Pedicle Screws In Patients Research Articles

Using a 3D Navigation Template to Increase the Accuracy of Thoracic Pedicle Screws in Patients with Scoliosis.

This study compares the accuracy and safety of pedicle screw placement using a 3D navigation template with the free-hand fluoroscopy technique in scoliotic patients. Fifteen scoliotic patients were recruited and divided into a template group (eight cases) and a free-hand group (seven cases). All patients received posterior corrective surgeries, and the pedicle screw was placed using a 3D navigation template or a free-hand technique. After surgery, the positions of the pedicle screws were evaluated using CT. A total of 264 pedicle screws were implanted in 15 patients. Both the two techniques were found to achieve satisfactory safety of screw insertion in scoliotic patients (89.9% vs. 90.5%). In the thoracic region, the 3D navigation template was able to achieve a much higher accuracy of screw than the free-hand technique (75.3% vs. 60.4%). In the two groups, the accuracy rates on the convex side were slightly higher than on the concave side, while no significance was seen. In terms of rotational vertebrae, no significant differences were seen in Grades I or II vertebrae between the two groups. In conclusion, the 3D navigation template technique significantly increased the accuracy of thoracic pedicle screw placement, which held great potential for extensively clinical application.

Blood Loss Following Open Posterior Spinal Fusion in Fractures: Cannulated vs. Solid Pedicle Screws.

We aim to delineate whether there is increased blood loss with the use of cannulated pedicle screws compared to solid pedicle screws in patients undergoing posterior spinal fusion. A single-centre retrospective case-control study was undertaken on patients undergoing PSF for spinal fractures. Cannulated screw fixation was compared with solid screw fixation. Intraoperative blood loss was estimated using pre and postoperative haemoglobin levels, recorded estimated blood loss and cell saver reports. Anticoagulation, blood product administration, operative time and number of levels fused were assessed. A total of 64 cases, 32 in each cohort, were included in the analysis. Overall mean haemoglobin reduction from pre- to post-operative was 2.82 ± 1.85 g/L per screw inserted in the cannulated group, compared to a haemoglobin decrease of 2.81 ± 1.521 g/L per screw inserted in the solid screw group (p = 0.971). Total estimated intraoperative blood loss was 616.3 + 355.4 mL in the cannulated group, compared to 713.6 + 473.5 mL in the solid screw group (p = 0.456). Patients with preoperative thrombocytopenia had a transfusion rate of 0.5 ± 0.71 units/patient compared to 0.04 ± 0.19 units/patient in patients with normal platelet levels (p < 0.005). The differences in blood loss observed between cannulated and solid pedicle screws are non-significant overall. The largest predictor for need of transfusion was pre-operative thrombocytopenia, regardless of the type of screw used.

Predictors of the Pedicle Screw Misplacement in Patients with Thoracolumbar Fracture

Objectives: To investigate the prevalence and risk factors of the misplacement of the pedicle screw in patients with thoracolumbar spine fracture. Methods: Patients who underwent posterior stabilization procedure due to thoracolumbar spine fracture were included. Association between potential risk factors and the misplacement of the pedicle screw were evaluated by logistic regression analysis. Results: A total of 88 consecutive patients with thoracolumbar spine fracture who underwent posterior stabilization surgery using pedicle screws and rods (mean age 43 ± 14, male 52.3 %). On post-operation CT evaluation, 98 (14.8 %) pedicle screws were misplaced (34 thoracic screws and 64 lumbar screws) and the prevalence of the misplaced pedicle screw was not significantly different between thoracic and lumbar screws (13.2 % vs. 15.8 %, p = 0.347). Among risk factors including location of spine fracture, multiple spine fracture and location of screws, the AO classification of spine fracture was significantly associated with the misplacement of the pedicle screw (OR = 1.27, 95 % CI 1.06 - 1.53, p = 0.011). Conclusion: High grade spine fracture, as assessed by the AO classification, was significantly associated with pedicle screw misplacement in patients with thoracolumbar spine fracture.

