Lumbar Pedicle Research Articles

F170. Usefulness of t-EMG of the pedicle hole after withdrawal of lumbar pedicle screws

t-EMG of the pedicle hole before the placement of lumbar pedicle screws, and later stimulation of the screw is an established neurophysiologic method to avoid lumbar pedicle screw malposition. Occasionally it is necessary to remove some of the instrumentation in a later surgery, which made us wonder if it is necessary to stimulate the trajectories of the screws once they have been removed, before the re-instrumentation of those levels. We have studied 12 patients with previous surgeries for the correction of vertebral deformities, in which a posterior surgery for the removal of part of the instrumentation was performed. In this second surgery, screws were stimulated before their removal, and their pedicle trajectories were performed afterwards. We have considered of risk t-EMG values below 10 mA 62 screws were removed, all lumbar. In the first surgery t-EMG values were all normal, both the trajectory and the screw. None of the patients presented neurological symptoms. A CT scan was performed before the second surgery, and 16 of the 62 screws to be removed had a certain degree of medial-caudal displacement. During the surgery for their removal, t-EMG of the screws was performed, being normal in all cases, and after the withdrawal of the screws, their trajectories were also stimulated. A 48% of the screws’ trajectories had t-EMG values under 10 mA. None of the removed screws was repositioned, regardless of their t-EMG value. In an off-line analysis of the results, 14 out of the 16 malpositioned screws (87%) had a low t-EMG value of the pedicle hole after their removal. And 16 out of the 46 well-positioned screws (34%) presented a low t-EMG value of the pedicle hole after their removal. Even though the usefulness of the t-EMG of the pedicle track before the screw placement has been proven to avoid lumbar pedicle screw malposition, it seems that the stimulation of the pedicle track once a screw has been removed does not have the same implication, at least with the current threshold values. We need more cases to be able to establish t-EMG of the pedicle trajectories of the removed screws as a useful tool to decide the replacement of a screw using the same trajectory.

Does postoperative PI-LL mismatching affect surgical outcomes in thoracolumbar kyphosis associated with ankylosing spondylitis patients?

ObjectiveTo investigate if pelvic incidence (PI) and lumbar lordosis (LL) mismatching affects surgical outcomes for ankylosing spondylitis (AS) related kyphosis following 1-level lumbar pedicle subtraction osteotomy (PSO). Patients and methodsAS patients with thoracolumbar kyphosis, who underwent 1-level lumbar PSO from March 2006 and February 2014 in our institution, were retrospectively reviewed. The radiographic measurements and health-related quality of life (HRQoL) scores, including Oswestry Disability Index (ODI) and Visual Analogue Scale (VAS) for pain, were recorded at baseline and the last follow-up. Patients were divided into 2 groups according to PI-LL matching or not postoperatively (Match Group, Mismatch Group), and comparison of the aforementioned parameters between the two groups was performed. ResultsSeventy patients were enrolled with a mean age of 34.60 ± 9.45 years (range, 17 yrs.–59 yrs.). Among them, 44 were included in the Match Group and 26 in the Mismatch Group. At baseline, patients in the Match Group had larger LL (p = 0.014) and smaller pelvic tilt (PT, p < 0.001) than patients in the Mismatch Group. At the last follow-up, along with larger LL (p = 0.004) and smaller PT (p = 0.001), Match Group patients also had significantly smaller sagittal vertical axis (SVA, 3.31 cm vs 6.27 cm, p = 0.001) than those in the Mismatch Group. Seventy-five percent (33/44) of the patients in the Match Group had a SVA < 5 cm at the last follow-up, while in the Mismatch Group, only 35% (9/26) of the patients did. However, no significant difference was found between the two groups regarding HRQoL scores. ConclusionPatients with postoperative PI-LL matching were more likely to have a better correction of SVA; they also tended to have a smaller preoperative PT. However, PI-LL mismatching didn’t affect HRQoL scores at the last follow-up, which was different from the results of previous studies in the settings of ASD.

