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Objective: Few studies have examined a possible correlation between cervical disc degeneration and disc height. The aim of this study was to establish age-related changes and sex-specific differences of cervical disc height using magnetic resonance imaging (MRI) and to evaluate the relationship between degree of cervical disc degeneration and disc height in asymptomatic subjects., Methods: We measured the intervertebral disc anteroposterior diameter and disc height in each disc level using MRI in 1211 relatively healthy volunteers (606 men and 605 women, mean age 49.5 years). We included at least 100 males and 100 females in each decade of life between the 20s and the 70s. Cervical disc degeneration was defined according to the modified Pfirrmann classification system, and disc index and intervertebral disc height narrowing ratio were evaluated on sagittal plane MRI., Results: Intervertebral disc height decreased gradually with increasing age in both sexes. The grade of disc degeneration significantly increased with age in both sexes at every level. Mild disc degeneration was observed even in subjects their 20s. Disc degeneration occurred around the C5-C6 level. The average disc height decreased with aging after the 40s. Disc index and intervertebral disc height narrowing ratio decreased with a progression in the disc degeneration grade in both sexes., Conclusions: This large-scale cross-sectional analysis of cervical spine MRI data in healthy subjects demonstrated that cervical disc height narrowing progresses with age. Cervical disc height narrowing is highly correlated with the progression of disc degeneration., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Study Design: A cross-sectional analysis using T1 slope (T1S) and C7 slope (C7S) in asymptomatic individuals., Objective: The aim of this study was to identify normative values, ranges of motion (ROMs), age-related changes in T1S and C7S, and correlation between the two slopes., Summary of Background Data: Few studies have reported age-related changes in the T1S and C7S angles. Additionally, studies investigating the effects of cervical position on these slopes are limited., Methods: A total of 388 asymptomatic subjects (162 males and 226 females) for whom T1S measurement was performed on radiographs were enrolled in the study. The T1S and C7S angles were measured using neutral radiography of the cervical spine. ROMs were assessed by measuring the difference in alignment in the neutral position, flexion, and extension., Results: The mean C7S and T1S angles were 19.6° (22.2° in males, 17.9° in females) and 24.0° (26.7° in men and 22.1° in women), respectively. The T1S angle was significantly greater than the C7S angle. Both the C7S and T1S angles significantly increased with age. The flexion ROM of C7S was higher than that of T1S, whereas no significant difference was detected between the extension ROMs of the two slopes. The flexion ROMs of the two slopes did not change, whereas the extension ROMs significantly increased with age. A significant positive correlation was observed between the C7S and T1S angles (r2 = 0.75)., Conclusion: The normative values and age-related changes in C7S and T1S were analyzed. Both the C7S and T1S angles increased with age. The C7S angle was strongly correlated with the T1S angle, suggesting that C7S can substitute T1S on radiographic images.Level of Evidence: 3., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: To identify age-related changes and the relationship between upper and lower cervical sagittal alignment and the range of motion (ROM)., Methods: A total of 600 asymptomatic volunteers were enrolled. There were 50 males and 50 females in each decade of life between the third and the eighth. The O-C2 angle and the C2-7 angle were measured using the neutral radiographs of the cervical spine. ROM was assessed by measuring the difference in alignment in the neutral, flexion, and extension positions., Results: The mean O-C2 angle in the neutral position was 14.0° lordotic. The mean ROM of the O-C2 angle was 23.1°. The mean C2-7 angle in the neutral position was 14.3° lordotic. The mean ROM of the C2-7 angle was 56.0°. The O-C2 angle was 16.1° in the third decade and gradually decreased to 11.4° in the eighth decade. There were no significant age-related changes in the ROM of the O-C2 angle. The C2-7 angle was 7.2° in the third decade and gradually increased to 20.8° in the eighth decade, and the ROM gradually decreased with increasing age. Significant negative correlation was observed between O-C2 angle and C2-7 angle., Conclusion: The O-C2 angle gradually decreased and the C2-7 angle increased with age. The ROM of the O-C2 angle did not change, but the ROM of the C2-7 angle decreased with age. The upper and lower cervical spine showed different age-related changes.

Study Design: A prospective cohort study., Objective: This study aimed to investigate the relationship between preoperative cervical sagittal alignment and postoperative kyphosis in patients with cervical spondylotic myelopathy (CSM) and to determine the cut-off angle for predicting the postlaminoplasty kyphosis., Summary of Background Data: There have been several reports describing a cervical kyphosis after laminoplasty. However, there has been no study on the cut-off angle for predicting the postoperative kyphosis in a large series of patients with CSM., Methods: A total of 1025 consecutive patients with CSM (642 men and 383 women; mean age, 64.4 yr; range, 23-93 yrs) who underwent laminoplasty were included. The average follow-up period was 30.0 months. Radiography was performed before the surgery and at final follow-up. The cervical alignment with neutral view was measured by using the Cobb method. An alignment of C2-7 lordotic angle more than 0° was defined as lordosis and C2-7 lordotic angle less than 0° was defined as kyphosis. The incidence of postoperative kyphosis was evaluated on lateral radiographs., Results: In all patients, the mean C2-7 alignment in the neutral position was 11.5° lordotic before surgery and 14.2° lordotic at final follow-up. In the patient without preoperative kyphotic alignment, receiver operating characteristic curve of preoperative C2-7 lordotic angle showed 7° as a predictor for the postlaminoplasty kyphosis (area under the curve  = 0.75, P < 0.0001). Among the preoperatively 720 patients with lordosis more than 7°, postoperative kyphosis was observed in 20 patients (2.8%), whereas in the preoperatively 191 patients with lordosis less than 7°, postoperative kyphosis was seen in 28 patients (14.7%)., Conclusion: The cut-off value of preoperative C2-7 lordotic angle for predicting the postlaminoplasty kyphosis was 7° in CSM patient without preoperative kyphotic alignment., Level of Evidence: 3.

Although a majority of spinal cord herniation reportedly occurs idiopathically, postoperative iatrogenic spinal cord herniation is rare. Therefore, the incidence rate, pathogenic mechanism, and clinical outcomes are not clear. We present three cases of postoperative iatrogenic spinal cord herniation and present a literature review. Our data base included 32253 patients who underwent spinal surgery, and among these patients, 3 showed postoperative spinal cord herniation. Postoperative spinal cord herniation was observed in a 55-year-old man and a 60-year-old man. Both these patients underwent cervical laminoplasty for degenerative cervical myelopathy; however, intraoperative dural tear was reported. They presented with severe quadriplegia and sensory disorders at 8 years and 2 months after initial surgery. The third case of postoperative spinal cord herniation was of a 47-year-old woman who underwent Th11/12 schwannoma resection. Her neurological symptoms did not improve after tumor resection, and MRI at 2 months after surgery revealed spinal cord herniation. All the 3 patients underwent spinal cord reduction surgery; one patient showed sufficient neurological improvement while 2 patients with cervical spinal cord herniation showed limited neurological improvement due to preoperative severe quadriplegia. Although postoperative iatrogenic spinal cord herniation is a relatively rare pathology, careful observation with postoperative MRI is required in cases of patients with new neurological symptoms after dural injury and durotomy., Competing Interests: Tokumi Kanemura is a consultant of NUVASIVE, Medtronic and Baxter.

Study Design: A prospective comparative imaging study., Objective: This study investigated whether postoperative resolution of spinal cord increased signal intensity (ISI) reflected symptom improvement and surgical outcomes in cervical spondylotic myelopathy (CSM) patients., Summary of Background Data: Although some CSM patients exhibit magnetic resonance imaging (MRI) ISI, its alteration and resolution have not been investigated. The association between postoperative ISI resolution and surgical outcomes in CSM patients remains controversial., Methods: A total of 505 consecutive CSM patients (311 males; 194 females) aged a mean of 66.6 years (range, 41-91) were enrolled. All were treated with laminoplasty and underwent MRI scans preoperatively and after an average of 26.5 months postoperatively (range 12-66 months). ISI was classified pre- and postoperatively based on sagittal T2-weighted magnetic resonance images into Grade 0, none; Grade 1, light (obscure); and Grade 2, intense (bright). The patients' pre- and postoperative neurological statuses were evaluated using the Japanese Orthopedic Association scoring system for cervical myelopathy [Japanese Orthopedic Association (JOA) score] and other quantifiable tests, including the 10-s grip and release (10-s G&R) test and 10-s step test., Results: A total of 337 patients showed preoperative ISI. Among these, 42 (12.5%) showed postoperative ISI resolution, associated with better postoperative JOA score and recovery rate, 10-s G&R and 10-s step test scores than those who retained it. Patients with preoperative Grade 2 ISI had no postoperative ISI resolution. Patients with ISI improvement from Grade 1 to Grade 0 had better outcomes than those with ISI worsening from Grade 1 to Grade 2., Conclusion: Postoperative ISI resolution in CSM patients reflects postoperative symptoms and surgical outcomes. Patients who exhibit ISI resolution have better clinical outcomes., Level of Evidence: 3.