Minimally Invasive Stent Screw-Assisted Internal Fixation Technique Corrects Kyphosis in Osteoporotic Vertebral Fractures with Severe Collapse: A Pilot "Vertebra Plana" Series.

Fractures with "vertebra plana" morphology are characterized by severe vertebral body collapse and segmental kyphosis; there is no established treatment standard for these fractures. Vertebroplasty and balloon kyphoplasty might represent an undertreatment, but surgical stabilization is challenging in an often elderly osteoporotic population. This study assessed the feasibility, clinical outcome, and radiologic outcome of the stent screw-assisted internal fixation technique using a percutaneous implant of vertebral body stents and cement-augmented pedicle screws in patients with non-neoplastic vertebra plana fractures. Thirty-seven consecutive patients with vertebra plana fractures were treated with the stent screw-assisted internal fixation technique. Vertebral body height, local and vertebral kyphotic angles, outcome scales (numeric rating scale and the Patient's Global Impression of Change), and complications were assessed. Imaging and clinical follow-up were obtained at 1 and 6 months postprocedure. Median vertebral body height restoration was 7 mm (+74%), 9 mm (+150%), and 3 mm (+17%) at the anterior wall, middle body, and posterior wall, respectively. Median local and vertebral kyphotic angles correction was 8° and 10° and was maintained through the 6-month follow-up. The median numeric rating scale score improved from 8/10 preprocedure to 3/10 at 1 and 6 months (P < .001). No procedural complications occurred. The stent screw-assisted internal fixation technique was effective in obtaining height restoration, kyphosis correction, and pain relief in patients with severe vertebral collapse.

Safety and efficacy of cement augmentation with fenestrated pedicle screws for tumor-related spinal instability

Achieving rigid spinal fixation can be challenging in patients with cancer-related instability, as factors such as osteopenia, radiation, and immunosuppression adversely affect bone quality. Augmenting pedicle screws with cement is a strategy to overcome construct failure. This study aimed to assess the safety and efficacy of cement augmentation with fenestrated pedicle screws in patients undergoing posterior, open thoracolumbar surgery for spinal metastases. A retrospective review was performed for patients who underwent surgery for cancer-related spine instability from 2016 to 2019 at the Massachusetts General Hospital. Patient demographics, surgical details, radiographic characteristics, patterns of cement extravasation, complications, and prospectively collected Patient-Reported Outcomes Measurement Information System Pain Interference and Pain Intensity scores were analyzed using descriptive statistics. Logistic regression was performed to determine factors associated with cement extravasation. Sixty-nine patients underwent open posterior surgery with a total of 502 cement-augmented screws (mean 7.8 screws per construct). The median follow-up period for those who survived past 90 days was 25.3 months (IQR 10.8-34.6 months). Thirteen patients (18.8%) either died within 90 days or were lost to follow-up. Postoperative CT was performed to assess the instrumentation and patterns of cement extravasation. There was no screw loosening, pullout, or failure. The rate of cement extravasation was 28.9% (145/502), most commonly through the segmental veins (77/145, 53.1%). Screws breaching the lateral border of the pedicle but with fenestrations within the vertebral body were associated with a higher risk of leakage through the segmental veins compared with screws without any breach (OR 8.77, 95% CI 2.84-29.79; p < 0.001). Cement extravasation did not cause symptoms except in 1 patient who developed a symptomatic thoracic radiculopathy requiring decompression. There was 1 case of asymptomatic pulmonary cement embolism. Patients experienced significant pain improvement at the 3-month follow-up, with decreases in Pain Interference (mean change 15.8, 95% CI 14.5-17.1; p < 0.001) and Pain Intensity (mean change 28.5, 95% CI 26.7-30.4; p < 0.001). Cement augmentation through fenestrated pedicle screws is a safe and effective option for spine stabilization in the cancer population. The risk of clinically significant adverse events from cement extravasation is very low.

