Posterior Segmental Instrumentation Research Articles

Long-term functional results after short-segment pedicle fixation of thoracolumbar fractures

PurposeA retrospective study to assess the health-related quality of life in patients undergoing posterior fixation of thoracolumbar fractures, and to compare the outcome with norm scores and HRQL in patients undergoing surgical treatment for degenerative conditions of the spine. MethodsThe study population consisted of 93 consecutive patients surgically treated for a thoracolumbar fracture from 2005 to 2009. All patients underwent posterior pedicle screw fixation and fusion. 83 patients were available for follow-up. Three questionnaires reflecting health-related quality of life (HRQL) were mailed to the patients: SF-36, ODI, and EQ-5D. Results52 men and 31 women were operated with an average age at the time of surgery of 46 years. All fractures were AO-type A3.1 and A3.2 with L1 being the primary fracture level. All patients were neurologically intact; Frankel E.The overall response rate on the questionnaires was 75% with no significant differences between responders and non-responder on basic demographic characteristics. The median follow up period was 3.8 years (range 2–6 years). The scores on all three questionnaires were significantly reduced compared to the national norm scores (p<0.05). ConclusionHealth-related quality of life is affected several years after short segment posterior instrumentation of thoracolumbar fractures without neurological deficit.

Effectiveness of cross-linking posterior segmental instrumentation in adolescent idiopathic scoliosis: a 2-year follow-up comparative study

Background contextSurgeons continue to debate the need for a cross-link (CL) in posterior spinal instrumentation constructs with segmental pedicle screws in adolescent idiopathic scoliosis (AIS). Advantage of CLs is increased stiffness of the construct, and disadvantages include added expense and risk of late operative-site pain and pseudarthrosis. PurposeTo compare the effectiveness of using CLs versus using no cross-links (NCLs) in posterior segmental instrumentation in AIS. Study designRetrospective comparative study, level of evidence 3. Patient sampleSeventy-five AIS patients less than 21 years of age, who underwent posterior spinal instrumentation with segmental pedicle screws (25 with CLs and 50 with NCLs) at a single institution with 2-year follow-up, are described. Outcome measuresPhysiologic measures include imaging: thoracic and lumbar Cobb angles, correction rate, apical vertebral translation (AVT), and apical vertebral rotation (AVR); self-report measures include Scoliosis Research Society (SRS) domain outcome scores. MethodsPreoperative (pre-op) and postoperative first erect, 1-year, and 2-year follow-up radiographs were measured. Instrumentation-related complications and normalized SRS scores were recorded. Independent sample t test, χ2 test, and repeated-measures analysis of variance were used for analyses. ResultsThe average age at surgery was 14 years, the mean pre-op Cobb angle was 57°, and the mean number of levels fused was 10.9. The groups were similar preoperatively with respect to age, sex, Lenke curve, Cobb angle, AVT, and Risser grade and were similar intraoperatively for levels fused and anchor density. There was no difference in AVR, Cobb angle, correction rate, or AVT between the groups (p>.05). Complications included one wound infection in the CL group and one painful scar in the NCL group. There were no differences in SRS domain scores. ConclusionWe observed no differences in maintenance of correction, SRS scores, and complications with or without cross-linking posterior segmental instrumentation in AIS patients over 2-year follow-up. Further follow-up is necessary.

SURGICAL CORRECTION OF THORACIC SCOLIOSIS THROUGH ANTERIOR AND POSTERIOR APPROACHES

Objective . Comparative analysis of treatment outcomes in patients with idiopathic scoliosis in the thoracic spine using anterior and posterior segmental instrumentation. Material and Methods. The study included 56 patients aged 12 to 18 years with Lenke type 1 scoliotic deformity in the thoracic spine. Correction with anterior instrumentation was performed in 36 cases and with posterior – in 20. Results. The mean value of deformity correction in patients with anterior instrumentation was 81.1 %. Physiological sagittal contour was formed in all patients after surgery. The mean value of deformity correction in patients with posterior instrumentation was 52.5 %. After surgery the magnitude of the primary curve was 32.2° (range, 30–42°), of the compensatory curve – 12.4° and at long-term follow-up it comprised 13.3°. Conclusion. Efficacy of anterior correction is comparable with results of posterior segmental instrumentation. Correction of the thoracic scoliosis using anterior instrumentation is the equivalent method of choice for surgical treatment of idiopathic scoliosis.

