Tatsuya Yasuda

Craniopelvic alignment in elderly asymptomatic individuals: analysis of 671 cranial centers of gravity.

Study Design. Prospective radiographical analysis using the cranial center of gravity (CCG) of sagittal vertical axis (SVA) in elderly asymptomatic individuals. Objective. To determine sex differences and age-related correlations of CCG and relationships between CCG and other spinopelvic parameters/health-related quality of life (HRQOL) measures. Summary of Background Data. Few studies have investigated CCG in a relatively large sample of elderly asymptomatic individuals. Methods. Six hundred seventy-one healthy participants older than 50 years (mean age, 72.9 yr; range, 50–92 yr) were enrolled. Whole-spine standing radiographs were obtained. The following radiographical measurements were obtained: (1) CCG–C7 SVA, (2) C7–SVA, (3) CCG–SVA, (4) C2–C7 lordosis angle, (5) thoracic kyphosis, (6) lumbar lordosis, (7) pelvic incidence, and (8) sacral slope. HRQOL measures included the EuroQol-5D and Oswestry Disability Index. Pearson product-moment correlation coefficients were calculated between pairs of radiographical measures and HRQOL. Results. Sex differences were observed in CCG–C7 SVA, CCG–SVA, C2–C7 Cobb angle, thoracic kyphosis, and pelvic incidence. Three SVA parameters (CCG–C7 SVA, C7–SVA, CCG–SVA) rapidly increased between seventh and ninth decades and were approximately 40, 80, and 120 mm, respectively, in the ninth decade. Age-related correlations were observed for all parameters without pelvic incidence, and the CCG measurement correlated the most with age. Furthermore, CCG–SVA correlated with other spinopelvic measurements and HRQOL. Conclusion. Age-related changes and sex difference in craniopelvic alignment were analyzed. Craniopelvic alignment became rapidly positive with age, particularly in the eighth decade. The CCG measurement correlated the most with age and may be a useful index marker of global spinal balance in decision making for surgical treatment of adult deformity involving cervical and thoracolumbar lesions. Level of Evidence: 4

The Influence of Age and Sex on Cervical Spinal Alignment Among Volunteers Aged Over 50

Study Design. Large cohort study of volunteers aged over 50. Objective. To investigate influence of age and sex on cervical sagittal alignment among volunteers aged over 50. Summary of Background Data. Few large-scale studies have described normative values in cervical spine alignment regarding age and sex among volunteers aged over 50. Methods. The study cohort included 656 volunteers aged 50 to 89 years. Pelvic tilt, sacral slope, pelvic incidence, lumbar lordosis, pelvic incidence−lumbar lordosis, thoracic kyphosis, T1 slope (T1S), cervical lordosis (CL), C7 sagittal vertical axis (C7 SVA), C2−C7 SVA, and T1S−CL were measured using whole spine and pelvic radiographs taken in the standing position. Health-related quality of life was assessed using the EuroQOL (EQ-5D) standardized instrument for measurement of health outcome and Oswestry Disability Index. Results. There were 36 subjects aged 50 to 59 years, 174 aged 60 to 69 years, 311 aged 70 to 79 years, and 135 aged 80 to 89 years. Average T1S for each decade was 32°, 31°, 33°, and 36° for males, and 28°, 29°, 32°, and 37° for females, respectively. Average C2–C7 SVA was 25, 28, 34, and 35 mm for males, and 20, 21, 22, and 28 mm for females, respectively. C2–C7 SVA 40 mm or more, T1S 40° or more, and T1S–CL 20° or more pertaining to EQ-5D were significantly worse in other cases. Conclusion. C2–C7 SVA was significantly greater in males among all age groups, particularly among those with C2–C7 SVA of 40 mm or more [males, 69% (82/118) vs. females, 33% (36/118)]. Sagittal parameters of cervical spine were significantly worse in males than females. C2–C7 SVA, T1S, and T1S–CL negatively influenced EQ-5D. These results help to explain the greater prevalence of cervical spondylotic myelopathy among elderly males. Level of Evidence: 3

Blockade of IL-6 signaling by MR16-1 inhibits reduction of docosahexaenoic acid-containing phosphatidylcholine levels in a mouse model of spinal cord injury