Single-center outcomes for percutaneous pedicle screw fixation in metastatic spinal lesions: can spontaneous facet fusion occur?

Survival of cancer patients continues to improve with systemic treatment advancements, leading to an increase in cancer-related complications such as pathological spinal fractures. In this study, the authors aimed to evaluate the outcome of percutaneous stabilization with cement augmentation of the pedicle screws in the management of patients with metastatic cancer to the spine. The authors reviewed a retrospective case series of 74 patients with symptomatic pathological spine fractures treated with cement-augmented pedicle screws implanted with a percutaneous technique. The mean imaging follow-up was 11.3 months. Data on demographics, clinical outcomes, and complications were collected. Cement extravasation, spinal hardware integrity, and fusion rates were assessed on CT scans. Among 50 patients with follow-up imaging, 23 patients (46%) showed facet joint fusion. The length of segmental stabilization was not a significant predictor of the occurrence of fusion. Pre- or postoperative radiation therapy, postoperative chemotherapy, and the location of spinal lesions did not have a statistically significant effect on the occurrence of fusion. Patients older than 60 years of age were more likely to have fusion across facet joints compared with younger patients. There was a significant difference in the mean visual analog scale pain score, with 6.28 preoperatively and 3.41 postoperatively, regardless of fusion status (p < 0.001). Cement extravasation was seen in 51% of the cohort, but in all instances, patients remained asymptomatic. Most importantly, the incidence of hardware failure was low (4%). Percutaneous fixation with cement-augmented pedicle screws in patients with pathological spine fractures provides an improvement in mechanical back pain, with a low incidence of failure, and in some patients, spontaneous facet fusion was observed. Further research is necessary with regard to both short-term benefits and long-term outcomes.

Potential Risk of Thoracic Aorta Injury from Excessively Long Right Pedicle Screws in Patients with Left Thoracic Scoliosis: A Computed Tomography Image Study

We sought to investigate the changed position of thoracic aorta relative to spine in patients with left thoracic scoliosis and to analyze the potential risks of thoracic aorta injury from pedicle screw insertion in these patients. Twenty patients with left thoracic scoliosis (Group A) and 15 normal subjects with a straight spine (Group B) were included. Axial computed tomography images from T5 to T12 of all these subjects were obtained to measure the aorta-vertebral angle. The percentages of thoracic aorta located anteriorly to the screw trajectory were calculated on both the left and right sides. The average aorta-vertebral angle in Group A was significantly larger than that in Group B at each level (P < 0.05) except T5. In Group A, both left and right pedicle screws might pose threats to the thoracic aorta. The percentages of aortas at risk from the right pedicle screw were high in the apical region. However, in Group B, only the left pedicle screw might pose threats to the aorta. No aorta was found to be at risk of injury from right pedicle screw insertion in Group B. The thoracic aorta often lies anteriorly to the left pedicle screw trajectory in normal subjects, especially in the lower thoracic region. However, the thoracic aorta moves to the right side in patients with left thoracic scoliosis, making a large proportion of patients at risk of injury from right pedicle screw insertion in the apical region.

Morphological Differences Between the Pedicles in Nondystrophic Scoliosis Secondary to Neurofibromatosis Type 1 and Those in Adolescent Idiopathic Scoliosis

To compare the pedicle morphology of nondystrophic scoliosis secondary to neurofibromatosis type 1 (ND-NF1) scoliosis secondary to neurofibromatosis type 1 (NF1-S) and adolescent idiopathic scoliosis (AIS) using computed tomography (CT) in a consistent classification system. The transverse pedicle widths of cancellous and cortical channels were measured using preoperative spinal CT images (T1-L5) and then classified as having type A-E pedicles; type B, C, D, and E pedicles were regarded as abnormal. A subset of these patients, a postoperative CT was performed to evaluate the accuracy of pedicle screw placement. According to the perforation of the medial or lateral pedicle walls by the pedicle screw, the placement of screw was classified by a grade ranging from 0 to 3, and grades 2 and 3 were regarded as misplacement. In total, 3230 pedicles were measured and classified, and the incidence rate of abnormal pedicles in the ND-NF1 group was significantly greater than that of the AIS group (65.9% vs. 61.4%, P= 0.03). The misplacement rate in the ND-NF1 group was significantly greater than that in the AIS group (12.2% vs. 7.4%; P=0.01), and in terms of the corresponding 1100 pedicles, the incidence rate of abnormal pedicles in the ND-NF1 group was higher than that in the AIS group (71.7% vs. 64.9%; P= 0.02). The incidence rate of abnormal pedicles in patients with ND-NF1 is significantly greater than that of patients with AIS, and it may the reason for the higher misplacement rate of pedicle screws in patients with ND-NF1.

