm (range, 5.0–10.0 mm). When height was under 156.3 cm, the diameter of the cylindrical implant was smaller than 7.0 mm (p

Dorsal root entry zone (DREZ) lesioning is an effective method to treat refractory neuropathic pain in patients with radicular avulsion. In this procedure, we penetrate the spinal cord with a radiofrequency electrode using the posterior lateral sulcus as a guide. The intraspinal electrode trajectory has to be angled medially about 25°-45° to spare the corticospinal tract, which lies lateral to the DREZ, and also to spare the posterior column, which lies medial to it. Here we present a case of a patient with radicular avulsion lesion of rootlets of the cervical spinal cord successfully treated with DREZ lesioning using intraoperative ultrasound as a guide to perform the spinal cord lesions. The use of intraoperative ultrasound during DREZ lesioning in patients with radicular avulsion improves the neurosurgeon ability to precisely localize the posterior lateral sulcus and also to better define the correct angulation of the trajectory.

Graphical abstract, Highlights • Ultrahigh-b DWI (UHb-DWI) method applied to MS spinal cords. • UHb-DWI provides quantitative measures of the MS lesions in the spinal cord. • High-b diffusion coefficient (DH) is theoretically sensitive for demyelination. • DH in MS lesion is significantly elevated compared to that of normal spinal cords., Purpose The purpose of this study was to investigate UHb-rDWI signal in white matter tracts of the cervical spinal cord (CSC) and compare quantitative values between healthy control WM with both MS NAWM and MS WM lesions. Methods UHb-rDWI experiments were performed on (a) 7 MS patients with recently active or chronic lesions in CSC and on (b) 7 healthy control of similar age range and gender distribution to MS subjects. All MRI data were acquired using clinical 3T MRI system. Axial high-b diffusion images were acquired using 2D single-shot DW stimulated EPI with reduced FOV and a CSC-dedicated 8 channel array coil. High-b diffusion coefficient DH was estimated by fitting the signal-b curve to a double or single-exponential function. Results The high-b diffusivity DH values were measured as (0.767 ± 0.297) × 10−3 mm2/s in the posterior column lesions, averaged over 6 MS patients, and 0.587 × 10−3 mm2/s in the corticospinal tract for another patient. The averaged DH values of the 7 healthy volunteers from the posterior and lateral column were (0.0312 ± 0.0306) × 10−3 and (0.0505 ± 0.0205) × 10−3 mm2/s, respectively. UHb-rDWI signal-b curves of the MS patients revealed to noticeably behave differently to that of the healthy controls. The patient signal-b curves decayed with greater high-b decay constants to reach lower signal intensities relative to signal-b curves of the healthy controls. Conclusion UHb-DWI of the CSC reveals a marked difference in signal-b-curves and DH values in MS lesions compared to NAWM and healthy control WM. Based on physical principles, we interpret these altered observations of quantitative diffusion values to be indicative of demyelination. Further studies in animal models will be required to fully interpret UHb-DWI quantitative diffusion values during demyelination and remyelination.

Objectives We hypothesize that inserting a curved intramedullary internal fixation device which follows curved osseous fixation paths (OFPs) would be more versatile and mechanically stronger than straight screws for fixation of pelvic ring and acetabular injuries. This study characterizes the dimensions of curved OFPs of the pelvic ring and acetabulum and suggests design parameters for such a curved device. Methods CT scans of intact pelves of 50 female and 50 male subjects were studied using MIM Maestro™ and Solidworks™ to determine the constriction points (smallest cross sections) and the tightest radii of curvature (RoC) in the anterior column, posterior column, iliosacral and pubic symphysis OFPs. Results The constriction point diameters for the superior pubic ramus and supra-acetabular areas were 13 ± 3 mm and 12 ± 3 mm, respectively. The anterior column RoC was greater than 65 mm in all cases. The minimum observed RoC for the path from one ilium, across the SI joint, the sacrum and to the other ilium was 71 mm, with 99% of the cases having a RoC of at least 80 mm, in both the inlet and outlet views. Conclusion This study shows that if a flexible implant which could be stiffened once in place was available, it would enable the use of larger and longer fixation taking advantage of the pelvis’s curved intracortical spaces. Even for dysmorphic pelves, accessible tunnels support a long, strong, curved fixation device.