Thoracoscopically assisted corpectomy and percutaneous transpedicular instrumentation in management of burst thoracic and thoracolumbar fractures

This is a prospective observational study. The aim of this study was to determine whether the combination of thoracoscopically assisted corpectomy with posterior percutaneous transpedicular instrumentation in prone position achieves treatment goals in burst thoracic or thoracolumbar fractures and minimizes the associated morbidities. Between December 2007 and December 2008, 26 patients with acute burst spinal fractures were operated upon in our hospital. Those patients underwent posterior percutaneous stabilization plus anterior thoracoscopically assisted corpectomy and fusion in prone position. Clinical and radiological outcomes of these patients were evaluated after a minimum follow-up period of 2 years. The Oswestry Disability Index (ODI) combined with clinical examination was used for clinical evaluation. Plain X-ray in two views was used for the radiological evaluation. The mean operative time was 248 min. The average blood loss was 765 ml. Ten patients had preoperative neurological deficits ranging from Frankel A to D. One patient did not show any neurological improvement at the final follow-up. The mean ODI at final follow-up was about 7. The mean preoperative kyphosis angle was 25.58°, improved to 9.2° postoperatively and to 13.8° at the final follow-up. No cases of implant failure were reported at the final follow-up. Minimal invasive spinal techniques including thoracoscopic decompression and fusion and short segment posterior percutaneous instrumentation showed good clinical outcomes and can be considered as alternative to open procedures with decreased rates of morbidities in managing burst thoracic and thoracolumbar fractures.

The use of X‐shaped cross‐link in posterior spinal constructs improves stability in thoracolumbar burst fracture: A finite element analysis

Posterior instrumentation is a common fixation method used to treat thoracolumbar burst fractures. However, the role of different cross-link configurations in improving fixation stability in these fractures has not been established. A 3D finite element model of T11-L3 was used to investigate the biomechanical behavior of short (2 level) and long (4 level) segmental spine pedicle screw fixation with various cross-links to treat a hypothetical L1 vertebra burst fracture. Three types of cross-link configurations with an applied moment of 7.5 Nm and 200 N axial force were evaluated. The long construct was stiffer than the short construct irrespective of whether the cross-links were used (p < 0.05). The short constructs showed no significant differences between the cross-link configurations. The XL cross-link provided the highest stiffness and was 14.9% stiffer than the one without a cross-link. The long construct resulted in reduced stress to the adjacent vertebral bodies and screw necks, with 66.7% reduction in bending stress on L2 when the XL cross-link was used. Thus, the stability for L1 burst fracture fixation was best achieved by using long segmental posterior instrumentation constructs and an XL cross-link configuration. Cross-links did not improved stability when a short structure was used.

Comparison of Short Segment and Long Segment Posterior Instrumentation of Thoracolumbar and Lumbar Bursting Fractures at Load Sharing Score 7 or Above

Comparison of Short Segment and Long Segment Posterior Instrumentation of Thoracolumbar and Lumbar Bursting Fractures at Load Sharing Score 7 or Above

Biomechanical comparison of anterior cervical spine instrumentation techniques with and without supplemental posterior fusion after different corpectomy and discectomy combinations

