Search

Lateral interbody fusion and posterior percutaneous pedicle screw (LIF-PPS) fixation has been performed in two-stage positioning. The aim of this study was to investigate the surgical outcomes of simultaneous single-position LIF-PPS fixation using O-arm-based navigation. Overall, 102 consecutive subjects underwent indirect decompression surgery for spondylolisthesis with LIF-PPS fixation. Fifty-one subjects underwent surgery with repositioning, and 51 in the right lateral decubitus position. We compared these two groups in terms of the surgery time, occupancy time in the operating room, intraoperative blood loss, Japanese Orthopaedic Association (JOA) score, local lordosis acquisition in postoperative radiographs, and accuracy of screw insertion using postoperative CT scans. In the single-position group, surgery time, occupancy time of the operating room, and estimated blood loss were 93.3 ± 19.3 min (vs. the repositioning group: 121.0 ± 37.1 min; p

Study Design: A retrospective cohort study.Purpose: The purpose of this study was to investigate the prevalence and risk factors for S2 alar-iliac (SAI) screw loosening following lumbosacral fixation, with a minimum 2-year follow-up.Overview of Literature: Although SAI screws allow surgeons to perform lumbosacral fixation with a low profile and enhanced biomechanical strength, screw loosening following surgery can occur in some cases. However, few studies have investigated the prevalence and risk factors for SAI screw loosening.Methods: This retrospective study included 35 patients (mean age, 72.8±8.0 years; male, 10; female, 25) who underwent lumbosacral fixation using SAI screws with at least 2 years of follow-up. SAI screw loosening and L5–S bony fusion were assessed using computed tomography. The period for which the screws appeared loose and the risk factors for SAI screw loosening were investigated 2 years after surgery.Results: A total of 70 SAI screws and 70 S1 pedicle screws were inserted. Loosening was observed 0.5, 1, and 2 years after surgery in 17 (24.3%), 35 (50.0%), and 35 (50.0%) SAI screws, respectively. Bony fusion rate at L5–S was significantly lower in patients with SAI screw loosening than in those without screw loosening (65.0% vs. 93.3%, p =0.048). The score for SAI screw contact with the iliac cortical bone and the bony fusion rate at L5–S were significantly lower in the loosening group than in the non-loosening group (1.8±0.5 vs. 2.2±0.3, p

The purpose of this study was to investigate the effectiveness of early (72 h) versus late (≥72 h) decompression surgery after the onset of drop foot caused by root disorder in lumbar degenerative diseases (LDDs). Data were included from 60 patients who underwent decompression surgery for drop foot caused by LDDs, including lumbar disk herniation or lumbar spinal stenosis. The primary outcome was ordinal change in the manual muscle test (MMT) at 2 years follow-up. Secondary outcomes included changes in the Japanese Orthopedic Association's (JOA) score. The early- and late-stage surgery groups included 20 and 40 patients with mean durations from the onset of drop foot to operation of 0.8 days (range, 0-3 days) and 117.1 days (range, 10-891 days), respectively. There was no significant difference (p = 0.33) between the early- and late-stage surgery groups in the improvement of MMT scores to4 (90% versus 80%, respectively). However, more patients in the early-stage group achieved an MMT score5 compared with those in the late-stage surgery group (80% versus 45%; p = 0.03). Furthermore, the recovery rate of JOA scores was significantly higher in the early-stage (89.1%) compared with the late-stage surgery group (68.6%; p 0.001). Early decompression surgery produced better neurological recovery; however, an improvement of4 in the MMT score was achieved in 80% of cases with late decompression.

Study Design Retrospective case-control study. Purpose We aimed to compare radiologic outcomes between posterior (PLIF) and lateral lumbar interbody fusion (LLIF) in short-level spinal fusion surgeries. Overview of Literature Although LLIF enables surgeons to insert large lordotic cages, it is unknown whether LLIF more effectively corrects local and global sagittal alignments compared with PLIF in short-level spinal fusion surgeries. Methods Radiographic data acquired from patients with lumbar interbody fusion (≤3 levels) using PLIF or LLIF for degenerative lumbar diseases were analyzed. The following radiographic parameters were evaluated preoperatively and at 2 years postoperatively: segmental lordotic angle, disk height, lumbar lordosis (LL), pelvic tilt (PT), C7 sagittal vertical axis, and thoracic kyphosis (TK). Results In total, 144 patients with PLIF (193 fused levels) and 101 with LLIF (159 fused levels) were included. Patients’ backgrounds and preoperative radiographic parameters for any level of fusion did not differ significantly between PLIF and LLIF procedures. The LLIF group exhibited significantly greater changes at 1-level fusion compared to the PLIF group in the parameters of segmental lordotic angle (5.1°±5.8° vs. 2.1°±5.0°, p

Study Design Retrospective case–control study. Purpose To compare surgical invasiveness and radiological outcomes between posterior lumbar interbody fusion (PLIF) and lateral lumbar interbody fusion (LLIF) for degenerative lumbar kyphosis. Overview of Literature LLIF is a minimally invasive interbody fusion technique; however, few reports compared the clinical outcomes of conventional PLIF and LLIF for degenerative lumbar kyphosis. Methods Radiographic data for patients who have undergone lumbar interbody fusion (≥3 levels) using PLIF or LLIF for degenerative lumbar kyphosis (lumbar lordosis [LL]

Study Design Prospective cohort study. Purpose To identify factors that affect sagittal alignment correction in lateral lumbar interbody fusion (LIF) surgery for adult spinal deformity (ASD) and to investigate the degree of correction in each condition. Overview of Literature LIF is a useful procedure for ASD, but the degree of correction can be affected by posterior osteotomy, intraoperative endplate injury, or anterior longitudinal ligament (ALL) rupture. Methods Radiographical data for 30 patients who underwent LIF for ASD were examined prospectively. All underwent two-stage surgery (LIF followed by posterior fixation). Radiographical parameters were measured preoperatively, after LIF, and after posterior fixation; these included the segmental lordotic angle, lumbar lordosis (LL), and other sagittal alignment factors. Results LL was corrected from 16.5°±16.7° preoperatively to 33.4°±13.8° after LIF (p

Study Design: The efficacy of use of a drain tip culture for early detection of surgical-site infection (SSI) was investigated in 329 patients after spinal surgery. Objective: To examine the efficacy of a wound drain tip culture for detection of SSI in spinal surgery. Summary of Background Data: A complication of SSI after spinal surgery has high associated morbidity and mortality, and is often difficult to treat. Materials and Methods: The subjects were patients who underwent spinal surgery at our institution between January 2010 and March 2013. All subjects were treated with antimicrobial prophylaxis based on evidence-based guidelines and were followed for at least 6 months after surgery. Data from culture studies using the distal tip of the wound drain were used for analysis. Results: Drain tip cultures were positive in 34 cases and there were 19 SSIs. Ten of the 34-tip culture-positive wounds developed SSI. Drain tip cultures had a sensitivity of 52%, specificity of 92%, positive predictive value (PPV) of 29%, and negative predictive value of 97% for predicting a wound infection. The association between a positive suction tip culture and wound infection was significant (P, ファイル公開：2018/10/01

