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The purposes of this study were to evaluate the clinical outcome after surgical treatment of patients with the proximal type of cervical spondylotic amyotrophy (CSA) and to explore the appropriate timing for surgical intervention.A retrospective review was performed on a consecutive cohort of 41 patients who underwent surgical treatment for the proximal type of CSA between 1995 and 2011 at the Nagoya Spine Group Hospitals. We collected information regarding age, type of muscle atrophy, preoperative and final manual muscle test, duration of symptoms, high-intensity areas on T2-weighted MRI images, low-intensity areas on T1-weighted MRI images, levels of spinal canal stenosis, the compression lesion site, cervical kyphosis and surgical procedures (laminoplasty, anterior spinal fusion and posterior spinal fusion). Univariate analyses and multivariate logistic regression analysis were performed to identify correlates of a poor outcome. To explore the appropriate timing for performing surgery, we analyzed the data using receiver operating characteristic (ROC) analysis.The duration of CSA symptoms was 11.6 months on average. The surgical results were excellent for 25 patients, good for six, fair for nine and poor for one. On multivariate logistic regression analysis, the duration of symptoms was statistically associated with a poor surgical outcome (OR 1.393, p = 0.011). ROC analysis demonstrated that 4.3 months from the onset of CSA symptoms was the appropriate time to undergo surgery.Our results indicate that we should recommend surgical intervention to patients with the proximal type of CSA within about 4 months after the onset of symptoms if conservative treatment has not been successful.

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.

Six consecutive pediatric patients with chronic atlantoaxial rotatory fixation (AARF) underwent posterior fixation. All patients were first treated conservatively such as with a neck collar, traction, Minerva jacket, or halo-vest; however, they failed to achieve successful reduction because of the C2 facet deformity or C1-2 facet fusion. We performed C1-2 fusion using a C1 lateral mass screw and a C2 pedicle screw, a C1-2 transarticular screw, or an occipitocervical fusion using a rod and wiring system. Five patients achieved solid fusion with no torticollis or neck pain by the final follow-up. One patient had mild torticollis after surgery but no pain. Although we believe that with early diagnosis of AARF and appropriate conservative treatment we can avoid surgery, even with conservative treatment from the onset of symptoms, five patients in our series required surgery because conservative treatment did not lead to successful reduction. When conservative treatment for chronic AARF patients fails, C1-2 transarticular fixation, and C1 lateral mass screw and C2 pedicle screw fixation are reliable methods to treat these patients.

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).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.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).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 A case-control clinical study. Objectives To assess the usefulness and safety of a novel reconstructive procedure known as transforaminal thoracic interbody fusion (TTIF) in the treatment of lower thoracic spine fracture dislocations, and to compare its efficacy with posterior/anterior combined surgery (PACS). Summary of background data We developed a TTIF procedure for thoracic spine lesions, and obtained good clinical outcomes for degenerative disorders of the thoracic spine. However, the technique of TTIF in the lower thoracic spine fracture dislocation has never been reported. Methods Seven consecutive patients with lower thoracic spine fracture dislocations underwent TTIF (6 males, 1 female; mean age, 32 y), and 16 consecutive patients with lower thoracic spine fracture dislocations underwent PACS (14 males, 2 females; mean age, 37 y). Surgical complications, clinical outcomes, and sagittal alignment were investigated. Bony fusion was assessed using plain and functional x-rays and computed tomography scans. Results In the TTIF group and the PACS group, the mean operative times were 153 and 224 minutes, respectively, and the mean operative bleeding was 421 and 698 mL, respectively. All patients in the TTIF group were ambulatory within 2 days after surgery. Preoperative local sagittal alignments (kyphotic angles) were 22.9 and 22.5 degrees, respectively. Postoperative local sagittal alignments were 9.9 and 7.2 degrees, respectively. There were no instances of instrumentation failure or nonunion, and there were no serious complications such as neurological deficits in either group. In addition, a chest tube was necessary in 11 cases (69%) of PACS after thoracotomy, but was not required in any TTIF cases. Conclusions TTIF achieves posterior rigid fixation with instrumentation, and anterior column reconstruction by interbody fusion. This procedure also enables early postoperative ambulation without respiratory problems. TTIF can be a useful option for reconstructive surgery of the lower thoracic spine after fracture dislocations.

Some reported studies have evaluated the dural sac in patients with lumbar spinal stenosis (LSS) by computed tomography (CT) after conventional myelography or magnetic resonance imaging (MRI). But they have been only able to evaluate static factors. No reports have described detailed dynamic changes in the dural sac during flexion and extension observed by multidetector-row computed tomography (MDCT). The aim of this study was to elucidate or demonstrate, in detail, the influence of dynamic factors on the severity of stenosis.One hundred patients with LSS were enrolled in this study. All underwent MDCT in both flexion and extension positions after myelography, in addition to undergoing MRI. The anteroposterior diameter (AP-distance) and cross-sectional area of the dural sac (D-area) were measured at each disc level between L1-2 and L5-S1. The dynamic change in the D-area was defined as the absolute value of the difference between flexion and extension. The rate of dynamic change (dynamic change in D-area/D-area at flexion) in the dural sac at each disc level was also calculated.The average AP-distance in flexion/extension (mm) was 9.2/7.4 at L3-4 and 8.3/7.4 at L4-5. The average D-area in flexion/extension (mm(2)) was 96.3/73.6 at L3-4 and 72.3/61.0 at L4-5. The values were significantly lower in extension than in flexion at all disc levels from L1-2 to L5-S1. AP-distance was narrowest and D-area smallest at L4-5 during extension. The rates of dynamic changes at L2-3 and L3-4 were higher than those at L4-5.MDCT clearly elucidated the dynamic changes in the lumbar dural sac. Before surgery, MDCT after myelography should be used to evaluate the dynamic change during flexion and extension, especially at L2-3, L3-4, and L4-5.

The 10-s grip and release (GR) test and 10-s step test were reported to be useful tools to evaluate the severity of cervical myelopathy quantitatively. The purpose of this study is to establish the standard values of the 10-s GR test and 10-s step test as quantitative tests for cervical myelopathy and to elucidate the aging variation and gender difference of those values in a large cohort of normal subjects.A total of 1230 healthy volunteers were enrolled. They included at least 100 men and 100 women in each decade from the 20s to 70s. Three tests were performed: the number of finger grips and releases in 10 s, number of steps in 10 s, and gripping power.The average number of GRs on the weaker side was 21.5 ± 5.5, whereas the average number of steps was 19.7 ± 3.4. The average gripping power on the weaker side was 29.5 ± 9.6 kg. The number of GRs and steps in 10 s decreased significantly with age (r = -0.58, -0.43, respectively). The average number of GRs on the weaker side was20 in the 60s and 70s. The number of GRs was significantly correlated with the number of steps and gripping power. A significant difference was seen between the genders in all three tests.The standard values of the 10-s GR test, 10-s step test, and gripping power were established in this study. When these quantifiable tests are used as screening tests of cervical myelopathy, aging variation and gender difference should be considered.