The objective of this study was to compare the stiffness and range of motion (ROM) of 4 cervical spine constructs and the intact condition. The 4 constructs consisted of 3-level anterior cervical discectomy with anterior plating, 1-level discectomy and 1-level corpectomy with anterior plating, 2-level corpectomy with anterior plating, and 2-level corpectomy with anterior plating and posterior fixation. Eight human cadaveric fresh-frozen cervical spines from C2-T2 were used. Three-dimensional motion analysis with an optical tracking device was used to determine motion following various reconstruction methods. The specimens were tested in the following conditions: 1) intact; 2) segmental construct with discectomies at C4-5, C5-6, and C6-7, with polyetheretherketone (PEEK) interbody cage and anterior plate; 3) segmental construct with discectomy at C6-7 and corpectomy of C-5, with PEEK interbody graft at the discectomy level and a titanium cage at the corpectomy level; 4) corpectomy at C-5 and C-6, with titanium cage and an anterior cervical plate; and 5) corpectomy at C-5 and C-6, with titanium cage and an anterior cervical plate, and posterior lateral mass screw-rod system from C-4 to C-7. All specimens underwent a pure moment application of 2 Nm with regards to flexion-extension, lateral bending, and axial rotation. In all tested motions the statistical comparison was significant between the intact condition and the 2-level corpectomy with anterior plating and posterior fixation construct. All other statistical comparisons between the instrumented constructs were not statistically significant except between the 3-level discectomy with anterior plating and the 2-level corpectomy with anterior plating in axial rotation. There were no statistically significant differences between the 1-level discectomy and 1-level corpectomy with anterior plating and the 2-level corpectomy with anterior plating in any tested motion. There was also no statistical significance between the 3-level discectomy with anterior plating and the 2-level corpectomy with anterior plating and posterior fixation. This study demonstrates that segmental plate fixation (3-level discectomy) affords the same stiffness and ROM as circumferential fusion in 2-level cervical spine corpectomy in the immediate postoperative setting. This obviates the need for staged circumferential procedures for multilevel cervical spondylotic myelopathy. Given that the posterior segmental instrumentation confers significant stability to a multilevel cervical corpectomy, the surgeon should strongly consider the placement of segmental posterior instrumentation to significantly improve the overall stability of the fusion construct after a 2-level cervical corpectomy.

The Biomechanical Effect of Transverse Connectors Use in a Pre- and Postlaminectomy Model of the Posterior Cervical Spine

An in vitro biomechanical study investigating the effect of transverse connectors on posterior cervical stabilization system in a laminectomy model. To evaluate the optimal design, number, and location of the transverse connectors in stabilizing long segment posterior instrumentation in the cervical spine. In the cervical spine, lateral mass screw (LMS) fixation is used for providing stability after decompression. Transverse connectors have been used to augment segmental posterior instrumentation. However, in the cervical region the optimal design, number, and the location of transverse connectors is not known. Seven fresh human cervicothoracic cadaveric spines (C2-T1) were tested by applying ±1.5 Nm moments in flexion (F), extension (E), lateral bending (LB), and axial rotation (AR). After testing the intact condition, LMS/rods were placed and then were tested with two different transverse connectors (top-loading connector [TL] and the head-to-head [HH] connector) in multiple levels, pre- and postlaminectomy (PL). LMS significantly reduced segmental motion by 77.2% in F, 75.6% in E, 86.6% in LB, and 86.1% in AR prelaminectomy and by 75.4% in F, 76% in E, 80.6% in LB, and 76.4% in AR postlaminectomy compared to intact (P < 0.05). Only in AR, PL constructs with HH connectors at C3 & C7, TL connectors at C4-C5 & C5-C6, and at C3-C4 & C6-C7 significantly reduced the range of motion by 12.9%, 11.9%, and 11.9%, respectively, compared to PL LMS (P < 0.05). No statistical significance was observed between TL connector and HH connector in all loading directions. The biomechanical advantage of transverse connectors is significant in AR, when using two connectors at the proximal and distal ends, compared to one connector. In a clinical setting, this data may guide surgeons on transverse connector configurations to consider during posterior cervical instrumentation.

Comparison of intraoperative supine and postoperative standing radiographs after posterior instrumentation for adolescent idiopathic scoliosis

The utility of intraoperative radiographs after posterior spinal segmental instrumentation for adolescent idiopathic scoliosis (AIS) is debatable. A retrospective review of 74 patients with moderately severe AIS revealed the main thoracic Cobb measurements of 57° preoperatively, 17° intraoperatively, 18° on initial postoperative, and 20° on final postoperative radiographs. On the basis of the extent and type of instrumentation (pedicle screws vs. hybrid construct), there was no clinically significant difference in curve magnitude between intraoperative and postoperative radiographs. After posterior segmental instrumentation for moderate AIS, frontal plane correction measured on intraoperative supine radiographs are comparable with similar measurements made on full-length postoperative standing radiographs.

