Comparison of Surgical Outcomes After Posterior Decompression by Junior or Senior Surgeons for Patients With Cervical Ossification of the Posterior Longitudinal Ligament: Results From Retrospective Multicenter Cohort Study.

STUDY DESIGN: Retrospective multicenter study. OBJECTIVES: To investigate surgical outcomes following posterior decompression for cervical ossification of the posterior longitudinal ligament (OPLL) when performed by board-certified spine (BCS) or non-BCS (NBCS) surgeons. METHODS: We included 203 patients with cervical OPLL who were followed for a minimum of 1 year after surgery. Demographic information, medical history, and imaging findings were collected. Clinical outcomes were assessed preoperatively and at the final follow-up using the Japanese Orthopedic Association (JOA) score and the visual analog scale (VAS) for the neck. We compared outcomes between BCS surgeons, who must meet several requirements, including experience in more than 300 spinal surgeries, and NBCS surgeons. RESULTS: BCS surgeons performed 124 out of 203 cases, while NBCS surgeons were primary in 79 cases, with 73.4% were directly supervised by a BCS surgeon. There was no statistically significant difference in surgical duration, estimated blood loss, and perioperative complication rates between the BCS and NBCS groups. Moreover, no statistically significant group differences were observed in each position of the C2-7 angle and cervical range of motion at preoperation and the final follow-up. Preoperative and final follow-up JOA scores, VAS for the neck, and JOA score recovery rate were comparable between the two groups. CONCLUSIONS: Surgical outcomes, including functional recovery, complication rates, and cervical dynamics, were comparable between the BCS and NBCS groups. Consequently, posterior decompression for cervical OPLL is considered safe and effective when conducted by junior surgeons who have undergone training and supervision by experienced spine surgeons.

Risk factors for early reoperation in patients after posterior lumbar interbody fusion surgery. A propensity-matched cohort analysis.

BACKGROUND: Reoperation is usually associated with poor results and increased morbidity and hospital costs. However, the rates, causes, and risk factors for reoperation in patients undergoing lumbar spinal fusion surgery remain controversial. This study aimed to identify the risk factors for early reoperation after posterior lumbar interbody fusion surgery and to compare the clinical outcomes between patients who underwent reoperation and those who did not. METHODS: We investigated a multicenter medical record database of 1263 patients who underwent posterior lumbar interbody fusion surgery between 2012 and 2015. A total of 72 (5.7%) reoperations within two years after surgery were identified and were propensity-matched for age, sex, number of fusion segments, and surgeon's experience. RESULTS: We analyzed a total of 114 patients (57 who underwent reoperation (R group) and 57 who did not (C group)). The mean age was 62.6 ± 13.4 years, with 78 men and 36 women. The mean number of fused segments was 1.2 ± 0.5. Surgical site infection was the most common cause of reoperation. There were significant differences in the incidence of diabetes mellitus (p = 0.024), preoperative ambulation status (p = 0.046), and ASA grade (p < 0.001) between the C and R groups. The recovery rate of the Japanese Orthopaedic Association score was significantly lower in the R group compared to the C group (R: 50.5 ± 28.8%, C: 63.9 ± 33.7%, p = 0.024). There were significant differences in the bone fusion rate (R: 63.2%, C: 96.5%, p < 0.001) and incidence of screw loosening (R: 31.6%; C: 10.5%; p = 0.006). CONCLUSION: Diabetes mellitus, preoperative ambulation status, and ASA grade were significant risk factors for early reoperation following posterior lumbar interbody fusion surgery. The patients who underwent early reoperation had worse clinical outcomes than those who did not.

Minimally Invasive Spine Stabilization for Pyogenic Spondylodiscitis: A 23-Case Series and Review of Literature.

Background and Objectives: The incidence of pyogenic spondylodiscitis has been increasing due to the aging of the population. Although surgical treatment is performed for refractory pyogenic spondylodiscitis, surgical invasiveness should be considered. Recent minimally invasive spine stabilization (MISt) using percutaneous pedicle screw (PPS) can be a less invasive approach. The purpose of this study was to evaluate surgical results and clinical outcomes after MISt with PPS for pyogenic spondylodiscitis. Materials and Methods: Clinical data of patients who underwent MISt with PPS for pyogenic spondylitis were analyzed. Results: Twenty-three patients (18 male, 5 female, mean age 67.0 years) were retrospectively enrolled. The mean follow-up period was 15.9 months after surgery. The causative organism was identified in 16 cases (69.6%). A mean number of fixed vertebrae was 4.1, and the estimated blood loss was 145.0 mL. MISt with PPS was successfully performed in 19 of 23 patients (82.6%). Four cases (17.4%) required additional anterior debridement and autologous iliac bone graft placement. CRP levels had become negative at an average of 28.4 days after surgery. There was no major perioperative complication and no screw or rod breakages during follow-up. Conclusions: MISt with PPS would be a less invasive approach for pyogenic spondylodiscitis in elderly or immunocompromised patients.