Posterior Device Fixation Using Pedicle Screws in Patients with Degenerative Spine Disease: A Prospective, Single-Group, Therapeutic Pilot Study

Posterior Device Fixation Using Pedicle Screws in Patients with Degenerative Spine Disease: A Prospective, Single-Group, Therapeutic Pilot Study

Wednesday, September 26, 2018 7:35 AM–9:00 AM ePosters

BACKGROUND CONTEXT Proximal junctional kyphosis (PJK) is a significant concern following long posterior spinal fusion. Biomechanically, proximal hook placement at the upper instrumented vertebra have been shown to allow a more gradual transition to normal motion compared with pedicle screws in a long posterior instrumented spinal fusion. PURPOSE The purpose of this study was to evaluate the risk of developing proximal junctional kyphosis with sublaminar hooks versus pedical screw fixation at the upper instrumented vertebra of a posterior spine fusion for adult spinal deformity. STUDY DESIGN/SETTING Retrospective cohort study. PATIENT SAMPLE Consecutive patients who underwent elective posterior spinal fusion for adult deformity at a single academic institution from 2008 to 2014 with a minimum of 2years of follow-up were identified. Patients with proximal hooks and those with proximal screws were separated into 2 groups. OUTCOME MEASURES Preoperative, first postoperative, and final postoperative standing radiographs were reviewed. Radiographic assessments included: sagittal vertical axis (SVA), pelvic incidence, lumbar lordosis, thoracic kyphosis, T1 pelvic angle (TPA) and kyphosis at one- and two-levels above the upper instrumented vertebra (UIV+1, UIV+2). Two common methods of assessing PJK were used. At two levels above the upper instrumented vertebra (UIV+2), kyphosis greater than 10° and more than a 10° increase from the preoperative film was defined as PJK. At UIV+1, PJK was defined as a greater than 15° increase from the preoperative film. METHODS Multivariate logistic regression was used to test the association between proximal hooks and development of PJK while controlling for differences in patient and operative characteristics. RESULTS A total of 142 patients fulfilled inclusion criteria. Average follow-up was (52.8 ±29.1 months). There were no significant differences in demographic characteristics between the 2 groups. Patients with sublaminar hooks at the UIV presented with significantly fewer instances of PJK using UIV+1 (44.0% vs. 63.1%; p=.029) and UIV+2 (52.0% vs. 76.1%; p=.048) measurements compared to those who received pedicle screws at the UIV. Patients with laminar hooks experienced a significantly greater increase in SVA from preoperative to immediate postoperative (13.6±11.6 mm vs. 1.8±12.4 mm; p CONCLUSIONS Laminar hooks at the upper instrumented vertebra were associated with reduced rates of PJK compared with pedicle screws in patients who undergo deformity-correcting spine fusion for adult spinal deformity. This information may be useful for operative planning to minimize the occurrence of PJK after adult deformity surgery.

Augmentation of fenestrated pedicle screws with cement in patients with osteoporotic spine.