STUDY DESIGN A review of accident and incident reports. OBJECTIVE To analyze prevalence, characteristics, and details of perioperative incidents and accidents in patients receiving spine surgery. SUMMARY OF BACKGROUND DATA In our institution, a clinical error that potentially results in an adverse event is usually submitted as an incident or accident report through a web database, to ensure anonymous and blame-free reporting. All reports are analyzed by a medical safety management group. These reports contain valuable data for management of medical safety, but there have been no studies evaluating such data for spine surgery. METHODS A total of 320 incidents and accidents that occurred perioperatively in 172 of 415 spine surgeries were included in the study. Incidents were defined as events that were "problematic, but with no damage to the patient," and accidents as events "with damage to the patient." The details of these events were analyzed. RESULTS There were 278 incidents in 137 surgeries and 42 accidents in 35 surgeries, giving prevalence of 33% (137/415) and 8% (35/415), respectively. The proportion of accidents among all events was significantly higher for doctors than non-doctors [68.0% (17/25) vs. 8.5% (25/295), P

Study design Retrospective clinical study. Objective To evaluate the clinical outcome of patients who had undergone occipitocervical (OC) fusion using pedicle screws and rods over a minimum 5-year follow-up. Summary of background data Few studies have evaluated occipitocervical (OC) fusion using pedicle screws and rods for long-term follow-up. Methods Twenty-seven consecutive patients treated underwent posterior OC fusion using pedicle screws and rods over a minimum 5-year follow-up. The Modified McCormick scale to grade a patient's functional status and the Japanese Orthopaedic Association (JOA) scoring system were used to evaluate preoperative and postoperative neurological function. We assessed fusion by both direct and indirect evidence; bony trabeculae at the graft-recipient interface on lateral cervical radiographs and sagittal computed tomography reconstruction was considered direct evidence of union. Results The mean follow-up period was 7.2 years (5-14 y). JOA scores were 8.1±3.8 before surgery and 11.7±3.7 at the final follow-up. The recovery rate calculated from the JOA scores was 42.0±30.0%. Functional status did improve at least 1 grade according to the modified McCormick scale in 18 patients (66.7%). There was no deterioration at the final follow-up.There were postoperative implant-related complications in 8 patients (29.6%): loosening of pedicle screws in 2, rod breakage in 2, plate breakage in 1, screw breakage in 1, pullout of pedicle screws in 1, and wiring induced myelopathy in 1 patient. The average duration between surgery and implant failure was 31.2 months (12-60 mo) except for 2. Conclusions Sufficient bone grafting, proper decortication of the bone bed, using thicker and high stiffness rods, and ultra-high molecular weight polyethylene tape as a fixation or reinforcement of implant may help prevent implant failure.

Study Design: Prospective study. Objective: Investigate factors associated with preoperative motor paresis, recovery, ambulatory status, and intraoperative neurophysiological monitoring (IONM) among patients with no preoperative paresis (N group), complete preoperative motor recovery (CR group), and no complete recovery (NCR group) in patients with intramedullary spinal cavernous hemangioma to determine the optimal timing of surgery. Methods: The study evaluated 41 surgical cases in our institute. Disease duration, tumor lesion, manual muscle testing (MMT), and gait at onset, just before surgery, and final follow-up (FU), tumor and lesion volume, IONM, extent of tumor resection, and tumor recurrence were evaluated among N, CR, and NCR groups. Results: Motor paresis at onset was found in 26 patients (63%), with 42% of those in CR group. Disease duration from onset negatively affected stable gait just before surgery and FU as well as lower preoperative MMT ( P < .05). Thoracic tumors were associated with patients with unstable gait before surgery ( P < .05). Tumor volume was larger in NCR group ( P < .05). IONM significantly decreased in NCR and CR groups than in N group ( P < .05). The NCR group had residual mild motor paresis at FU ( P < .05). Stable gait at FU was similar in N group and CR group, though lower in NCR group ( P < .05). Conclusions: Early surgery is generally recommended for thoracic tumors and large tumors during stable gait without motor paresis before long disease duration. Surgery may be postponed until patients recover from preoperative motor paresis to allow optimal surgical outcome. IONM should be carefully monitored in patients with a history of preoperative paresis even with preoperative complete motor recovery.

Study Design: A retrospective analysis of a prospective database. Objective: To compare preoperative symptoms, ambulatory ability, intraoperative spinal cord monitoring, and pathologic cell proliferation activity between intramedullary only and intramedullary plus extramedullary hemangioblastomas, with the goal of determining the optimal timing for surgery. Methods: The subjects were 28 patients (intramedullary only in 23 cases [group I] and intramedullary plus extramedullary in 5 cases [group IE]) who underwent surgery for spinal hemangioblastoma. Preoperative symptoms, ambulatory ability on the McCormick scale, intraoperative spinal cord monitoring, and pathologic findings using Ki67 were compared between the groups. Results: In group IE, preoperative motor paralysis was significantly higher (100 versus 26%, p < 0.005), the mean period from initial symptoms to motor paralysis was significantly shorter (3.5 versus 11.9 months, p < 0.05), and intraoperative spinal cord monitoring aggravation was higher (65 versus 6%, p < 0.05). All 5 patients without total resection in group I underwent reoperation. Ki67 activity was higher in group IE (15% versus 1%, p < 0.05). Preoperative ambulatory ability was significantly poorer in group IE (p < 0.05), but all cases in this group improved after surgery, and postoperative ambulatory ability did not differ significantly between the two groups. Conclusions: Intramedullary plus extramedullary spinal hemangioblastoma is characterized by rapid preoperative progression of symptoms over a short period, severe spinal cord damage including preoperative motor paralysis, and poor gait ability compared with an intramedullary tumor only. Earlier surgery with intraoperative spinal cord monitoring is recommended for total resection and good surgical outcome especially for an IE tumor compared with an intramedullary tumor.

Study Design: Prospective clinical study. Objective: Many oral surgeons use platelet-rich plasma (PRP) for bone defects, but the efficacy of PRP for spinal arthrodesis remains uncertain. The objective was to compare the efficacy of autologous local bone graft and PRP with local bone graft alone for promotion of bony union in posterolateral lumbar fusion (PLF) surgery, with investigation of the safety of PRP over 10 years. Methods: A prospective study was conducted in 29 consecutive patients who underwent one-level PLF at L4/5 for degenerative lumbar disease. Local bone on the left (control) side and local bone with PRP on the right side were grafted. The fusion area and absorption of grafted bone at 58 regions were determined using computed tomography at 2 weeks and 3, 6, and 12 months after surgery. Results: Average bone fusion areas on the PRP side were significantly wider at 3 and 6 months after surgery ( P < .05). Average absorption values were significantly lower on the PRP side than on the control side at 3 and 6 months after surgery ( P < .05). The PRP/control ratio was significantly different at 3 and 6 months compared to that at 2 weeks ( P < .005). No adverse events related to PRP occurred with good clinical outcome over 10 years follow-up. Conclusions: Local application of PRP combined with autologous local bone graft has a positive impact on early fusion for lumbar arthrodesis with no adverse events over 10 years, and thus is a safe and low cost autologous option in spinal fusion.