Background Open surgical access to the postero-lateral talar dome for the treatment of osteochondral lesions is challenging, often requiring a segmental osteotomy of the fibula (fibular window) and division of the anterior inferior tibiofibular ligament (AITFL) or a fibular osteotomy with division of the AITFL and the anterior talofibular ligament (ATFL) (fibular door). Alternatively, to preserve the tibiofibular syndesmosis both the fibula and the lateral tibial plafond can be osteotomised to expose the entire lateral talar dome. All of these techniques involve extensive surgical exposures and a significant amount of internal fixation of the osteotomy to achieve surgical access. Methods A trapezoidal fibular osteotomy which hinges on the AITFL thus preserving the syndesmotic and lateral ligamentous complex was developed to permit perpendicular access to the lateral talar dome. The remaining posterior column of fibula allows keying in of the osteotomy requiring minimal internal fixation. Results A 43 year old male with a displaced osteochondral fracture of the superolateral talar dome underwent the osteotomy to provide perpendicular fixation with two Herbert's screws. The osteotomy was reduced and fixed with a single 3.5mm lag screw. At 3 month follow up the osteotomy had healed both clinically and radiographically. Conclusions Our technique utilizes a novel trapezoidal fibular osteotomy with preservation of key syndesmotic and ligamentous structures and requires minimal internal fixation.

Background Surgical management of advanced periacetabular lesions is challenging because of extensive bone loss, particularly for Modified American Academy of Orthopaedic Surgeons Classification defects type IV (pelvic discontinuity with posterior column involvement). Multiple methods for rebuilding the acetabulum have been described; all involve passing Steinmann pins in a retrograde or an antegrade fashion from the anterior iliac wing or iliac crest around the acetabulum in an attempt to recreate the normal bony anatomy. However, these techniques fail to engage the ischium in its entirety. The ischial contribution to the posterior column is a critical element in a stable acetabular construct. Methods After curettage of the acetabular lesion, Steinmann pins are passed through the ischial tuberosity and posterior column into the sciatic buttress in a retrograde manner. The number of pins depends on the size of the defect and involvement of the posterior column. Patients and Methods Medical records of 11 patients with a Modified American Academy of Orthopaedic Surgeons Classification defect type IV treated with retrograde ischioacetabular Steinmann pin reconstruction at our institution between 2007 and 2012 were reviewed. European Quality of Life-5 dimensions and Lower Extremity Functional Scale questionnaires were used to assess patient functional outcomes. Results The 6 patients (4 females and 2 males; age range, 56-81 years) surviving 12 months postoperatively reported improved mobility and good quality-of-life scores. Conclusion We described a new method for posterior acetabular column reconstruction that uses the ischial tuberosity and body as additional points of stabilization during the reconstruction of the posterior column.

Sciatic nerve injuries associated with acetabular fractures can be post-traumatic, perioperative or postoperative. Late postoperative injury is very uncommon and can be due to heterotopic ossifications, muscular scarring, or implant migration. A case is presented of a patient with a previous transverse acetabular fracture treated with a reconstruction plate for the posterior column. After 17 years, she presented with progressive pain and motor deficit in the sciatic territory. Radiological and neurophysiological assessments were performed and the patient underwent surgical decompression of the sciatic nerve. A transection of the nerve was observed that was due to extended compression of one of the screws. At 4 years postoperatively, her pain had substantially diminished and the paresthesias in her leg had resolved. However, her motor symptoms did not improve. This case report could be relevant due to this uncommon delayed sciatic nerve injury due to prolonged hardware impingement.

The objective of this study was to define a safe zone for antegrade lag screw fixation of fracture of posterior column of the acetabulum using a novel 3D technology. Pelvic CT data of 59 human subjects were obtained to reconstruct three-dimensional (3D) models. The transparency of 3D models was then downgraded along the axial perspective (the view perpendicular to the cross section of the posterior column axis) to find the largest translucent area. The outline of the largest translucent area was drawn on the iliac fossa. The line segments of OA, AB, OC, CD, the angles of OAB and OCD that delineate the safe zone (ABDC) were precisely measured. The resultant line segments OA, AB, OC, CD, and angles OAB and OCD were 28.46mm(13.15-44.97mm), 45.89mm (34.21-62.85mm), 36.34mm (18.68-55.56mm), 53.08mm (38.72-75.79mm), 37.44° (24.32-54.96°) and 55.78° (43.97-79.35°) respectively. This study demonstrates that computer-assisted 3D modelling techniques can aid in the precise definition of the safe zone for antegrade insertion of posterior column lag screws. A full-length lag screw can be inserted into the zone (ABDC), permitting a larger operational error.