Clinical and radiological effect of medialized cortical bone trajectory for lumbar pedicle screw fixation in patients with degenerative lumbar spondylolisthesis: study protocol for a randomized controlled trial (mPACT)

BackgroundSpinal fusion with pedicle screw fixation represents the gold standard for lumbar degenerative disc disease with instability. Although it is an established technique, it is nevertheless an invasive intervention with high complication rates. Therefore, minimally invasive approaches have been developed, the medialized bilateral screw pedicel fixation (mPACT) being one of them. The study objective is to evaluate prospectively the efficacy and safety of the mPACT technique compared with the traditional trajectory for degenerative lumbar spondylolisthesis.Methods/designThis is a single-center, randomized, controlled, parallel group, superiority trial. A total of 154 adult patients are allocated in a ratio of 1:1. Sample size and power calculation were performed to detect the minimal clinically important difference of 10%, with an expected standard deviation of 20% in the primary outcome parameter, the Oswestry Disability Index, with power of 80%, based on an assumed maximal dropout rate of 20%. Secondary outcome parameters include the EuroQoL 5-Dimension questionnaire, the Beck Depression Inventory, the painDETECT questionnaire and the “timed up and go” test. Furthermore, radiological and health economic outcomes will be evaluated. Follow up is performed until 5 years after surgery. Major inclusion criteria are lumbar degenerative spondylolisthesis with Meyerding grade I or II, which qualifies for decompression and fusion by medialised posterior screw placement with cortical trajectory (mPACT) or by a traditional trajectory for lumbar pedicle screw placement.DiscussionThis trial will contribute to the understanding of the short-term and long-term clinical and radiological postoperative course in patients with lumbar degenerative disc disease, in which the mPACT technique is used.Trial registrationISRCTN registry, ISRCTN99263604. Registered on 3 November 2016.

Feasibility and accuracy of computer-assisted individual drill guide template for minimally invasive lumbar pedicle screw placement trajectory

ObjectiveTo discuss the feasibility and accuracy of a specific computer-assisted individual drill guide template (CIDGT) for minimally invasive lumbar pedicle screw placement trajectory (MI-LPT) through a bovine cadaveric experimental study. DesignA 3-D reconstruction model, including lumbar vertebras (L1–L5), was generated, and the optimal MI-LPTs were determined. A drill guide template with a surface made of the antitemplate of the vertebral surface, including the spinous process and the entry point vertebral surface, was created by reverse engineering and rapid prototyping techniques. Then, MI-LPTs were determined by the drill guide templates, and the trajectories made by K-wires were observed by postoperative CT scan. SettingGeneral Hospital of Shenyang Military Area Command of Chinese PLA. ResultsIn total, 150 K-wires for MI-LPTs were successfully inserted into L1-L5. The required mean time and fluoroscopy times between fixation of the template to the spinous process, entry point vertebral surface, and insertion of the K-wires for minimally invasive lumbar pedicle screw placement trajectories into each vertebra were 79.4 ± 15.0 s and 2.1 ± 0.8 times. There were no significant differences between the preoperative plan and postoperative assessment in the distance from the puncture to the midline and inclination angles according to the different levels (P > 0.05, respectively). The mean deviation between the preoperative plan and postoperative assessment in the distance from the puncture to the midline and inclination angles were 0.8 ± 0.5 mm and 0.9 ± 0.5°, respectively. ConclusionsThe potential use of the novel CIDGT, which was based on the unique morphology of the lumbar vertebra to place minimally invasive lumbar pedicle screws, is promising and could prevent too much radiation exposure intraoperatively.

Safe placement of pedicle screw in lumbar spine with minimum threeyear follow-up: a case series and technical note.