Objectives: The purpose of this study was to establish the clinical cut-off values of the 10-s grip and release (G&R) and 10-s step quantitative tests for the diagnosis of cervical spondylotic myelopathy (CSM) and to elucidate the aging variation and gender difference of those values in a large cohort of healthy subjects., Patients and Methods: Patients with CSM (n = 454) and asymptomatic subjects (n = 818) were included. Subjects were aged 40-70 years; according to their age, they were categorized by decades. The 10-s G&R and 10-s step tests were used to quantitatively assess performance. The receiver operating characteristic (ROC) curves were plotted to evaluate the cut-off value of the 10-s G&R and 10-s step tests for determining the presence or absence of CSM in each gender and decade., Results: The cut-off values in the G&R test were 20 in 40 s, 19 in 50 s, 17 in 60 s, and 16 in 70 s groups respectively. The cut-off values in the 10-s step test were 19 in 40 s, 18 in 50 s, 16 in 60 s, and 15 in 70 s groups respectively. The cut-off value of the G&R test in females was lower than that in the males. The cut-off value of 10-s step test was lower in the females than in the males in 40 s and 50 s groups., Conclusions: The cut-off values in the 10-s G&R test and 10-s step decreased with age. When these quantifiable tests are used as screening tests of CSM, age and gender difference should be considered., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Objectives: Although patients with cervical spinal cord injury without radiographic abnormality (SCIWORA) present increased signal intensity (ISI) on magnetic resonance imaging (MRI), its degree has not been examined. This study evaluated the clinical effectiveness of MRI-based ISI in adult patients of SCIWORA. Its predictive value for symptom severity was also evaluated., Patients and Methods: One-hundred consecutive SCIWORA patients who had undergone expansive laminoplasty were enrolled. Among them, 79 were male and 21 were female. The mean age was 55 years (range 20-87). All patients underwent MRI in the acute phase, and ISI was classified into three groups based on sagittal T2-weighted MRI: Grade 0, none; Grade 1, light (obscure); and Grade 2, intense (bright). The pre- and postoperative neurological status was evaluated using the Japanese Orthopaedic Association scoring system for cervical myelopathy (JOA score) and the ASIA impairment scale (AIS)., Results: Preoperative MRI showed Grade 0 in 8 patients, Grade 1 in 49 patients, and Grade 2 in 43 patients. There were no differences in age and gender among three groups. The pre- and postoperative JOA scores decreased significantly with an increasing ISI grade. The recovery rate of JOA score decreased with the ISI grade. The ISI grade tended to increase with the pre- and postoperative AIS grades. ISI Grade 2 on MRI was observed in severely paralyzed cases., Conclusions: MRI-based ISI classification is correlated with preoperative symptom severity in adult patients with SCIWORA and can be a predictor of surgical outcome., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Study Design: A prospective comparative imaging study., Objective: This study investigated whether the postoperative classification of and alterations in increased signal intensity (ISI) of the spinal cord reflected the postoperative severity of symptoms and surgical outcomes in cervical spondylotic myelopathy (CSM) patients., Summary of Background Data: Although ISI on performing magnetic resonance imaging (MRI) is observed in CSM patients, alterations in ISI have not been investigated. The association of postoperative ISI with surgical outcomes in CSM patients remains controversial., Methods: Totally, 505 consecutive CSM patients (311 males) with a mean age of 66.6 (range, 41-91) years were enrolled. All were treated with laminoplasty and underwent MRI scans: preoperatively and after an average of 26.5 months postoperatively (range 12-66 months). ISI was classified pre- and postoperatively into three groups based on sagittal T2-weighted magnetic resonance images: Grade 0, none; Grade 1, light (obscure); and Grade 2, intense (bright). The patients' pre- and postoperative neurological statuses were evaluated using the Japanese Orthopaedic Association scoring system for cervical myelopathy (JOA score) and other quantifiable tests, including the 10-s grip and release (10-s G&R) test and 10-s step test., Results: Preoperatively, 168 patients had Grade 0 ISI, 169 had Grade 1, and 168 had Grade 2; postoperatively, 210 patients had Grade 0 ISI, 94 had Grade 1, and 201 had Grade 2. Patients with postoperative Grade 0 ISI had a better postoperative JOA score, recovery rate, and 10-s G&R and 10-s step test scores than those with other grades. The postoperative ISI grade improved in 66 patients (13.1%), worsened in 57 (11.3%), and remained unchanged in 382 (75.6%)., Conclusion: Postoperative ISI partially reflects postoperative symptoms and surgical outcomes. Alterations in ISI were observed postoperatively in 123 patients (24.4%) and were not correlated with surgical outcomes., Level of Evidence: 2.

To evaluate the sagittal alignment and range of motion (ROM) of the cervical spine during cervical flexion and extension ,using multi-detector-row-computed tomography (MDCT) in asymptomatic subjects.Understanding the normal alignment and range of motion of the cervical spine is very important while evaluating patients with cervical spine instability and abnormal alignment. Several reports using plain radiographic data have assessed the alignment and ROM of the cervical spine during flexion and extension. However, there has been no such report using MDCT. Ninety-eight subjects who did not have cervical spine-related symptoms were enrolled. After myelography, all subjects underwent cervical MDCT in cervical flexion and extension. Sagittal alignment and ROM between C2 and C7 were measured.The sagittal alignment between C2 and C7 was -11.7°±8.3° (mean ± standard deviation) in flexion and 26.5°± 12.9° in extension. The C5/6 level showed maximum kyphosis in flexion. The C6/C7 level demonstrated maximum lordosis in extension. ROM between C2 and C7 was 37.9°±11.2°. The C2/3 level showed the lowest ROM and the C5/C6 level showed the highest ROM among the intervertebral levels evaluated.The sagittal alignment and ROM of the cervical spine during flexion and extension in asymptomatic subjects were measured using MDCT. Each level between C2 and C7 could be evaluated in detail without any influence due to degenerative changes in the spine or soft tissues of the shoulder. MDCT generated a more precise understanding of the dynamic changes at each evaluated intervertebral level in the cervical spine. Level of Evidence : Level II.

Study Design: A prospective cohort study., Objective: The purpose of this study was to compare the surgical outcomes between nonelderly and elderly patients with cervical spondylotic myelopathy (CSM) and to characterize the preoperative symptoms and postoperative residual symptoms in elderly patients., Summary of Background Data: Age at the time of surgery influences the surgical outcome. However, no report has elucidated residual symptoms after surgery in elderly patients with CSM. We designed a large-scale cohort study examining the surgical outcomes of CSM in elderly patients from a single surgery., Methods: A total of 1025 consecutive patients with CSM (642 men and 383 women; mean age, 64.4 yr; range, 23-93 yr) who underwent laminoplasty were included. Patients were divided into three groups based on age: nonelderly (<65 yr), young-old (65-74 yr), and old-old (≥75 yr), and the number of patients in each group was 488, 329, and 208, respectively. The pre- and postoperative neurological statuses were evaluated using the Japanese Orthopaedic Association (JOA) scoring system for cervical myelopathy. The recovery rate (RR) of each function was compared among the three groups. Radiographic data including alignment and range of motion were also assessed., Results: The mean preoperative JOA scores of motor function of the lower extremity in nonelderly, young-old, and old-old groups were 2.8, 2.2, and 1.6, respectively (P < 0.0001). Elderly patients showed significantly lower JOA scores for bladder function than nonelderly patients (2.7, 2.5, and 2.2, P < 0.0001). Cervical lordosis in the neutral position increased gradually with age. Total range of motion decreased with increasing age. After surgery, the mean RRs of motor function of the lower extremity were 57.7%, 38.6%, and 24.0%, respectively. Gait disturbance significantly increased with age (P < 0.0001)., Conclusion: Postoperative gait disturbance persisted more than other symptoms in elderly patients than in nonelderly patients., Level of Evidence: 2.

Study Design: A prospective imaging study., Objective: The study investigated whether the classification of increased signal intensity (ISI) using magnetic resonance imaging (MRI) reflects the severity of symptoms in patients with cervical spondylotic myelopathy (CSM)., Summary of Background Data: Although the ISI on MRI in patients with CSM is observed, the degree of ISI has not been examined. The association between ISI and the surgical outcomes in cervical myelopathy remains controversial., Methods: A total of 505 consecutive patients with CSM (311 males; 194 females) were enrolled. The mean age was 66.6 years (range, 41-91 yrs), with an average postoperative follow-up period of 26.5 ± 12.5 months. The ISI was classified into three groups based on sagittal T2-weighted MRI as follows: Grade 0, none; Grade 1, light (obscure); and Grade 2, intense (bright). Pre- and postoperative neurological status was evaluated using the Japanese Orthopedic Association scoring system for cervical myelopathy (JOA score) and quantifiable tests, including the 10-s grip and release test (10-s G&R test) and the 10-s step test., Results: The preoperative MRI showed 168 patients in Grade 0, 169 patients in Grade 1, and 168 in Grade 2, with no age differences among three groups. Grade 2 patients had a longer duration of symptom compared with the other grades. Grade 0 patients had a better postoperative JOA score and recovery rate compared with the other grades. The preoperative and postoperative scores in the G&R test and steps were better in the Grade 0 patients compared with the other grades. Grade 1 and 2 patients had similar outcomes and recovery rates., Conclusion: ISI on MRI in patients with CSM was prospectively classified into three grades. The ISI grading was not associated with the preoperative severity of myelopathy and outcomes., Level of Evidence: 2.