Study design Retrospective multi-institutional study. Objective The purpose of this study was to describe the surgical outcomes in patients with ossification of the ligamentum flavum (OLF) and determine the influence of an ossified anterior longitudinal ligament (OALL) on the clinical features and surgical outcomes in thoracic OLF. Summary of background data Detailed analyses of surgical outcomes of thoracic OLF have been difficult because of rarity of this disease. Methods We identified 96 patients (77 males and 19 females with a mean age at surgery of 63.4 ± 10.3 yr) who underwent surgery for thoracic OLF and investigated their preoperative symptoms, severity of symptoms and myelopathy, disease duration, magnetic resonance imaging and computed tomographic findings, surgical procedure, intraoperative findings, and postoperative recoveries. The presence of OALL found at or near the most severely affected OLF level on sagittal computed tomographic images was classified into 1 of the following 4 types: (1) "no discernible type" (type N); (2) "one-sided type" (type O); (3) "discontinuous type" (type D); and (4) "continuous type" (type C). Multivariate logistic regression analysis was used to compute odds ratios and 95% confidence intervals to identify the risk factors associated with surgical outcomes. Results The mean Japanese Orthopaedic Association score was 5.6 points preoperatively and 7.8 points 2 years postoperatively, yielding a mean recovery rate of 44.6%. Disease duration, presence of ossified dura mater, and type D OALL were the important factors for predicting surgical outcomes. Conclusion After evaluating surgical outcomes on the largest sample size of OLF surgical procedures thus far, our results show that disease duration, ossification of the dura mater, and the presence of type D OALL were risk factors related to surgical outcomes. Level of evidence 3.

There have been few reports on the risk factors for tracheostomy and the possibility of patients for decannulation. The purpose of this study was to identify factors necessitating tracheostomy after cervical spinal cord injury (SCI) and detect features predictive of successful decannulation in tracheostomy patients.One hundred and sixty four patients with cervical fracture/dislocation were retrospectively reviewed. The patients comprised 142 men and 22 women with a mean age of 44.9 years. The clinical records were reviewed for patients' demographic data, smoking history, level of cervical spine injury, injury patterns, neurological status, evidence of direct thoracic trauma and head injury, tracheostomy placement, and decannulation. Risk factors necessitating tracheostomy and factors predicting decannulation were statistically analysed.Twenty-five patients (15.2%) required tracheostomy. Twenty-one patients were successfully decannulated. Smoking history (relative risk [RR], 3.05; p = 0.03) and complete SCI irrespective of injury level (C1-4 complete SCI: RR, 67.55; p0.001, C5-7 complete SCI: RR, 57.88; p0.001) were significant risk factors necessitating tracheostomy. C1-4 complete SCI was more frequent among those who could not be decannulated. However, even in patients with high cervical complete SCI at the time of injury, patients regaining sufficient movement to shrug their shoulders within 3 weeks after injury could later be decannulated.The risk factors for tracheostomy after complete SCI were a history of smoking and complete paralysis irrespective of the level of injury. High cervical level complete SCI was found to be a risk factor for the failure of decannulation in patients without shoulder shrug within 3 weeks after injury.

The purpose of this study is to compare bone union rate between autologous iliac bone and local bone graft in patients treated by posterior lumbar interbody fusion (PLIF) using carbon cage for single level interbody fusion.The subjects were 106 patients whose course could be observed for at least 2 years. The diagnosis was lumbar spinal canal stenosis in 46 patients, herniated lumbar disk in 12 patients and degenerative spondylolisthesis in 51 patients. Single interbody PLIF was done using iliac bone graft in 53 patients and local bone graft in 56 patients. Existence of pseudo-arthrosis on X-P (AP and lateral view) was investigated during the same follow up period.No significant differences were found in operation time and blood loss. Significant differences were also not observed in fusion grade at any follow up period or in fusion progression between the two groups. Donor site pain continued for more than 3 months in five cases (9%). The final fusion rate was 96.3 versus 98.3%.Almost the same results in fusion were obtained from both the local bone group and the autologous iliac bone group. Fusion progression was almost the same. Complications at donor sites were seen in 19% of the cases. From the above results, it was concluded that local bone graft is as beneficial as autologous iliac bone graft for PLIF at a single level.

The classification and therapeutic strategy for thoracolumbar burst fractures are controversial. The load-sharing classification (LSC) and thoracolumbar injury classification system (TLICS) are both quantitative evaluation systems for thoracolumbar burst fractures. We hypothesized that their combination would be helpful not only for surgical indications but also for deciding on the surgical approach. However, no reports have evaluated the relationship between them. The purpose of this study was to clarify the relationship between the LSC and TLICS and investigate the clinical usefulness of their combination.This study included 100 consecutive patients surgically treated for thoracolumbar burst fractures (71 men and 29 women; mean age 36 years). Clinical and radiographical data as well as thoracolumbar injury classification systems were evaluated.LSC and TLICS scores were found to be statistically correlated. The mean LSC score with a TLICS score of 5 or more (surgical treatment recommended) was 7.3 ± 1.2 points, and the mean LSC score with a TLICS score of 3 or less (conservative treatment recommended) was 6.1 ± 1.3 points. The mean TLICS score with an LSC score of 7 or more (additional anterior reconstruction recommended) was 6.6 ± 2.7 points, and the mean TLICS score with an LSC score of 6 or less (expectation of good clinical results with posterior short fusion) was 5.0 ± 2.5 points. The TLICS score was 3 or less, and the LSC score was 7 or more in 13 patients (13 %).Although the TLICS scores correlated with the LSC scores, a single application of TLICS might not be sufficient to identify those patients who have a TLICS score of 3 or less and an LSC score of 7 or more as surgically indicated. However, an additional LSC evaluation avoided deviations as the two classifications complemented each other, and it was useful in determining the best treatment options for thoracolumbar burst fractures.

Background: Degenerative cervical myelopathy (DCM) is an all-encompassing term that includes cervical spondylotic myelopathy (CSM), ossification of the posterior longitudinal ligament (OPLL), and other spinal abnormalities that cause cervical cord compression. It is unclear whether surgery is equally effective and safe for patients with OPLL as it is for those with other forms of DCM. The purpose of this study was to compare surgical outcomes of patients with OPLL and those with other forms of DCM. Methods: Four hundred and seventy-nine patients with symptomatic DCM were prospectively enrolled in the CSM-International study at sixteen sites. Patients’ functional status was evaluated using the modified Japanese Orthopaedic Association scale (mJOA) and the Nurick score. Quality of life was assessed using patient-reported outcome measures, including the Neck Disability Index (NDI) and the Short Form (SF)-36. Postoperative functional and quality-of-life outcomes were assessed at two years of follow-up, and scores were compared between patients with and without OPLL. Results: Of 479 patients, 135 (28.2%) had radiographic evidence of OPLL, and 344 (71.8%) had other forms of DCM. The two groups did not differ significantly in demographics, surgical approach, or baseline myelopathy severity. Patients with OPLL achieved similar functional outcomes by two years following surgery compared with patients with other forms of DCM. With respect to quality of life, the NDI and most of the subscales of the SF-36 were not different between the two diagnostic groups. There was a higher risk of perioperative complications in the OPLL group (p = 0.054), although this relationship did not reach statistical significance. Rates of neurological complications did not differ significantly between diagnostic groups. Conclusions: Surgical decompression for the treatment of OPLL resulted in improvements in functional status and quality of life comparable to those seen in patients with other forms of DCM. Patients with OPLL were at a higher risk of perioperative complications than patients with other forms of DCM. Level of Evidence: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

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.