This study aims to find a safe and easy-to-perform strategy for lumbar pedicle screw insertion based on anatomical landmarks. From March 2011 to January 2012, 74 patients underwent posterior lumbar interbody fusion or transforaminal lumbar interbody fusion using the new-designed screw insertion technique. During the operation, the entry site for screw insertion was on the outer edge of the superior facet joint, 4mm downward from upper border of processus transversus. A connecting line between superior and inferior facet joints was used to determine the direction of screw insertion. Postoperative radiograph and computed tomography (CT) were taken routinely to show the position of the screws. Functional outcomes were evaluated using Oswestry Disability Index score, Japanese Orthopedic Association score, and Visual Analogue Scale, respectively. Sixty-two patients (27 males and 35 females, average age 58.95 ± 8.45) finished the follow-up visit with an average of 46.03months (36-60). The mean operation time and the blood loss were 169.60 ± 41.21min and 489.52 ± 189.38ml, respectively. A total of 274 pedicle screws were inserted following the new technique. According to Lothar Wiesner's classification, 11 screws (4.01%) caused minor violation into wall, two screws (0.73%) caused moderate violation, and other screws were in proper position. A new-designed surgical strategy for pedicle screw insertion of lumbar spine was introduced and performed, which featured a series of original and easily distinguished landmarks. Clinical application demonstrated the safety and effectiveness of this novel technique for pedicle screw insertion.

Analysis of cervical sagittal alignment variations after lumbar pedicle subtraction osteotomy for severe imbalance: study of 59 cases.

To evaluate postoperative changes within the cervical alignment following surgical lumbar correction by pedicle subtraction osteotomy (PSO) in patients affected with sagittal global malalignment disease. This was a monocentric, radiographic, and prospective study. 79 patients, who underwent sagittal correction by PSO, performed an EOS imaging pre- and postoperatively between January 2008 and December 2013 at the University Hospital of Bordeaux. Inclusion criteria were a performed pre- and postoperative EOS imaging and a preoperative C7SVA >5cm. Were excluded patients who did not allow EOS with a viewable cervical spine due to hyperkyphosis. The study involved the analysis of pelvic, lumbar, thoracic, cervical, and cranial parameters before and after the surgery. 59 patients met the criteria. Mean follow-up was 38months. The lumbar PSO significantly improved sagittal alignment including L1S1 lordosis, T1T12 kyphosis, and C7SVA (p<0.001). We did not reported a significant change within cervical parameters after PSO (C2C7 lordosis 22.7°-21.5° p=0.64, C1C7 lordosis 50.6°-48.8° p=0.56, C1C2 angle 28.2°-27.9° p=0.82, C7 slope stayed constant 32.3°-30.5° p=0.47, OC2 angle 15.54°-15.56° p=0.99). However, cranial slope decreased significantly (p<0.05). We did not find correlation between lumbar lordosis and cervical lordosis variations (R=0.265). Cervical lordosis was highly correlated with the C7 slope (R=0.597) and with the Spino Cranial Angle (R=-0.867). Reciprocal changes in cervical spine after PSO are difficult to approach. Maintaining a horizontal gaze involves locoregional mechanisms of compensation adapting to the slope of C7. The cranial system by decreasing the cranial slope allows the gaze alignment and is the first compensation mechanism to get involved after a loss of lumbar lordosis. Restoring optimal C7SVA is necessary to prevent the development of secondary cervical painful symptomatology when the cranial compensation is outdated.

102 lumbar pedicle subtraction osteotomies: one surgeon's learning curve.