BACKGROUND Thoracic ossification of the posterior longitudinal ligament (T-OPLL) is treated surgically with instrumented posterior decompression and fusion. However, the factors determining the outcome of this approach and the efficacy of additional resection of T-OPLL are unknown. OBJECTIVE To identify these factors in a prospective study at a single institution. METHODS The subjects were 70 consecutive patients with beak-type T-OPLL who underwent posterior decompression and dekyphotic fusion and had an average of 4.8 years of follow-up (minimum of 2 years). Of these patients, 4 (6%; group R) had no improvement or aggravation, were not ambulatory for 3 weeks postoperatively, and required additional T-OPLL resection; while 66 (group N) required no further T-OPLL resection. Clinical records, gait status, intraoperative ultrasonography, intraoperative neurophysiological monitoring (IONM), plain radiography, computed tomography and magnetic resonance imaging findings, and Japanese Orthopaedic Association (JOA) score were compared between the groups. RESULTS Preoperatively, patients in group R had significantly higher rates of severe motor paralysis, nonambulatory status, positive prone and supine position test, no spinal cord floating in intraoperative ultrasonography, and deterioration of IONM at the end of surgery ( P < .05). In preoperative radiography, the OPLL spinal cord kyphotic angle difference in fused area, OPLL length, and OPLL canal stenosis were significantly higher in group R ( P < .05). At final follow-up, JOA scores improved similarly in both groups. CONCLUSION Preoperative severe motor paralysis, nonambulatory status, positive prone and supine position test, radiographic spinal cord compression due to beak-type T-OPLL, and intraoperative residual spinal cord compression and deterioration of IONM were associated with ineffectiveness of posterior decompression and fusion with instrumentation. Our 2-stage strategy may be appropriate for beak-type T-OPLL surgery.

MINI: On magnetic resonance imaging, indirect decompression using lateral lumbar interbody fusion and posterior fixation was confirmed immediately after surgery and also continuously progressed after surgery, particularly during the first 6 months. Thecal sac enlargement was also confirmed, and is suspected to be caused by the atrophy of the ligamentum flavum and the disc.A prospective cohort study.The aim of this study was to investigate radiographical changes related to indirect decompression using lateral lumbar interbody fusion (LLIF) with posterior fixation.Indirect lumbar decompression via LLIF is used to treat degenerative lumbar diseases requiring neural decompression. Although evidence suggests that thecal sac enlargement follows shortly after surgery, few studies have described the postoperative changes on MRIs.This study involved 102 patients who underwent indirect decompression at 136 levels, with LLIF and posterior fixation. Magnetic resonance imaging (MRIs) were collected preoperatively and several times postoperatively (over a 2-year period starting immediately after surgery). We then quantified the cross-sectional areas of the thecal sac and ligamentum flavum, as well as the anteroposterior diameter of disc bulging, and qualitatively assessed lumbar spinal stenosis according to a modified version of Schizas' classification [Grades A (mild) to C (severe)]. The Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) was used for the assessment of the clinical symptoms.All changes were observable immediately after surgery, progressed over time, and were significantly different statistically at 2 years after surgery. The thecal sac was significantly larger (189% of preoperative; P 0.0001), while the ligamentum flavum and disc bulge were significantly smaller [58.9% and 67.3% of preoperative (P 0.001), respectively]. The number of patients with grade C (severe) lumbar stenosis also dropped significantly (preoperative, 17.6%; 2 years postoperative, 0%). There were no significant differences in JOABPEQ results at 6 months, 1 year, and 2 years postsurgery.Indirect decompression produces immediate positive results that continue to improve over time. The cross-sectional area of the thecal sac doubled by 2 years after surgery, and the ligamentum flavum cross-sectional area and disc bulging both shrank significantly. At the same time, however, postoperative radiographical improvements do not appear to correlate with clinical symptoms.3.A prospective cohort study. The aim of this study was to investigate radiographical changes related to indirect decompression using lateral lumbar interbody fusion (LLIF) with posterior fixation. Indirect lumbar decompression via LLIF is used to treat degenerative lumbar diseases requiring neural decompression. Although evidence suggests that thecal sac enlargement follows shortly after surgery, few studies have described the postoperative changes on MRIs. This study involved 102 patients who underwent indirect decompression at 136 levels, with LLIF and posterior fixation. Magnetic resonance imaging (MRIs) were collected preoperatively and several times postoperatively (over a 2-year period starting immediately after surgery). We then quantified the cross-sectional areas of the thecal sac and ligamentum flavum, as well as the anteroposterior diameter of disc bulging, and qualitatively assessed lumbar spinal stenosis according to a modified version of Schizas’ classification [Grades A (mild) to C (severe)]. The Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) was used for the assessment of the clinical symptoms. All changes were observable immediately after surgery, progressed over time, and were significantly different statistically at 2 years after surgery. The thecal sac was significantly larger (189% of preoperative; P 0.0001), while the ligamentum flavum and disc bulge were significantly smaller [58.9% and 67.3% of preoperative (P 0.001), respectively]. The number of patients with grade C (severe) lumbar stenosis also dropped significantly (preoperative, 17.6%; 2 years postoperative, 0%). There were no significant differences in JOABPEQ results at 6 months, 1 year, and 2 years postsurgery. Indirect decompression produces immediate positive results that continue to improve over time. The cross-sectional area of the thecal sac doubled by 2 years after surgery, and the ligamentum flavum cross-sectional area and disc bulging both shrank significantly. At the same time, however, postoperative radiographical improvements do not appear to correlate with clinical symptoms. Level of Evidence: 3.