Study design A large-scale analysis of radiographical results of patients with cervical spondylotic myelopathy and a review of the literature. Objective To identify changes in sagittal alignment and range of motion (ROM) after cervical laminoplasty. Summary of background data Cervical laminoplasty is an effective procedure for decompressing multilevel spinal cord compression. It often induces postoperative complications such as loss of lordotic alignment and restriction of neck motion. Although numerous studies have reported the loss of flexion-extension ROM after laminoplasty, no large-scale study has been reported. Methods Five hundred twenty consecutive patients with cervical spondylotic myelopathy (331 male and 189 female; mean age, 62.2 yr) who underwent modified double-door laminoplasty were enrolled. The average follow-up period was 33.3 months. All patients were allowed to sit up and walk on the first postoperative day using an orthosis, which could be removed within the first 2 weeks, even if long. Early cervical ROM exercises were performed as a part of the rehabilitation schedule. Radiography was performed before surgery and at the final follow-up. Cervical alignment in the neutral and flexion-extension view were measured by the Cobb method at C2-C7. The ROM was assessed by measuring the difference in alignment between flexion and extension. Results The mean C2-C7 alignment in the neutral position was 11.9° lordotic preoperatively and 13.6° lordotic postoperatively; the alignment increased by 1.8° in lordosis. The mean total ROM decreased from a preoperative value of 40.1° to 33.5° at the final follow-up, showing a significant difference of 6.6°. The mean total ROM preservation after laminoplasty was 87.9%. Conclusion Sagittal alignment was slightly changed, with only a 1.8° increase in lordosis. The ROM of the cervical spine was preserved by 87.9%. This preservation of alignment and ROM might be attributable to improvements including early removal of the cervical orthosis, postoperative neck exercises, and some surgical modifications.

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.

Literature has described a risk for subsequent vertical subluxation (VS) and subaxial subluxation (SAS) following atlantoaxial subluxation in rheumatoid patients; however, the interaction of each subluxation and the radiographic findings for atlantoaxial fixation has not been described. The purpose of this study was to evaluate the effects of two different posterior atlantoaxial screw fixation on the development of subluxation in patients with rheumatoid atlantoaxial subluxation.Between 1996 and 2006, rheumatoid patients treated with transarticular fixation and posterior wiring (TA) or C1 lateral mass-C2 pedicle screw fixations (SR) in the Nagoya Spine Group hospitals, a multicenter cooperative study group, were included in this study. VS, SAS, craniocervical sagittal alignment, and range of motion (ROM) at the atlantoaxial adjacent segments were investigated to determine whether posterior atlantoaxial screw fixation is a prophylactic or a risk factor for the development of VS and SAS.The mean follow-up was 7.2 years (4-12). No statistically significant difference was observed among the patients treated with either of the procedure during the follow-up period. Of 34 patients who underwent posterior atlantoaxial screw fixation, SAS was observed in 26.5 % during the follow-up period; however, VS was not observed. Postoperative C2-7 angle, and Oc-C1 and C2-3 ROM were significantly different between patients with and without postoperative SAS. The incidence of SAS was 38.9 % for TA and 12.5 % for SR; statistically significant differences were observed in the postoperative C1-2 and C2-7 angles, and C2-3 ROM.Atlantoaxial posterior screw fixation may be an appropriate prophylactic intervention for VS and SAS if the atlantoaxial joint develops bony fusion following physiological alignment. Compared to TA, SR provided optimal atlantoaxial angle and prevented lower adjacent segment degeneration, thereby reducing SAS.

To clarify the relative frequency of various histopathological primary spinal cord tumors and their features in Japanese people and to compare this data with other reports.Primary spinal cord tumor surgical cases from 2000 to 2009, which were registered in our affiliated hospital database were collected. We examined age at surgery, sex, anatomical location, vertebral level of the tumor, and pathological diagnosis in each case.Of the 678 patients in our study, 377 patients (55.6 %) were males and 301 patients (44.4 %) were females (male/female ratio 1.25). The mean age at surgery was 52.4 years. Of these tumors, 123 cases (18.1 %) were intramedullary, 371 cases (54.7 %) were intradural extramedullary, 28 cases (4.1 %) were epidural, and 155 cases (22.9 %) were dumbbell tumors. The pathological diagnoses included 388 schwannomas (57.2 %), 79 meningiomas (11.6 %), 54 ependymomas (8.0 %), 27 hemangiomas (4.0 %), 23 hemangioblastomas (3.4 %), 23 neurofibromas (3.4 %), and 9 astrocytomas (1.3 %). The male/female ratios for schwannomas, meningiomas, ependymomas, hemangiomas, hemangioblastomas, neurofibromas, malignant lymphomas, and lipomas are 1.4, 0.34, 1.3, 1.5, 2.3, 1.3, 2.7 and 2.3, respectively.This is the first published research in English on the epidemiology of primary spinal cord tumors in Japanese people. Similar to other reports from Asian countries, our data indicates a higher male/female ratio overall for spinal cord tumors, a higher proportion of nerve sheath cell tumors, and a lower proportion of meningiomas and neuroepithelial tumors compared to reports from non-Asian countries. Data in the current study represent the characteristics of primary spinal cord tumors in Asian countries.

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. 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. 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.

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.

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.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.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%).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.

Object The purpose of this study was to provide the first evidence for the influence of an ossified anterior longitudinal ligament (OALL) on the clinical features and surgical outcomes in an ossified ligamentum flavum (OLF) in the thoracic region. Methods Sixty-three patients who underwent surgery for a 1-level thoracic OLF were identified, and preoperative symptoms, severity of symptoms and myelopathy, disease duration, MR imaging and CT findings, surgical procedure, intraoperative findings, complications, and postoperative recovery were investigated in these patients. Entities of OALLs were found on sagittal CT images to be adjacent to or at the same vertebral level as the OLF were classified into 4 types: no discernible type (Type N), one-sided (Type O), discontinuous (Type D), and continuous (Type C). Results The duration of symptoms was especially long for Types D and C OALLs. Patients with Type D OALLs had a significantly worse percentage of recovery, as well as worse preoperative JOA scores. Conclusions The authors' results showed that a Type D OALL had strong associations with preoperative severity of symptoms and surgical outcomes. These findings may allow surgeons to determine the severity of preoperative symptoms and the probable surgical outcomes from the OALL classifications. Moreover, surgery with instrumentation for Type D OALLs may produce better surgical outcomes.