Background:Backing out and failure of pedicle screws in patients with osteoporosis is becoming a big problem due to wide use of these screws nowadays.Purpose:The aim of this study is to evaluate the purchase of fenestrated pedicle screws augmented with cement in patients with osteoporosis.Study Design:This was retrospective observational study.Patients and Methods:From May 2015 to January 2016, 25 patients with a poor bone stock condition underwent posterior fixation by fenestrated pedicle screws and cement augmentation. Assessment of pain improvement was done by visual analogue score (VAS) score while the long-term clinical outcome was assessed using Oswestry low back disability questionnaire (Oswestry disability index [ODI]). Implant stability was evaluated by plain radiography. Complications were evaluated in all cases.Results:All patients were followed up clinically and radiographically for a mean age of 24.84 months. There was a significant reduction in pain and improvement of the quality of life as detected using VAS scores and ODI questionnaire consecutively (P < 0.001). No radiological loosening or backing out of screws was observed. Cement leakage occurred in five cases.Conclusion:Augmentation of fenestrated screws with cement provided effective and lasting purchase in patients with osteoporosis. The only clinical complication strictly related to this technique was cement leakage.

A New Navigational Tool for Pedicle Screw Placement in Patients With Severe Scoliosis: A Pilot Study to Prove Feasibility, Accuracy, and Identify Operative Challenges.

Pilot study. To develop and validate the feasibility and accuracy of a newly designed navigational spinal instrument guiding tool for patient-matched thoracic and lumbar pedicle screw placement in patients with severe scoliosis, and to identify intraoperative challenges that may be relevant. Pedicle screw placement is challenging in severely rotated scoliotic spine with small diameters and asymmetrical shape of the pedicles and vertebrae. Patient-specific drill/positioning guides with preplanned trajectory have been developed as a promising solution in spinal surgery for precise screw insertion. In 4 patients with severe scoliosis, navigational templates and models of all vertebrae to be instrumented were manufactured using a computed tomography (CT)-based 3-dimensional model of the thoracic and lumbar spine. The guides were designed differently for thoracic and lumbar segments according to the individual anatomy to achieve an optimal coupling to the surface of the patient's spine, to maximize the stability of the device itself, and to increase user friendliness for the complete screw positioning process. Intraoperative challenges and opportunities for device and process improvements regarding the handling of the guides during the surgery were recorded. Postoperatively, the intrapedicular screw positions were evaluated versus the preoperative plan and evaluated for cortical violation based on CT scans. A total of 76 pedicle screws were implanted (56 thoracic, 20 lumbar). Two screws (2.6%) were assessed to be misplaced intraoperatively and repositioned. Eighty-four percent of the pedicle screws were completely intrapedicular, 96.1% within <2 mm cortical breech. CT scans did not demonstrate medial pedicle violation, or misplaced screw contact to neurovascular structures. No screw-related clinical complaints were reported postoperatively. The new custom-made positioning guide is a feasible navigational tool that permits a safe and accurate implantation of pedicle screws in patients with severe scoliosis.

Intraoperative image guidance compared with free-hand methods in adolescent idiopathic scoliosis posterior spinal surgery: a systematic review on screw-related complications and breach rates