Chondroitin sulfate (CS) and heparan sulfate (HS) are glycosaminoglycans that both bind the receptor-type protein tyrosine phosphatase PTPRσ, affecting axonal regeneration. CS inhibits axonal growth, while HS promotes it. Here, we have prepared a library of HS octasaccharides and, together with synthetic CS oligomers, we found that PTPRσ preferentially interacts with CS-E—a rare sulfation pattern in natural CS—and most HS oligomers bearing sulfate and sulfamate groups. Consequently, short and long stretches of natural CS and HS, respectively, bind to PTPRσ. CS activates PTPRσ, which dephosphorylates cortactin—herein identified as a new PTPRσ substrate—and disrupts autophagy flux at the autophagosome–lysosome fusion step. Such disruption is required and sufficient for dystrophic endball formation and inhibition of axonal regeneration. Therefore, sulfation patterns determine the length of the glycosaminoglycan segment that bind to PTPRσ and define the fate of axonal regeneration through a mechanism involving PTPRσ, cortactin and autophagy. 15;7

STUDY DESIGN Retrospective analysis. OBJECTIVE The goal of this study was to examine the relationship of the proliferation potency based on the MIB-1 index and motor status with features of T2-weighted images (T2WI) and contrast T1-weighted images (T1WI) of spinal schwannoma. SUMMARY OF BACKGROUND DATA Spinal schwannomas account for 55% of spinal tumors, but the relationship of cellular proliferation with MRI findings for spinal schwannoma is unknown. METHODS The subjects were 48 patients (22 males and 26 females) with spinal schwannoma who were classified into three subgroups: iso/homo, high/rim, and hetero/hetero, based on T2WI/contrast T1WI. A retrospective analysis of tumor size and MIB-1 index was performed in the context of these MRI findings. Intraoperative findings and pre- and postoperative motor performance were also examined. RESULTS The average tumor size was 32.4 mm (range 10-130 mm) and the average MIB-1 index was 3.8% (range 1-12). In the three subgroups, there were no significant differences in sex, age, duration of disease, tumor lesion, and dumbbell type. In the hetero/hetero group, the tumor size was significantly greater and the MIB-1 index was significantly higher (both P

OBJECTIVE Corrective surgery for spinal deformities can lead to neurological complications. Several reports have described spinal cord monitoring in surgery for spinal deformity, but only a few have included patients younger than 20 years with adolescent idiopathic scoliosis (AIS). The goal of this study was to evaluate the characteristics of cases with intraoperative transcranial motor evoked potential (Tc-MEP) waveform deterioration during posterior corrective fusion for AIS. METHODS A prospective database was reviewed, comprising 68 patients with AIS who were treated with posterior corrective fusion in a prospective database. A total of 864 muscles in the lower extremities were chosen for monitoring, and acceptable baseline responses were obtained from 819 muscles (95%). Intraoperative Tc-MEP waveform deterioration was defined as a decrease in intraoperative amplitude of ≥ 70% of the control waveform. Age, Cobb angle, flexibility, operative time, estimated blood loss (EBL), intraoperative body temperature, blood pressure, number of levels fused, and correction rate were examined in patients with and without waveform deterioration. RESULTS The patients (3 males and 65 females) had an average age of 14.4 years (range 11–19 years). The mean Cobb angles before and after surgery were 52.9° and 11.9°, respectively, giving a correction rate of 77.4%. Fourteen patients (20%) exhibited an intraoperative waveform change, and these occurred during incision (14%), after screw fixation (7%), during the rotation maneuver (64%), during placement of the second rod after the rotation maneuver (7%), and after intervertebral compression (7%). Most waveform changes recovered after decreased correction or rest. No patient had a motor deficit postoperatively. In multivariate analysis, EBL (OR 1.001, p = 0.085) and number of levels fused (OR 1.535, p = 0.045) were associated with waveform deterioration. CONCLUSIONS Waveform deterioration commonly occurred during rotation maneuvers and more frequently in patients with a larger preoperative Cobb angle. The significant relationships of EBL and number of levels fused with waveform deterioration suggest that these surgical invasions may be involved in waveform deterioration.

The aim of this study was to present cases of upper cervical fixation in Down syndrome patients younger than 5 years. In two cases, C1 lateral mass screws were installed. However, owing to the irreducible atlantoaxial dislocation, the screw backed out and fractured. Therefore, O-C2 fusion was performed. Furthermore, C2 bilateral lamina screws were added to the C2 pedicle screw for reinforcement. C1-C2 fusion is an option for Down syndrome patients younger than 5 years with atlantoaxial dislocation, when the dislocation is reducible. If the dislocation is irreducible, or the implant cannot be firmly secured, the fixation range should be expanded to O-C2 or below.

STUDY DESIGN Self-assembling peptide gel (SPG-178) provides new evidence for the role of a scaffold for treatment of the spinal cord through induction of neuroprotective factors. OBJECTIVE To verify the reproducibility of SPG-178 as scaffold after spinal cord injury, we examine the characteristics of SPG-178 and protective effect on neural cells in vitro and in vivo. SUMMARY OF BACKGROUND DATA The central nervous system extracellular matrix may play a role in maintenance of the neuronal network by inhibiting axonal growth and suppressing formation of additional inadequate synapses. In this study, we show increased expression of nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-4 (NT-4), and tropomyosin receptor kinase (TrkA and TrkB) in SPG-178-promoted neurite outgrowth of motor neurons in vitro, and decreased inflammation and glial scar with use of SPG-178 in vivo. METHODS We examined the effect of a self-assembling peptide, SPG-178, as a scaffold for neurite outgrowth of spinal motor neurons in vitro. An in vivo analysis was performed to evaluate if the SPG-178 scaffold attenuated or enhanced expression of various genes after spinal cord injury model rats. RESULTS Expression of NGF, BDNF, NT-4, TrkA, and TrkB increased in SPG-178-promoted neurite outgrowth of motor neurons in vitro. In vivo, SPG-178 increased expression of glial cell line-derived neurotrophic factor and NGF, and decreased glial scar. CONCLUSION This study provides new evidence for the role of SPG-178 as a scaffold in the spinal cord and suggests that this peptide is a neuroprotective factor that may serve as an alternative treatment for neuronal injuries. LEVEL OF EVIDENCE 5.

[Introduction][1] We describe the surgical technique and the pitfalls of French-door laminoplasty. [Step 1: Patient Positioning][2] Position the patient to keep the cervical spine “parallel to the floor” or in the “reverse Trendelenburg position” with only a slight incline and place intraoperative neurological monitors to prevent intraoperative neurological deterioration. [Step 2: Surgical Approach][3] Use the common cervical posterior approach to expose the lamina and ligamentum flavum. [Step 3: Create Grooves][4] Cut the center of each lamina and create bilateral grooves using a high-speed burr. [Step 4: Open the Lamina][5] Open the lamina bilaterally and create a small hole in each one using a high-speed burr. [Step 5: Create Bone Struts][6] Create bone struts from the spinous processes and tie them to each lamina. [Step 6: Wound Closure][7] Perform meticulous closure of the wound to avoid wound-healing complications. [Results][8] In our original study[12][9], we treated forty-six patients with French-door laminoplasty and compared the surgical results of this procedure with those of open-door laminoplasty in a prospective, randomized controlled manner. [Indications][10] [Contraindications][11] [Pitfalls & Challenges][12] [Introduction][1] We describe the surgical technique and the pitfalls of French-door laminoplasty. [Step 1: Patient Positioning][2] Position the patient to keep the cervical spine “parallel to the floor” or in the “reverse Trendelenburg position” with only a slight incline and place intraoperative neurological monitors to prevent intraoperative neurological deterioration. [Step 2: Surgical Approach][3] Use the common cervical posterior approach to expose the lamina and ligamentum flavum. [Step 3: Create Grooves][4] Cut the center of each lamina and create bilateral grooves using a high-speed burr. [Step 4: Open the Lamina][5] Open the lamina bilaterally and create a small hole in each one using a high-speed burr. [Step 5: Create Bone Struts][6] Create bone struts from the spinous processes and tie them to each lamina. [Step 6: Wound Closure][7] Perform meticulous closure of the wound to avoid wound-healing complications. [Results][8] In our original study[12][9], we treated forty-six patients with French-door laminoplasty and compared the surgical results of this procedure with those of open-door laminoplasty in a prospective, randomized controlled manner. [Indications][10] [Contraindications][11] [Pitfalls & Challenges][12] [1]: #sec-10 [2]: #sec-11 [3]: #sec-12 [4]: #sec-13 [5]: #sec-14 [6]: #sec-15 [7]: #sec-16 [8]: #sec-17 [9]: #ref-12 [10]: #sec-19 [11]: #sec-20 [12]: #sec-21