Study Design. Prospective imaging study of patients with cervical spondylotic myelopathy (CSM). Objectives. To measure dural sac and spinal cord cross-sectional area during flexion and extension in patients with CSM using multidetector-row CT (MDCT) and to investigate the influence of dynamic factors on the spinal cord. Summary of Background Data. In patients with CSM, the spinal cord is likely to be compressed during neck extension, because the ligamentum flavum and intervertebral discs protrude into the spinal canal during neck extension. Generally, spinal cord cross-sectional area becomes narrower during extension due to dynamic factors. There are few reports that have assessed the dural sac and spinal cord cross-sectional area during flexion and extension. Methods. A total of 100 patients with CSM were prospectively enrolled. Patients with rheumatoid arthritis, cerebral palsy, thoracic spondylotic myelopathy, and lumbar spinal canal stenosis were excluded. Magnetic resonance imaging in a neutral position, and MDCT scan during flexion and extension after myelography were taken in all patients before surgery. Dural sac and spinal cord cross-sectional area at each disc level between C2―C3 and C7―T1 were measured using Scion imaging software. Results. The average dural sac and spinal cord cross-sectional area were less during extension than during flexion from the C3―C4 to C7―T1 disc levels. The decreasing changes during extension occurred mostly at the C5―C6 disc level. The differences in spinal cord cross-sectional area were statistically significant at each disc level between C3―C4 and C7―T1. Conclusion. MDCT demonstrated dynamic factors in patients with CSM. The spinal cord cross-sectional area became narrower during extension in patients with CSM. The decreasing change during extension occurred mostly at the C5―C6 disc level among all disc levels evaluated.

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. Questionnaires administered to practicing orthopedic and neurosurgical spine surgeons from North America, Europe, Asia, Australia, and New Zealand. Objective. To determine diversity and commonalities in the treatment of spine trauma internationally. Summary of Background Data. Previous studies have had suggested that there is significant variability in the treatment of common spinal trauma conditions. Methods. Questionnaires based on 10 commonly encountered spine trauma cases were administered to 77 experienced spinal surgeons across 4 continents. The questions for each case scenario were similar, but were tailored to be appropriate for the case being presented. Questions focused on the discipline of the specialist who would treat the injury, the treatment itself, and how long it would take for the patient to return home or to work. Questions pertaining to investigations, funding, estimated in-hospital length of stay, prehospital care, and mortality were also included. Each question was followed by 4 to 8 options from which the surgeon could chose a response. Data were analyzed using, SAS v9.2, a software analytical package, to determine the level of agreement between respondents on different items. Results. Of the 77 surgeons completing the questionnaire, 66% were fellowship trained spine surgeons, 20% orthopedic surgeons, and 14% neurosurgeons. In all regions, the majority of spinal trauma care is provided in a regional trauma center with dedicated spine surgeons. In all but 1 case significant differences were found in treatment with European and Asian surgeons have a higher operative rate. A combined anterior/posterior surgical approach was more commonly used in Europe and Asia. North American patients are expected to have a shorter hospital stay and return to work earlier. Significant differences exist between Asia and the other regions with regard to prehospital care. Conclusion. These findings suggest that despite the subspecialty focus in the care of spinal trauma, there continues to exist a lack of consensus among treating surgeons as to the optimum management and appropriateness of multiple aspects of specific operative and non-operative interventions and indeed the postinjury management.

Study design A case report. Objective To report a rare complication associated with lumbar decompression surgery. Summary of background data Decompression surgery for lumbar degenerative canal stenosis is one of the most commonly performed spinal procedures. A dural tear is a common troublesome complication of the surgery. Occasionally, dural tear can lead to cerebrospinal fluid (CSF) fistula. However, there is no report of a CSF fistula between the subdural space and a facet joint. Methods A 79-year-old woman underwent lumbar decompression surgery at L3-L5 level. During the surgery, a minimal dural tear was detected although the arachnoid membrane was intact. Because of the absence of CSF leakage and small size of the torn area, repair was not performed. After surgery, she complained of intermittent left buttock pain after ambulation. Her magnetic resonance imaging showed enlarged subdural space and tethering of the dura at L3-L4. CSF aspiration from subdural space was conducted during myelography. However, pain relief was only temporary. CSF fistula between subdural space and facet joint was detected on computed tomographic myelography (CTM). She subsequently underwent second surgery. Results After separation of the adhesion between the dural tear and the facet joint, CSF leakage was observed. Water-tight sutures, free fat graft, and fibrin glue were applied for repair. She demonstrated complete resolution of her preoperative symptoms at 1 year after surgery. Follow-up magnetic resonance imaging showed no recurrence of the fistula and an adequately decompressed lumbar canal. Conclusion Computed tomographic myelography was essential to diagnose the rare complication after dural tear. Even in cases of minimal dural tears without arachnoid tear, we suggest repair in order to prevent the rare case of fistula formation.

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.

Object The purpose of this study was to provide the first evidence for image classification of idiopathic spinal cord herniation (ISCH) in a multicenter study. Methods Twelve patients who underwent surgery for ISCH were identified, and preoperative symptoms, severity of paralysis and myelopathy, disease duration, plain radiographs, MR imaging and CT myelography findings, surgical procedure, intraoperative findings, data from spinal cord monitoring, and postoperative recovery were investigated in these patients. Findings on sagittal MR imaging and CT myelography were classified into 3 types: a kink type (Type K), a discontinuous type (Type D), and a protrusion type (Type P). Using axial images, the location of the hiatus was classified as either central (Type C) or lateral (Type L), and the laterality of the herniated spinal cord was classified based on correspondence (same; Type S) or noncorrespondence (opposite; Type O) with the hiatus location. A bone defect at the ISCH site and the laterality of the defect were also noted. Results Patients with Type P herniation had a good postoperative recovery, and those with a Type C location had significant severe preoperative lower-extremity paralysis and a significantly poor postoperative recovery. Patients with a bone defect had a significantly severe preoperative myelopathy, but showed no difference in postoperative recovery. Conclusions The authors' results showed that a Type C classification and a bone defect have strong relationships with severity of symptoms and surgical outcome and are important imaging and clinical features for ISCH. These findings may allow surgeons to determine the severity of preoperative symptoms and the probable surgical outcome from imaging.