Long-Term Magnetic Resonance Imaging Follow-up Demonstrates Minimal Transitional Level Lumbar Disc Degeneration After Posterior Spine Fusion for Adolescent Idiopathic Scoliosis

Retrospective cohort study. To describe long-term clinical and imaging results focusing on the uninstrumented lumbar spine after posterior spinal fusion for adolescent idiopathic scoliosis. Although previous studies found rates of low back pain after long fusion for adolescent idiopathic scoliosis which are comparable to rates found in the general population, many surgeons believe that the long lever arm associated with the fusion mass will result in increased stress at uninstrumented caudal intervertebral discs and accelerated degenerative changes. This is a retrospective chart and imaging review of adolescent idiopathic scoliosis patients treated with posterior fusion and segmental instrumentation. Patients completed follow-up examination, outcome questionnaires, radiographs, and magnetic resonance (MR) imaging. MR images were scored for evidence of degeneration of lumbar discs below the level of the fusion. Twenty patients participated in the study, providing 90 discs below fusions for evaluation. The average follow-up was 11.8 years. The distal level of fixation was at L1 on average. The major curve averaged 55° ± 11° before surgery and was corrected to 25° ± 10° at follow-up. Follow-up MR imaging demonstrated new disc pathology in 85% of patients enrolled. Only one patient demonstrated significant degenerative disc disease at the junctional level, whereas most pathology was seen at the L5-S1 disc. The average Pfirrmann grade at uninstrumented levels deteriorated from 1.1 before surgery to 1.8 at follow-up. The greatest degree of degeneration was seen at the L5-S1 disc space where average degenerative scores increased from 1.2 before surgery to 2.3 after surgery. Three patients with severe disc disease were taking nonsteroidal anti-inflammatory drugs for pain, but no narcotics. Only mild scoliosis research society (SRS) and Oswestry changes were noted in this severe degeneration group. Despite demonstrating an accelerated rate of L5-S1 disc degeneration, our study group has good functional scores and maintenance of correction over 10 years postfusion. In this long-term MR imaging follow-up study, disc degeneration was found remote to the lowest instrumented vertebra.

Epidural Hematoma Associated With Occult Fracture in Ankylosing Spondylitis Patient

A case report and review of the literature. To highlight the risk of occult fracture associated with symptomatic epidural hematoma in patient with ankylosing spondylitis. Hyperextension injuries are common in patients with ankylosed spine. Failure of standard imaging to detect these fractures may result in delayed diagnosis. Ossification of the ligaments in these patients makes even subtle fractures grossly unstable owing to the increased lever arm. Delayed diagnosis of fractures may result in further displacement and increased risk of neurological injury. The clinical findings, roentgenographic appearance, and treatment were presented. A 69-year-old patient with a history of ankylosing spondylitis fell 9 feet from a ladder. The patient developed pain in his neck and numbness in his hands. Initial computed tomography (CT) scan of spine showed a subtle fracture in the vertebral body of C7. A magnetic resonance imaging scan showed an epidural hematoma extending from C5 to T3. The patient was taken to the operating room urgently for decompression. Laminectomy was performed from C5 to T3 and a large epidural hematoma was evacuated. After decompression the patient had some improvement in his neurological status. A postdecompression repeat CT scan revealed obvious fracture at C6-C7 with anterior distraction indicating a hyperextension injury. The patient was taken back to the operating room within 16 hours of his decompression for C4 to T3 posterior segment instrumentation and fusion. Patients with ankylosing spondylitis who sustain low-energy injuries should be considered to have a fracture especially if they develop epidural hematoma. A high index of suspicion is necessary in such a case. Imaging studies including magnetic resonance imaging and CT scans should be reviewed carefully to rule out any occult fracture.