Influence of Intervertebral Level of Stenosis on Neurological Recovery and Reduction of Neck Pain After Posterior Decompression Surgery for Cervical Spondylotic Myelopathy: A Retrospective Multicenter Study with Propensity Scoring.

STUDY DESIGN: Retrospective multicenter study. OBJECTIVE: To identify the impact of the intervertebral level of stenosis on surgical outcomes of posterior decompression for cervical spondylotic myelopathy (CSM). SUMMARY OF BACKGROUND DATA: As the upper affected cervical levels in elderly patients result from degenerative changes in the lower cervical levels with aging, it is usually difficult to determine the influence of the upper affected cervical levels on surgical outcomes after posterior decompression for CSM in older age. METHODS: This study involved 636 patients with CSM who underwent posterior decompression. According to the most stenotic intervertebral level, patients were divided into upper (n = 343, the most stenotic intervertebral level was C2/3, C3/4, or C4/5) and lower (n = 293, the most stenotic intervertebral level was C5/6, C6/7, or C7/T1) cervical stenosis groups. Propensity score matching of the baseline factors (characteristics, comorbidities, and neurological function) was performed to compare surgical outcomes, the Japanese Orthopaedic Association (JOA) scores, and visual analog scale (VAS) for neck pain between the upper (n = 135) and lower (n = 135) cervical stenosis groups. RESULTS: Before propensity score matching, age at surgery was older and pre- and postoperative JOA scores were lower in the upper cervical stenosis group (P < 0.001, P < 0.001, and P < 0.001, respectively). Following matching, baseline factors were comparable between the groups. Postoperative JOA scores, preoperative-to-postoperative changes in the JOA scores, and the JOA score recovery rate were not significantly different between the groups (P = 0.866, P = 0.825, and P = 0.753, respectively). No differences existed in postoperative VAS for neck pain and preoperative-to-postoperative changes in VAS for neck pain between the groups (P = 0.092 and P = 0.242, respectively). CONCLUSION: The intervertebral level of stenosis did not affect surgical outcomes after posterior decompression for CSM.Level of Evidence: 3.

Metabolic Syndrome is a Predisposing Factor for Diffuse Idiopathic Skeletal Hyperostosis.

OBJECTIVE: Diffuse idiopathic skeletal hyperostosis (DISH) causes spinal ankylosis, which can result in patients suffering specific spinal fractures that lead to a reduction in the activities of daily life in older patients. Currently, DISH is associated with diabetes mellitus and cardiovascular disease; however, the association between DISH and metabolic syndrome has not been established. The purpose of this study was to investigate a potential association between DISH and metabolic syndrome. METHODS: We retrospectively reviewed clinical data from consecutive subjects undergoing the musculoskeletal health medical checkups, and enrolled 327 subjects (174 men and 153 women; mean, 63.4 ± 13.7-years). Subjects who had spinal ankylosis at least 4 contiguous vertebral bodies were classified as the DISH group (n = 39) while the others were part of the non-DISH group (n = 288). The definition of the metabolic syndrome comes from diagnostic criteria used by the Japanese Society for Internal Medicine. Age, sex, body max index (BMI), hematological evaluation, blood pressure, presence of metabolic syndrome, the visceral fat area on abdominal computed tomography, and spinal epidural lipomatosis (SEL) on magnetic resonance imaging were evaluated. RESULTS: Compared to the non-DISH group, in the DISH group, mean age (DISH group, 74.3 years; non-DISH group, 1.9 years; p < 0.001), male prevalence were higher (DISH group, 82.1%; non-DISH group, 49.3%; p < 0.001), and BMI was greater (DISH group, 24.8; non-DISH group, 23.0; p = 0.006). the metabolic syndrome was more frequently observed in DISH group (28.9%) than in the non-DISH group (16.0%) (p = 0.045). The visceral fat area was significantly larger in the DISH group than in the non-DISH group (DISH group, 130.7 ± 58.2 cm2; Non-DISH group, 89.0 ± 48.1 cm2; p < 0.001). The prevalence of SEL was similar between the 2 groups (10.3% in the DISH group vs. 8.7% in the nonDISH group; p = 0.464). Poisson regression analysis revealed that the metabolic syndrome was significantly associated with DISH with odds ratio of 2.0 (95% confidence interval, 1.0-3.7; p = 0.004). CONCLUSION: Metabolic syndrome was significantly associated with DISH. Our data showed metabolic syndrome is potentially related to DISH.