Study design A retrospective multicenter study of series of 20 patients with myxopapillary ependymomas, which underwent surgery. OBJECTIVE.: To evaluate the postoperative outcomes of patients surgically treated for spinal myxopapillary ependymoma. Neurologic deterioration after tumor resection is discussed in terms of the tumor encapsulation. SUMMARY OF BACKGROUND DATA.: Myxopapillary ependymomas occur most commonly in the cauda equina and/or conus medullaris region. Most series published in the literature have covered postoperative tumor recurrence and role of adjuvant radiotherapy. Few contradistinctive studies in postoperative neurological deficit were reviewed from the standpoints of MRI and histopathologic findings. Methods A total of 20 patients were recruited and charts, MRI, intraoperative findings, and pathologic findings were reviewed. The follow-up period ranged from 2 to 12 years (median, 72.9 months). The surgical procedures were defined as gross total removal, piecemeal total removal, and subtotal removal. Postoperative radiotherapy was given in 3 patients in whom removal had been subtotal. Results Gross total removal was achieved in 14 patients, piecemeal gross total and subtotal removal in 3 patients each. Neurologic deterioration after surgery was seen in 5 patients, all of which were unencapsulated tumors consisting of piecemeal gross total removal in 2 patients and subtotal removal in 3 patients. Recovery of postoperative bladder dysfunction remained unchanged in 2 patients. There were no tumor recurrence and progression of the remaining tumors. Unencapsulated tumors were more frequently seen in heterogeneously enhanced tumors on MRI than in homogenously enhanced tumors with significant difference. Conclusion In the unencapsulated ependymomas, tumor separation and manipulation of the surrounding neural tissue caused neurologic injury. The heterogeneously enhanced ependymoma not only should be evaluated and treated meticulously, but also surgeons should not stick to total removal in infiltrated and adhering tumors as subtotally resected tumors with postoperative radiotherapy have not always recurred.

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). 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.

Object The authors investigated the outcome of intramedullary spinal cord tumor surgery, focusing on the effect of preoperative neurological status on postoperative mobility and the extent of tumor excision guided by intraoperative spinal cord monitoring prospectively. Methods Intramedullary spinal cord tumor surgery was performed in 131 patients between 1997 and 2007. The authors compared the pre- and postoperative neurological status and examined the type of surgery in 106 of these patients. A modified McCormick Scale (Grades I–V) was used to assess ambulatory ability (I = normal ambulation; II = mild motor sensory deficit, independent without external aid; III = independent with external aid; IV = care required; and V = wheelchair required). The type of surgery was classified into 4 levels: total resection, subtotal resection, partial resection, and biopsy. Results The 106 patients consisted of 47 females and 59 males, whose average age was 42.5 years (range 6–75 years). The mean follow-up period was 7.3 years (range 2.5 months–21 years). The tumor types included astrocytoma (12 cases), ependymoma (46 cases), hemangioblastoma (16 cases), cavernous hemangioma (17 cases), and others (15 cases overall: gangliocytoma, 1; germ cell tumor, 1; lymphoma, 3; neurinoma, 1; meningioma, 1; oligodendroglioma, 1; sarcoidosis, 2; glioma, 1; and unknown, 4). Initial total excision, subtotal resection, partial resection, biopsy, and duraplasty were performed in 59, 12, 22, 12, and 1 patients, respectively. According to the preoperative McCormick Scale, ambulatory status was classified as Grades I, II, III, IV, and V in 41(38%), 30 (28%), 14 (13%), 19 (19%), and 2 (2%) patients, respectively. Thirty-three (31%) of 106 patients suffered postoperative neurological deterioration. The number of patients who did not lose ambulatory ability or who achieved an ambulatory status of Grade I or II postoperatively was 33 (80%), 21 (70%), 10 (71%), 8 (42%), and 1 (50%) in patients with preoperative Grades I, II, III, IV, and V, respectively. Total excision was performed in 31 (79%) of 39 patients with preoperative Grade I, 12 (40%) of 30 patients with Grade II, 7 (50%) of 14 patients with Grade III, and 9 of 21 patients (38%) with Grade IV or V, indicating that the rate of total excision was significantly higher in patients with Grade I status. Conclusions The postoperative ambulatory ability was excellent in patients with a good preoperative neurological status. Total excision in patients with Grade I or II ambulation was associated with a good prognosis for postoperative mobility. However, the rate of postoperative deterioration was 31.5%, which is relatively high, and patients should be fully informed of this concern prior to intramedullary spinal cord tumor surgery.

To investigation of the outcomes of indirect posterior decompression with corrective fusion for myelopathy associated with thoracic ossification of the longitudinal ligament, and prognostic factors. Conservative treatment for myelopathy associated with thoracic ossification of the longitudinal ligament (OPLL) is mostly ineffective, and treatment is necessary. However, many authors have reported poor surgical outcomes, and no standard surgical procedure has been established. We have been performing indirect spinal cord decompression by posterior laminectomy and simultaneous corrective fusion of the thoracic kyphosis. Twenty patients underwent indirect posterior decompression with corrective fusion, and were included in this study. The follow-up period was minimum 2 years and averaged 2 years and 9 months (2-5 years 6 months). Operative results were examined using JOA scoring system (full marks: 11 points) and Hirabayashi's recovery rate, as excellent (100-75%), good (74-50%), fair (49-25%), unchanged (24-0%) and deteriorated (i.e., decrease in score less than 0%). Cases in which the spinal cord is floating from OPLL on intraoperative ultrasonography were defined as the floating (+) group, and those without floating as the floating (-) group. In addition, we used compound muscle action potentials (CMAP) as intraoperative spinal cord monitoring and the cases were divided into three groups: Group A, no change in potential; Group B, potential decreased, and Group C, potential improved. The mean pre- and postoperative JOA scores were 6.2 and 8.9 points, respectively, and the recovery rate was 56%. The outcome was rated excellent in three, good in eight, fair in six, unchanged in two, and deteriorated in one. The mean preoperative thoracic kyphosis measured 58 degrees , and was corrected to 51 degrees after surgery. On intraoperative ultrasonography, 12 cases were included in the floating (+) and 8 in the floating (-) groups; the recovery rates were 58 and 52%, respectively, showing no significant difference between the recovery rates of the two groups. Regarding intraoperative CMAP, the outcome was excellent in one, good in seven, fair in four, and unchanged in one in Group A; fair in one, unchanged in one, and deteriorated in one in Group B, and excellent in two and good in one in Group C. The recovery rates were 50, 48 and 68.3% in Groups A, B and C, respectively, showing that the postoperative outcome was significantly poorer in Group B. Although indirect posterior decompression with corrective fusion using instruments obtained satisfactory outcomes, not all cases achieved good outcomes using this procedure. We consider that additional application of anterior decompressive fusion is preferable when improvement of symptoms occurs not satisfactory after indirect posterior decompression with corrective fusion using instruments. Intraoperative spinal cord monitoring of CMAP demonstrated that the spinal cord was already impaired during the laminectomy via the posterior approach. Concomitant intraoperative monitoring of CMAP to avoid impairment of the vulnerable spinal cord and corrective posterior spinal fusion with indirect spinal cord decompression is recommendable as a method capable of preventing postoperative neurological aggravation.