Pincer-type femoroacetabular impingement may be caused by acetabular retroversion or global acetabular overcoverage. Recent evidence suggests that open or arthroscopic acetabular rim resection for pincer-type impingement may remove essential weight bearing lunate cartilage with preliminary clinical results suggesting improved hip survivorship with anteverting periacetabular osteotomy (PAO) rather than rim resection. In cases of symptomatic pincer-type femoroacetabular impingement related to global acetabular overcoverage (lateral and anterior center edge angles >40°), a true reverse PAO, which flexes and abducts the acetabular fragment, may be used to reduce anterior and lateral coverage. We present the novel technique for true reverse PAO. Modifications of the reverse PAO when compared to the traditional PAO include: different orientation of the posterior column and ischial osteotomy cuts; the distinct corrective maneuvers to displace the acetabular fragment; bone resection from the iliac osteotomy surfaces to facilitate adequate correction; additional osteoplasty of the anterior ilium to prevent postoperative pressure on the femoral nerve, and steps to prevent subsidence into and nonunion of the posterior column gap created through correction. The reverse PAO is a powerful tool for surgical correction of global acetabular overcoverage. Further study is needed to demonstrate clinical efficacy and outcomes of this modification.

Background: Tibial plateau fractures are complex and may result in sub-optimal results despite a timely and excellent reduction. An important cause for this may be the inability to detect and correct sagittal malalignment consequent to a reversal of the posterior tibial slope. We describe here the surgical steps to restore posterior tibial slope in a series of our patients with tibial condyle fractures involving the posterior column fragment using a fixed-angle locking plate. Methods: This was a prospective cohort study of 4 cases who had sustained closed, bicondylar tibial plateau fractures (AO/OTA 41-C3) involving the posterior column fragment and reversed sagittal slope. All patients were operated in a prone position through a posterior approach. The fixation was done with a fixed angle locking plate. Results: The average time taken for fracture union was 12 (range 10–15) weeks. The posterior tibial slope was restored in all the four patients (mean posterior proximal tibial angle = 8.5°, mean medial proximal tibial angle = 88°). There were no procedure-related complications. All patients attained excellent Knee Society Score at one year follow up (mean score = 93). Conclusion: A posterior approach in the prone position gives direct access to the fracture apex which eases the fracture reduction and fixation to correct the sagittal malalignment in tibial condyle fractures involving the posterior column fragment. We propose this approach as an critical surgical technique which helps in improved outcomes of tibial condylar fractures. Keywords: Tibial plateau fracture, Posterior column fracture, Coronal plane fracture, Tibial slope, Sagittal alignment

Background Acetabular fracture surgery is demanding and screw placement along narrow bony corridors remains challenging. It necessitates x-ray radiation for fluoroscopically assisted screw insertion. The purpose of this cadaver study was to evaluate the feasibility, accuracy and operation time of a novel electromagnetic navigation system for screw insertion along predefined acetabular corridors. Methods A controlled laboratory study with a total of 24 electromagnetically navigated screw insertions was performed on 8 cadaveric acetabula. 3 peri-acetabular bony corridors (QSS, Quadrilateral Surface Screw; IAS, Infra-Acetabular Screw; PCS, Posterior Column Screw) were defined and screws were placed in a defined order without fluoroscopy. Operation time was documented. Postoperative CT scans were performed to analyse accuracy of screw placement. Results Mean cadaver age was 70.4 ± 11.7. Successful screw placement was accomplished in 22 out of 24 (91.7%) cases. The overall mean time for all 3 acetabular screws was 576.6 ± 75.9s. All 3 complications occurred during the placement of the IAS due to an impassable narrow bony corridor. QSS mean length was 50 ± 5mm, IAS mean length was 85 ± 10mm and PCS mean length was 120 ± 5mm. Conclusion In this cadaver study the novel electromagnetic navigation system was feasible to allow accurate screw placement without fluoroscopy in defined narrow peri-acetabular bony corridors.