Radiographic Features of the Lenke 1A Curves to Help to Determine the Optimum Distal Fusion Level Selection

Retrospective study. Investigate the radiographic features of the subtypes of Lenke 1A curves to help to determine the optimum distal fusion level selection. The Lenke 1A was the most frequently evaluated curve type in adolescent idiopathic curves. Miyanji et al suggested that the lumbar modifier type A does not accurately define the behavior of the compensatory lumbar curve in Lenke 1A. The tilt of L3 and L4 in the coronal plane may have a significant role in determining distal fusion level. Thirty-six patients with Lenke type 1A idiopathic scoliosis treated by segmental posterior instrumentation with an average of 52.1-month follow-up were retrospectively analyzed. Four different curve types depending on L3-L4 vertebral tilt were described. The radiographic measurements including proximal and distal junctional kyphosis was obtained at latest follow-up. RESULTS.: Preoperative mean major curve Cobb angle of 47.6° was corrected to 12.9° showing a correction rate of 72.8% and maintained at 14.2°. Loss of correction at final follow-up was 2.7%. The mean compensatory curve Cobb angle of 24.4° was corrected to 8.2°. All patients balanced after surgery although seven had more than -5° clavicle angle before surgery. The mean preoperative and postoperative sagittal T5-T12 angles were 30.6° and 26.2°, respectively, and 29.1° at latest follow-up. The mean preoperative, postoperative, and latest follow-up T10-L2 sagittal Cobb angles were -0.2°, 2.0°, and 4.2°. Three patients diagnosed as distal junctional kyphosis at latest follow-up. Distal fusion level should be extended to at least lower end vertebra (LEV) -1 in type 1A-A and type 1A-D curves, while it might be necessary to go down to LEV in the type 1A-B and 1A-C. It seems that LEV might be a reliable guide to select ideal distal fusion level in Lenke type 1A curves.

Multicentric Chordoma

Chordomas are relatively rare tumors that arise from the neuraxis. Most often, chordomas are single lesions that metastasize late. There have been very few cases of chordomas arising from multiple foci along the neuraxis. Here, we present a case of a multicentric chordoma. The patient presented with pain in her right neck and soreness in her right shoulder that she had experienced for about 2.5 years that she attributed to a muscle strain. She experienced worsening of her symptoms, which prompted her to seek medical care. The patient underwent an occiput-to-C6 posterolateral fusion with autograft and an occiput-to-C6 posterior segmental instrumentation, along with decompression of the spinal cord. One month after the initial surgery, the patient underwent a second surgery. The C2 and C3 vertebral bodies were completely resected, and a C1-C4 anterior fusion was then carried out. A C5 vertebrectomy and C4-C6 fusion were also performed at this time. The patient then received proton beam radiation to the entire affected area. Recent studies have suggested that chordomas arise from benign notochordal tumors. We suggest that our patient suffered from multicentric chordomas with possible benign notochordal tumors. Although benign notochordal tumors do not require surgical resection, the possibility of transformation to a malignant lesion requires close follow-up.

Spinal Instrumentation after Complete Resection of the Last Lumbar Vertebra

Human cadaveric ilio-lumbosacral spines were tested in an in vitro biomechanical flexibility experiment to investigate the biomechanical stability provided by four different types of spinal reconstruction techniques after spondylectomy of the L5 vertebral body. To compare the biomechanical stability provided by four reconstruction methods after L5 spondylectomy. Clinical studies have shown that total spondylectomy of the L5 vertebral body presents a challenging scenario for spinal reconstruction. Biomechanical studies on spinal reconstruction after total spondylectomy have been performed at the thoracolumbar junction. However, there have been no biomechanical studies after L5 spondylectomy. Seven cadaveric lumbosacral spines (L2-S1) with intact ilium were used. After intact testing, spondylectomy of the L5 vertebra was performed and the spine was reconstructed using an expandable cage for anterior column support. Supplementary fixation was performed as a sequential order of: (1) bilateral pedicle screws at L4-S1 (SP), (2) anterior plate and bilateral pedicle screws at L4-S1 (ASP), (3) bilateral pedicle screws at L3-S1 and iliac screws (MP), and (4) anterior plate at L4-S1, bilateral pedicle screws at L3-S1 and iliac screws (AMP). Range of motion (ROM) for each construct was obtained by applying pure moments in flexion, extension, lateral bending, and axial rotation. In flexion, extension and lateral bending all the instrumented constructs significantly decreased (P < 0.05) the range of motion (ROM) compared to intact. In axial rotation, only the circumferential support constructs (ASP, AMP) provided significantly decreased (P < 0.05) ROM, whereas posterior instrumentations alone (SP, MP) were comparable to intact spines. After L5 spondylectomy, the L4-S1 cage with posterior short segment instrumentation provides stability in lateral bending that is not further increased by adding L3 pedicle-iliac screws and L4-S1 anterior plate. However, an anterior L4-S1 plate provides additional stability in flexion, extension, and axial rotation.