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° of kyphosis preoperatively, which improved to 6.8° of lordosis postoperatively and 5.2° 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 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.

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. 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. NCC (

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.

Ossification of the posterior longitudinal ligament (OPLL) in the thoracic spine produces myelopathy through anterior spinal cord compression that is usually progressive and unaffected by conservative treatment. Therefore, early decompressive surgery is imperative. However, decompression surgery of thoracic myelopathy is difficult, and the outcome is often poor. A retrospective study was conducted to investigate the surgical outcome of 21 patients with thoracic OPLL to evaluate which type of surgical approach is better and which type of thoracic OPLL results in a better surgical outcome.A total of 21 patients with thoracic OPLL (10 men and 11 women; mean age 54 years), who underwent surgical treatment at our department from March 1985 to October 2000, were included in the study. Seven patients exhibited the flat-type OPLL and underwent either anterior decompression and fusion (one patient), anterior decompression via a posterior approach (three patients), or expansive laminoplasty (three patients). Fourteen patients exhibited the beak-type OPLL and also underwent either anterior decompression and fusion (two patients), anterior decompression via a posterior approach (six patients), or expansive laminoplasty (six patients).Regarding of operative time and blood loss, there were no marked differences between the two types of OPLL, regardless of the type of surgical procedure; anterior decompression and fusion and anterior decompression via a posterior approach yielded longer operative times and larger blood loss volumes than expansive laminoplasty. Concerning clinical outcome, there were five cases of neurologic deterioration. All of the five deteriorated cases were of the beak-type OPLL treated by a posterior approach. Two of these patients were treated with expansive laminoplasty.There were five instances of neurologic deterioration in our thoracic OPLL series, and all of them exhibited beak-type OPLL. In the beak-type OPLL, a subtle alteration in the spinal alignment during posterior decompression procedures may increase spinal cord compression, leading to the deterioration of symptoms. A potential increase in kyphosis following laminectomy should be avoided by fixation with a temporary rod. If intraoperative monitoring suggests spinal cord dysfunction, an anterior decompression procedure should be attempted as soon as possible.

Study Design. A prospective randomized clinical trial in preemptive analgesia for postoperative pain was conducted. Objective. To compare the efficacy of three preemptive analgesics combined with local anesthesia: continuous subcutaneous morphine (SC), continuous epidural morphine (ED), and diclofenac sodium (DS). Summary of Background Data. Systemic opioids are known to be effective methods of postoperative pain control. The use of epidural morphine for postoperative analgesia has been a standard treatment in spinal surgery. Only a few studies in the literature have investigated the efficacy of preemptive analgesia using morphine. This is the first prospective randomized clinical trial to assess both subcutaneous and epidural continuous administration of opioids for preemptive analgesia. Methods. For this study, 73 patients were assigned randomly to one of three treatment groups: SC, ED, or DS. All patients underwent posterior lumbar interbody fusion with instrumentation. Pain management was assessed using the visual analogue scale (VAS). Usage of supplemental analgesics, the time to first request of them, and side effects were also investigated. Results. Twenty-two patients were randomized to SC, 23 to ED, and 27 to DS. No baseline variable differences among the three groups were seen. The results showed no significant difference in analgesic effects among those three preemptive analgesics. Only immediately after surgery (at 0 hours), the VAS of the DS group was lowest among three groups. But the DS group took more supplemental analgesic drugs until 72 hours, and the time to first request of this group was shorter than that of the other two groups. High rates of minor side effects were seen in both the ED and DS groups. SC gave moderate analgesic effects as well as the other two groups with few adverse effects. Conclusions. DS provided a favorable effect immediately after surgery, but the effective time was short and the patient needed more supplemental drugs after that. ED did not give the expected effect, with comparativelyhigh rates of side effects. Continuous epidural anesthesia did not seem to be suitable for preemptive analgesia. Continuous subcutaneous morphine brought some analgesic effects with a low rate of complications. It can be an attractive method for postoperative analgesia with technical ease.

The aim of this work was to elucidate the relation between the clinical course and morphologic changes of lumbar disc herniation on magnetic resonance imaging (MRI).Twenty-one patients with lumbar disc herniation treated nonsurgically were followed for a minimum of 7 years and investigated with regard to their clinical outcome and the initial, 2-year, and final stage MRI findings. The space-occupying ratio of herniation to the spinal canal and the degree of disc degeneration were evaluated on serial MRI.The mean space-occupying ratio of herniation showed significant reduction both on the 2-year and on the final scans. Progression of degeneration of the intervertebral disc was seen in all patients at the final investigation. Comparing patients with and without symptoms, no factors were detected on the initial and 2-year MR images capable of distinguishing patients who were and were not destined to develop lumbago and/or sciatica in the future. Morphologic changes of lumbar disc herniation continued to occur even after 2 years.Clinical outcome did not depend on the size of herniation or the grade of degeneration of the intervertebral disc in the minimum 7-year follow-up.

The lumbar spinous process–splitting laminectomy (LSPSL) procedure was developed as an alternative to lumbar laminectomy. In the LSPSL procedure, the spinous process is evenly split longitudinally and then divided at its base from the posterior arch, leaving the bilateral paravertebral muscle attached to the lateral aspects. This procedure allows for better exposure of intraspinal nerve tissues, comparable to that achieved by conventional laminectomy while minimizing damage to posterior supporting structures. In this study, the authors make some modifications to the original LSPSL procedure (modified LSPSL), in which laminoplasty is performed instead of laminectomy. The purpose of this study was to compare postoperative outcomes in modified LSPSL with those in conventional laminectomy (CL) and to evaluate bone unions between the split spinous process and residual laminae following modified LSPSL. Forty-seven patients with lumbar spinal stenosis were enrolled in this study. Twenty-six patients underwent modified LSPSL and 21 patients underwent CL. Intraoperative blood loss and surgical duration were evaluated. The Japanese Orthopaedic Association (JOA) scale scores were used to assess parameters before surgery and 12 months after surgery. The recovery rates were also evaluated. Postoperative paravertebral muscle atrophy was assessed using MRI. Bone union rates between the split spinous process and residual laminae were also examined. The mean surgical time and intraoperative blood loss were 25.7 minutes and 42.4 ml per 1 level in modified LSPSL, respectively, and 22.7 minutes and 29.5 ml in CL, respectively. The recovery rate of the JOA score was 64.2% in modified LSPSL and 68.7% in CL. The degree of paravertebral muscle atrophy was 7.8% in modified LSPSL and 22.2% in CL at 12 months after surgery (p < 0.05). The fusion rates of the spinous process with the arcus vertebrae at 6 and 12 months in modified LSPSL were 56.3% and 81.3%, respectively. The modified LSPSL procedure was less invasive to the paravertebral muscles and could be a laminoplasty; therefore, the modified LSPSL procedure presents an effective alternative to lumbar laminectomy.