Study Design: A prospective cohort study., Objective: The purpose of this study was to compare cervical laminoplasty outcomes between diabetic and nondiabetic patients with cervical spondylotic myelopathy (CSM), and to characterize residual symptoms of diabetic patients., Summary of Background Data: Diabetes is one of the most frequent comorbidities in CSM patients. However, no report has elucidated residual symptoms following surgery in diabetic patients with CSM., Methods: .: A total of 505 consecutive patients with CSM (331 males, 189 females; mean age, 66.6 years; age range, 41-91 years; >1-year follow up after laminoplasty) were enrolled and divided into diabetic group (n = 105) and nondiabetic group (n = 400). The Japanese Orthopedic Association (JOA) scores and recovery rate (RR) of each function were compared between the groups. To quantitatively assess performance, the 10-s grip and release (G&R) test and the 10-s step test were evaluated., Results: There was no significant difference in the mean RRs of upper extremity motor function between diabetic and nondiabetic patients (59.2% vs. 60.5%, respectively; P = 0.789). The RR of lower extremity motor function was lower in the diabetic group than in the nondiabetic group (36.1% vs. 43.4%, respectively; P = 0.047); the RR of upper extremity sensory function also was lower (36.8% vs. 49.6%, respectively; P = 0.006). However, the mean RRs of sensory functions of lower extremities were 59.7% (diabetic) and 59.2% (nondiabetic) (P = 0.953). There was no significant difference in the mean RRs of trunk sensory function between the groups (69.3% vs. 74.1%, respectively; P = 0.303). The mean RRs of urinary bladder function were 42.1% (diabetic) and 53.7% (nondiabetic) (P = 0.035). The preoperative mean number of the 10-s step test was lower in the diabetic group than in the nondiabetic group, and the postoperative mean number also was significantly lower in the diabetic group., Conclusion: Gait disturbance, hand numbness, and bladder dysfunction after surgery persisted more than other symptoms in the diabetic than in the nondiabetic patients., Level of Evidence: 2.

Study Design: A prospective comparison., Objective: The purpose of this prospective study was to verify the clinical effectiveness of the 10-s grip and release (G&R) and 10-s step quantitative tests for assessing the severity of cervical spondylotic myelopathy (CSM) and to compare age- and sex-related differences in the results between large cohorts of CSM patients and asymptomatic subjects., Summary of Background Data: To determine the severity of CSM, objective and reproducible means of measuring patient disability are essential. No studies have evaluated differences in quantitative test results between a large series of CSM patients and healthy subjects., Methods: Four hundred fifty-four CSM patients and 818 asymptomatic subjects were included. The Japanese subjects were in their 40s to 70s and were divided according to their age by decade. The 10-s G&R and 10-s step tests were used to quantitatively assess performance. The severity of myelopathy before surgery was evaluated according to a scoring system proposed by the Japanese Orthopaedic Association for cervical myelopathy (JOA score) in the CSM patients., Results: In the CSM patients, the 10-s G&R and step test results significantly correlated with the JOA score (P < 0.0001). The number of the 10-s G&R and step tests significantly decreased with age in both groups. There was a difference in the 10-s G&R and step test results between males and females. In the asymptomatic subjects, the number of the 10-s G&R and step tests in the females was less than that in the males. The numbers in the 10-s G&R and step tests were significantly lower in CSM patients than those in asymptomatic subjects in each decade (P < 0.01)., Conclusion: The 10-s G&R and 10-s step tests were useful for quantitatively assessing CSM severity, and age and sex differences in results should be considered in screening., Level of Evidence: 2.

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.

Objectives: To examine the clinical efficacy of intrathecal morphine as postoperative analgesia for cervical laminoplasty., Summary of Background Data: Patients who undergo posterior cervical spinal surgery frequently experience significant postoperative pain. Postoperative pain contributes to patient morbidity because of decreasing early voluntary mobilization and delayed rehabilitation. Intrathecal morphine is known to be a simple and effective analgesia. However, the effectiveness of intrathecal morphine for cervical spinal surgery has not yet been reported., Methods: Seventy-eight patients with cervical spondylotic myelopathy were divided into two groups prospectively, a diclofenac suppository (DS) group who received 50 mg diclofenac suppository at the end of the surgery, and an intrathecal morphine (ITM) group who were preoperatively administered 0.3 mg of morphine chloride, intrathecally, via a lumbar puncture. All patients underwent double-door laminoplasty of C3-6 or C3-7 level. Visual analog scale (VAS) of cervical pain, self-rating pain impression, supplemental analgesic usage, and complication rate were evaluated until the seventh postoperative day., Results: Thirty-one patients in the DS group and 32 patients in the ITM group were finally assessed. No baseline variable differences between the two groups were observed. The VAS was significantly lower in the ITM group at 4 h and 24 h until the seventh postoperative day. Self-rating pain impression was significantly better in the ITM group. No significant difference was observed in complication rate., Conclusions: Intrathecal morphine was an effective and safe analgesic method for cervical laminoplasty in patients with cervical spondylotic myelopathy., (Copyright © 2016 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.)

Purpose: Narrow cervical canal (NCC) has been a suspected risk factor for later development of cervical myelopathy. However, few studies have evaluated the prevalence in asymptomatic subjects. The purpose of this study was to investigate the prevalence of NCC in a large cohort of asymptomatic volunteers., Methods: This study was a cross-sectional study of 1211 asymptomatic volunteers. Approximately 100 men and 100 women representing each decade of life from the 20s to the 70s were included in this study. Cervical canal anteroposterior diameters at C5 midvertebral level on X-rays, and the prevalence of spinal cord compression (SCC) and increased signal intensity (ISI) changes on MRI were evaluated. Receiver operating characteristic analysis was performed to determine the cut-off value of the severity of canal stenosis resulting in SCC., Results: NCC (<14 mm) was observed in 123 (10.2 %) subjects. SCC and ISI were found in 64 (5.3 %) and 28 (2.3 %) subjects, respectively. The prevalence of NCC was significantly higher in females and older subjects, but the occurrence of severe NCC (<12 mm) did not increase with age. The canal size in subjects with SCC or ISI was significantly smaller than in those without SCC (p < 0.0001). The cut-off values of cervical canal stenosis resulting in SCC were 14.8 and 13.9 mm in males and females, respectively., Conclusions: The prevalence of NCC was considerably lower among asymptomatic healthy volunteers; the cervical canal diameter in subjects with SCC or ISI was significantly smaller than in asymptomatic subjects; NCC is a risk factor for SCC.

Study Design: A prospective cohort study., Objective: The purpose of this study was to compare surgical outcomes between non-elderly and elderly patients with cervical spondylotic myelopathy (CSM) who underwent laminoplasty., Summary of Background Data: Since age at the time of surgery influences the surgical outcome, we designed a large-scale cohort study to examine the surgical outcome for CSM from a single operative procedure used exclusively in elderly patients., Methods: A total of 505 consecutive patients with CSM (311 men; 194 women) were prospectively enrolled. The mean age was 66.6 years (range, 41-91), and the average postoperative follow-up period was 26.5 ± 12.5 months. Patients were divided into three groups according to age: non-elderly (<65 yr, n = 201), young-old (65-74 yr, n = 186), and old-old (≥75 yr, n = 118). Pre- and postoperative neurological status was evaluated using the Japanese Orthopaedic Association scoring system for cervical myelopathy (JOA score) and quantifiable tests-the 10-s grip and release test (10-s G&R test) and the 10-s step test., Results: Mean achieved JOA scores in non-elderly, young-old, and old-old groups were 3.1, 3.2, and 3.0, respectively, with no significant difference among three groups (P = 0.5735). Mean preoperative 10-s G&R test results were 17.3, 14.4, and 13.0, respectively, indicating a significant decrease with increasing age, whereas postoperative results significantly improved in all groups (21.0, 17.9, and 16.3, respectively). Similarly, the 10-s step test significantly decreased with age, with preoperative scores of 14.3, 11.5, and 8.6, respectively, whereas postoperative scores improved to 17.3, 14.9, and 12.5, respectively. The three groups showed no significant difference in the rate of postoperative complications., Conclusion: Elderly patients adequately recovered from laminoplasty in terms of achieved JOA score, the 10-s G&R test, and the 10-s step test. Therefore, laminoplasty for CSM is beneficial in elderly patients., Level of Evidence: 2.

Study Design: A prospective comparative study., Objective: This study aimed to establish cervical spine morphometry, alignment, and range of motion (ROM) and to clarify the impact of these age-related and degenerative changes., Summary of Background Data: There are no studies that have evaluated differences in the results of cervical spine radiographs between a large series of cervical spondylotic myelopathy (CSM) patients and healthy subjects., Methods: We enrolled 1016 consecutive CSM patients who underwent laminoplasty. CSM patients were also divided based on each decade of life between the fourth and ninth decades. We also enrolled a total of 1230 healthy volunteers as asymptomatic subjects in this study. There were at least 100 men and 100 women in each decade of life between the third and eighth decades. Cervical sagittal alignment on neutral and flexion-extension views was measured by the Cobb method at C2-7. ROM was assessed by measuring the difference in alignment between flexion and extension., Results: Cervical lordosis in the neutral position increased gradually with age in both groups. CSM patients showed significantly smaller lordotic angles compared with those shown by asymptomatic subjects within each decade. The total ROM decreased with increasing age in both groups. The total ROM of females was larger than males. The ROM of CSM patients was significantly smaller than asymptomatic subjects. The flexion ROM did not change with aging in either group. There was no significant difference in the flexion ROM between males and females in the two groups. However, the extension ROM decreased gradually in both groups. The extension ROM of CSM patients was significantly smaller than asymptomatic subjects., Conclusion: Age-related and degenerative changes in the cervical spine, alignment, and ROM in each decade of life were established between CSM patients and asymptomatic subjects.