Study Design Prospective clinical study. Objective Posterior decompression and fusion surgery for beak-type thoracic ossification of the posterior longitudinal ligament (T-OPLL) generally has a favorable outcome. However, some patients require additional surgery for postoperative severe paralysis, a condition that is inadequately discussed in the literature. The objective of this study was to describe the efficacy of a procedure we refer to as “resection at an anterior site of the spinal cord from a posterior approach” (RASPA) for severely paralyzed patients after posterior decompression and fusion surgery for beak-type T-OPLL. Methods Among 58 consecutive patients who underwent posterior decompression and fusion surgery for beak-type T-OPLL since 1999, 3 with postoperative paralysis (5%) underwent RASPA in our institute. Clinical records, the Japanese Orthopaedic Association score, gait status, intraoperative neurophysiological monitoring (IONM) findings, and complications were evaluated in these cases. Results All three patients experienced a postoperative decline in Manual Muscle Test (MMT) scores of 0 to 2 after the first surgery. RASPA was performed 3 weeks after the first surgery. All patients showed gradual improvements in MMT scores for the lower extremity and in ambulatory status; all could walk with a cane at an average of 4 months following RASPA surgery. There were no postoperative complications. Conclusions RASPA surgery for beak-type T-OPLL after posterior decompression and fusion surgery resulted in good functional outcomes as a salvage surgery for patients with severe paralysis. Advantages of RASPA include a wide working space, no spinal cord retraction, and additional decompression at levels without T-OPLL resection and spinal cord shortening after additional dekyphosis and compression maneuvers. When used with IONM, this procedure may help avoid permanent postoperative paralysis.

OBJECT Little is known about the progression of spinal schwannomas. The aim of this study was to determine the natural progression of spinal schwannomas and establish the risk of tumor growth. METHODS This study retrospectively analyzed data from 23 patients (12 men and 11 women, 40–89 years old) with schwannomas detected by MRI. The mean follow-up period was 5 years (range 2–10 years). The absolute and relative growth rates of the tumors were calculated. RESULTS The average tumor size was 1495 mm3 at the initial visit and 2224 mm3 at the final follow-up. The average absolute growth rate was 139 mm3 per year, and the average relative growth rate was 5.3% per year. Tumors were classified into 3 groups based on enhancement patterns: isointense/hyperintense (iso/high; 11 cases), rim enhancement when enhancement was peripheral (high/rim; 5 cases), and heterogeneous/heterogeneous (hetero/hetero; 7 cases) based on Gd-enhanced T2-weighted MRI. The average absolute growth rates of the 3 lesion groups were 588 mm3, 957 mm3, and 3379 mm3, respectively (p < 0.01). CONCLUSIONS Although the tumors classified as iso/high and high/rim on T2-weighted Gd-enhanced MR images were small and grew very little, most tumors with hetero/hetero classification increased in size. Hetero/hetero-type tumors should be followed closely and may require surgery.

Study Design: Animal study. Purpose: To review the present warning point criteria of the compound muscle action potential (CMAP) and investigate new criteria for spinal surgery safety using an animal model. Overview of Literature: Little is known about correlation palesis and amplitude of spinal cord monitoring. Methods: After laminectomy of the tenth thoracic spinal lamina, 2-140 g force was delivered to the spinal cord with a tension gage to create a bilateral contusion injury. The study morphology change of the CMAP wave and locomotor scale were evaluated for one month. Results: Four different types of wave morphology changes were observed: no change, amplitude decrease only, morphology change only, and amplitude and morphology change. Amplitude and morphology changed simultaneously and significantly as the injury force increased (p

Background: Postoperative pancreatitis has primarily been reported as a complication of abdominal surgery, but there are some case reports of postoperative pancreatitis after spinal surgery. The objective of this study was to investigate a case series of hyperamylasemia and pancreatitis following posterior spinal surgery. Methods: The serum amylase level was measured following posterior spinal surgery in the prone position. Patients were divided into groups with a normal serum amylase level (0–125 IU/L) and with hyperamylasemia (>125 IU/L), based on the upper limit of normal of 125 IU/L in our institution. Relationships among preoperative factors, perioperative factors, and the serum amylase level were investigated. Results: Hyperamylasemia (serum amylase >125 IU/L) following posterior spinal surgery was found in 92 cases (35 %). Among perioperative factors, intraoperative estimated blood loss (EBL) and operating time were significantly higher in patients with high serum amylase than in patients with normal serum amylase (P < 0.01). In a multivariate regression model, intraoperative EBL (OR 1.001, 95 % CI 1.000–1.002; P = 0.001) and operation time (OR 1.006, 95 % CI 1.003–1.009; P = 0.006) were significantly associated with postoperative pancreatitis. Serum amylase levels of ≥5 times the upper limit of normal were found in six cases. Five of these cases were asymptomatic and one was caused by severe pancreatitis. Conclusions: In our case series, intraoperative blood loss caused a rise in the serum amylase level following posterior spinal surgery. Thus, this level should be carefully monitored after spinal surgery with significant blood loss. Clinical symptoms of pancreatitis, such as abdominal pain and vomiting, should also be monitored following spinal surgery.