Item does not contain fulltext STUDY DESIGN: Prospective, multicenter international cohort. OBJECTIVE: To evaluate outcomes of surgical decompression for cervical spondylotic myelopathy (CSM) at a global level. SUMMARY OF BACKGROUND DATA: CSM is a degenerative spine disease and the most common cause of spinal cord dysfunction worldwide. Surgery is increasingly recommended as the preferred treatment strategy for CSM to improve neurological and functional status and quality of life. The outcomes of surgical intervention for CSM have never been evaluated at an international level. METHODS: Between October 2007 and January 2011, 479 symptomatic patients with image evidence of CSM were enrolled in the prospective, multicenter AOSpine CSM-International study from 16 global sites. Preoperative and postoperative clinical status, functional impairment, and quality of life were evaluated using the modified Japanese Orthopaedic Assessment Scale, Nurick Scale, Neck Disability Index, and Short-Form-36v2. Preoperative and 12- and 24-month postoperative outcomes were compared using mixed-model analysis of covariance for repeated measurements. RESULTS: The study cohort consisted of 310 males and 169 females, with a mean age of 56.37 +/- 11.91 years. There were significant differences in age, etiology, and surgical approaches between the regions. At 24 months postoperatively, the mean modified Japanese Orthopaedic Assessment Scale score improved from 12.50 (95% confidence interval [CI], 12.24-12.76) to 14.90 (95% CI, 14.64-15.16); the Neck Disability Index improved from 36.38 (95% CI, 34.33-38.43) to 23.20 (95% CI, 21.24-25.15); and the SF36v2 Physical Component Score and Mental Composite Score improved from 34.28 (95% CI, 33.46-35.10) to 40.76 (95% CI, 39.71-41.81) and 39.45 (95% CI, 38.25-40.64) to 46.24 (95% CI, 44.94-47.55), respectively. The rate of neurological complications was 3.13%. CONCLUSION: Surgical decompression for CSM is safe and results in improved functional status and quality of life in patients around the world, irrespective of differences in medical systems and sociocultural determinants of health. LEVEL OF EVIDENCE: 3.

Background: The relationship between objective measurements and subjective symptoms of patients with spinal stenosis and the degree of narrowing of the spinal canal is not clear. The purpose of this study was to evaluate patients undergoing surgery for lumbar spinal stenosis and intermittent neurogenic claudication with functional testing, quantitative imaging, and patient self-assessment. Methods: Sixty-two patients with lumbar spinal stenosis and neurogenic claudication were prospectively enrolled in the study. All underwent preoperative magnetic resonance imaging and/or computed tomography myelography, and all were treated with decompressive surgery and were followed for a minimum of two years. The evaluation included treadmill and bicycle exercise tests as well as patient self-assessment with use of the Oswestry Disability Index and a visual analog pain scale preoperatively and postoperatively. Results: Preoperatively fifty-eight (94%) of the patients had a positive result (provocation of symptoms) on the treadmill test and twenty-seven (44%) had a positive result on the bicycle test, whereas postoperatively six and twelve, respectively, had positive results. The mean preoperative scores on the Oswestry Disability Index and visual analog pain scale were 58.4 and 7.1, respectively. Postoperatively, these scores decreased to 21.1 and 2.3, respectively, and both decreases were significant (p < 0.05). Forty-seven (76%) of the patients were seen to have central stenosis on the preoperative imaging studies; forty-one of them had a cross-sectional area of the dural tube of 90% of the patients preoperatively. Following surgical decompression of the lumbar spinal stenosis, more functional improvement was demonstrated by the treadmill test than by the bicycle test. The scores on the Oswestry Disability Index and visual analog pain scale also improved postoperatively. The severity of central canal narrowing at a single level does not appear to limit the postoperative improvement in either functional ability or patient self-assessment. Patients with multilevel central stenosis were, on the average, older and walked a shorter distance preoperatively and postoperatively, although the improvement in their postoperative self-assessment scores was similar to that of patients with single-level stenosis.

The purpose of this study was to measure range of motion (ROM) in patients with cervical ossification of posterior longitudinal ligament (C-OPLL) by multidetector-row computed tomography (MDCT), and to investigate the influence of dynamic factors. The study included 101 patients with C-OPLL and 99 normal control patients. Preoperative MDCT were taken in all subjects in maximum neck flexion and extension. ROM at each disc level between C2/3 and C7/T1 in sagittal view was measured. Ossification morphology at each disc segment was divided into 6 groups: covered disc, covered vertebra, unconnected vertebra, connected vertebra (continuous), connected vertebra (localized), and others. The relationship between ROM and the group of ossification morphology was also investigated. ROM of adjacent intervertebral disc in connected vertebrae (continuous and localized) and those of others were investigated for each group. The average ROM of covered disc group was significantly higher than that of connected vertebra (continuous, localized). The average ROM of connected vertebra (continuous) group was significantly lower than that of covered disc group, others group, and normal control. There was no significant difference between ROM of adjacent intervertebral disc in connected vertebrae and others, but the average ROM of the connected vertebra group was significantly lower than that of the covered disc group and normal control group. Dynamic factor was reduced at continuous segment, but it was not increased in adjacent intervertebral disc.

Cervical spondylosis that causes upper-extremity muscle atrophy without gait disturbance is called cervical spondylotic amyotrophy (CSA). The distal type of CSA is characterized by weakness of the hand muscles. In this retrospective analysis, the authors describe the clinical features of the distal type of CSA and evaluate the results of surgical treatment.The authors performed a retrospective review of 17 consecutive cases involving 16 men and 1 woman (mean age 56.3 years) who underwent surgical treatment for the distal type of CSA. The condition was diagnosed on the basis of cervical spondylosis in the presence of muscle impairment of the upper extremity (intrinsic muscle and/or finger extension muscles) without gait disturbance, and the presence of a compressive lesion involving the anterior horn of the spinal cord, the nerve root at the foramen, or both sites as seen on axial and sagittal views of MRI or CT myelography. The authors assessed spinal cord or nerve root impingement by MRI or CT myelography and evaluated surgical outcomes.The preoperative duration of symptoms averaged 11.8 months. There were 14 patients with impingement of the anterior horn of the spinal cord and 3 patients with both anterior horn and nerve root impingement. Twelve patients were treated with laminoplasty (plus foraminotomy in 1 case), 3 patients were treated with anterior cervical discectomy and fusion, and 2 patients were treated with posterior spinal fixation. The mean manual muscle testing grade was 2.4 (range 1-4) preoperatively and 3.4 (range 1-5) postoperatively. The surgical results were excellent in 7 patients, good in 2, and fair in 8.Most of the patients in this series of cases of the distal type of CSA suffered from impingement of the anterior horn of the spinal cord, and surgical outcome was fair in about half of the cases.