The interleukin (IL)-6 pathway plays an important role in recovery after spinal cord injury (SCI). The anti-IL-6 receptor antibody MR16-1 has been shown to suppress inflammation after SCI and promote recovery of motor function. The purpose of this study was to analyze the effects of MR16-1 on the expression patterns of phospholipids in the spinal cord in a mouse model of SCI. Eight-week-old C57BL/6JJmsSlc mice were used in this study. Laminectomy was performed at the ninth and tenth thoracic levels (T9-T10), and contusion injury of the spinal cord was induced at level T10. Immediately after SCI, mice were intraperitoneally injected with a single dose of MR16-1 (MR16-1 group) or a single dose of phosphate-buffered saline of the same volume (control group). Imaging mass spectrometry was performed to visualize phosphatidylcholine (PC) expression in the spinal cord 7 days after SCI. We found that MR16-1 treatment suppressed the infiltration of immune cells after SCI, and was able to increase the locomotor function post-injury. Phospholipid imaging revealed that the MR16-1 was able to prevent the reduction of docosahexaenoic acid (DHA)-containing PC in comparison with the control group. We also observed high levels of glial fibrillary acidic protein (GFAP) at the site of DHA-containing PC expression in the MR16-1 group. These results suggest that MR16-1 treatment influences the DHA-containing PC composition of GFAP-positive cells at the injury site as early as 7 days post-SCI.

Calculation of the Target Lumbar Lordosis Angle for Restoring an Optimal Pelvic Tilt in Elderly Patients With Adult Spinal Deformity.

Study Design. This investigation consisted of a cross-sectional study and a retrospective multicenter case series. Objective. This investigation sought to identify the ideal lumbar lordosis (LL) angle for restoring an optimal pelvic tilt (PT) in patients with adult spinal deformity (ASD). Summary of Background Data. To achieve successful corrective fusion in ASD patients with sagittal imbalance, it is essential to correct the sagittal spinal alignment and obtain a suitable pelvic inclination. We determined the LL angle that would restore the optimal PT following ASD surgery. Methods. The cross-sectional study included 184 elderly volunteers (mean age 64 years) with an Oswestry Disability Index score less than 20%. The relationship between PT or LL and the pelvic incidence (PI) in normal individuals was investigated. The second study included 116 ASD patients (mean age 66 years) who underwent thoracolumbar corrective fusion at 1 of 4 spine centers. The postoperative PT values were calculated using the parameters measured. On the basis of these studies, an ideal LL angle was determined. Results. In the cross-sectional study, the linear regression equation for the optimal PT as a function of PI was “optimal PT = 0.47 × PI – 7.5.” In the second study, the postoperative PT was determined as a function of PI and corrected LL, using the equation “postoperative PT = 0.7 × PI – 0.5 × corrected LL + 8.1.” The target LL angle was determined by mathematically equalizing the PTs of these 2 equations: “target LL = 0.45 × PI + 31.8.” Conclusion. The ideal LL angle can be determined using the equation “LL = 0.45 × PI + 31.8,” which can be used as a reference during surgical planning in ASD cases. Level of Evidence: 4

Feasibility of a novel diagnostic chart of intramedullary spinal cord tumors in magnetic resonance imaging.

Study design:Retrospective chart review.Objectives:Each type of intramedullary spinal cord tumor (IMSCT) has specific anatomical and pathological features visible on magnetic resonance (MR) imaging. The purpose of this study was to investigate the accuracy of preoperative IMSCT diagnosis using our diagnostic chart of tumor-specific MR imaging findings.Setting:Hamamatsu, Japan.Methods:From 2009 to 2013, 28 consecutive patients with IMSCT who underwent surgery in our university hospital were included in this study. There were 17 men and 11 women with an average age of 49 years (12–81). The pathological diagnoses were hemangioblastoma (12), ependymoma (11), astrocytoma (4) and squamous cell carcinoma (1). Tumor-specific MR imaging findings were as follows: ependymoma ((a) spinal cord swelling, (b) contrast effect with necrosis, (c) tumor in the center of the spinal cord), hemangioblastoma ((a) spinal cord swelling, (b) homogeneous contrast effect) and astrocytoma ((a) spinal cord swelling, (b) contrast effect is either, (c) eccentric tumor). Based on these features, we generated a diagnostic chart to investigate the MR imaging diagnosis accuracy for IMSCTs.Results:The accuracy of preoperative diagnosis was 89% (25/28 cases). Correct diagnoses were made in 100% of hemangioblastomas (12/12 cases), 90% of ependymomas (9/11 cases) and 100% of astrocytomas (4/4 cases).Conclusions:Different types of IMSCTs exhibit unique MR imaging characteristics. These features can be used to preoperatively diagnose IMSCTs with high accuracy.