Efficacy and safety of S-1 monotherapy in previously treated elderly patients (aged ≥75 years) with non-small cell lung cancer: A retrospective analysis.

BACKGROUND: S-1 monotherapy is effective and feasible for previously treated patients with advanced non-small cell lung cancer (NSCLC). However, it is not clear whether its effectiveness and tolerability in elderly patients are equivalent to those in younger patients. Hence, this study aimed to evaluate the efficacy and feasibility of S-1 monotherapy in elderly patients with NSCLC who had previously received other treatments. METHODS: We included 96 elderly patients (aged ≥75 years) with advanced NSCLC treated with S-1 alone as a subsequent-line treatment at 12 medical facilities between January 2005 and March 2018 in this study. The baseline characteristics of the patients, response to S-1 monotherapy, and adverse events (AEs) were investigated, retrospectively. RESULTS: A total of 68 male and 28 female patients (median age, 78 [range: 75-86] years) were analyzed. In elderly patients who were treated with S-1 monotherapy as a subsequent-line treatment, the objective response rate, disease control rate, median progression-free survival (PFS), and overall survival (OS) were 8.3%, 43.8%, 3.4 months, and 9.6 months, respectively. Observed AEs included anorexia, anemia, nausea, fatigue, reduced platelet count, and skin hyperpigmentation. Treatment-related death was observed in one patient because of pneumonitis. In patients who experienced no progressive disease, subsequent-line S-1 alone was associated with longer PFS and OS. CONCLUSIONS: S-1 monotherapy is effective and feasible as a subsequent-line treatment in elderly patients who were previously treated for NSCLC, and it produces results. S-1 monotherapy could be one of the treatment choices for elderly patients with previously treated NSCLC.

Efficacy and safety of immune checkpoint inhibitor monotherapy in pretreated elderly patients with non-small cell lung cancer.

PURPOSE: Immune checkpoint inhibitors (ICIs) are an effective subsequent-line treatment for patients with advanced non-small cell lung cancer (NSCLC). However, it remains unclear whether the efficacy and safety of subsequent-line ICI monotherapy in elderly patients (aged ≥ 75 years) are similar to that in non-elderly patients. Therefore, we aimed to investigate the efficacy and safety of ICI monotherapy in pretreated elderly patients with NSCLC. METHODS: Between January 2016 and February 2018, 131 elderly patients with advanced NSCLC who received subsequent-line ICI monotherapy at 13 Japanese institutions were enrolled in this study. Baseline characteristics, the efficacy of ICI treatment, and adverse events were evaluated. RESULTS: Ninety-eight men and 33 women (median age 77 [range 75-87] years) were enrolled. Among those who received subsequent-line ICI monotherapy, the overall response, disease control rates, median progression-free survival (PFS), and overall survival (OS) were 27.4%, 61.8%, 4.5 months, and 16.0 months, respectively. Adverse events such as anorexia, fatigue, pneumonitis, and hypothyroidism were observed. There were two treatment-related deaths due to pneumonitis and thrombocytopenia. Subsequent-line ICI monotherapy in patients with good performance status (PS), receiving steroids for immune-related adverse events (irAEs), and exhibiting partial response (PR) was associated with improved PFS, as well as OS in patients with good PS and PR. CONCLUSIONS: Subsequent-line ICI monotherapy in elderly patients, with previously treated NSCLC, was effective, safe and showed outcomes equivalent to those in non-elderly patients. Immunotherapy provides a survival benefit for elderly patients, who exhibit its efficacy and a favorable general condition.

Potential association of metabolic and musculoskeletal disorders with lumbar intervertebral disc degeneration: Cross-sectional study using medical checkup data.