To investigate what type of Lenke 5C patient benefits most from a fusion to L3 as the LIV. The subjects were 16 patients who underwent fusion surgery to L3 as the lowest instrumented vertebra (LIV), and who were then observed for a minimum of 2 years postoperatively. We considered an unsatisfactory radiologic outcome for the distal adjacent curve (DAD) to be an L3 or L4 tilt angle less than 10° or L3/4 disc wedging less than 10°. Patients were divided into 2 groups based on the radiologic outcome of the distal curve: the distal adjacent disorder+ (DAD+) and the distal adjacent disorder− (DAD−). We compared global balance, Cobb angles (thoracic and lumbar), L3 and L4 tilt angles and L3/4/5 disc angles between the 2 groups on preoperative, postoperative and final radiographs. Seven patients (43.8 %) met the criteria for the DAD+ group. On preoperative radiographs, there was a significant difference in the L3/4 disc angle: the DAD+ group opened to the preoperative convex side (−2.1° ± 3.0°) and the DAD− group opened to the preoperative concave side (4.7° ± 5.1°). The standing L3- and L4-CSVL and the L4-CSVL under traction were significantly different. In Lenke 5C patients who underwent fusion surgery to L3 as the LIV, preoperative LIV (L3), LIV + 1 (L4) translation and L3/4 disc angle on standing, plus LIV + 1 translation under traction were very important parameters correlating with postoperative global coronal balance.

Study DesignCase report.ObjectivesTo describe a case of delayed-onset spinal hematoma following the breakage of a spinal epidural catheter.MethodsThe authors describe the clinical case review.ResultsA 64-year-old woman had undergone epidural anesthesia 18 years before she was referred to our hospital because of lower-back pain and lower neurologic deficit with leg pain. The clinical examination showed the presence of a fragment of an epidural catheter in the thoracolumbar canal, as assessed by computed tomography, and a spinal hematoma that compressed the spinal cord at the same spinal level, as assessed by magnetic resonance imaging. Surgical removal of the epidural catheter and decompression surgery were performed. The patient exhibited substantial clinical improvement 1 month after surgery; she achieved a steady gait without the need for a cane and had no leg pain.ConclusionThis is the first report of delayed onset of spinal hematoma following the breakage of an epidural catheter. Generally, when the breakage of an epidural catheter occurs without symptoms, follow-up alone is recommended. However, because spinal hematoma might exhibit a late onset, the possibility of this complication should be considered when deciding whether to remove the catheter fragment. We believe that in our patient, there could be a relationship between the catheter fragment and subdural hematoma, and catheter breakage could have been a risk factor for the spinal hematoma.

Introduction This retrospective study was performed to evaluate the clinical influence of - and to identify the risk factors for nonunion of transpsoas lateral lumbar interbody fusion (LLIF) with use of allograft. Methods Sixty-three patients who underwent transpsoas LLIF (69.8 ± 8.9 years, 21 males and 42 females, 125 segments) were followed for a minimum 2 years postoperatively. For all LLIF segments, polyetheretherketone (PEEK) cages packed with allogenic bone were applied with supplemental bilateral pedicle screws (PSs). Bone bridge formation was evaluated by computed tomography (CT) 2 years postoperative, and a segment without any bridge formation was determined to be a nonunion. Sixty-one participants (96.8%) were classified into two groups for clinical evacuation: Group N that contained one or more nonunion segments and Group F that contained no nonunion segment. Visual analogue scales (VAS) scores and the effective rates of the five domains of the Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ) were compared between Groups N and F. The risk factors for nonunion were determined by univariate and multivariate analyses. Results Twenty segments (16%) were diagnosed as nonunion. There were no significant differences in all VAS scores, and the ratio of effective cases in all domains of JOABPEQ between Group N (n = 14) and F (n = 47). Multivariate analysis identified percutaneous PS (PPS) usage (odds ratio [OR]: 3.14, 95% confidence interval: 1.13-8.68, p = 0.028) as a positive risk factor for nonunion. Conclusions We should be aware of the higher nonunion rate in the LLIF segments supplemented with PPS, though nonunion does not affect significantly clinical outcomes at 2 years postoperative.

Sarcopenia reduces physical function, while chronic inflammation causes arteriosclerosis and decreases skeletal muscle. We conducted a cross-sectional study to elucidate the associations among sarcopenia, physical function, arteriosclerosis, and inflammation in community-dwelling people.We recruited 335 participants in an annual health checkup. We diagnosed sarcopenia based on appendicular skeletal muscle mass index (aSMI) assessed by bioelectrical impedance analysis. We measured several physical function tests, blood pressure, and serum levels of high-sensitivity C-reactive protein (hs-CRP), total cholesterol, and low-density lipoprotein cholesterol.After controlling for age, sex, and BMI, participants in the sarcopenia group showed lower performance in all measured physical tests than the normal group. Arteriosclerosis risk factors, including blood pressure, cholesterol levels, and hs-CRP, were significantly higher in the sarcopenia group than in the normal group. hs-CRP and total cholesterol levels were significant risk factors of sarcopenia. The aSMI, grip strength, and maximum stride length were negatively related to hs-CRP level.Community-dwelling people with sarcopenia had higher levels of hs-CRP and a higher risk for arteriosclerosis. The serum level of hs-CRP was an independent risk factor for sarcopenia and was associated with physical function. These findings indicate that chronic inflammation may relate arteriosclerosis and sarcopenia simultaneously.

Diabetes mellitus (DM) is known as an important risk factor for surgical site infection (SSI) in spine surgery. It is still unclear however which DM-related parameters have stronger influence on SSI. The purpose of this study is to determine predisposing factors for SSI following spinal instrumentation surgery for patients with DM.110 DM patients (66 males and 44 females) who underwent spinal instrumentation surgery in one institute were enrolled in this study. For each patient, various preoperative or intraoperative parameters were reviewed from medical records. Patients were divided into two groups (SSI or non-SSI) based on the postoperative course. Each parameter between these two groups was compared. Univariate and multivariate analyses were performed to determine predisposing factor for SSI.The SSI group consisted of 11 patients (10%), and the non-SSI group of 99 patients (90%). Univariate analysis revealed that preoperative proteinuria (p = 0.01), operation time (p = 0.04) and estimated blood loss (p = 0.02) were significantly higher in the SSI group compared to the non-SSI group. Multivariate logistic regression identified preoperative proteinuria as a statistically significant predictor of SSI (OR 6.28, 95% CI 1.58-25.0, p = 0.009).Proteinuria is a significant predisposing factor for SSI in spinal instrumentation surgery for DM patients. DM patients with proteinuria who are likely to suffer latent nephropathy have a potential risk for SSI. For them less invasive surgery is recommended for spinal instrumentation. In this retrospective study, there was no significant difference of preoperative condition in glycemic control between the two groups.