Pedicle Subtraction Osteotomy (PSO) is an effective surgical technique for the correction of fixed sagittal malalignment of the spine. It is a demanding technique that requires a long learning curve. The aim of this study is to analyze a surgeon's learning curve for lumbar PSO in relation to the preoperative, perioperative, and postoperative management, with assessment of the global outcome. 102 patients operated over an 8-year period were included, distributed in 3 groups over the time, and retrospectively analyzed. The following data were collected: demographic characteristics, preoperative and postoperative radiological parameters, operative technical details, and complications. Multiple regression analysis was performed, and while the number of cases was the predictor, other variables such as demographic, radiographical, and surgical variables were considered as a covariate in the final model. When comparing the first group and the last group of patients, the mean surgical time had decreased by 50min, the estimated blood loss was decreased by 655ml, and a significant decrease in dural tear occurrence was noticed. In addition, we found a significant decrease in the hospital stay length. Multivariate linear regression analysis showed that when the surgeon's experience doubles, the operative time decreases by 29min, the blood loss by 281ml, and the odds of hospital stay≥21days decrease by 0.66 times. PSO technique has a relatively long learning curve. This study showed that accumulating the experience over the years, while performing cases on a regular basis, is definitely the key in mastering this complex and risky technique, with significant improvements in the perioperative parameters that directly impact the recovery and global outcome. These slides can be retrieved under Electronic Supplementary Material.

Early experience of placing image-guided minimally invasive pedicle screws without K-wires or bone-anchored trackers.

OBJECTIVE Image guidance for spine surgery has been reported to improve the accuracy of pedicle screw placement and reduce revision rates and radiation exposure. Current navigation and robot-assisted techniques for percutaneous screws rely on bone-anchored trackers and Kirchner wires (K-wires). There is a paucity of published data regarding the placement of image-guided percutaneous screws without K-wires. A new skin-adhesive stereotactic patient tracker (SpineMask) eliminates both an invasive bone-anchored tracker and K-wires for pedicle screw placement. This study reports the authors' early experience with the use of SpineMask for "K-wireless" placement of minimally invasive pedicle screws and makes recommendations for its potential applications in lumbar fusion. METHODS Forty-five consecutive patients (involving 204 screws inserted) underwent K-wireless lumbar pedicle screw fixation with SpineMask and intraoperative neuromonitoring. Screws were inserted by percutaneous stab or Wiltse incisions. If required, decompression with or without interbody fusion was performed using mini-open midline incisions. Multimodality intraoperative neuromonitoring assessing motor and sensory responses with triggered electromyography (tEMG) was performed. Computed tomography scans were obtained 2 days postoperatively to assess screw placement and any cortical breaches. A breach was defined as any violation of a pedicle screw involving the cortical bone of the pedicle. RESULTS Fourteen screws (7%) required intraoperative revision. Screws were removed and repositioned due to a tEMG response < 13 mA, tactile feedback, and 3D fluoroscopic assessment. All screws were revised using the SpineMask with the same screw placement technique. The highest proportion of revisions occurred with Wiltse incisions (4/12, 33%) as this caused the greatest degree of SpineMask deformation, followed by a mini midline incision (3/26, 12%). Percutaneous screws via a single stab incision resulted in the fewest revisions (7/166, 4%). Postoperative CT demonstrated 7 pedicle screw breaches (3%; 5 lateral, 1 medial, 1 superior), all with percutaneous stab incisions (7/166, 4%). The radiological accuracy of the SpineMask tracker was 97% (197/204 screws). No patients suffered neural injury or required postoperative screw revision. CONCLUSIONS The noninvasive cutaneous SpineMask tracker with 3D image guidance and tEMG monitoring provided high accuracy (97%) for percutaneous pedicle screw placement via stab incisions without K-wires.

Patient-specific interactive software module for virtual preoperative planning and visualization of pedicle screw entry point and trajectories in spine surgery.

Lumbar pedicle screw insertion involves a steep learning curve for novice spine surgeons and requires image guidance or navigation. Small volume centers may be handicapped by the lack of cost-effective user-friendly tools for preoperative planning, guidance, and decision making. We describe a patient-specific interactive software module, pedicle screw simulator (PSS), for virtual preoperative planning to determine the entry point and visualize the trajectories of pedicle screws. The PSS was coded in Python for use in an open source image processing software, 3D Slicer. Preoperative computed tomography (CT) data of each subject was loaded into this module. The entry-target (ET) mode calculates the ideal angle from the entry point through the widest section of the pedicle to the desired target in the vertebral body. The entry-angle (EA) mode projects the screw trajectory from the desired entry point at a desired angle. The performance of this software was tested using CT data from four subjects. PSS provided a quantitative and qualitative feedback preoperatively to the surgeon about the entry point and trajectories of pedicle screws. It also enabled the surgeons to visualize and predict the pedicle breach with various trajectories. This interactive software module aids in understanding and correcting the orientation of each vertebra in three-dimensions, to identify the ideal entry points, angles of insertion and trajectories for pedicle screw insertion to suit the local anatomy.