Hypoglossal Nerve Palsy as a Complication of an Anterior Approach for Cervical Spine Surgery

A recurrent laryngeal nerve injury is known as a complication referring to an anterior cervical spine surgery. However, hypoglossal nerve injury is not well known yet. Herein we report a rare case of a 39-years-old male with a hypoglossal nerve injury after C3/4 osteophyte resection with Smith-Robinson approach. In this case there appeared difficulties of articulation and tongue movement with deviation of the tongue to the left side after the surgery and we diagnosed a hypoglossal nerve injury due to retraction against the nerve during the operation. During the operative approach to the upper cervical spine we had to retract the internal carotid artery and the soft tissue to reach the vertebrae. This retract was the cause of the hypoglossal nerve injury. A gently traction and intermittent release is important to avoid a hypoglossal nerve damage.

Preoperative T1 Slope More Than 40° as a Risk Factor of Correction Loss in Patients With Adult Spinal Deformity.

Study Design. A retrospective study of surgical outcomes of adult spinal deformity (ASD) cases. Objective. The aim of the study was to investigate the effects of high T1 slope (T1S) on surgical outcomes in patients with ASD. Summary of Background Data. Few studies have evaluated the surgical outcomes of patients with ASD with cervical deformities. Methods. Eighty-eight patients with ASD who underwent posterior spinal corrective fusion were assigned to either group A (T1S <40°) or group B (T1S ≥40°). Whole-spine standing radiographs of both groups were preoperatively assessed: at first standing after the surgery and at 1 and 2 years postoperatively. Results. There were 56 patients in group A and 32 in group B. The preoperative C7 sagittal vertical axis (SVA) improved from 61 to 41 mm in group A and from 161 to 64 mm in group B at first standing after the surgery. C7 SVA at 2 years after the surgery was, however, 57 mm in group A and 98 mm in group B because of correction loss (P = 0.003). T1S measurements before and immediately after the surgery and 2 years after the surgery were, however, 25°, 23°, and 27° in group A and 53°, 36°, and 41° in group B, respectively. There were no significant differences among measurements in group A. Those in group B were, however, significantly improved in the first standing, but T1S of 40° or higher deteriorated toward 2 years after the surgery. Conclusion. Among patients with T1S of 40° or higher, C7 SVA improved immediately after the surgery but worsened at 2 years after the surgery. These results suggested that cervicothoracic parameters were important predictors of correction loss. Level of Evidence: 4

Accuracy of Iliac Screws Insertion in Adult Spinal Deformity Surgery: Relationship between Misplacement and the Iliac Morphologies.

Study design: Retrospective study. Objective: To investigate the accuracy of freehand iliac screw insertion and to determine how this can be performed safely. Background and Methods: Seventy-seven adult scoliosis patients with an average age of 70.1 years who underwent spinal deformity surgery with spinopelvic fixation using bilateral iliac screws were enrolled. Penetration of the iliac table was assessed using postoperative computed tomography. Screw penetration of the iliac table or screw insertion from the sacroiliac joint was considered misplacement. Screw positioning was classified as the screw being in the proper position (group C), the screw penetrating the outer table (group O), and the screw penetrating the inner table (group I). The iliac opening angle and the distance between the posterior superior iliac spines (PSISs) were measured using preoperative computed tomography. The angle between the sacral slope and the iliac screw, termed as the sagittal screw angle, was measured using postoperative lateral lumbar radiography. Results: Of the 154 iliac screws in 77 patients, 14 screws in 12 patients penetrated the outer table and 12 screws in 11 patients penetrated the inner table. The total proportion of misplacement was 18.8%, although there were no major complications. With regard to iliac morphology, the iliac opening angle was 24.2±4.3 degrees and the distance between the PSISs was 90.6±7.7 mm. The distance between the PSISs correlated negatively with the iliac opening angle. The iliac opening angle was smaller in group O than in group C (P<0.05). The sagittal screw angle in group I was smaller than that in group C (P<0.01). Conclusions: Screw penetration of the outer iliac table possibly occurred in patients with a narrow iliac opening angle. Screw penetration of the inner table occurred when the screw was inserted more cranially than the sacral slope. Therefore, the iliac screw should be inserted approximately parallel to the sacral slope.