Purpose This study was aiming to investigate intraoperative and postoperative complications and outcomes of a posterior reversed L-shaped approach (PRLA) in the treatment of the tibial plateau fractures. Methods Inclusion criterion was tibial plateau fractures treated through the PRLA either separated or combined with other approaches. Main exclusion criterion was poly-trauma patients. Ninety-five patients with tibial plateau fractures from a prospectively collected database were included and followed in this study. The intraoperative and postoperative complications consisted of vascular and nerve injury, wound infection, dehiscence, haematoma, nonunion, skin necrosis and skin paresthesia. Hospital for Special Surgery Knee Score (HSS) was adopted to evaluate patients’ knee function while Short Form 36 Health Survey (SF-36) was used to investigate the patients’ general health status. Results Patients’ average age was 46.2 years old (range, 22.0–89.0). The fractures were mainly from high energy injuries involving posterior (and medial) column. 78 of 95 cases were combined with an additional anterolateral approach due to the lateral column involvement. The average follow-up was 52.0 months (range, 12.4–102.6). The total complications rate was 4.2% (4/95). Intraoperative complications occurred in two patients (2.1%). One suffered a popliteal artery injury resulted from an antero-posteriorly drilled K-wire. The patient had a loss of 7° knee extension at one year's follow-up. The other endured an injury of nutrient vessel within the medial head of gastrocnemius. Postoperative skin paresthesia occurred in two patients (2.1%). The other complications associated with the PRLA were not observed. The mean HSS score was 96.1 (range, 80–100). The mean SF-36 score was 94.2 (range, 80–100). Conclusions The posterior reversed L-shaped approach allows satisfied visualization of the medial and posterior tibial plateau and has promising clinical results with low complication occurrence. It can be recommended as a routine approach for the treatment of the tibial plateau fractures involving the posterior column.

We present two cases of occult internal iliac arterial injury identified during operative reduction of a widely displaced posterior column posterior wall acetabular fracture. This complication was not recognised until reduction of the column fracture. There were no preoperative signs or symptoms indicative of a vascular injury. These cases emphasise the heightened awareness one must have when treating widely displaced posterior column fractures of the acetabulum, especially those fractures with extension into the greater sciatic notch, as previously formed clot can become dislodged and hemostasis lost. We also present management options when this complication occurs. We believe any surgeon treating acetabular fractures should be aware of this serious and potentially fatal complication.

Periprosthetic hip fractures around acetabular components are rare with little information available to guide surgical management of these complex injuries. A retrospective review of intraoperative isolated acetabular periprosthetic fractures from three tertiary surgical units was done. A total of 32 patients were identified with 9 initially missed. Acetabular components were stable (type 1) in 11 patients with no failures; unstable (type 2) in 12 patients and treated with supplemental fixation. Non-union and displacement were correlated with absent posterior column plating. Missed fractures (type 3) had the highest reoperation rate. Anterior patterns all healed, whereas fractures with posterior column instability had a 67% failure rate. Periprosthetic acetabular fracture can heal successfully with posterior column stability. Plating is mandatory for large posterior wall fragments to achieve osteointegration.

Introduction Operative treatments of T-type acetabular fractures are challenging surgical procedures. Open reduction and internal fixation is the standard method for the operative management of these fractures, however this is associated with high blood loss, long hospital stay and longer rehabilitation. Anterior subcutaneous pelvic fixation (internal fixation = INFIX) and retrograde pubic screw fixation have shown promising results in minimally invasive treatment of pelvic ring fractures. For T-type acetabular fractures, however, minimally invasive treatment concepts are still rare. Therefore we performed a mechanical in vitro study to: (1) investigate the potential favorability of minimally invasive treatment options over the already established open anterior locking plate osteosynthesis of acetabular T-fractures regarding biomechanical stability and post-surgical stiffness, (2) explore the biomechanical feasibility of the INFIX, (3) assess its potential ability to reduce the anterior acetabular column. Hypothesis A minimally invasive treatment of acetabular T- type fractures is biomechanically equivalent to an open anterior plate osteosynthesis. Methods Twenty-four synthetic hemipelvis specimens with a T-type acetabular fracture were divided in four groups. A posterior column screw was placed in every pelvis of every group. The anterior column was fixed with (1) anterior column screw, (2) anterior column screw including INFIX, (3) INFIX alone, (4) 14-hole angular stable locking plate (standard fixation method). Displacement of the anterior column was reduced in group 2 + 3 using the INFIX. All specimens were cyclically loaded with 200 N until a maximum of 600 N. Movement/displacement of the fracture fragments were detected with a 3D-ultrasound measuring system. Displacement (mm) and stiffness (N/mm) of the construction were analyzed. Results Statistical assessment showed no significant differences between the four fixation types (p > 0.05). The 14-whole locking plate (group 4) displayed the overall highest stability with a displacement of 1.3 ± 0.04 mm and stiffness of 76.3 ± 2.4 N/mm. Anterior screw fixation (group 1) proved to be the minimally invasive fixation method with the least displacement and highest stiffness (1.5 ± 0.2 mm, 68.3 ± 6.8 N/mm). The combination of an INFIX and an anterior column screw (group 2), showed a mean stiffness of 62.1 ± 6.0 N/mm and a mean displacement of 1.7 ± 0.2 mm. INFIX only (group 3) presented a displacement of 1.6 ± 0.1 mm and a stiffness of 64.5 ± 4.5 N/mm. Discussion Minimally invasive fixation techniques for T-type acetabular fractures show promising biomechanical stability in non- or slightly displaced fractures. Furthermore, INFIX could be a feasible tool for the reduction of the anterior acetabular column. Level of evidence Level III case control prospective experimental study.