Total laminectomy combined with lumbar pedicle screw fixation for treatment of lower back and leg pain in older adult patients with degenerative lumbar spinal stenosis: study protocol for a self-control trial and preliminary results

Background and objectives: Senile degenerative lumbar spinal stenosis typically manifests clinically as lower back and leg pain caused by compression of the nerve root. Conventional total laminectomy for degenerative lumbar spinal stenosis can quickly alleviate a patient's symptoms, but produces an unsatisfactory therapeutic effect because of spinal instability caused by degenerative spondylolisthesis, and also has many adverse reactions. The purpose of this study is to investigate whether total laminectomy combined with lumbar pedicle screw fixation for treatment of senile degenerative lumbar spinal stenosis can effectively reduce lower back and leg pain caused by compression of the nerve root, increase lumbar spine stability, and reduce adverse reactions. Design: A prospective, single-center, self-control, interventional trial. Methods: One hundred and sixty older adult patients with degenerative lumbar spinal stenosis who will receive treatment at the Department of Orthopedics, Qinghai Provincial People's Hospital, China will be included in this study. All patients will undergo total laminectomy combined with lumbar pedicle screw fixation, with follow-up at 3, 6, 9, and 12 months post-surgery. Outcome measures and preliminary results: The primary outcome measure of this study is recovery rate in Japanese Orthopedic Society (JOA) score at 12 months post-surgery, which is used to evaluate improvements in patients lower back and leg pain. Secondary outcome measures of this study include changes in JOA score, spinal canal diameter, lumbar spine morphology displayed on computed tomography images, and incidence of adverse events post-surgery. Results of a preliminary study involving 71 older adult patients with degenerative lumbar spinal stenosis who received the same treatment showed that at 3 months post-surgery, JOA score and spinal canal diameter were significantly increased compared with before surgery (P Discussion: Findings from this study may provide clinical evidence supporting that total laminectomy combined with lumbar pedicle screw fixation is a safe and reliable method for treatment of senile degenerative lumbar spinal stenosis because it rapidly alleviates lower back and leg pain and provides spine stability. Ethics and dissemination: This study was approved by Medical Ethics Committee of Qinghai Provincial People's Hospital of China (approval No. QHY201602G). This study will be performed in strict accordance with the Declaration of Helsinki formulated by the World Medical Association. Participants will provide signed informed consent prior to participation in the study. This study was designed in December 2017. Patient recruitment and data collection will begin in August 2018. Data analysis will be performed in October 2019. The study will be completed in December 2019. Results will be disseminated through presentations at scientific meetings and/or by publication in a peer-reviewed journal. Protocol version: 1.0. Trial registration: This trial was registered with the Chinese Clinical Trial Registry (registration number: ChiCTR1800014726).

Broken lumbar pedicle screw – a short report

Abstract Spinal fixation is one of the common surgical procedure performed by spine surgeons. Among the various spinal fixation technique, pedicle screw fixation is of paramount importance especially when instability is in dorsolumbar and sacral region of spine. Like any surgical procedure, pedicle screw fixation is not devoid of complications. Broken pedicle screws are one of the rare complication of this procedure with a great challenge to deal with such situation. We are reporting one of the rare complication of pedicle screw fixation with literature review and our philosophy to deal such complication.

Role of Visuohaptic Surgical Training Simulator in Resident Education of Orthopedic Surgery.