BACKGROUND: The pathogenesis of intervertebral disc (IVD) degeneration is complex and involves the interaction of multiple factors. However, few systemic studies have explored the associations of metabolic disorders and age-related musculoskeletal disorders with the development of IVD degeneration. METHODS: We analyzed clinical data obtained from healthy individuals who had undergone a musculoskeletal checkup. In total, 276 subjects comprising 142 males and 134 females were enrolled. The subjects were divided into two groups based on the degree of IVD degeneration according to Pfirrmann grading: those with grades 1-3, the group with non-degenerative discs; and grades 4 and 5, the group with degenerative discs. The subjects underwent examinations including abdominal circumference, blood pressure, bilateral hand grip strength, abdominal computed tomography, magnetic resonance imaging of the lumbar spine, and dual X-ray absorptiometry. To examine the independent association with IVD degeneration at L3/4, L4/5, and L5/S levels, we constructed a Poisson regression model and estimated relative risks (RRs) and 95% confidence intervals (CIs) of IVD degeneration. RESULTS: Multivariable analysis showed that advanced age was markedly associated with IVD degeneration at all levels and that men had an inverse association with the IVD degeneration, particularly at the L4/5 level (RR = 0.7, 95% CI = 0.6-0.9). In addition, metabolic syndrome was significantly associated with IVD degeneration at the L5/S level (RR = 1.4, 95% CI = 1.1-1.8). Meanwhile, sarcopenia showed no significant association with IVD degeneration at any level. Osteoporosis was inversely associated with IVD degeneration, particularly at the L4/5 level (RR = 0.7, 95% CI = 0.6-0.9). CONCLUSIONS: Our data suggest that advanced age, female sex, and metabolic syndrome are associated with IVD degeneration. In addition, osteoporosis showed an inverse association with IVD degeneration. Our data should promote understanding of the etiology of lumbar IVD degeneration.

Bacteriologically Determined De Novo Tuberculosis during Tumor Necrosis Factor-α Inhibitor Therapy.

A 58-year-old man with Crohn's disease received adalimumab for 13 months after screening results for tuberculosis were found to be negative. He was diagnosed with de novo mediastinal lymph-node tuberculosis, which was proved to be bacteriologically identical to that of an individual with smear positive lung tuberculosis by a variable number of tandem repeat analyses. After initiating anti-tuberculosis therapy, the patient developed immune reconstitution syndrome, which was improved by the re-administration of adalimumab. Even in countries with an intermediate tuberculosis burden, including Japan, we need to be alert for de novo tuberculosis as well as its reactivation during tumor necrosis factor-α inhibitor therapy.

Negative impact of spinal epidural lipomatosis on the surgical outcome of posterior lumbar spinous-splitting decompression surgery: a multicenter retrospective study.

BACKGROUND CONTEXT: Spinal epidural lipomatosis (SEL) results from excess lumbar epidural fat (EF) accumulation that compresses the cauda equina or nerve roots. Guidelines for the therapeutic management of SEL are not currently available. PURPOSE: To elucidate the efficacy of lumbar decompression surgery in SEL. STUDY DESIGN: Multicenter retrospective study. PATIENT SAMPLE: A total of 288 consecutive patients who underwent posterior lumbar spinous-splitting decompression surgery for lumbar spinal canal stenosis and followed up greater than 2 years at participating institutions were retrospectively reviewed. OUTCOME MEASURES: Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ) and Roland-Morris Disability Questionnaire (RDQ). METHODS: Participants were divided into two groups according to the ratio of EF to anteroposterior diameter of the spinal canal (EF/SC-L) at the spinal level with maximum dural tube compression. Patients with EF/SC-L of ≥0.6 and <0.6 were defined as those with SEL and non-SEL, respectively. We assessed whether surgical treatment was "effective" or "not effective" using the JOABPEQ based on the following: an increase of ≥20 points in the postoperative score compared with the preoperative score, or a preoperative score <90 with a postoperative score ≥90 points. We constructed a multiple Poisson regression model by adjusting for confounding factors, and determined estimated relative risk (RR) for "not effective" with surgical treatment using the JOABPEQ. Additionally, we selected age-, sex-, BMI-, and decompression levels-matched patients with non-SEL and compared the frequency of "not effective" between SEL patients (n=60) and non-SEL patients (n=60). RESULTS: Analysis using the RDQ and JOABPEQ showed that the 1- and 2-year postoperative scores were significantly better than the preoperative scores in the both groups. Multivariable Poisson regression analysis demonstrated that SEL was significantly associated with "not effective" for decompression surgery in the 1-year postoperative outcomes of walking ability ([RR] 1.5, 95% confidence interval [CI] 1.0-2.2) and social life (RR 1.3, 95% CI 1.0-1.8) and the 2-year postoperative outcomes of walking ability (RR 1.6, 95% CI 1.2-2.3). Matching analysis showed that SEL was significantly associated with "not effective" with lumbar decompression surgery in the 2-year postoperative outcomes of walking ability (p=.02). CONCLUSIONS: Patients with SEL exhibited significant improvements in surgical outcomes at 1 and 2 years postoperatively. However, compared with the non-SEL group, the efficacy of posterior lumbar spinous-splitting decompression surgery was worse in the SEL group, especially for walking ability. These results indicate that EF accumulation should be considered when planning treatment for patients with lumbar spinal canal stenosis and estimating the efficacy of lumbar decompression surgery.