BACKGROUND CONTEXT Many clinical and biomechanical studies have delineated the injuries and injury mechanisms to the thoracolumbar spine in the civilian population. The stability of the spine is assessed based on the three-column, AO, and other classifications. Thoracolumbar injuries are also prevalent in military populations due to recent events such as underbody blast loading from improvised explosive devices, IEDs. These injuries have not been reproduced in a realistic laboratory setting. The stability associated with military injuries and their comparison with the civilian automobile trauma have not been addressed. PURPOSE Reproduce military injuries, determine their mechanisms and compare with the civilian trauma. STUDY DESIGN/SETTING Field data using motor vehicle databases and biomechanical study using a human cadaver model simulating military loads. PATIENT SAMPLE Fourteen human cadaver specimens and civilian field data. OUTCOME MEASURES Injuries to human cadaver specimens, classification based on clinical scales, and identification of injuries to the civilian trauma population. METHODS Real-world data consisted of an analysis of motor vehicle crash injuries to restrained occupants using US national databases for the years 1993-2012. Thoracolumbar injuries and their patterns were obtained from medical records, X-ray images, and CT scans. For the biomechanical study, 14 human cadaver thoracolumbar spines (T12-S1) were procured, pretest CT scans were taken, and QCT-based BMD were obtained. They were fixed at the ends using PMMA, and they were positioned according to the military seating posture, that is the T12 midbody was oriented at 5° above the horizontal, and the line joining the center of T12-L1 and L5-S1 discs was aligned at a posterior angle of 12° from the vertical line. X-ray studies were taken in the aligned posture before loading, while the specimen was still in the impacting device. The specimens were accelerated from S1 along the caudal to cephalad direction. The impact trajectory was applied from a custom vertical accelerator, simulating underbody blast conditions, with velocities up to 9 m/s and time to peak within 0.002 to 0.01 seconds. Forces and bending moments were recorded at the distal and proximal ends using six-axis load cells. Post-test X-ray images and CT were obtained, and dissection was done. Injuries were identified and classified using standard classification systems. RESULTS In the field data study, the thoracolumbar junction was found to be most susceptible to fractures, more commonly at the L1 level (30%). The vertebral body compression was most common (37%) followed by burst (33%) fractures. In the biomechanical study, L1 was most frequently involved in the injuries, and vertebral body compression and burst fractures occurred in all specimens. However, 58% had burst fractures with posterior column involvements, and 43% had fractures at more than one level and all were contiguous. These burst fracture injuries were more severe and typically of the three-column type, ie, unstable. CONCLUSIONS Similarities of burst fractures were noted in military and civilian populations; however, there was an increased incidence of L1 injuries in the military and a higher occurrence of injuries to the posterior columns in the military. The proposed mechanism is that the personal protective equipment required by the military may alter the normal seating posture, exposing the individual to altered axial load patterns allowing for greater involvement of the posterior column resulting in more unstable injuries with potential consequences. Because of the greater instability, MRI should be considered to assess the status of the adjacent vertebral bodies and ligamentous structures. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT The approach selection for subaxial cervical fracture dislocations (SCFD) is controversial. While spinal surgeons increasingly prefer a single anterior approach, the complication of postoperative cervical kyphosis is worrisome. Hence, identification of suitable candidates requiring a second posterior reconstruction is necessary, thus preventing the failure of anterior-only surgery in patients with SCFD. PURPOSE To introduce a novel classification and scoring system called the posterior ligament-bone injury classification and severity (PLICS) score and verify whether this system can be generally utilized for the treatment of the SCFD to predict the failure of anterior-only surgery. STUDY DESIGN/SETTING A retrospective cohort study. PATIENT SAMPLE A total of 394 patients with SCFD who underwent anterior decompression, reduction, and fusion between January 2002 and December 2017 in one center were retrospectivelyenrolled