We sought to assess the validity of a virtual surgical training system on lumbar pedicle screw placement for residents. Ten inexperienced residents were randomly assigned to the simulation training (ST) group (n= 5) and control group (n= 5). The ST group performed the lumbar pedicle screw placement on the virtual surgical training system, and the control group was given an introductory teaching session before the cadaver test. A total of 8 adult fresh cadavers including 5 males and 3 females were collected and randomly allocated to the 2 groups. Each group performed the bilateral L1-L5 pedicle screw instrumentation in the cadaver specimens, respectively. Accuracy was assessed by computed tomography after instrumentation. The screw penetration rates, acceptable rates, and average screw penetration distance of the 2 groups were compared using statistical analysis. The screw penetration rate of the ST group (12.5%) was significantly lower than the control group (37.5%, P < 0.05). The screw acceptable rates in ST and control groups were 100% and 85%, respectively, with statistical differences between each other (P < 0.05). There was also a statistically significant difference of the average screw penetration distance between the ST (1.37 ± 0.62 mm) group and control group (2.42 ± 0.51 mm, P < 0.05). The virtual surgery simulation with greater accuracy is superior to the traditional teaching methods in surgical training of pedicle screw placement and can be used as a promising alternative for training of neurosurgical procedures.

The Effectiveness of Bioskills Training for Simulated Lumbar Pedicle Screw Placement.

Study Design:Prospective randomized study.Objectives:To define the impact of an inexpensive, user-friendly, and reproducible lumbar pedicle screw instrumentation bioskills training module and evaluation protocol.Methods:Participants were randomized to control (n = 9) or intervention (n = 10) groups controlling for level of experience (medical students, junior resident, or senior resident). The intervention group underwent a 20-minute bioskills training module while the control group spent the same time with self-directed study. Pre- and posttest performance was self-reported (Physician Performance Diagnostic Inventory Scale [PPDIS]). Objective outcome scores were obtained from a blinded fellowship-trained attending orthopedic spine surgeon using Objective Structured Assessment of Technical Skills (OSATS) and Objective Pedicle Instrumentation Score metrics. In addition, identification of pedicle breach and breach anatomic location was measured pre- and posttest in lumbar spine models.Results:The intervention group showed a 30.8% improvement in PPDIS scores, compared with 13.4% for the control group (P = .01). The intervention group demonstrated statistically significant 66% decrease in breaches (P = .001) compared with 28% decrease in the control group (P = .06). Breach identification demonstrated no change in accuracy of the control group (incorrect identification from 32.2% pre- to posttest 35%; P = .71), whereas the intervention group’s improvement was statistically significant (42% pre- to posttest 36.5%; P = .0047).Conclusions:We conclude that a concise lumbar pedicle screw instrumentation bioskills training session can be a useful educational tool to augment clinical education.

Do Sublaminar Polyester Bands Affect the Outcomes of Postoperative Infections After Adolescent Idiopathic Scoliosis Surgery?

The incidence of surgical site infections (SSI) after adolescent idiopathic scoliosis (AIS) surgery ranges from 0.5% to 7%. There is currently a regain of interest in hybrid constructs, combining lumbar pedicle screws and thoracic sublaminar bands, but some authors have raised concerns about the risk of SSI and the difficulty of bacterial eradication. The goal of this study was therefore to assess the outcomes of SSI after AIS surgery using sublaminar bands. A total of 524 consecutive patients operated for AIS using sublaminar bands between June 2006 and June 2014 were included. SSI cases were identified and analyzed retrospectively. Radiologic and functional outcomes were evaluated at follow-up using EOS imaging and SRS 30 scores, and compared with a control group. The overall SSI rate was 5.3%, with a majority of monomicrobial (86%) infections occurring in the first 6 weeks postoperative (93%). The most frequent pathogens were skin germs (Staphylococcus aureus and Propionibacterium acnes) with a community profile. Patients were treated successfully with surgical debridement without implants removal, associated with 6 weeks of antibiotherapy. However, 25% of patients required >1 surgical debridement. Instrumentation removal was decided in the 2 cases with late SSI, and performed uneventfully. Radiologic and functional outcomes at follow-up were not affected by the occurrence of SSI. Sublaminar bands are not associated with a higher risk of infection. However, the SSI rate in the current study stands in the upper range of the literature, and other preventive strategies should be considered. In case of early infection, bands removal is not necessary to obtain pathogen eradication, but the sublaminar implants can be pulled out safely in case of late SSI. The occurrence of SSI does not alter the outcomes at follow-up. Level III.