Spinal epidural lipomatosis is a previously unrecognized manifestation of metabolic syndrome.

BACKGROUND CONTEXT: Spinal epidural lipomatosis (SEL) is a condition in which excess lumbar epidural fat (EF) deposition often leads to compression of the cauda equina or nerve root. Although SEL is often observed in obese adults, no systematic research investigating the potential association between SEL and metabolic syndrome has been conducted. PURPOSE: To elucidate potential association between SEL and metabolic syndrome. STUDY DESIGN: An observational study used data of a medical checkup. PATIENT SAMPLE: We retrospectively reviewed data from consecutive subjects undergoing medical checkups. A total of 324 subjects (174 men and 150 women) were enrolled in this study. OUTCOME MEASURES: The correlation of EF accumulation with demographic data and metabolic-related factors was evaluated. METHODS: The degree of EF accumulation was evaluated based on the axial views of lumbar magnetic resonance imaging. Visceral and subcutaneous fat areas were measured at the navel level using abdominal computed tomography. Metabolic syndrome was diagnosed according to the criteria of the Japanese Society of Internal Medicine. The correlation of SEL with metabolic syndrome and metabolic-related conditions was statistically evaluated. RESULTS: The degree of EF accumulation demonstrated a significant correlation to body mass index, abdominal circumference, and visceral fat area. However, age, body fat percentage, and subcutaneous fat area showed no correlation with the degree of EF accumulation. Logistic regression analysis revealed that metabolic syndrome (odds ratio [OR]=3.8, 95% confidence interval [CI]=1.5-9.6) was significantly associated with SEL. Among the diagnostic criteria for metabolic syndrome, visceral fat area ≥100 cm2 (OR=4.8, 95% CI=1.5-15.3) and hypertension (OR=3.5, 95% CI=1.1-11.8) were observed to be independently associated with SEL. CONCLUSION: This is the first study to demonstrate that metabolic syndrome is associated with SEL in a relatively large, unbiased population. Our data suggest that metabolic-related conditions are potentially related to EF deposition and that SEL could be a previously unrecognized manifestation of metabolic syndrome.

A phase II study of afatinib treatment for elderly patients with previously untreated advanced non-small-cell lung cancer harboring EGFR mutations.

OBJECTIVE: The efficacy and safety of afatinib in elderly patients with EGFR-mutated non-small-cell lung cancer (NSCLC) have not been evaluated. This study aimed to assess the efficacy and safety of afatinib in elderly chemotherapy-naive patients with NSCLC harboring sensitive EGFR mutations. MATERIALS AND METHODS: We prospectively assessed the clinical effects of afatinib as a first-line treatment for elderly (age ≥70 years) NSCLC patients with EGFR mutations (exon 19 deletion or exon 21 L858R mutation). All patients were initially administered afatinib (30 mg/day). RESULTS: Between May 2014 and August 2017, 40 patients (13 men, 27 women) with adenocarcinoma were included in our analysis. The median age was 77 years (range, 70-85 years). The dose was reduced in 19 patients. The objective overall response and disease control rates were 72.5% and 100%, respectively, and the median progression-free survival and overall survival were 12.9 months and not reached, respectively. Common adverse events (AEs) included diarrhea, rash/acne, and anemia. Major grade 3 or higher toxicities included diarrhea (12.5%), mucositis (7.5%), and pneumonitis (7.5%). Afatinib treatment was discontinued in 8 patients owing to AEs of elevated amylase (n = 1), liver dysfunction (n = 1), rash/acne (n = 1), nail change (n = 1), anorexia (n = 2), pneumonitis (n = 2), and diarrhea (n = 2). Two patients died due to treatment-related pneumonitis. CONCLUSIONS: This is the first study that verified the efficacy and feasibility of first-line chemotherapy with afatinib at 30 mg/day in elderly patients with advanced NSCLC harboring sensitive EGFR mutations. First-line afatinib of 30 mg/day could be a treatment option in this patient population.

Kinetic and kinematic variables affecting trunk flexion during level walking in patients with lumbar spinal stenosis.