Introduction: Nonunion is a major complication of anterior cervical fusion that causes poor outcomes and occasionally requires additional operative intervention. The purpose of this study is to evaluate the accuracy of functional computed tomography (CT) scanning for determining fusion status after anterior cervical fusion by comparing with functional radiographs., Materials and Methods: The fusion status in 59 patients treated by anterior cervical fusion was assessed by functional radiography and functional CT scanning at 6 and 12 months after surgery. Fusion rates and clinical symptoms were evaluated. Fusion on functional radiography was defined as less than 2 mm of motion between adjacent spinous processes and a particular bony trabeculation on functional CT; fusion was defined as nonexistence of a clear zone or a gas pattern and a particular bone connection on reconstructed sagittal-view images., Results: Functional radiographs demonstrated solid fusion in 83.9% at 6 months and 91.1% at 12 months postoperatively; functional CT showed solid fusion in 55.3 and 78.6%, respectively. The fusion rate detected on functional CT images was significantly lower than that on functional radiographs at each period. At 6 months postoperatively, patients with incomplete union on functional CT were more likely to have neck pain than those who had complete union on functional CT. (46.2 vs 13.3%, P < 0.05) CONCLUSION: Functional CT can detect nonunion more clearly than functional radiography. At 6 months postoperatively, patients with incomplete union on functional CT images were likely to have more neck pain. Functional CT may allow accurate detection of symptomatic nonunion after anterior cervical fusion.

Study Design: Cross-sectional study., Objective: The purposes of this study were (1) to investigate the frequency and degree of cervical disc degeneration and protrusion on cervical spine magnetic resonance (MR) images and (2) to analyze the correlation between the severity of disc degeneration and disc protrusion., Summary of Background Data: Cervical disc degenerative changes or protrusion is commonly observed on MR images in healthy subjects. However, there are few large-scale studies, and the frequency and range of these findings in healthy subjects have not been clarified. Moreover, there are no reports regarding the correlation between cervical disc degeneration and disc protrusion., Methods: Cervical disc degeneration and protrusion were prospectively measured using magnetic resonance imaging in 1211 relatively healthy volunteers. These included at least 100 males and 100 females in each decade of life between the 20s and the 70s. Cervical disc degeneration was defined according to the modified Pfirrmann classification system, and the amount of disc protrusion was evaluated using the anteroposterior diameter of disc protrusion on sagittal MR image., Results: Mild disc degeneration was very common, including 98.0% of both sexes in their 20s. The severity of cervical disc degeneration significantly increased with age in both sexes at every level. The disc degeneration predominantly occurred at C5-C6 and C6-C7. The difference between sexes was not significant except for individuals in their 50s. The average anteroposterior diameter of disc protrusion increased with aging, especially from the 20s to the 40s. The anteroposterior diameter of disc protrusion increased with a progression in the disc degeneration grade., Conclusion: Cervical disc degeneration and protrusion were frequently observed in healthy subjects even in their 20s and deteriorated with age. Cervical disc protrusion was significantly correlated with cervical disc degeneration, and spatial cervical disc protrusion was affected by biochemical degenerative changes as observed on MR images., Level of Evidence: 2.

Study Design: Cross-sectional study., Objective: The purpose of this study was to determine the prevalence and distribution of abnormal findings on cervical spine magnetic resonance image (MRI)., Summary of Background Data: Neurological symptoms and abnormal findings on MR images are keys to diagnose the spinal diseases. To determine the significance of MRI abnormalities, we must take into account the (1) frequency and (2) spectrum of structural abnormalities, which may be asymptomatic. However, no large-scale study has documented abnormal findings of the cervical spine on MR image in asymptomatic subjects., Methods: MR images were analyzed for the anteroposterior spinal cord diameter, disc bulging diameter, and axial cross-sectional area of the spinal cord in 1211 healthy volunteers. The age of healthy volunteers prospectively enrolled in this study ranged from 20 to 70 years, with approximately 100 individuals per decade, per sex. These data were used to determine the spectrum and degree of disc bulging, spinal cord compression (SCC), and increased signal intensity changes in the spinal cord., Results: Most subjects presented with disc bulging (87.6%), which significantly increased with age in terms of frequency, severity, and number of levels. Even most subjects in their 20s had bulging discs, with 73.3% and 78.0% of males and females, respectively. In contrast, few asymptomatic subjects were diagnosed with SCC (5.3%) or increased signal intensity (2.3%). These numbers increased with age, particularly after age 50 years. SCC mainly involved 1 level (58%) or 2 levels (38%), and predominantly occurred at C5-C6 (41%) and C6-C7 (27%)., Conclusion: Disc bulging was frequently observed in asymptomatic subjects, even including those in their 20s. The number of patients with minor disc bulging increased from age 20 to 50 years. In contrast, the frequency of SCC and increased signal intensity increased after age 50 years, and this was accompanied by increased severity of disc bulging., Level of Evidence: 2.

Background Context: Dynamic changes in the spinal cord cross-sectional area due to cervical ossification of the posterior longitudinal ligament (C-OPLL) are unknown, but dynamic multidetector-row computed tomography (MDCT) may be a useful tool., Purpose: The purpose of this study was to evaluate the influence of dynamic factors on the spinal cord in patients with C-OPLL using MDCT during flexion and extension after myelography., Study Design/setting: This was a prospective cohort study., Patient Sample: Participants included 107 prospectively enrolled consecutive patients with C-OPLL and myelopathy., Outcome Measure: The outcome measure was the extension/flexion ratio at the spinal cord cross-sectional area at the most stenotic cervical level (SCASL)., Methods: Dynamic MDCT was performed, and the SCASL was measured. Patients were divided into the kyphosis group or lordosis group according to C2-C7 alignment. They were divided further into the K-line (-) group or K-line (+) group. The Japanese Orthopedic Association (JOA) score was used to determine myelopathy severity., Results: All patients with C-OPLL had myelopathy, with a mean JOA score of 10.7 and mean disease duration of 16.7 months. The average extension/flexion ratio at all disc levels was less than 100%, suggesting that the spinal cord was compressed more during extension. In the kyphosis group, the spinal cord was compressed slightly more during flexion than during extension. In the K-line (-) group, the spinal cord was compressed more during flexion, although C2-C7 alignment was slightly lordotic on average. Large changes in the spinal cord cross-sectional area during extension-flexion and disease duration significantly influenced the severity of myelopathy., Conclusions: Dynamic MDCT was useful for evaluating dynamic changes in the spinal cord. At the most stenotic level, the spinal cord became narrower during extension at all disc levels. In the kyphosis group and K-line (-) group, it became narrower during flexion. Cervical flexion may induce greater spinal cord compression in patients with kyphosis and K-line (-)., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Study Design: Prospective randomized study., Objective: This study aimed to prospectively compare the surgical results of the open- and French-door laminoplasty., Summary of Background Data: Cervical laminoplasty is a common surgical procedure for the treatment of cervical compressive myelopathy. These procedures are primarily classified as either open- or French-door laminoplasties. Only few prospective studies comparing the surgical results of the 2 procedures are available., Methods: A total of 92 patients with cervical compressive myelopathy who underwent cervical laminoplasty were prospectively enrolled and randomized into the following 2 groups according to the type of laminoplasty: open-door and French-door groups. A single attending spine surgeon performed all surgical procedures. The following factors were evaluated: surgical duration, blood loss, perioperative complications, neurological assessment using the Japanese Orthopedic Association score, and recovery rate. Radiological evaluations included assessment of the cervical lordotic angle and cervical range of motion. In addition, the ratio of postoperative spinal lamina opening was evaluated by magnetic resonance imaging., Results: There were no differences in perioperative complications and neurological outcomes between the 2 groups. The mean reduction in cervical lordotic angle after surgery was significantly greater in the open-door group than the French-door group (3.0° vs. 5.6°). Postoperative cervical range of motion significantly decreased in the open-door group than in the French-door group (19.3° vs. 26.0°). Postoperative cervical lordotic angle in the extension position significantly diminished in the open-door group than in the French-door group (7.9° vs. 14.1°). The ratio of opening of the spinal lamina after surgery was significantly larger in the open-door group than in the French-door group., Conclusion: The 2 laminoplasty methods showed almost the same neurological recovery as well as perioperative complications. In cases of open-door laminoplasty, postoperative cervical alignment became more kyphotic and cervical range of motion was more restricted than that in French-door laminoplasty cases after surgery. French-door laminoplasty is preferable to open-door laminoplasty for postoperative cervical alignments., Level of Evidence: 1.