Background ContextSevere adolescent idiopathic scoliosis (AIS) is a three-dimensional spinal deformity requiring surgery to stop curve progression. Posterior spinal instrumentation and fusion with pedicle screws is the standard surgery for AIS curve correction. Vascular and neurologic complications related to screw malpositioning are concerns in surgeries for AIS. Breach rates are reported at 15.7%, implant-related complications at 1.1%, and neurologic deficit at 0.8%. Free-hand screw insertion remains the prevailing method of screw placement, whereas image guidance has been suggested to improve placement accuracy. PurposeThis study aimed to systematically review the screw-related complication and breach rates from posterior spinal instrumentation and fusion with pedicle screws for patients with AIS when using free-hand methods for screw insertion compared with image guidance methods. Study DesignThis is a systematic review of prognosis, comparing image guidance with no image guidance in surgery. Patient SampleOne randomized controlled trial and multiple prospective cohort studies that reported complication or breach rates in posterior spinal instrumentation and fusion with pedicle screws for AIS. Outcome MeasuresNumber of complications and breaches reported in databases or recorded from postoperative imaging. MethodsDatabases searched included MEDLINE, Embase, CINAHL, CENTRAL, and Web of Science. Studies of Level 3 evidence or greater as defined by the Centre for Evidence-Based Medicine were included. Articles were screened to focus on patients with AIS undergoing posterior fusion with pedicle screws or hybrid systems. Two independent reviewers screened abstracts, full texts, and extracted data. The Quality in Prognostic Studies (QUIPS) appraisal tool was used to determine studyrisk of bias (ROB). Level of evidence summary statements were formulated based on consistency and quality of reporting. ResultsSeventy-nine cohort studies were identified, including four comparing computed tomography (CT) guidance with free-hand methods head-to-head, eight on image guidance, and 671. on free-hand methods alone. Moderate evidence from individual head-to-head studies show CT guidance has lower breach rates than free-hand methods. No complications were found in these studies. From individual cohort studies, moderate evidence shows CT guidance has lower point estimates of breach rates than free-hand methods at 7.9% compared with 9.7%–17.1%. Screw-related complication rates are conflicting at 0% in CT navigation compared with 0%–1.7% in 13 low- and moderate-quality studies. ConclusionsAlthough point estimates on breach rates are decreased with CT navigation compared with free-hand methods, complication rates remain conflicting between the two methods. Current evidence is limited by small sample sizes, lack of comparison groups, and poorly predefined complications. Randomized controlled trials with larger samples with standardized definitions and recording of predefined breach and complication occurrences are recommended.

ELECTROMYOGRAPHY AND INSTRUMENTATION IN PATIENTS WITH IDIOPATHIC SCOLIOSIS

ABSTRACT Objective: The objective of this study is to relate the use of intraoperative electromyography with surgical time, proper placement of screws, type of curve and time spent per screw in idiopathic scoliosis correction surgery in a group of surgeons from Belo Horizonte. This study used the database of protocol evaluation of patients operated in the service, and separately analyzed the results of motor and somatosensory potentials. Methods: Retrospective study of 80 patients undergoing surgery for correction of idiopathic scoliosis between December 2008 and January 2015. A single group of Belo Horizonte spine surgeons performed the intraoperative electromyographic (EMG) monitoring. EMG was performed with stimulation of pedicle screws in patients undergoing instrumentation with pedicle screws as fixation elements. Results: The sample consisted of 85% females (mean age 17 years) and 37.5% of cases had classification type 1AN of Lenke. Of the total surgical cases, 60% had EMG changes. Of the total cases analyzed, 66.3% were true positives for the result. Conclusion: Intraoperative monitoring with EMG is a very important tool for the surgical treatment of patients with scoliosis undergoing instrumentation with pedicle screws. It enables to check if the screw is located on the correct path, helping to decrease the error rate and providing corrections to the surgical approach through a change of strategies. Moreover, it contributes to decrease the time to screw positioning and the total surgical time.

Safety and Efficacy of Lumbar Spine Radiofrequency Neurotomy in the Presence of Posterior Pedicle Screws

Objective: To determine the safety and the efficacy of lumbar spine radiofrequency neurotomy performed in the presence of pedicle screws in patients with chronic low back pain. Methos: Retrospective practice audit. Review of charts of all patients who underwent lumbar radiofrequency neurotomy in the presence of pedicle screws. Patients were tested with a minimum of two controlled medial branch blocks and treated with radiofrequency neurotomy. A successful outcome was defined as at least 50% pain reduction for a minimum of three month. Results: Thirty eight patients were identified with pedicle screws present at the time of the neurotomy. No adverse effects were observed and no patients reported a worsening of the pain after RFN. No clinical effect related from heating of the metal devices was observed. A pain reduction of at least 50% for a minimum of three months was achieved in 20 patients (52.6%). Pain in the index segments and also in adjacent segments was treated with no difference in success. Conclusion: Some 50% of the patients with pedicle screws benefits from radiofrequency neurotomy for about six months. This potential benefit for the patient must be offset against the risk of the procedure, which might be higher because of the increase in temperature of the metal devices. Still, no adverse effects were observed. Selection of treatment level and positioning the electrode next to the pedicle screws are challenging.