Diplopia Following Spine Surgery: A Case Series

Introduction: Cranial traction leading to 6th nerve palsy is the main cause of developing diplopia following spinal surgery. Very few cases of abducens nerve palsy as a complication of surgery without cranial traction have been described. We review a series of four patients who developed diplopia following spinal surgery only one of which had cranial pins or apparent traction on the abducens nerve. Case presentations: Case 1, a 14-year-old girl who had a posterior segmental instrumentation correction and fusion under general anesthesia in the prone position. Case 2, a 34 year old woman who had posterior fusion and fixation. Case 3, a 67 year-old woman who had a C5-C6, C6-C7 anterior cervical diskectomy and fusion procedure. Cranial traction was util- ized. Case 4, an 18 year-old woman who had an anterior interbody spinal fusion. All cases developed facial edema and diplopia on the first day postoperatively. Conclusion: Diplopia is a rare complication following spine surgery. It needs special attention as it can be attributed to several reasons. Facial edema, face traction and CSF leakage were the possible reasons in our cases. Diplopia was tempo- rary and resolved spontaneously in all our cases.

Surgical treatment of scoliosis associated with Marfan syndrome by using posterior-only instrumentation

Surgical treatment of scoliosis associated with Marfan syndrome poses a challenge to spine surgeons. This retrospective study was undertaken to determine whether posterior-only surgery with instrumented fixation and fusion addresses the correction of scoliosis and maintains curve correction. Twelve consecutive patients with Marfan syndrome were treated between 2002 and 2007 for scoliosis by posterior segmental instrumentation using pedicle screws or hybrid thoracic-hook and lumbar-screw constructs. Their preoperative Cobb angle averaged 66 ± 10° (range: 55-90°). The average operation time was 252 ± 36 min (range: 200-300 min) and the average blood loss was 690 ± 117 ml (range: 550-920 ml). No significant complications were found. All the patients were followed for a minimum of 2 years (range: 2.4-6.8 years). The average Cobb angle was corrected to 23 ± 8° (range: 13-35°) immediately after surgery and 28 ± 9° (range: 14-43°) with a correction rate of 58 ± 13% at final follow-up. The results indicate that posterior-only surgery with instrumented fixation and fusion is effective and safe for the treatment of scoliosis in selected patients with Marfan syndrome.

History of Spinal Deformity Surgery Part II: The Modern Era

Spinal deformity is one of the oldest known diseases that date back thousands of years in human history. It appears in fairy tales and mythologies in association with evil as its dramatic appearance in patients suffering from the disease easily lent itself to be thought of as a form of divine retribution. The history of spinal deformity dates back to prehistoric times. The early attempts to treat patients suffering from this disease started from Hippocrates age. Side traction or axial traction and cast immobilization were the only possible option prior to the discovery of anesthesia. The first surgical attempts to correct scoliosis occurred in the mid 19 th century with percutaneous myotomies of the vertebral musculature followed by postoperative bracing, which outcomes were very quite horrifying. Hibbs’ fusion operation had become a realistic treatment option to halt the progression of deformity in the early 20th century. Harrington’s introduction of the internal fixation device to treat paralytic scoliosis in 1960’s started revolution on deformity correction surgery. Luque developed a segmental spinal using sublaminar wiring technique in 1976 and Cotrel developed Cotrel-Dubousset (CD) instrumentation, which was a posterior segmental instrumentation system that used pedicle and laminar hooks on either thoracic or lumbar spine and pedicle screws on the lumbar spine.