BACKGROUND Surgery for thoracic ossification of the posterior longitudinal ligament (T-OPLL) is still challenging, and factors for good surgical outcomes are unknown. OBJECTIVE To identify factors for good surgical outcomes with prospective and comparative study. METHODS Seventy-one consecutive patients who underwent posterior decompression and instrumented fusion were divided into good or poor outcome groups based on ≥50% and

STUDY DESIGN: Retrospective multi-center study. OBJECTIVE: This study was conducted in order to clarify the incidence and neurological outcomes of fall-related deterioration of subjective symptoms in patients undergoing surgical treatment. SUMMARY OF BACKGROUND DATA: The evidence that minor trauma, including falls, increases the risk of worsening cervical myelopathy is insufficient. METHODS: A retrospective analysis of patients who had undergone surgery for cervical myelopathy at 12 participating institutes was conducted. Patients who had undergone surgery for symptomatic cervical myelopathy from January 2012 to December 2013 and completed at least 1-year follow-up were included in this study. Data were collected by chart review and a questionnaire that included numbers of recalled falls during the last preoperative year and first postoperative year, circumstances of falls, and whether the patient had experienced fall-related deterioration of subjective symptoms. RESULTS: A total of 360 eligible patients were recruited into the study. Of these, 177 (49%) reported at least one fall during the last preoperative year, and 105 (29%) experienced fall-related deterioration of subjective symptoms. Forty (11%) reported deterioration of numbness in the arms or legs, and 65 (18%) reported deterioration of motor deficits. Incidences of falls and fall-related deterioration of symptoms decreased significantly after surgery. Patients who experienced fall-related deterioration of motor deficits showed significantly worse surgical outcomes as assessed by Japanese Orthopaedic Association (JOA) score compared with those who did not experience deterioration. The optimal cut-off for preoperative JOA score in predicting an increased risk of fall-related deterioration in motor deficits was 8. CONCLUSION: Patients with cervical myelopathy commonly experienced preoperative fall-related deterioration of subjective symptoms, associated with significantly worse neurological outcomes. Surgical treatment significantly reduced the incidence of both falls and fall-related deterioration of subjective symptoms. LEVEL OF EVIDENCE: 4. Language: en

STUDY DESIGN A prospective clinical study of factors related to myelopathy deterioration caused by thoracic myelopathy because of ossification of the posterior longitudinal ligament (T-OPLL). OBJECTIVE The objective of the study was to investigate factors related to myelopathy deterioration caused by T-OPLL. SUMMARY OF BACKGROUND DATA Detailed analyses of factors related to myelopathy deterioration caused by T-OPLL have not been reported. METHODS Twenty-two patients (group O) received observation therapy because of the absence of or mild myelopathy, which was defined as walking unaided or with support, and a Japanese Orthopedic Association (JOA) score above 7 points; and 24 patients (group S) were treated with posterior decompression and fusion with instrumentation. Age, sex, body mass index (BMI), presence of diabetes mellitus (DM), and JOA score were obtained for all patients. Radiologically, the T-OPLL level, number of T-OPLLs, canal diameter ratio (CDR), morphology, ossification of the ligamentum flavum (OLF), and cervical OPLL were examined on reconstructed CT, and the presence of hyperintense areas (HIAs) on T2-weighted sagittal MR images. RESULTS In total, the patients included 22 males and 24 females and had an age range from 18 to 80 years. Sex, DM, JOA score in each domain, OPLL location, OPLL number, CDR of OPLL, morphology, OLF, and cervical OPLL did not differ significantly between groups N and S. However, cases in group N had a significantly higher age, lower weight, lower BMI, lower discontinuous rate on sagittal CT, and a lower HIA rate on MRI. Postoperatively, discontinuous segments connected and became continuous across the disc space in all patients in group S without progression of OPLL thickness. CONCLUSION Age, weight, BMI, discontinuity between rostral and caudal OPLL lesions, and occurrence of a high intensity area on MRI are likely to be associated with development of myelopathy. LEVEL OF EVIDENCE 3.

Study design Prospective cohort study. Objective To investigate whether classification of increased signal intensity (ISI) on magnetic resonance imaging (MRI) of spinal cord in patients with cervical ossification of the posterior longitudinal ligament (C-OPLL) reflects severity of myelopathy and surgical outcome. Summary of background data The relationship between classification of ISI on C-OPLL and severity is unknown. Methods The 119 consecutive patients (91 men, 28 women) with C-OPLL who underwent surgery were enrolled. T2-weighted MRI was performed before surgery and ISI was classified into three groups as follows, Grade 0, none; Grade 1, light (obscure); and Grade 2, intense (bright). The severity of myelopathy and surgical outcome were evaluated by the Japanese Orthopedic Association score. To determine factors that influence ISI, the change of the spinal cord cross-sectional area (SCA) during flexion and extension was calculated by computed tomography after myelography. Results The preoperative MRI showed 55 patients in Grade 0, 46 patients in Grade 1, and 18 patients in Grade 2. The preoperative Japanese Orthopedic Association score (Grade 0, 11.2; Grade 1, 10.3; Grade 2, 9.6 points) and surgical outcome got worsened with increasing ISI grade. The patients in Grade 2 had a longer duration of disease, while those in Grade 1 and Grade 2 had a larger change of SCA during flexion and extension (Grade 0, 4.8 mm; Grade 1, 7.3 mm; Grade 2, 7.8 mm). However age, alignment of the cervical spine, range of motion, and occupying ratio of the ossification were not different in the three grades. Conclusion Grade of ISI correlated with preoperative severity of myelopathy and surgical outcome in patients with C-OPLL. Increased signal intensity of the spinal cord on MRI was associated with a larger change in SCA and longer duration of disease. Level of evidence 3.

Object Postoperative C-5 palsy is a significant complication resulting from cervical decompression procedures. Moreover, when cervical degenerative diseases are treated with a combination of decompression and posterior instrumented fusion, patients are at increased risk for C-5 palsy. However, the clinical and radiological features of this condition remain unclear. Therefore, the purpose of this study was to clarify the risk factors for developing postoperative C-5 palsy. Methods Eighty-four patients (mean age 60.1 years) who had undergone posterior instrumented fusion using cervical pedicle screws to treat nontraumatic lesions were independently reviewed. The authors analyzed the medical records of some of these patients who developed postoperative C-5 palsy, paying particular attention to their plain radiographs, MRI studies, and CT scans. Risk factors for postoperative C-5 palsy were assessed using multivariate logistic regression analysis. The cutoff values for the pre- and postoperative width of the intervertebral foramen (C4–5) were determined by receiver operating characteristic curve analysis. Results Ten (11.9%) of 84 patients developed postoperative C-5 palsy. Seven patients recovered fully from the neurological complications. The pre- and postoperative C4–5 angles showed significant kyphosis in the C-5 palsy group. The pre- and postoperative diameters of the C4–5 foramen on the palsy side were significantly smaller than those on the opposite side in the C-5 palsy group and those bilaterally in the non–C5 palsy group. Risk factors identified by multivariate logistic regression analysis were as follows: 1) ossification of the posterior longitudinal ligament (relative risk [RR] 7.22 [95% CI 1.03–50.55]); 2) posterior shift of the spinal cord (C4–5) (RR 1.73 [95% CI 1.00–2.98]); and 3) postoperative width of the C-5 intervertebral foramen (RR 0.33 [95% CI 0.14–0.79]). The cutoff values of the pre- and postoperative widths of the C-5 intervertebral foramen for C-5 palsy were 2.2 and 2.3 mm, respectively. Conclusions Patients with preoperative foraminal stenosis, posterior shift of the spinal cord, and additional iatrogenic foraminal stenosis due to cervical alignment correction were more likely to develop postoperative C-5 palsy after posterior instrumentation with fusion. Prophylactic foraminotomy at C4–5 might be useful when preoperative foraminal stenosis is present on CT. Furthermore, it might be useful for treating postoperative C-5 palsy. To prevent excessive posterior shift of the spinal cord, the authors recommend that appropriate kyphosis reduction should be considered carefully.