Lumbar spinal stenosis causes cauda equina and nerve root compression, resulting in neurological symptoms. Although trunk flexion during level walking may alleviate these symptoms by enabling spinal canal decompression, some patients do not use this strategy. We aimed to identify the kinetic and kinematic variables that affect trunk flexion in patients during level walking. Gait was recorded in 111 patients using a three-dimensional motion capture system and six force plates. From the data recorded, walking velocity, bilateral step length, cycle time, maximum trunk flexion angle, forward pelvic tilt angle, pelvic rotation angle, maximum and minimum joint angles, and moment and power of the lower limb were calculated. Then a step-wise multiple regression analysis was conducted to identify kinetic and kinematic variables affecting trunk flexion. The maximum hip extension angle (ß = 0.416), maximum hip flexion moment (ß = -0.348), and step length (ß = 0.257) were identified as variables significantly affecting the trunk flexion angle. The coefficient of determination adjusted for the degree of freedom was 0.294 (p < 0.05). Our results suggest that patients with lumbar spinal stenosis choose one of two strategies to alleviate symptoms during walking. One strategy is gait with trunk flexion posture to increase step length and hip extension angle. The other strategy is gait with trunk upright posture to decrease step length and hip extension angle.

Optimized Screw Trajectory for Lumbar Cortical Bone Trajectory Pedicle Screws Based on Clinical Outcome: Evidence Favoring the Buttress Effect Theory.

BACKGROUND: Cortical bone trajectory (CBT) is a relatively new technique for pedicle screw insertion in the field of spine surgery. Previous studies have demonstrated the significantly better pullout and toggle characteristics the new method offers, and it appears to have certain advantages over the widely used traditional trajectory. The mechanism of the pullout and toggle characteristics still remains unknown. PURPOSE: To report the medium- to long-term follow-up findings of patients who underwent posterior lumbar interbody fusion or posterior lumbar fusion (PLIF/PLF) at our institution and to discuss the ideal screw trajectory when using this technique. STUDY DESIGN: Retrospective radiologic study. METHODS: Fifty-five patients who underwent PLIF/PLF for lumbar spondylosis using the new technique between January 2011 and January 2016 were included. Clinical outcome was assessed using the Japanese Orthopaedic Association scores for low back pain and visual analog scale scores. Screw loosening was evaluated via the presence of a translucent zone surrounding the pedicle screw using plain X-radiography (Xp). The screw trajectory was evaluated by measuring the rostral range (RR) and the lateral range score (LRS). The RR is the angle between the line drawn along the distal end plate of the vertebra and the line drawn along the screw on the lateral view. The LRS is the score given depending on the position of the tip of the screw seen on the Xp taken in the anteroposterior (AP) view. The pedicle ring is equally divided into the medial third (zone A), central third (zone B), and the lateral third (zone C) by four vertical lines. A score of 0 to 3 points is given depending on the position of the tip of the screw: 0, outside the pedicle ring; 1, zone A; 2, zone B; and 3, zone C. RESULTS: Bone fusion was recorded in 49 patients (49/55 patients). The total number of screws with a visible translucent zone on Xp was 26 (26/242 screws). When the screws are inserted at a more acute angle in the lateral view (low RR) or when the screws are directed more medially (low LRS), the risk of developing a translucent zone around the pedicle screw increased. CONCLUSION: With CBT, the pedicle screws are inserted from the pars interarticularis that is rich in cortical bone, strong enough to withstand the substantial forces usually encountered in the region. Our clinical data suggest that the optimal screw trajectory is one where the screw is inserted at an angle > 22.55 degrees (high RR) on the lateral view Xp and where the tip of the screw is directed toward the lateral third of the pedicle on the AP Xp. We believe the naturally occurring buttress effect that exists in the vertebra may give CBT a mechanical and anatomical advantage over the traditional screw trajectory.

[Surgical Technique for Lumbar Spinal Extraforaminal Schwannoma].

INTRODUCTION: Spinal neurinomas are frequently observed in the cauda equina, particularly within the dura mater. However, extraforaminal schwannomas(EFS), which are neither intradural nor dumbbell type, are relatively rare; hence, different surgical procedures have been employed. Here, we report 12 cases of lumbar EFS with total resection that were safely performed. METHODS AND SUBJECTS: This study was comprised of 12 patients with lumbar EFS(excluding those with neurofibromas)who were previously treated at our hospital. Using the Wiltse paraspinal approach, we inserted the microscope until it reached the tumor surface. After confirming the tumor surface, we inserted a scalpel to make an incision in a portion of the outer capsule. Then, we confirmed that the surfaces of the outer capsule and the tumor within the capsule could be dissected. Next, a thread was attached to the outer capsule and pulled upwards so that there was enough space to perform the required procedures within the capsule. Using a CUSA®, we removed the intracapsular tumor. After its removal, the outer capsule was treated carefully to ensure that the origin nerve was not damaged. RESULTS: In all cases, we successfully performed a total removal of the intracapsular tumor;in the mean postoperative observation period of 8 years, no recurrence was observed. Although temporary paralysis was observed in three patients, this improved over time. CONCLUSION: We report our experience with a surgical technique that ensured the safe removal of lumbar EFS. Satisfactory results were achieved, with no recurrences observed during the mean 8-year postoperative observation period.