Study Design: A prospective cohort study., Objective: This study aimed to compare the outcome of cervical laminoplasty between diabetic patients and nondiabetic patients with cervical spondylotic myelopathy., Summary of Background Data: A few retrospective studies have investigated the outcomes of cervical myelopathy in diabetic patients; therefore, our large-scale cohort study was designed to assess these outcomes in cervical spondylotic myelopathy., Methods: In total, 505 consecutive patients with cervical spondylotic myelopathy (311 males, 194 females; mean age, 66.6 yr; range, 41-91 yr) who underwent double-door laminoplasty were prospectively enrolled. They were followed up for more than 12 months after surgery (mean follow-up period, 25.6 ± 12.6 mo). The patients were divided on the basis of diabetic criteria for glucose intolerance into 2 groups: the diabetic group (n = 105) and nondiabetic group (n = 400). We evaluated differences in pre- and postoperative Japanese Orthopaedic Association (JOA) scores, recovery rate, achieved JOA scores (postoperative JOA score - preoperative JOA score), and complications between both groups., Results: The mean JOA scores in the diabetic and nondiabetic groups were 10.1 and 10.8 points before surgery and 13.1 and 13.9 points after surgery, respectively. The diabetic group showed significantly low pre- and postoperative JOA scores and low recovery rate of JOA scores compared with the nondiabetic group (47.3% vs. 53.6%, P < 0.05). However, mean achieved JOA scores in the diabetic and nondiabetic groups were 3.0 and 3.1 points respectively, with no significant difference between both groups (P = 0.343). The groups showed no significant difference in the postoperative complication rate., Conclusion: Pre- and postoperative JOA scores and recovery rates were lower in the diabetic group than the nondiabetic group. However, the achieved JOA scores were not significantly different between both groups. Diabetic and nondiabetic patients experienced similar benefits from laminoplasty., Level of Evidence: 3.

Purpose: The pathomechanism of cervical myelopathy due to cervical ossification of posterior longitudinal ligament (C-OPLL) remains unclear. No previous literature has quantified the influence of dynamic factors on cervical myelopathy due to C-OPLL. The purpose was to investigate the influence of dynamic factors on the spinal column in the patients with C-OPLL using CT scan after myelography (MCT)., Methods: The study included 41 patients with cervical myelopathy due to C-OPLL. An MCT was done during neck flexion and extension, and spinal cord cross-sectional areas (SCCSA) were measured at each disc level between C2/3 and C7/T1. Ossification morphology at each segment was divided into three groups, connection department, coating part, and non-connection department of OPLL group. Dynamic changes of SCCSA in each group of ossification morphology were calculated. The relationship between clinical results and SCCSA at the narrowest level was investigated., Results: MCT showed SCCSA changes during neck extension; 7.4 ± 5.1 mm(2) in the connection department, 5.8 ± 6.0 mm(2) in the coating part, and 6.7 ± 6.4 mm(2) in the non-connection department of OPLL group. There difference was not statistically significant. There was a weak correlation between the JOA score and SCCSA at the narrowest level (R = 0.49). There was no significant correlation between the recovery rate of JOA score and SCCSA at the narrowest level (R = 0.37)., Conclusion: Dynamic factors are seen both in cervical myelopathy patients with the continuous type of OPLL and others. Deterioration of myelopathy could be induced by motion effects even in the connection department of OPLL.

Study Design: This is a prospective study on surgical outcomes of double-door laminoplasty in patients with cervical spondylotic myelopathy (CSM)., Objective: The purpose of this study was to report the efficacy and safety of modified double-door laminoplasty in a large series of patients with CSM., Summary of Background Data: Laminoplasty is an established procedure for the decompression of multisegmental CSM. However, no report has described the clinical outcomes of laminoplasty for a large number of patients with CSM (>500 patients)., Methods: Between April 1995 and December 2006, 520 consecutive patients (331 male and 189 female) with CSM who underwent double-door laminoplasty and were followed-up for more than 1 year were enrolled in this study. The mean age was 62.2 years (23 to 93 y), and the mean duration of disease was 20.1 ± 32.0 months. The severity of myelopathy before and after surgery was evaluated according to a scoring system proposed by the Japanese Orthopedic Association for cervical myelopathy (JOA score). Functional improvement was expressed by the recovery rate (RR) of the JOA score., Results: The average surgery time for laminoplasty was 75.2 ± 23.3 minutes, and the average blood loss was 72.6 ± 84.6 mL. The average follow-up period was 33.3 ± 15.7 months. The mean JOA score was 10.4 ± 2.8 points preoperatively and 13.6 ± 2.5 points at final follow-up. The mean RR was 51.2 ± 2 9.0%. On the basis of RR, we found that the conditions of 493 patients (94.8%) improved (RR, >1%), 20 patients (3.8%) showed no change (RR, 0%), and 7 patients (1.3%) in worse condition (RR, < 0%). The 7 patients deteriorated for reasons (lumbar spinal canal stenosis and cerebral infarction) that were unrelated to CSM., Conclusions: Modified double-door laminoplasty is a safe, reliable, and effective procedure for patients with CSM.

Study Design: A retrospective single-center study., Objective: To investigate the prevalence of symptoms before and after surgery in a large series of patients with cervical spondylotic myelopathy (CSM)., Summary of Background Data: No study has elucidated the epidemiological data regarding the prevalence of pre- and postoperative symptoms in patients with CSM., Methods: Five hundred twenty consecutive patients with CSM (331 male and 189 female; mean age, 62.2 yr) treated by laminoplasty were enrolled. The average follow-up period was 33.3 months. Severity of myelopathy was evaluated according to a scoring system proposed by the Japanese Orthopedic Association for CSM, and prevalence was determined by the presence or absence of a full Japanese Orthopedic Association score for each function. The persistence rate (%) (postoperative prevalence/preoperative prevalence × 100) of each function impairment was also assessed after surgery., Results: The preoperative prevalence of motor function impairment in the upper and lower extremities was 77.7% and 80.4%, respectively, whereas that of sensory function impairment in the upper and lower extremities and trunk was 88.6%, 56.5%, and 48.3%, respectively. The preoperative prevalence of urinary bladder function impairment was 41.2%. The persistence rate of motor function impairment in the upper and lower extremities was 52.7% and 71.5%, respectively, whereas that of sensory function impairment in the upper and lower extremities and trunk was 72.0%, 56.8%, and 61.4%, respectively. The persistence rate of urinary bladder function impairment was 49.1%., Conclusion: The preoperative prevalence of motor function impairment in the upper and lower extremities and that of sensory function impairment in the upper extremity is higher than that of other function impairments, and impairments in lower extremity motor function and upper extremity sensory function often persist after surgery. These findings provide baseline data that may allow clinicians to accurately assess preoperative impairment and postoperative outcomes in patients with CSM.

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.

Purpose: The aim of this study is to establish standard MRI values for the cervical spinal canal, dural tube, and spinal cord, to evaluate age-related changes in healthy subjects, and to assess the prevalence of abnormal findings in asymptomatic subjects., Methods: The sagittal diameter of the spinal canal and the sagittal diameter and cross-sectional area of the dural tube and spinal cord were measured on MRIs of 1,211 healthy volunteers. These included at least 100 men and 100 women in each decade of life between the third (20s) and eighth (70s). Abnormal findings such as spinal cord compression and signal changes in the spinal cord were recorded., Results: The sagittal diameter of the spinal canal was 11.2 ± 1.4 mm [mean ± standard deviation (SD)]/11.1 ± 1.4 mm (male/female) at the mid-C5 vertebral level, and 9.5 ± 1.8/9.6 ± 1.6 mm at the C5/6 disc level. The cross-sectional area of the spinal cord was 78.1 ± 9.4/74.4 ± 9.4 mm² at the mid-C5 level and 70.6 ± 11.7/68.9 ± 11.3 mm² at the C5/6 disc level. Both the sagittal diameter and the axial area of the dural tube and spinal cord tended to decrease with increasing age. This tendency was more marked at the level of the intervertebral discs than at the level of the vertebral bodies, especially at the C5/6 intervertebral disc level. The spinal cord occupation rate in the dural tube at the C5 vertebral body level averaged 58.3 ± 7.0%. Spinal cord compression was observed in 64 cases (5.3%) and a T2 high-signal change was observed in 28 cases (2.3%)., Conclusions: Using MRI data of 1,211 asymptomatic subjects, the standard values for the cervical spinal canal, dural tube, and spinal cord for healthy members of each sex and each decade of life and the age-related changes in these parameters were established. The relatively high prevalence of abnormal MRI findings of the cervical spine in asymptomatic individuals emphasizes the dangers of predicating operative decisions on diagnostic tests without precisely correlating these findings with clinical signs and symptoms.

Purpose: This study aimed to establish radiographic standard values for cervical spine morphometry, alignment, and range of motion (ROM) in both male and female in each decade of life between the 3rd and 8th and to elucidate these age-related changes., Methods: A total of 1,230 asymptomatic volunteers underwent anteroposterior (AP), lateral, flexion, and extension radiography of the cervical spine. There were at least 100 men and 100 women in each decade of life between the 3rd and 8th. AP diameter of the spinal canal, vertebral body, and disc were measured at each level from the 2nd to 7th cervical vertebra (C2-C7). C2-C7 sagittal alignment and ROM during flexion and extension were calculated using a computer digitizer., Results: The AP diameter of the spinal canal was 15.8 ± 1.5 [mean ± standard deviation (SD)] mm at the mid-C5 level, and 15.5 ± 2.0 mm at the C5/6 disc level. The disc height was 5.8 ± 1.3 mm at the C5/6 level, which was the minimum height, and the maximum height was at the C6/7 level. Both the AP diameter of the spinal canal and disc height decreased gradually with increasing age. The C2-C7 sagittal alignment and total ROM were 13.9 ± 12.3° in lordosis and 55.3 ± 16.0°, respectively. The C2-C7 lordotic angle was 8.0 ± 11.8° in the 3rd decade and increased to 19.7 ± 11.3 in the 8th decade, whereas the C2-C7 ROM was 67.7 ± 17.0° in the 3rd decade and decreased to 45.0 ± 12.5 in the 8th decade. The extension ROM decreased more than the flexion ROM, and lordotic alignment progressed with increasing age. There was a significant difference in C2-C7 alignment and ROM between men and women., Conclusions: The standard values and age-related changes in cervical anatomy, alignment, and ROM for males and females in each decade between the 3rd and 8th were established. Cervical lordosis in the neutral position develops with aging, while extension ROM decreases gradually. These data will be useful as normal values for the sake of comparison in clinical practice.