Surgical treatment of a hangman's fractures is technically demanding, even when using the standard open procedure. In this case report, a type II hangman's fracture was treated by percutaneous posterior screw fixation, without a midline incision, using intraoperative, full rotation, three-dimensional (3D) image (O-arm)-based navigation. A 48-year-old woman was injured in a motor vehicle accident and diagnosed with a unilateral hangman's fracture associated with subluxation of the C2 vertebral body on C3. After attaching the reference arc of the 3D-imaging system to the headholder, the cervical spine was screened using an O-arm without anatomical registration. Drilling and screw fixation were performed using a guide tube while referring to the reconstructed 3D-anatomical views. The operation was successfully completed without technical difficulties or neurovascular complications. This percutaneous procedure requires less dissection of normal tissue, which may allow earlier recovery. However, further validation of this procedure for its effectiveness and safety is required.

Object The cervical pedicle screw (PS) provides strong stabilization but poses a potential risk to the neurovascular system, which may be catastrophic. In particular, vertebrae with degenerative changes complicate the process of screw insertion, and PS misplacement and subsequent complications are more frequent. The purpose of this study was to evaluate the peri- and postoperative complications of PS fixation for nontraumatic lesions and to determine the risk factors of each complication. Methods Eighty-four patients who underwent cervical PS fixation for nontraumatic lesions were independently reviewed to identify associated complications. The mean age of the patients was 60.1 years, and the mean follow-up period was 4.1 years (range 6–168 months). Pedicle screw malpositioning was classified on postoperative CT scans as Grade I (< 50% of the screw outside the pedicle) or Grade II (≥ 50% of the screw outside the pedicle). Risk factors of each complication were evaluated using a multivariate analysis. Results Three hundred ninety cervical PSs and 24 lateral mass screws were inserted. The incidence of PS misplacement was 19.5% (76 screws); in terms of malpositioning, 60 screws (15.4%) were classified as Grade I and 16 (4.1%) as Grade II. In total, 33 complications were observed. These included postoperative neurological complications in 11 patients in whom there was no evidence of screw misplacement (C-5 palsy in 10 and C-7 palsy in 1), implant failure in 11 patients (screw loosening in 5, broken screws in 4, and loss of reduction in 2), complications directly attributable to screw insertion in 5 patients (nerve root injury by PS in 3 and vertebral artery injury in 2), and other complications in 6 patients (pseudarthrosis in 2, infection in 1, transient dyspnea in 1, transient dysphagia in 1, and adjacent-segment degeneration in 1). The multivariate analysis showed that a primary diagnosis of cerebral palsy was a risk factor for postoperative implant failure (HR 10.91, p = 0.03) and that the presence of preoperative cervical spinal instability was a risk factor for both Grade I and Grade II screw misplacement (RR 2.12, p = 0.03), while there were no statistically significant risk factors for postoperative neurological complications in the absence of evidence of screw misplacement or complications directly attributable to screw insertion. Conclusions In the present study, misplacement of cervical PSs and associated complications occurred more often than in previous studies. The rates of screw-related neurovascular complications and neurological deterioration unrelated to PSs were high. Insertion of a PS for nontraumatic lesions is surgically more challenging than that for trauma; consequently, experienced surgeons should use PS fixation for nontraumatic cervical lesions only after thorough preoperative evaluation of each patient's cervical anatomy and after considering the risk factors specified in the present study.

Object The aim of this study was to retrospectively evaluate the reliability and accuracy of cervical pedicle screw (CPS) placement using an intraoperative, full-rotation, 3D image (O-arm)–based navigation system and to assess the advantages and disadvantages of the system. Methods The study involved 21 consecutive patients undergoing posterior stabilization surgery of the cervical spine between April and December 2009. The patients, in whom 108 CPSs had been inserted, underwent screw placement based on intraoperative 3D imaging and navigation using the O-arm system. Cervical pedicle screw positions were classified into 4 grades, according to pedicle-wall perforations, by using postoperative CT. Results Of the 108 CPSs, 96 (88.9%) were classified as Grade 0 (no perforation), 9 (8.3%) as Grade 1 (perforations < 2 mm, CPS exposed, and < 50% of screw diameter outside the pedicle), and 3 (2.8%) as Grade 2 (perforations between ≥ 2 and < 4 mm, CPS breached the pedicle wall, and > 50% of screw diameter outside the pedicle). No screw was classified as Grade 3 (perforation > 4 mm, complete perforation). No neurovascular complications occurred because of CPS placement. Conclusions The O-arm offers high-resolution 2D or 3D images, facilitates accurate and safe CPS insertion with high-quality navigation, and provides other substantial benefits for cervical spinal instrumentation. Even with current optimized technology, however, CPS perforation cannot be completely prevented, with 8.3% instances of minor violations, which do not cause significant complications, and 2.8% instances of major pedicle violations, which may cause catastrophic complications. Therefore, a combination of intraoperative 3D image–based navigation with other techniques may result in more accurate CPS placement.

Early-stage TB meningitis has no specific symptoms in patients, potentially leading to delayed diagnosis and consequently worsening prognosis. The authors present the fatal case with a delayed diagnosis of tuberculous (TB) meningitis with dementia as the presenting symptom after intramedullary spinal cord tumor resection. The medical records, operative reports, and radiographical imaging studies of a single patient were retrospectively reviewed. A 77-year-old man who underwent thoracic intramedullary hemangioblastoma resection for 2 times. The postoperative course was uneventful, but 1.5 months after surgery, the patient suffered from dementia with memory loss and diminished motivation and speech in the absence of a fever. No abnormalities were detected on blood test, brain computed tomography and cerebrospinal fluid (CSF) analysis. A sputum sample was negative for Mycobacterium tuberculosis in the QuantiFERON®-TB Gold (QFT-G) In-Tube Test and the tuberculin skin test was also negative. The patient was diagnosed with senile dementia by a psychiatrist. However, the patient’s symptoms progressively worsened. Despite the absence of TB meningitis findings, we suspected TB meningitis from the patient’s history, and administered a four-drug regimen. However the patient died 29 days after admission, subsequently M. tuberculosis was detected in the CSF sample. This case is a rare case of TB meningitis initially mistaken for dementia after intramedullary spinal cord tumor resection. Symptoms of dementia after intramedullary spinal cord tumor resection should first be suspected as one of TB meningitis, even if the tests for meningitis are negative. We propose that anti-tuberculosis therapy should be immediately initiated in cases of suspected TB meningitis prior to positive identification on culture.