Posterior Spinal Fusion With Pedicle Screws in Patients With Idiopathic Scoliosis and Open Triradiate Cartilage: Does Deformity Progression Occur?

Anterior-posterior spinal fusion (APSF) is the traditional treatment for patients with idiopathic scoliosis and open triradiate cartilage (OTRC). Our goals were to assess whether posterior-only spinal fusion (PSF) with pedicle screws can halt deformity progression as effectively as APSF in patients with OTRC, and whether selection of the distal fusion level influences curve progression. We studied a prospective multicenter database to identify all children with 2-year radiographic and clinical follow-up who were 11 years or younger with Risser grade 0 and OTRC who were treated with (1) PSF (OTRC-PSF group, N=20); or (2) APSF (OTRC-APSF group, N=9). A reference group was constructed of 20 children who were 18 years or younger with Risser grade 4 or 5 and closed triradiate cartilage (CTRC) and who were treated with PSF (CTRC-PSF group) and matched in preoperative curve magnitude and type to the OTRC-PSF group. The 3 groups were compared with respect to operative time, blood loss, length of hospital stay, and radiographic and functional outcomes (significance, P<0.05). OTRC-APSF patients had significantly longer operative time (P<0.01), greater blood loss (P=0.02), and longer hospital stays (P<0.01) than OTRC-PSF patients. At 2 years, 7 (35%) OTRC-PSF patients had >10 degrees of curve progression compared with no patients in the OTRC-APSF group (P=0.042) and 1 patient in the CTRC-PSF group (P=0.018). The OTRC-PSF group had the highest number of patients fused to the stable vertebra. Of the 11 OTRC-PSF patients fused to 1 vertebra short of stable, 6 (55%) had >10 degrees of curve progression. Of the 9 OTRC-PSF patients fused to at least the stable vertebra or lower, only 1 (11%) had curve progression. There were no significant differences in Scoliosis Research Society outcome scores between OTRC-PSF patients who did and those who did not have >10 degrees of curve progression. PSF with pedicle screws was associated with curve progression in a significantly greater proportion of patients with OTRC compared with APSF. Not fusing to stable was also associated with curve progression in patients treated with PSF but not APSF. Level III-therapeutic.

The feasibility of inserting a C1 pedicle screw in patients with ponticulus posticus: a retrospective analysis of eleven patients.

Ponticulus posticus is a common anatomic variation that can be mistaken for a broad posterior arch during C1 pedicle screw placement. When the atlas lateral mass screws are placed via the posterior arch, injury to the vertebral artery may result. To our knowledge, there are few clinical studies that have analyzed the feasibility of C1 pedicle screw fixation in patients with ponticulus posticus, in clinical practice. To evaluate the feasibility of inserting a C1 pedicle screw in patients with ponticulus posticus. Between January 2008 and January 2012, 11 consecutive patients with atlantoaxial instability, and with a ponticulus posticus at C1, underwent posterior fusion surgery in our institution. According to preoperative computed tomography (CT) reconstruction, a complete ponticulus posticus was found unilaterally in nine patients and bilaterally in two. Postoperative CT reconstructive imaging was performed to assess whether C1 pedicle screw placement was successful. Patients were followed up at regular intervals and evaluated for symptoms of ponticulus posticus syndrome. Thirteen C1 pedicles (atlas vertebral artery groove), each with a complete ponticulus posticus, were successfully inserted with thirteen 3.5- or 4.0-mm diameter pedicle screws, without resection of the bony anomaly. No intraoperative complications (venous plexus, vertebral artery, or spinal cord injury) occurred. The mean follow-up period was 21 (range 14-30) months. Postoperative CT reconstructive images showed that all 13 pedicle screws were inserted in the C1 pedicles without destruction of the atlas pedicle cortical bone. In the follow-up period, none of the patients demonstrated clinical symptoms of ponticulus posticus syndrome or developed bone fusion. Three-dimensional CT imaging should be considered prior to C1 pedicle screw fixation in patients with ponticulus posticus, to avoid mistaking the ponticulus posticus for a widened dorsal arch of the atlas. If there is no ponticulus posticus syndrome preoperatively, C1 pedicle screw fixation can be successfully performed without removing the bony anomaly.