Objective: Operative decompression is indicated for progressive neurological deterioration in patients with cervical compressive myelopathy (CCM). However, the best timing to ensure clinical recovery has not been determined because of the lack of a suitable method. 10 s step ("step") test is an easily performed physical test to assess the severity of CCM, particularly for the severity of lower limb dysfunction. The purpose of this study was to analyze the predictive value of preoperative step test results in relation to the results of expansive laminoplasty in patients with CCM., Materials and Methods: Clinical and imaging data were prospectively collected from 101 patients who underwent cervical expansive laminoplasty for CCM. The Japanese Orthopedic Association (JOA) score and the lower limb function section of the Japanese Orthopedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ-L) were used to evaluate surgical outcomes. Cutoff value was determined by receiver operating characteristic curve analysis to predict clinical recovery after surgery. JOA recovery rate exceeding 50% was defined as an effective clinical result. The treatment was judged to be effective in 30 patients based on the JOACMEQ-L. The cutoff value of the step test was 14.5 in cases of an effective judgment with JOA and JOACMEQ-L. Multivariate analysis showed that preoperative patient age and duration of symptoms were predictive parameters for effectively judging JOA scores. A preoperative step test result of greater than or equal to 14.5 and male gender were significant predictive parameters for an effective judgment with JOACMEQ-L., Conclusions: Preoperative step test results significantly reflected the effective results of JOACMEQ-L and were predictive of improved lower limb function after laminoplasty in patients with CCM. Patients with a score of greater than or equal to 14.5 can experience effective lower limb functional recovery.

Introduction: Atlantoaxial instability (AAI) is an uncommon disease in children. Surgical treatment of pediatric patients with AAI poses a challenge to spine surgeons because of the patients' immature bone quality, extensive anatomical variability, and smaller osseous structures. In this study, the authors report complications and outcomes after posterior fusion in children with AAI., Methods: The authors reviewed medical records of patients 13 years old and younger with AAI who underwent posterior fusion in the Nagoya Spine Group hospitals, a multicenter cooperative study group, from January 1995 to December 2007. We identified 11 patients who underwent posterior fusion, and analyzed their clinical outcomes and complications. To determine if vertical growth within the construct continued after posterior fusion, in three patients at 5 or more years following occipito-cervical (O-C) fusion, intervertebral disc heights and vertebral heights between the fused and non-fused levels were compared on the final follow-up., Results: The initial surgeries were C1-C2 fusions in six patients and O-C fusion in five patients. Successful fusion ultimately occurred in all patients, however, the complication rate related to the operations was high (64%). Complications included neurologic deterioration, pedicle fracture with pedicle screw insertion, C1 posterior arch fracture with lateral mass screw insertion, perforation of the skull with a head pin placement, and fusion extension to adjacent vertebrae. Two patients required reoperation. The mean fixed and non-fixed intervertebral disc heights on the final follow-up were 2.6 and 5.3 mm, respectively, showing that the disc height of the fixed level was less than the non-fused level. Each vertebra lengthened similarly between fused and non-fused levels except for C2 which had a lower growth rate than the other vertebrae., Conclusions: A high complication rate should be anticipated after posterior fusion in children with AAI. Careful consideration should be paid to pediatric patients with AAI treated by screw and/or rod systems. After posterior fusion in pediatric patients, each vertebra continued to grow, in contrast the disc height decreased between fused levels.

Study Design: A large-scale retrospective study of analysis of postoperative residual symptom in patients with cervical spondylotic myelopathy (CSM)., Objective: The purpose of this study was to investigate which symptom remains postoperatively in a large series of patients with CSM., Summary of Background Data: CSM is an increasingly common neurological disorder of the geriatric population. Cervical laminoplasty is an established procedure for the decompression of multisegmental CSM, and numerous studies have documented satisfactory surgical results. However, no report has yet elucidated the postoperative residual symptoms in patients with CSM., Methods: Between April 1995 and December 2006, 520 consecutive patients with CSM who underwent laminoplasty were enrolled in this study. They were 331 males and 189 females, and mean age was 62.2 years. Severity of myelopathy was evaluated according to a scoring system proposed by the Japanese Orthopedic Association for cervical myelopathy. Each functional improvement was expressed by the recovery rate (RR) of the Japanese Orthopedic Association score., Results: The average follow-up period was 33.3 months. The mean recovery rates of motor function of the upper and lower extremities were 59.6% and 44.9%, respectively. The mean recovery rates of sensory function of the upper extremity, lower extremity, and trunk were 48.1%, 56.6%, and 54.6%, respectively, and that of urinary bladder function was 59.6%., Conclusion: Motor function impairments of the lower extremities and sensory function impairments of the upper extremities persist more than other symptoms after surgery. Such findings should be incorporated within treatment-planning discussions.

Study Design: This was a prospective clinical comparative study of surgical outcomes for patients with cervical spondylotic myelopathy (CSM)., Objective: The purpose of this study was to compare the surgical outcomes between nonelderly and elderly patients with CSM who underwent laminoplasty., Summary of Background Data: Age at the time of surgery influences the surgical outcome. We designed a large-scale study of the surgical outcome for CSM from a single operative procedure used exclusively in elderly patients., Methods: A total of 520 consecutive patients with CSM (331 men; 189 women) who underwent double-door laminoplasty were included. Mean age was 62 years (range, 23-93), and mean duration of disease was 20.1 ± 32.0 months. Average postoperative follow-up period was 33.3 ± 15.7 months. Patients were divided into 3 groups by age: nonelderly (<65 years), young-old (65-74 years), and old-old (≥75 years). The number of patients in each group was 287, 143, and 90. Pre- and postoperative neurological status was evaluated using the Japanese Orthopaedic Association scoring system for cervical myelopathy (JOA score)., Results: Mean pre- and postoperative JOA scores in nonelderly, young-old, and old-old groups were 11.0 and 14.4, 10.2 and 13.2, and 8.7 and 11.8 points, respectively. The elderly group showed significantly low recovery rates of JOA scores compared with the nonelderly group (P < 0.0001). However, mean achieved JOA scores (postoperative JOA score - preoperative JOA score) were 3.4, 3.0, and 3.1 in nonelderly, young-old, and old-old groups, respectively, with no significant difference among these groups (P = 0.17)., Conclusion: Pre- and postoperative JOA scores were low in elderly patients. However, the achieved JOA score was almost similar among the 3 groups. Thus, elderly patients could obtain reasonable recovery after cervical laminoplasty.

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.

Study Design: This is a prospective imaging study of adult patients with cervical spinal cord injury without radiographic abnormality (SCIWORA)., Objective: The purpose of this study was to investigate the occurrence rate of intramedullary high-signal intensity (increased signal intensity [ISI]) and prevertebral hyperintensity (PVH) in patients with SCIWORA, and examine their relationship to symptom severity and surgical outcome., Summary of Background Data: SCIWORA is accompanied by the presence of neurologic symptoms in the absence of positive radiographic findings before the emergence of magnetic resonance imaging (MRI). There are few reports regarding the image features on MRI in these patients., Methods: One-hundred consecutive patients with SCIWORA who had undergone expansive laminoplasty were enrolled. There were 79 men and 21 women; the mean age was 55 years (range, 16-87 years). All patients underwent functional x-ray and MRI in the acute phase. On MR T2-weighted imaging sagittal view, occurrence of ISI and PVH was evaluated. Range of ISI and PVH was measured relative to C3 vertebral height. Japanese Orthopaedic Association (JOA) scoring system for cervical myelopathy (JOA score), it's recovery rate, and ASIA impairment scale were used to evaluate neurological status., Results: ISI was observed in 92 patients and PVH in 90 patients on MRI preoperatively. The range of ISI and PVH tended to increase with scores on the preoperative ASIA scale. ISI and PVH were seen in all patients with ASIA A and B. There was a significant negative correlation between the range of ISI and preoperative JOA score. A significant negative correlation between the range of ISI and recovery rate of JOA score was also seen., Conclusion: ISI and PVH occurred in more than 90% of patients with SCIWORA. The range of ISI significantly reflected symptom severity and prognosis for neurologic outcome.

The bacterium Pasteurella haemolytica is resident in the oral cavities of dogs and cats and is often a cause of zoonotic infection. However, it is rare for it to be the pathogenic bacteria behind pyogenic spondylitis, and few studies have been conducted on it. This article reports a case of pyogenic cervical spondylitis thought to be caused by excessive contact with pet dogs.A 52-year-old man reported neck pain and pain in the right upper limb. He was admitted after plain radiographs and magnetic resonance imaging suggested pyogenic spondylitis. Pasteurella haemolytica was detected by needle aspiration biopsy of the intervertebral disk. Because the patient owned 2 dogs and frequently kissed them on the mouth, the cause of infection was thought to be excessive contact with pet dogs. Symptoms were alleviated with bed rest and administration of antibiotics with a higher sensitivity to this bacterium., (Copyright 2011, SLACK Incorporated.)