With the aging of society, osteoporotic thoracolumbar compression fracture is a concern. This fracture occurs occasionally; however, some cases progress to neural compromise due to delayed vertebral body collapse requiring surgery. Surgical treatment and postoperative care are difficult because of patients’ serious comorbidities and poor bone quality, and hence, optimum treatment is not clear, even though some surgical approaches have been reported. There were 35 consecutive patients (5 males and 30 females) with osteoporotic delayed vertebral fractures and associated neurological deficit. Mean age at surgery was 70.7 years (range 60–84 years). Average postoperative follow-up was 3.8 years (range 0.6–11.3 years). All patients experienced a single vertebra collapse, except for 1 with a 2-level collapse of lumbar vertebrae. One thoracic (Th7), 19 thoracolumbar (Th12-L1), and 16 lumbar (L2-5) fractures were treated with combined posterior-anterior surgery. The American Spinal Injury Association (ASIA) impairment scale, activities of daily living (ADL) status, and local sagittal angle were evaluated both before and after surgery. Forty-six percent of all patients showed an improvement of more than 1 grade postoperatively on the ASIA impairment scale, and 74% demonstrated an improvement in ADL status. No deterioration was observed in neurological or ADL status after surgery. With regard to sagittal alignment, preoperative kyphosis of 18.4 degrees was corrected to 2.4 degrees of kyphosis postoperatively. However, 11.5 degrees loss of correction was observed at final follow-up observation. Combined posterior-anterior surgery could provide reliable improvement in both neurological and ADL status, although maintenance of postoperative alignment was difficult to achieve in some cases.

Imaging study of thoracic spine. The purpose of this study was to investigate dynamic alignment and range of motion (ROM) at all segmental levels of thoracic spine. Thoracic spine is considered to have restricted ROM because of restriction by the rib cage. However, angular movements of thoracic spine can induce thoracic compressive myelopathy in some patients. Although few previous studies have reported segmental ROM with regard to sagittal plane, these were based on cadaver specimens. No study has reported normal functional ROM of thoracic spine. Fifty patients with cervical or lumbar spinal disease but neither thoracic spinal disease nor compression fracture were enrolled prospectively in this study (34 males, 16 females; mean age 55.4 ± 14.7 years; range 27–81 years). After preoperative myelography, multidetector-row computed tomography scanning was performed at passive maximum flexion and extension position. Total and segmental thoracic kyphotic angles were measured and ROM calculated. Total kyphotic angle (T1/L1) was 40.2° ± 11.4° and 8.5° ± 12.8° in flexion and extension, respectively (P

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.

The thoracolumbar junction is a common site for spinal injuries. The thoracic spine is distinguished from the cervical and lumbar spine by the presence of the ribs and their articulations. The thoracic spine shows physiological kyphosis and the lumbar spine shows physiological lordosis. The rigid thoracic spine and the mobile lumbar spine create a junction exposed to a concentration of stresses, leading to a higher likelihood of injuries between T10 and L2 compared with other spinal regions. These injuries include compression fractures, burst fractures, flexion distraction injuries, seatbelt-type injuries, and fracture dislocations. Among these, the unstable injuries result in the loss of trunk support and neural injury to the spinal cord, conus medullaris, and/or cauda equina. Adequate neurologic and imaging examination should be done to assess the patients suspected of spinal injury at thoracolumbar level. In the treatment of thoracolumbar injury, conservative treatment like as hard corset is applied for stable injuries and surgical procedure is indicated for unstable injuries. Three representative procedures are often used in reconstruction of unstable injuries; posterior surgery, anterior surgery and anterior–posterior combined surgery. Appropriate procedure should be selected, according to doctor’s experience and pros and cons of each procedure.

STUDY DESIGN A clinical and cohort study. OBJECTIVE To evaluate the efficacy of the 10-second step test as a measure of the severity of thoracic compressive myelopathy. SUMMARY OF BACKGROUND DATA Objective measurement is essential for determining the severity of thoracic compressive myelopathy. Some useful measurements for cervical myelopathy have been identified; however, few reports have addressed the measurement of severity of thoracic myelopathy. METHODS Twenty-five presurgical patients with thoracic compressive myelopathy were included. Patients with cervical myelopathy and concomitant lumbar canal stenosis were excluded from this analysis. The subjects included 14 males and 11 females, with a mean age of 58.8 years (range, 36-81). The 10-second step test was performed, and the number of steps in 10 seconds was recorded. The Japanese Orthopedic Association (JOA) score for thoracic myelopathy, which was adapted from the JOA score for cervical myelopathy, was also used for assessment. RESULTS The average 10-second step test score in all patients was 9.6 ± 1.3 before surgery, which significantly correlated with the total JOA score (r = 0.69, P < 0.01) and its lower extremity motor function score (r = 0.92, P < 0.01). They were retested 12 months after surgery, but the postoperative scores for 5 patients were not available. The average preoperative 10-second step test score of the remaining 20 patients was 9.5 ± 1.5, which significantly improved to 15.1 ± 1.2 12 months after surgery. The step test score in those 20 patients significantly correlated with the total JOA score and lower extremity motor function score before and after surgery (P < 0.01). CONCLUSION The 10-second step test reflected the severity of thoracic compressive myelopathy. Moreover, this test was useful for evaluating surgical outcome in patients with thoracic compressive myelopathy.

Study design Prospective database study. Objectives To grasp the characteristics of surgically treated cases with lumbar spondylolysis or isthmic spondylolisthesis. Summary of background data A detailed analysis of surgically treated cases with spondylolysis or isthmic spondylolisthesis has never been reported. An epidemiological study in Japan conducted on 2000 subjects found the incidence of lumbar spondylolysis in the Japanese general population (population-based study) to be 5.9% (males: 7.9%, females: 3.9%). Among 124 vertebrae with spondylolysis, there were 0.8% L2 lesions, 3.2% L3 lesions, 5.6% L4 lesions, and 90.3% L5 lesions, including 5 cases (4.3%) with multiple-level lesions. Methods We have been registering surgically treated spine cases in our database since 2000. From this database, we prospectively collected cases with lumbar spondylolysis or isthmic spondylolisthesis that were treated surgically between January 2000 and December 2009. We determined the age at surgery, sex, and vertebral level of spondylolysis. Results Of the 564 spondylolysis patients treated surgically, 66.8% were male and 33.2% were female. The mean age at surgery was 52.5 years (range, 13-84 y). There were 585 vertebrae with spondylolysis including 21 cases (3.7%) with multiple-level lesions. L5 spondylolysis affected 432 vertebrae and was the most common location (73.8%), followed by 125 L4 lesions (21.4%), 24 L3 lesions (4.1%), and 2 L2 lesions (0.7%). Conclusions The percentage of L4 lesions in our study was significantly higher and of L5 lesions was significantly lower than those lesions' percentages in the population-based study. L4 spondylolysis may be more unstable or cause clinical symptoms more frequently leading to more surgical intervention. The percentage of multiple-level spondylolysis was similar between the 2 studies, suggesting these patients respond relatively well to conservative treatment. The male/female ratio was 2:1 in both studies, indicating that males and females require surgery at a similar frequency.