Spine Fractures in Patients With Ankylosing Spinal Disorders

Retrospective review. To describe the spine fracture characteristics, current treatments, and their results in patients with ankylosing spinal disorders (ASD), such as ankylosing spondylitis (AS) and diffuse idiopathic skeletal hyperostosis (DISH), with the hypothesis that complication and mortality rates are high. Spine fractures in patients with ASD are unique and have only been described in relatively small case series. Retrospective review of a large consecutive series of patients with spine fractures and ASD over a 7-year period. Complications were stratified according to parameters such as type and number of comorbidities, patient age, and mechanism of injury. Predictors of mortality were analyzed by linear regression. Similarities between patients with AS and DISH were evaluated by chi analysis. Of the 122 spine fractures in 112 consecutive patients with ASD, the majority were transdiscal extension injuries, most commonly affecting C6-C7. Eighty-one percent of the patients had at least 1 major medical comorbidity. Spinal cord injury was present in 58% of the patients, 34% of whom improved by at least 1 American Spinal Injury Association grade. Nineteen percent of patients had delayed diagnosis of their spine fracture, 81% of whom had resulting neurologic compromise. Surgery was performed on 67% of patients, consisting primarily of multilevel posterior instrumentation 3 levels above and below the injury. Eighty-four percent of all patients had at least 1 complication. Mortality was 32% and correlated with age > or =70 (P < 0.0001), number of comorbidities (P < 0.0001), and low-energy mechanism of injury (P = 0.009). AS patients were younger (P = 0.03) and had a higher risk of delayed fracture diagnosis (P = 0.012), but were otherwise similar to DISH patients. Patients with spine fractures and ASD are at high risk for complications and death and should be counseled accordingly. Multilevel posterior segmental instrumentation allows effective fracture healing. AS and DISH patients represent similar patient populations for the purpose of treatment and future research.

Bacterial Meningitis After Traumatic Thoracic Fracture-Dislocation: Two Case Reports and Review of the Literature

Bacterial meningitis occurs rarely in the setting of traumatic spinal injury. Bacterial meningitis after spinal surgery for traumatic thoracic fracture-dislocation injuries has not been reported. We report on two cases of bacterial meningitis in two pediatric patients undergoing posterior segmental instrumentation with pedicle screws after thoracic fracture-dislocation injuries with associated traumatic dural laceration and complete spinal cord transection. Both patients were treated and recovered. Early recognition of bacterial meningitis after traumatic spinal injury enables appropriate and timely treatment to be instituted and can yield a favorable outcome.

An unusual occurrence of chondromyxoid fibroma with secondary aneurysmal bone cyst in the cervical spine

Background context Chondromyxoid fibroma (CMF) and aneurysmal bone cysts (ABCs) are rare bone tumors and even rarer in the spine. To date, no report has been made of CMF with secondary ABC in the cervical spine. Purpose The purpose of this study was to describe the diagnosis and surgical treatment of a case of CMF with secondary ABC of C6, a rare occurrence in an uncommon location. Study design The study design is a case report. Methods A 27-year-old woman presented with numbness with paresthesias of the right upper extremity. Diagnostic imaging revealed diffuse enlargement of the right C6 lamina extending into the pedicle and medial facet joint. Surgical treatment consisted of complete C6 laminectomy, total resection of the extradural cervical mass, posterior lateral fusion at C5–C7, and posterior segmental instrumentation from C5 to C7. Histopathology was consistent with CMF with secondary ABC. Results Laminectomy and instrumented segmental fusion provided an excellent clinical outcome. The instrumented fusion maintained the sagittal balance of the spine and stabilized across a complete facetectomy. The excision will likely avoid recurrence of the lesion. Conclusions Treatment of CMF and ABC is challenging in the spine because of the proximity to neural structures. Aggressive surgical treatment makes recurrence less likely but creates the risk of spinal instability. Adequate surgical treatment needs to provide spinal stability.