33. The role of intraoperative neurophysiology in scoliosis surgery

The onset of neurological deficit is the most feared complications in surgical correction of spine deformities. Aim of this study is to assess the value of intraoperative neurophysiologic monitoring during scoliosis surgery. 173 scoliosis surgeries in 164 patients were monitored with muscle-motor evoked potentials (m-MEPs) and peripheral and cortical upper and lower limb Somatosensory Evoked Potentials (SEPs). In 45 surgeries, thoracic and lumbar pedicle screws were neurophysiologically tested by triggered-EMG. The overall monitor ability was 98.3%. Significant intraoperative modification occurred in 26 surgeries (15%). In 11 cases (6.4%) changes were consistent with spinal cord damage, in 6 (6.9%) with brachial plexopathy. Finally, three patients (1.7%) presented transient disappearance of four limbs MEPs and SEPs due to a pharmacological effect. 2 patients (1.2%) awaked with a brachial plexopathy: they all completely recovered within 3 months. In one patients, an intraoperative persistent disappearance of unilateral lower limb MEPs and SEPs was associated with a postoperative severe monoparesis: therefore, the rate of new neurological deficit was 0.6%. Intraoperative neurophysiology may provide a valuable biomarker in detection of impending central and/or peripheral nervous system injury at a reversible stage.

Pancreatic fracture: a rare complication following scoliosis surgery.

Grand Round case report. We report a pancreatic fracture associated with Wirsung duct disruption, following a scoliosis surgery in a cerebral palsy adolescent. Spinal fusion surgery is the standard treatment for severe neuromuscular scoliosis. Many complications such as digestive ones account for its complexity. Postoperative acute pancreatitis is well described, although its pathophysiology remains unclear. To our knowledge, pancreatic fracture following scoliosis correction has never been described to date. Clinical presentation is not specific, and management is not consensual. A 14-year-old adolescent had posterior spinal fusion for neuromuscular scoliosis due to cerebral palsy. During the postoperative course, she developed progressive nonspecific abdominal symptoms. The abdominal CT scan demonstrated a pancreatic fracture and a surgical exploration was decided as perforations of the bowel were highly suspected. Drains were placed around the pancreatic area as the retrogastric region was out of reach due to local inflammation. Conservative management led to the occurrence of a pseudocyst in the following weeks as the pancreatic leakage progressively dropped. Two hypotheses have been proposed: direct iatrogenic trauma from lumbar pedicle screws and pancreatic rupture related to the correction of the spinal deformity. As the latter seems the most likely, spinal surgeons should be aware of this occurrence following severe scoliosis correction. Spinal fusion for severe neuromuscular scoliosis is a difficult procedure, with a high rate of complications. Among them, pancreatic fracture should be considered when abdominal pain persists in the postoperative period. Conservative management is advocated especially in case of a poor general condition.

Free hand technique lumbar spine pedicle screw placement in Indian population

There are different pedicle screws entry point techniques are used for the lumbar pedicle screws placement. This study reported using confluence of pars, mamillary process, midpoint of transverse process, on lateral border of face joint as entry point of lumbar pedicle screws with free hand technique and the accuracy of this technique. Materials and Methods: A prospective study was done from may 2015 to November 2017 in our hospital using free hand technique lumbar pedicle screw placement includes 50 patients 270 screws. The diagnosis includes degenerative spine, trauma, and spondylolithesis. cortical breach by misplaced pedicle screw was determined by review of computed tomography. Results: Among the total 270 lumbar free hand placed pedicle screws, 10 screws with lateral breach, 1 screw inferior breach, 2 medial breach without significant neurological involvement with two cases of radicular pain which subsides over period of time without any revision. Conclusion: Free hand pedicle screw placement based on external landmark using confluence of pars, mamillary process, midpoint of transverse process, on lateral border of face joint as entry point of lumbar pedicle screws with free hand technique and the accuracy of this technique showed acceptable safety and accuracy and avoidance of radiation exposure.