Idiopathic Spinal Epidural Fat Accumulation Is Associated With Hyperlipidemia.

STUDY DESIGN: Single-center retrospective analysis of consecutively collected data. OBJECTIVE: To determine the clinical characteristics of idiopathic spinal epidural lipomatosis (SEL). SUMMARY OF BACKGROUND DATA: SEL is associated with the overt accumulation of nonencapsulated adipose tissue in the epidural space, leading to spinal cord or nerve root compression. The etiology of this condition is currently not completely understood. METHODS: Data of 166 male patients who underwent primary surgery for lumbar spinal canal stenosis (LSS) from May 2013 to February 2016 were retrospectively reviewed. Participants were divided into three groups based on the degree of epidural lipomatous lesion. Patient data of age at surgery, body mass index, prevalence of common noncommunicable diseases, blood tests, arteriosclerotic index, and preoperative clinical scores (assessed using the Japanese Orthopedic Association Back Pain Evaluation Questionnaire) were evaluated. Multivariate analysis was performed to assess the potential associated factors for idiopathic SEL. RESULTS: Patients with LSS with severe SEL had a significantly higher body mass index and elevated serum levels of total cholesterol and triglyceride compared with those without SEL. Analysis of preoperative clinical scores revealed that patients with SEL experienced pain more frequently and showed less walking ability than did those without SEL. Multivariate analysis revealed that hyperlipidemia was significantly associated with idiopathic SEL (odds ratio = 3.74, 95% confidence interval = 1.31-10.64). CONCLUSION: Our data suggest that aberrant lipid metabolism is related to the pathogenesis of idiopathic SEL and that patients with LSS with idiopathic SEL have more severe pain than do those without SEL. LEVEL OF EVIDENCE: 3.

Spine and Spinal Cord Injury Associated with a Fracture in Elderly Patients with Ankylosing Spondylitis.

There are few cases of spinal cord injury with ankylosing spondylitis (AS). This study investigated the clinical results of a spinal cord injury with a fracture in elderly patients with AS. Nine patients who had sustained a spinal cord injury with vertebral fractures in ankylosed spines were included in this study. The mean age was 79.3 years; two were male and seven were female. The mechanism of injury, the level of vertebral fractures, clinical methods, the follow-up period, and treatment outcomes were investigated. The mechanism of injury of six cases was a fall and in the others was a slip. The levels of vertebral fractures were a cervical lesion (n = 5), a thoracic lesion (n = 3), and a lumbar lesion (n = 1). Six cases underwent a surgical procedure with posterior fusion and decompression, two cases were treated only with a brace, and one case was treated with a halo vest. The mean follow-up period was 4.3 years. The neurological deficit treatment outcomes were improved or no change in four cases each and one case had died. There was not much difference in treatment outcomes between a surgical treatment and a conservative treatment. Computed tomography imaging to evaluate the entire spine is required in all patients with AS with a possible spinal fracture. A surgical treatment and early rising and rehabilitation should be recommended for patients with fractures and AS to avoid further complications, not from the standpoint of improving the neurological status.

Onset and remodeling of coronal imbalance after selective posterior thoracic fusion for Lenke 1C and 2C adolescent idiopathic scoliosis (a pilot study).