Study Design: Retrospective clinical case study., Objective: To evaluate whether spinal column injury severity influences neurological outcome after cervical spine injury patterns of Allen's classification., Summary of Background Data: Allen's classification is commonly used in cervical fracture/dislocation. Cervical spine injuries are classified into 6 common patterns by their mechanism. Each pattern is divided into stages according to spinal column damage severity, and these stages have been closely correlated with the neurological damage at injury. However, the validity of the relationship has not been adequately discussed. Moreover, only a few reports have assessed whether the injury pattern influences the neurological outcome., Methods: We selected 155 patients with unstable subaxial cervical spine injuries. Only 146 patients having more than 12-month postoperative follow-up were included. All were treated with posterior spinal arthrodesis. Supplemental anterior surgery was added in four patients. The injury patterns were graded using Allen's classification. The neurological status at injury and final follow-up was evaluated using the American Spinal Injury Association (ASIA) impairment scale., Results: Patients were categorized by using Allen's classification as follows: distractive flexion, 82; compressive flexion, 29; compressive extension, 21; vertical compression, 8; and distractive extension, 6. In distractive flexion cases, the ratios of ASIA A cases at final follow-up increased with advancing stage (27%, 18%, 63%, and 100% in stages 1-4; P < 0.001). Furthermore, in similar cases with neurological deficit, the ratio of postoperative improvement on the ASIA impairment scale (>1 level) decreased with advancing stage (62%, 67%, 27%, and 0% in stages 1-4; P < 0.01). With other patterns, neurological outcome was likely to be influenced by spinal column injury severity., Conclusion: Injury patterns based on Allen's classification well-correlated with the neurological outcome and recovery rate. This was especially evident distractive flexion cases. Thus, Allen's classification can be a predictor of neurological outcome after cervical spine injury.

In the treatment algorithm for cervical spine fracture-dislocations, the recommended approach for treatment if there is a disc fragment in the canal is the anterior approach. The posterior approach is not common because of the disadvantage of potential neurological deterioration during reduction in traumatic cervical herniation patients. However, reports about the frequency of this deterioration and the behavior of disc fragments after reduction are scarce. Forty patients with traumatic disc herniation were observed. They represented 29.2% of 137 consecutive patients with subaxial cervical spine fracture-dislocations. Surgical planning was performed according to our two-stage algorithm. In the first stage, they were treated with posterior open reduction and posterior spine arthrodesis. In the second stage, anterior surgery was added for cases where neurological deterioration attributed to non-reduced disc fragments on postoperative magnetic resonance imaging (MRI). Neurological deterioration after posterior open reduction was not observed. Furthermore, 25% of total cases and 75% of incomplete paralysis cases improved postoperatively by ≥ 1 grade in the American Spinal Injury Association impairment scale. Reduction or reversal of disc herniation was observed in all cases undergoing postoperative MRI. For local sagittal alignment, preoperative 9.4° kyphosis was corrected to 6.9° lordosis postoperatively. The disc height ratio was 72.4% preoperatively and 106.3% postoperatively. The second stage of our plan was not required after the posterior approach in this series. The incidence of neurological deterioration after posterior open reduction was zero, even in cases with traumatic cervical disc herniation. Favorable clinical and radiological outcomes could be obtained by the first stage alone. Although preparations for prompt anterior surgery should always be made to cover any contingency, the need for them is minimal.

Study Design: A retrospective multicenter study of series of 12 patients with spinal cord sarcoidosis who underwent surgery., Objective: To evaluate the postoperative outcomes of patients with cervical spinal cord sarcoidosis accompanied with compressive myelopathy and effect of decompressive surgery on the prognosis of sarcoidosis., Summary of Background Data: Sarcoidosis is a chronic, multisystem noncaseating granulomatous disease. It is difficult to differentiate spinal cord sarcoidosis from cervical compressive myelopathy. There are no studies regarding the coexistence of compressive cervical myelopathy with cervical spinal cord sarcoidosis and the effect of decompressive surgery., Methods: Nagoya Spine Group database included 1560 cases with cervical myelopathy treated with cervical laminectomy or laminoplasty from 2001 to 2005. A total of 12 patients (0.08% of cervical myelopathy) were identified spinal cord sarcoidosis treated with decompressive surgery. As a control subject, 8 patients with spinal cord sarcoidosis without compressive lesion who underwent high-dose steroid therapy without surgery were recruited., Results: In the surgery group, enhancing lesions on magnetic resonance imaging (MRI) were mostly seen at C5-C6, coincident with the maximum compression level in all cases. Postoperative recovery rates in the surgery group at 1 week and 4 weeks were -7.4% and -1.1%, respectively. Only 5 cases had showed clinical improvement, and the condition of these 5 patients had worsened again at averaged 7.4 weeks after surgery. Postoperative oral steroid therapy was initiated at an average of 6.4 weeks and the average initial dose was 54.0 mg in the surgery group, while 51.3 mg in the nonsurgery group. The recovery rate of the Japanese Orthopedic Association score, which increased after steroid therapy, was better in the nonsurgery group (62.5%) than in the surgery group (18.6%) with significant difference (P < 0.01)., Conclusion: The effect of decompression for spinal cord sarcoidosis with compressive myelopathy was not evident. Early diagnosis for sarcoidosis from other organ and steroid therapy should be needed.

Object: The purpose of this study was to evaluate the effect of a fixed atlantoaxial angle on subaxial sagittal alignment, and that of atlantoaxial fixation on adjacent-segment motion and degeneration., Methods: The authors retrospectively reviewed 65 patients in whom atlantoaxial instability was treated with atlantoaxial fixation by C-1 lateral mass and C-2 pedicle screw fixation (30 patients, Goel-Harms [GH] group) or a combination of transarticular screw fixation and posterior wiring (35 patients, Magerl-Brooks [MB] group). Angles of Oc–C1, C1–2, C2–3, and C2–7 were determined based on an upright lateral radiograph in flexion, neutral, and extension positions. The range of motion (ROM) at Oc–C1 and C2–3 was also determined. All patients were examined before and 2 years after surgery., Results: The mean preoperative atlantoaxial angles in the GH and MB groups were 20.9 ± 8.3° and 18.3 ± 7.2°, respectively, and the mean postoperative atlantoaxial angles in the same groups were 23.5 ± 5.6° and 29.7 ± 6.3°, respectively, with a statistically significant difference between the 2 groups (p < 0.05). The mean preoperative angles of C2–7 in the GH and MB groups were 15.4 ± 7.8° and 13.7 ± 9.5°, respectively, and after surgery, the angles were 11.8 ± 12° and 2.48 ± 12°, respectively, with a statistically significant difference between the 2 groups (p < 0.05). The postoperative angle of C1–2 showed a negative correlation with the extent of change observed in the C2–7 angle pre- and postoperatively in each of these 2 surgical procedures. The Oc–C1 ROM increased after surgery in both groups, but the difference was not statistically significant (p = 0.38). The C2–3 ROM decreased after surgery in both groups, and the difference was statistically significant (p < 0.05)., Conclusions: Atlantoaxial fixation in a hyperlordotic position produced kyphotic sagittal alignment after surgery in both GH and MB groups. Reduction of the atlantoaxial joint can be easily achieved through screw fixation at an optimal angle, thereby ameliorating the risk for subsequent subaxial kyphosis. Degeneration of lower adjacent segments appeared to be less with this procedure compared with using a combination of transarticular screw fixation and posterior wiring.

Study Design: Case Report., Objective: To present a case of undifferentiated spondyloarthropathy with sternocostoclavicular arthro-osteitis and osteolyis of cervical body requiring surgical reconstruction of the spine and describing the findings which resembled multiple metastases or infection., Summary of Background Data: Sternocostoclavicular arthro-osteitis is not infrequent in Japan. It has been reported in patients with seronegative spondyloarthropathies as psoriatic arthropathy or its variant, palmoplantar pustulosis. Cervical spine involvement in the seronegative spondyloarthropathy is usually in the form of syndesmophytes, subluxations, or facet erosions/ fusions. To the best of our knowledge, this is the first report on severe osteolytic cervical spondylitis associating anterior chest wall disease, to the extent that surgical reconstruction is needed., Methods: A 64 year-old woman presented with neck pain. Cervical spine imaging revealed osteolysis and crumbling of C5 vertebral body. Computed tomography of the thorax showed multiple erosions of the anterior chest wall. Multiple hot spots were detected by bone scan. Biopsies were obtained to exclude neoplasm and infection. Surgical reconstruction via combined anterior-posterior approach was performed to achieve solid spine arthrodesis., Results: Neoplasm and infection were excluded. Careful reassessment alerted to the diagnosis of undifferentiated spondyloarthropathy. Solid arthrodesis and pain relief could be obtained by surgery together with medical control of the disease.