in the study. The inclusion criteria included: 1. the preoperative magnetic resonance imaging (MRI) detected facture dislocation accompanying with an extruded disc, which deformed the dural sac beyond the line between the postero-inferior corner of cranial vertebrae and the postero-superior corner of caudal vertebrae; 2. the clinical level of neural dysfunction corresponds to the segment of reconstruction without the requirement of an extensive posterior decompression; 3. the reduction can be achieved under an attempt at the awake skull traction preoperatively or via anterior approach after the removal of herniated disc intraopertively. The exclusion criteria included: reduction can't be by preoperative skull traction, or by an anterior approach intraoperatively; the patients obtained a posterior reconstruction surgery when the intramedullary edema may extend beyond the segment of dislocation; severe traumatic cervical spondylolisthesis (over grade 3); the patients are accompanying by ankylosing spondylitis. OUTCOME MEASURES Clinical outcomes with respect to neck pain and function were recorded for each patient according to visual analog score (VAS) and the Neck Disability Index (NDI). We paired the equal number of patients between successful and unsuccessful groups to compare the difference in the clinical outcome. The American Spinal Injury Association (ASIA) impairment scale was recorded at each follow-up interval. Additionally, lateral radiography computed tomography (CT) and MRI were also recommended. METHODS Patients were divided into successful and unsuccessful groups according to whether failure of internal fixation was observed during follow-up. PLICS is based on the injury severity of the ligament-bone structure of three elements. Anatomically, the posterior column of cervical spine can be subdivided into three-column structure, including bilateral facet joints and the outside joint capsules, and posterior spinous processes and the attached ligament structures, so-called posterior ligamentous complex, including the supraspinal ligament and interspinous ligament. In this score system, a specific point value (0 - 3) is assigned to a particular variable within each element reflective of the severity of injury and its contribution to stability of posterior column of cervical spine. The preoperative PLICS score of all patients are recorded respectively. RESULTS Among 354 patients, 89.8% fulfilled the follow-up. Fifteen patients (4.2%) experienced hardware failure and progressive cervical kyphosis at the postoperative follow-up. The patients were divided into successful (15 patients) and unsuccessful (339 patients) groups. The average VAS score in the satisfactory group decreased from 6.7+0.8 to 1.3+0.6. The average VAS score in the unsatisfactory group decreased from 4.9+0.8 to 0.3+0.5. The average NDI score at the12-month follow-up was statistically low in the satisfactory group (6.2+2.1 vs 15.5+3.8, P= .028). It is worth noting that, except for only one patient with a PLICS score of 6, the PLICS score for the other 14 patients who experienced postoperative hardware failure was >7. However, the PLICS score for the other 339 patients (except for 2 cases) who obtained satisfactory radiological outcome was CONCLUSIONS When a PLICS score >7 is accompanied by severe lateral mass fracture, the risk of postoperative failure after an anterior-only reconstruction is high and supplemental posterior strengthening can be considered. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

The elderly patient with an acetabular fracture presents a unique surgical challenge because of medical comorbidities, decreased physiological reserve, reduced healing capacity, osteopenic bone, and atypical fracture patterns. Goals include rapid mobilization, early weight bearing, and a pain-free functional hip. Treatment options include initial nonoperative management with delayed total hip arthroplasty (THA), open reduction and internal fixation (ORIF), minimally invasive osteosynthesis, and acute total hip replacement combined with ORIF. Advantages of acute THA combined with ORIF in the elderly patient include the potential for 1-stage treatment with faster recovery and the avoidance of problems that can occur with delayed arthroplasty. Disadvantages include major technical challenges of simultaneously obtaining both implant and fracture stability. This review discusses the indications, contraindications, technique, and results of acute THA combined with ORIF for the management of acetabular fractures in the elderly. The technique for combined surgical treatment of an associated posterior wall/posterior column acetabular fracture with an ipsilateral femoral neck fracture is described.