Intraoperative Electromyography and Instrumentation in Patients with Idiopathic Scoliosis

Introduction The objective of this study is to relate the use of intraoperative electromyography surgical time, proper placement of screws, type of curve and time for screw in idiopathic scoliosis correction surgery in a group of surgeons of Belo Horizonte. Methods This was a retrospective study of 80 patients undergoing surgical treatment for idiopathic scoliosis correction between December 2008 and January 2015. All patients was performed electromyographic monitoring (EMG) intraoperative by a single column group of surgeons Belo Horizonte. EMG was performed with stimulation of pedicle screws in patients undergoing instrumentation using pedicle screws and fasteners. Results It was observed that 85% were female, with a mean age of 17 years (minimum of 6 years and maximum of 34 years), 37.5% of the cases represented the curve was idiopathic Lenke 1AN. 60.0% of all surgical cases had EMG change, and of these 1.3% had already had deficits Pre-procedure and 3.75% of cases post deficits. Of the total cases analyzed 66.3% were positive for real results. Conclusion Intraoperative monitoring with EMG is a very important tool for the surgical treatment of patients with scoliosis patients with instrumentation with pedicle screws. Through this feature you can check if the screw is on the correct path contributing to decrease the error rate, post surgical arthrodesis allowing the change in surgical strategy. Besides contributing to the positioning time reduction of the screw and the end of the surgical time.

Treatment strategies for early neurological deficits related to malpositioned pedicle screws in the lumbosacral canal: A pilot study.

ObjectivesTo employ a simple and fast method to evaluate those patients with neurological deficits and misplaced screws in relatively safe lumbosacral spine, and to determine if it is necessary to undertake revision surgery.MethodsA total of 316 patients were treated by fixation of lumbar and lumbosacral transpedicle screws at our institution from January 2011 to December 2012. We designed the criteria for post-operative revision scores of pedicle screw malpositioning (PRSPSM) in the lumbosacral canal. We recommend the revision of the misplaced pedicle screw in patients with PRSPSM = 5′ as early as possible. However, patients with PRSPSM < 5′ need to follow the next consecutive assessment procedures. A total of 15 patients were included according to at least three-stage follow-up.ResultsFive patients with neurological complications (PRSPSM = 5′) underwent revision surgery at an early stage. The other ten patients with PRSPSM < 5′ were treated by conservative methods for seven days. At three-month follow-up, only one patient showed delayed onset of neurological complications (PRSPSM 7′) while refusing revision. Seven months later, PRSPSM decreased to 3′ with complete rehabilitation.ConclusionsThis study highlights the significance of consecutively dynamic assessments of PRSPSMs, which are unlike previous implementations based on purely anatomical assessment or early onset of neurological deficits.and also confirms our hypothesis that patients with early neurological complications may not need revision procedures in the relatively broad margin of the lumbosacral canal.Cite this article: X-J. Lin. Treatment strategies for early neurological deficits related to malpositioned pedicle screws in the lumbosacral canal: A pilot study. Bone Joint Res 2016;5:46–51. DOI: 10.1302/2046-3758.52.2000477.

Safety and Efficacy of Lumbar Spine Radiofrequency Neurotomy in the Presence of Posterior Pedicle Screws.

Pedicle screws could serve as a possible source of tissue heating and thermal injury during radio frequency neurotomy (RFN). The safety and the efficacy of lumbar spine RFN performed in the presence of pedicle screws in patients with chronic low back pain was determined. Some 50% of the patients with pedicle screws benefits from RFN for about six months. No adverse effects were observed.