Arundic acid (ONO-2506) inhibits secondary injury and improves motor function in rats with spinal cord injury

BACKGROUND Arundic acid (ONO-2506) inhibits the production and release of S100 protein from astrocytes. While numerous studies have assessed the effect of ONO-2506 in the diseased brain, to the best of our knowledge, no study has examined the effect of ONO-2506 in spinal cord injury (SCI). In this study, we administered ONO-2506 to rats with SCI in order to evaluate its effectiveness in improving motor function and protecting against histological injury. METHODS All rats underwent laminectomy with SCI at the 10th thoracic vertebra. Rats were divided into 3 groups that received different concentrations of ONO-2506 as follows: 10 mg/kg (Group I) and 20 mg/kg (Group II). The third group (control group) was administered only saline. ONO-2506 or saline was administered by intravenous injection for a week after SCI. Recovery of motor function was assessed by determining the Basso, Beattie, and Bresnahan (BBB) scores and using the %grip test. Using immunohistochemistry, S100 protein and glial fibrillary acidic protein expression was assessed at week 12 post SCI. RESULTS The BBB score of Group II was significantly better than that of the control group. At week 12 post SCI, the %grip was 43.0% in Group II and 20.3% in Group I. The score for the %grip test was greater for Group II than for the control group (7.0%); thus, motor function improvement appeared to be dose dependent. Regarding immunostaining evaluation, S100 protein staining was lower in Group II compared to the control group, and the astrocytic morphology resembled that of normal spinal cord sections. The SCI lesion expanded from the injured site to both proximal and distal sites in the control group and in Group I. However, despite the presence of cavitation, secondary expansion of the SCI lesion was prevented in Group II as a result of inhibition of S100 protein. CONCLUSIONS Administration of ONO-2506 (20 mg/kg) improves motor function and inhibits expansion of secondary injury in SCI rats.

Discrepancy between Standing Posture and Sagittal Balance during Walking in Adult Spinal Deformity Patients.

Study Design. Retrospective case series. Objective. The present study aimed to determine the characteristics of patients with adult spinal deformity (ASD) with a discrepancy between standing and walking postures. Summary of Background Data. Standing radiographic parameters are typically used to evaluate patients with ASD. Patients with ASD with relatively good sagittal alignment on standing radiography have, however, been reported to walk with a forward trunk tilt. Methods. Patients with ASD (n = 93; 13 men, 80 women; mean age, 65.0 yr) who underwent corrective surgery and preoperative gait analysis at our hospital between 2011 and 2013 were included. Spine radiographs and gait analysis data were acquired preoperatively. Standing-trunk tilt angle (STA) on lateral standing x-ray, gait-trunk tilt angle (GTA) from lateral gait images, and radiographic parameters of the spine and pelvis (lumbar lordosis [LL], pelvic tilt, and sagittal vertical axis) were measured. We calculated the increasing trunk tilt angle (ITA), by subtracting the STA from the GTA, for use as an index of discrepancy between standing posture and sagittal balance during walking. We examined the relation between radiographic parameters and ITA. Results. The mean preoperative STA and GTA were 3.5° and 11.1°, respectively. The mean preoperative ITA, which represents the degree of discrepancy between standing posture and sagittal balance during walking, was 7.6°. The mean preoperative sagittal vertical axis, LL, pelvic incidence (PI), pelvic tilt, and PI minus LL were 102.6 mm, 20.3°, 52.9°, 32.1°, and 32.6°, respectively. The PI minus LL mismatch was positively correlated with the ITA (R = 0.237, P = 0.023). In particular, patients with ASD with a PI minus LL mismatch of more than 40° had a significantly greater ITA. Conclusion. Gait analysis revealed that a preoperative standing-walking discrepancy is associated with severe PI − LL mismatch. Level of Evidence: 4