BACKGROUND: Postoperative coronal imbalance is a significant problem after selective thoracic fusion for primary thoracic and compensatory lumbar curves in adolescent idiopathic scoliosis (AIS). However, longitudinal studies on postoperative behavior of coronal balance are lacking. This multicenter retrospective study was conducted to analyze factors related to onset and remodeling of postoperative coronal imbalance after posterior thoracic fusion for Lenke 1C and 2C AIS. METHODS: Twenty-one Lenke 1C or 2C AIS patients, who underwent posterior thoracic fusion ending at L3 or above, were included with a minimum 2-year follow-up. The mean patients' age was 15.1 years at the time of surgery. Radiographic measurements were performed on Cobb angles of the main thoracic (MT) and thoracolumbar/lumbar (TLL) curves and coronal balance. Factors related to the onset of immediately postoperative coronal decompensation (IPCD) and postoperative coronal balance remodeling (PCBR), defined as an improvement of coronal balance during postoperative follow-up, were investigated using comparative and correlation analyses. RESULTS: Mean Cobb angles for the MT and TLL curves were 57.3° and 42.3° preoperatively and were corrected to 22.8° and 22.5° at final follow-up, respectively. Mean preoperative coronal balance of -3.8 mm got worse to -21.2 mm postoperatively, and regained to -12.0 mm at final follow-up. Coronal decompensation was observed in two patients preoperatively, in ten patients immediately postoperatively, and in three patients at final follow-up. The preoperative coronal balance and lowest instrumented vertebra (LIV) selection relative to stable vertebra (SV) were significantly different between patients with IPCD and those without. PCBR had significantly negative correlation with immediately postoperative coronal balance. CONCLUSIONS: IPCD after posterior thoracic fusion for Lenke 1C and 2C AIS was frequent and associated with preoperative coronal balance and LIV selection. However, most patients with IPCD regained coronal balance through PCBR, which was significantly associated with immediately postoperative coronal balance. A fixation more distal to SV shifted the coronal balance further to the left postoperatively.

Evaluation of gefitinib efficacy according to body mass index, body surface area, and body weight in patients with EGFR-mutated advanced non-small cell lung cancer.

PURPOSE: In patients with epidermal growth factor receptor (EGFR)-mutated, advanced, non-small cell lung cancer (NSCLC), common gefitinib-sensitive EGFR mutations that predict a greater response to therapy include the exon 19 deletion and L858R point mutation. The objective of this study was to evaluate whether body surface area (BSA), body weight (BW), and body mass index (BMI) affect gefitinib efficacy in such patients. METHODS: The medical charts of 138 consecutive patients with advanced NSCLC harboring sensitive EGFR mutations, who underwent gefitinib treatment, were reviewed. The median BSA and BW were used as cutoff values to evaluate their impact on gefitinib efficacy. BMI was categorized as underweight (<18.5 kg/m2), normal (18.5-25 kg/m2), and overweight (≥25 kg/m2). RESULTS: The median BSA and BW were 1.48 m2 and 53 kg, respectively. The overall response rate, progression-free survival (PFS), and overall survival (OS) were 65.2%, 12.2, and 24.2 months, respectively. There were no significant differences in clinical outcomes according to BSA, BW, or BMI alone. Subgroup analysis based on the mutation type and BSA revealed no significant differences in PFS between the groups; however, the median OS in those with exon 19 deletion combined with low BSA was significantly favorable compared with the other groups. CONCLUSIONS: Gefitinib efficacy in patients with NSCLC harboring sensitive EGFR mutations did not differ according to BSA, BW, and BMI. However, OS was superior in patients with both the exon 19 deletion and low BSA.

First-line gefitinib treatment in elderly patients (aged ≥75 years) with non-small cell lung cancer harboring EGFR mutations.

PURPOSE: The efficacy of gefitinib [an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor] in elderly patients with non-small cell lung cancer (NSCLC) and EGFR mutation has not been elucidated. Therefore, the objective of this study was to investigate the efficacy and feasibility of gefitinib in elderly chemotherapy-naive patients with NSCLC harboring sensitive EGFR mutations. METHODS: We retrospectively evaluated the clinical effects of gefitinib as a first-line treatment for elderly (≥75 years) NSCLC patients with EGFR mutations (exon 19 deletion or exon 21 L858R mutation). All patients were initially treated with gefitinib (250 mg/day) at seven institutions. RESULTS: Between January 2006 and December 2012, 62 patients (17 men, 45 women) with a median age of 80 years (range, 75-89 years) were included in our analysis. The overall response and disease control rates were 61.2 and 83.8 %, respectively, and the median progression-free survival and overall survival were 13.2 and 19.0 months, respectively. Common adverse events included rash, diarrhea, and liver dysfunction. Major grade 3 or 4 toxicities included skin rash (3.2 %) and increased levels of aspartate aminotransferase or alanine aminotransferase (21.0 %). Gefitinib treatment was discontinued owing to adverse events of liver dysfunction in 3 patients, drug-induced pneumonitis in 2, and diarrhea in 1. CONCLUSION: First-line gefitinib could be a preferable standard treatment in elderly patients with advanced NSCLC harboring sensitive EGFR mutations.