Pediatric Lumbar Pedicle Screw Placement Using Navigation Templates: A Cadaveric Study.

Background:Pedicle screw technique is commonly used treatment of adult spinal trauma, tumor, degeneration. The application of pedicle screws is very challenging in children because children have a fast growing spine and spinal pedicle morphology of children and adult has large difference. 3 D reconstruction individual navigation templates improve the success rate of pediatric pedicle screw system. This study is aimed to provide a precise method for lumbar spine pedicle screw placement in children using computer-aided design and rapid prototyping technology.Materials and Methods:Computed tomography (CT) scans of cadaver specimens of 4 children were obtained, and the raw data were reconstructed using three-dimensional reconstruction software. Pedicle screws were placed using the conventional method or by using individually designed navigation templates based on the principles of reverse engineering and rapid prototyping technology.Results:We evaluated the accuracy of the pedicle screws placed using the two methods by CT scan. Ten navigation templates were designed for placement of 20 lumbar pedicle screws in the navigation group, and CT scan confirmed that all the screws were placed accurately in the corresponding pedicle. Conversely, of the 20 lumbar pedicle screws placed using the conventional method, 3 screws perforated the pedicle. The findings showed that lumbar pedicle screw placement was successful using navigation templates in children.Conclusions:This technique is simple, easy to master, and allows personalized screw placement, thus providing a new and feasible method for lumbar pedicle screw placement in children.

Intraoperative biomechanics of lumbar pedicle screw loosening following successful arthrodesis.

These data indicate that pedicle screws can loosen significantly in patients with recurrent back pain and warrant further research into methods to reduce the incidence of screw loosening and to understand the risks and potential benefits of instrumentation removal. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2673-2681, 2017.

Utility of Intraoperative Neuromonitoring for Lumbar Pedicle Screw Placement Is Questionable: A Review of 9957 Cases.

A retrospective database study. The goal of this study was to (1) evaluate the trends in the use of electromyography (EMG) for instrumented posterolateral lumbar fusions (PLFs) in the United States and (2) assess the risk of neurological injury following PLFs with and without EMG. Neurologic injuries from iatrogenic pedicle wall breaches during screw placement are known complications of PLFs. The routine use of intraoperative neuromonitoring (ION) such as EMG during PLF to improve the accuracy and safety of pedicle screw implantation remains controversial. A retrospective review was performed using the PearlDiver Database to identify patients who had PLF surgery with and without EMG for lumbar disorders from years 2007 to 2015. Patients undergoing concomitant interbody fusions or spinal deformity surgery were excluded. Demographic trends and risk of neurological injuries were assessed. During the study period, 2007 to 2015, 9957 patients underwent PLFs. Overall, EMG was used in 2495 (25.1%) of these patients. There was a steady increase in the use of EMG from 14.9% in 2007 to 28.7% in 2009, followed by a steady decrease to 21.9% in 2015 (P < 0.0001). The risk of postoperative neurological injuries following PLFs was 1.35% (134/9957) with a risk of 1.36% (34/2495) with EMG and 1.34% (100/7462) without EMG (P = 0.932). EMG is used most commonly for PLFs in the Southern part of the United States. In this retrospective national database review, we found that there was a steady increase in the routine use of EMG for PLFs followed by a steady decline. Regional differences were observed in the utility of EMG for PLFs. The risk of neurological complications following PLF in the absence of spinal deformity is low and the routine use of EMG for PLF may not decrease the risk. 4.