Cervical pedicle screw fixation is an effective procedure for stabilising an unstable motion segment; however, it has generally been considered too risky due to the potential for injury to neurovascular structures, such as the spinal cord, nerve roots or vertebral arteries. Since 1995, we have treated 144 unstable cervical injury patients with pedicle screws using a fluoroscopy-assisted pedicle axis view technique. The purpose of this study was to investigate the efficacy of this technique in accurately placing pedicle screws to treat unstable cervical injuries, and the ensuing clinical outcomes and complications. The accuracy of pedicle screw placement was postoperatively examined by axial computed tomography scans and oblique radiographs. Solid posterior bony fusion without secondary dislodgement was accomplished in 96% of all cases. Of the 620 cervical pedicle screws inserted, 57 (9.2%) demonstrated screw exposure (<50% of the screw outside the pedicle) and 24 (3.9%) demonstrated pedicle perforation (>50% of the screw outside the pedicle). There was one case in which a probe penetrated a vertebral artery without further complication and one case with transient radiculopathy. Pre- and postoperative tracheotomy was required in 20 (13.9%) of the 144 patients. However, the tracheotomies were easily performed, because those patients underwent posterior surgery alone without postoperative external fixation. The placement of cervical pedicle screws using a fluoroscopy-assisted pedicle axis view technique provided good clinical results and a few complications for unstable cervical injuries, but a careful surgical procedure was needed to safely insert the screws and more improvement in imaging and navigation system is expected.

Anterior procedures in the cervical spine are feasible in cases having anterior aetiologies such as anterior neural compression and/or severe kyphosis. Halo vests or anterior plates are used concurrently for cases with long segmental fixation. Halo vests are bothersome and anterior plate fixation is not adequately durable. We developed a new anterior pedicle screw (APS) and plate fixation procedure that can be used with fluoroscope-assisted pedicle axis view imaging. Six patients (3 men and 3 women; mean age, 54 years) with anterior multisegmental aetiology were included in this study. Their original diagnoses comprised cervical myelopathy and/or radiculopathy (n = 4), posterior longitudinal ligament ossification (n = 1) and post-traumatic kyphosis (n = 1). All patients underwent anterior decompression and strut grafting with APS and plate fixation. Mean operative time was 192 min and average blood loss was 73 ml. Patients were permitted to ambulate the next day with a cervical collar. Local sagittal alignment was characterised by 3.5 degrees of kyphosis preoperatively, which improved to 6.8 degrees of lordosis postoperatively and 5.2 degrees of lordosis at final follow-up. Postoperative improvement and early bony union were observed in all cases. There was no serious complication except for two cases of dysphagia. Postoperative imaging demonstrated screw exposure in one screw, but no pedicle perforation. APS and plate fixation is useful in selected cases of multisegmental anterior reconstruction of cervical spine. However, the adequate familiarity and experience with both cervical pedicle screw fixation and the imaging technique used for visualising the pedicle during surgery are crucial for this procedure.

Object: Increased signal intensity of the spinal cord on magnetic resonance (MR) imaging was classified pre- and postoperatively in patients with cervical compressive myelopathy. It was investigated whether postoperative classification and alterations of increased signal intensity could reflect the postoperative severity of symptoms and surgical outcomes., Methods: One hundred and four patients with cervical compressive myelopathy were prospectively enrolled. All were treated using cervical expansive laminoplasty. Magnetic resonance imaging was performed in all patients preoperatively and after an average of 39.7 months postoperatively (range 12-90 months). Increased signal intensity of the spinal cord was divided into 3 grades based on sagittal T2-weighted MR images as follows: Grade 0, none; Grade 1, light (obscure); and Grade 2, intense (bright). The severity of myelopathy was evaluated according to the Japanese Orthopedic Association (JOA) score for cervical myelopathy and its recovery rate (100% = full recovery)., Results: Increased signal intensity was seen in 83% of cases preoperatively and in 70% postoperatively. Preoperatively, there were 18 patients with Grade 0 increased signal intensity, 49 with Grade 1, and 37 with Grade 2; postoperatively, there were 31 with Grade 0, 31 with Grade 1, and 42 with Grade 2. The respective postoperative JOA scores and recovery rates (%) were 13.9/56.7% in patients with postoperative Grade 0, 13.2/50.7% in those with Grade 1, and 12.8/40.1% in those with Grade 2, and these differences were not statistically significant. The postoperative increased signal intensity grade was improved in 16 patients, worsened in 8, and unchanged in 80 (77%). There was no significant correlation between the alterations of increased signal intensity and surgical outcomes., Conclusions: The postoperative increased signal intensity classification reflected postoperative symptomatology and surgical outcomes to some extent, without statistically significant differences. The alteration of increased signal intensity was seen postoperatively in 24 patients (23%) and was not correlated with surgical outcome.

Study Design: A prospective randomized clinical trial in surgical treatment for cervical compressive myelopathy., Objective: We prospectively compared modified laminoplasty and skip laminectomy in terms of surgical invasiveness, postoperative range of cervical motion, axial pain, and surgical outcomes., Summary of Background Data: Laminoplasty is an established procedure for the decompression of multisegmental cervical compressive myelopathy. However, it often induces postoperative problems, such as axial pain, restriction of neck motion, and loss of lordotic alignment. Skip laminectomy was recently developed as a minimally invasive procedure., Methods: Forty-one patients with cervical spondylotic myelopathy (CSM), excluding developmental stenosis, were randomized to modified double-door laminoplasty (Lamino group; n = 21) or skip laminectomy (Skip group; n = 20), and followed for more than 1 year (average, 28.1 months). Of these patients, radiographs were taken in neutral, extension, and flexion positions before surgery and after surgery. The cervical alignment of C2-C7 curvature and range of motion (ROM) were calculated. After surgery patients were asked to rate their neck pain, using the visual analogue scale (VAS) periodically. Clinical outcomes were estimated with the Japanese Orthopedic Association scoring system (JOA score)., Results: There was no significant difference about operative time and blood loss between Lamino and Skip groups. The C2-C7 lordosis of neutral position in both groups was decreased by a few degrees at final follow-up. The final ROMs were 77.4/88.6% of preoperative ROM, respectively. At all collection times, no significant difference in VAS score of axial pain was seen in either group. There was no significant difference in JOA score between both groups before and after surgery., Conclusion: No significant differences were seen between Lamino and Skip groups, in terms of operative invasiveness, axial neck pain, cervical alignment, and ROM, and clinical results in the patients of CSM without developmental stenosis.

Study Design: Prospective imaging study of patients undergoing surgery for cervical compressive myelopathy. OBJECTIVES.: To investigate whether the classification of increased signal intensity (ISI) on magnetic resonance imaging (MRI) in patients with cervical compressive myelopathy reflects the severity of symptoms and surgical outcome., Summary of Background Data: The association between ISI and surgical outcome in cervical myelopathy remains controversial. The degree of ISI has not been well discussed., Methods: A total of 104 patients with cervical compressive myelopathy were prospectively enrolled. All were treated with cervical expansive laminoplasty. MRI was performed in all patients before surgery. ISI of spinal cord was classified into three groups based on sagittal T2-weighted images as follows: Grade 0, none; Grade 1, light (obscure); and Grade 2, intense (bright). The severity of myelopathy was evaluated according to the Japanese Orthopedic Association (JOA) score for cervical myelopathy., Results: Eighty-six patients (83%) showed ISI before surgery. Patients with ISI were significantly older, and had a longer duration of disease, a lower postoperative JOA score, and a worse postoperative recovery rate of JOA score than those without ISI. Preoperative MRI showed 18 patients in Grade 0, 49 patients in Grade 1, and 37 in Grade 2. Duration of disease was the shortest in Grade 0 and longest in Grade 2. Although there was no significant difference in preoperative JOA scores among the three groups, Grade 0 patients had a higher postoperative JOA score and the best postoperative recovery, and Grade 2 had a lower postoperative JOA score and the worst postoperative recovery., Conclusion: Preoperative ISI on T2-weighted sagittal MRI was correlated with patient age, duration of disease, postoperative JOA score, and postoperative recovery rate. Patients with the greatest ISI had the worst postop erative recovery. Classification of ISI can be a predictor of surgical outcome.

Object: The authors conducted a study to introduce the imaging technique in which pedicle axis views are obtained using fluoroscopy to match the screw entry point with pedicle orientation and to report the clinical results and safety of cervical pedicle screw fixation (PSF) in patients treated for unstable cervical injuries., Methods: One hundred consecutive patients with unstable cervical injuries underwent PSF in which the authors used fluoroscopic imaging to acquire pedicle axis views. There were 87 men and 13 women whose mean age was 42.5 years. The accuracy of PS placement was examined postoperatively using axial computed tomography (CT) and oblique radiography. Screw malpositioning was classified either as screw exposure (< 50% of the screw outside the pedicle) or pedicle perforation (> 50% of the screw outside the pedicle boundaries). The mean operative time was 97.6 minutes, and the mean estimated blood loss was 221 ml. Local vertebral alignment around the injured segment measured 6.0 degrees of kyphosis preoperatively and 6.7 degrees of lordosis postoperatively. Solid posterior bone fusion was achieved in all but three patients who died shortly after surgery. There was no secondary dislodgment of instrumentation in 95% of these 97 cases. Of the 419 cervical PSs, 43 (10.3%) were of the screw-exposure type and 17 (4.0%) of the pedicle-perforation type. There were two surgery-related complications: one penetration of a probe into the vertebral artery and one radiculopathy. There were six postoperative complications: two cases of instrumentation failure associated with loss of correction, three cases of correction loss (> 10 degrees), and one case of deep wound infection., Conclusions: Solid posterior fusion without secondary dislodgment of hardware was demonstrated in 95% of the cases. The incidence of complications associated with cervical PSF was not high. Postoperative CT scanning showed that 17 (4.0%) of 419 screws perforated the pedicle. It appears that fluoroscopy performed using pedicle axis views improves the accuracy and safety of cervical PS insertion.