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Background In several previous studies, Charlson comorbidity index (CCI) score was associated with postoperative complications, mortality, and re-admission. There are few reports about the influence of CCI score on postoperative clinical outcome. The purpose of this study was to investigate the influence of comorbidities as calculated with CCI on postoperative clinical outcomes after PLIF. Methods Three hundred sixty-six patients who underwent an elective primary single-level PLIF were included. Postoperative clinical outcome was evaluated with the Japanese Orthopaedic Association lumbar score (JOA score). The correlation coefficient between the CCI score and postoperative improvement in JOA score was investigated. Patients were divided into three groups according to their CCI score (0, 1, and 2+). JOA improvement rate, length of stay (LOS), and direct cost were compared between each group. Postoperative complications were also investigated. Results There was a weak negative relationship between CCI score and JOA improvement rate (r = − 0.20). LOS and direct cost had almost no correlation with CCI score. The JOA improvement rate of group 0 and group 1 was significantly higher than group 2+. LOS and direct cost were also significantly different between group 0 and group 2+. There were 14 postoperative complications. Adverse postoperative complications were equivalently distributed in each group, and not associated with the number of comorbidities. Conclusions A higher CCI score leads to a poor postoperative outcome. The recovery rate of patients with two or more comorbidities was significantly higher than in patients without comorbidities. However, the CCI score did not influence LOS and increased direct costs. The surgeon must take into consideration the patient’s comorbidities when planning a surgical intervention in order to achieve a good clinical outcome.

Background. In several previous studies Charlson comorbidity Index (CCI) score was associated with postoperative complications, mortality and re-admission. There are few reports about the influence of CCI score on postoperative clinical outcome. The purpose of this study was to investigate the influence of comorbidities as calculated with CCI on postoperative clinical outcomes after PLIF.Methods. 366 patients who underwent an elective primary single level PLIF were included. Postoperative clinical outcome was evaluated with the Japanese Orthopaedic Association lumbar score (JOA score). The correlation coefficient between the CCI score and postoperative improvement in JOA score was investigated. Patients were divided into three groups according to their CCI score (0, 1 and 2+). JOA improvement rate, length of stay (LOS) and direct cost were compared between each group. Postoperative complications were also investigated.Results. There was a weak negative relationship between CCI score and JOA improvement rate (r = -0.20). LOS and direct cost had almost no correlation with CCI score. The JOA improvement rate of Group 0 and Group 1 was significantly higher than Group 2+. LOS and direct cost were also significantly different etween Group 0 and Group 2+. There were 14 postoperative complications. Adverse postoperative complications were equivalently distributed in each group, and not associated with the number of comorbidities.Conclusions. A higher CCI score leads to a poor postoperative outcome. The recovery rate of patients with two or more comorbidities was significantly higher than in patients without comorbidities. However, the CCI score did not influence LOS and increased direct costs. The surgeon must take into consideration the patient’s comorbidities when planning a surgical intervention in order to achieve a good clinical outcome.

Anterior decompression with fusion (ADF) for patients with cervical ossification of the posterior longitudinal ligament (OPLL) is reportedly associated with a higher incidence of complications than is laminoplasty. However, the frequency of perioperative complications associated with ADF for cervical OPLL has not been fully established. The purpose of this study was to investigate the incidence of perioperative complications, especially neurological complications, following ADF performed to relieve compressive cervical myelopathy due to cervical OPLL.Study participants comprised 150 patients who had undergone ADF for cervical OPLL at 27 institutions between 2005 and 2008. Perioperative--especially neurological--complications occurring within 2 weeks after ADF were analyzed. Preoperative imaging findings, including Cobb angle, between C2 and C7 and occupying ratio of OPLL were investigated. Multivariate analysis with logistic regression was performed to identify independent risk factors for neurological complications.Three patients (2.0 %) showed deterioration of lower-extremity function after ADF. One of the three patients had not regained their preoperative level of function 6 months after surgery. Upper-extremity paresis occurred in 20 patients (13.3 %), five of whom had not returned to preoperative levels 6 months after surgery. Patients with upper-extremity paresis showed significantly higher occupying ratios of OPLL, greater blood loss, longer operation times, fusion of more segments, and higher rates of cerebrospinal fluid leakage than those without paresis. Independent risk factors for upper-extremity paresis were a high occupying ratio of OPLL and large blood loss during surgery.The incidences of deterioration in upper- and lower-extremity functions were 13.3 % and 2.0 %, respectively. Patients with a high occupying ratio of OPLL are at higher risk of developing neurological deterioration.

There are a variety of treatment options for patients with spinal metastasis, and predicting prognosis is essential for selecting the proper treatment. The purpose of the present study was to identify the significant prognostic factors for the survival of patients with spinal metastasis. We retrospectively reviewed 143 patients with spinal metastasis. The median age was 61 years. Eleven factors reported previously were analyzed using the Cox proportional hazards model:gender, age, performance status, neurological deficits, pain, type of primary tumor, metastasis to major organs, previous chemotherapy, disease-free interval before spinal metastasis, multiple spinal metastases, and extra-spinal bone metastasis. The average survival of study patients after the first visit to our clinic was 22 months. Multivariate survival analysis demonstrated that type of primary tumor (hazard ratio [HR] = 6.80, p0.001), metastasis to major organs (HR = 2.01, p = 0.005), disease-free interval before spinal metastasis (HR = 1.77, p = 0.028), and extra-spinal bone metastasis (HR = 1.75, p = 0.017) were significant prognostic factors. Type of primary tumor was the most powerful prognostic factor. Other prognostic factors may differ among the types of primary tumor and may also be closely associated with primary disease activity. Further analysis of factors predicting prognosis should be conducted with respect to each type of primary tumor to help accurately predict prognosis.

Study Design. Retrospective cohort study. Objective. To evaluate diagnostic validity of space available for the spinal cord (SAC) at C1 level for myelopathy in patients with rheumatoid arthritis (RA). Summary of Background Data. The relationship of SAC at C1 level with myelopathy has been evaluated by relatively small number of the patients, and 2 criteria have been proposed. Methods. Two cohorts of the patients with RA were established. Group A consisted of 140 patients with myeopathy due to upper cervical involvement selected from the database. Group B consisted of 99 patients with upper cervical subluxation, but not associated with myelopathy selected from the consecutive series of the hospitalized patients. Distributions of SAC at C1 level in both groups were evaluated. Efficacy indexes for screening (sensitivity, specificity, etc.) were calculated for these patients' population by previously demonstrated 2 criteria. In addition, analysis according to receiver operating characteristic (ROC) curve was performed. Results. The average values of SAC were 11.1 mm in Group A and 16.5 mm in Group B. When cut-off point for myelopathy was defined as 13 mm or less, sensitivity and specificity were 82% and 85%, respectively. When it was defined as 14 mm or less, sensitivity increased (88%) while specificity decreased (74%). Accuracies by these 2 criteria were almost the same (83%, 82%). The left upper corner point of ROC curve was located between these 2 cut-off points. Conclusion. Distributions of SAC showed that SAC was a reliable parameter for relating myelopathy in patients with upper cervical subluxation in RA. The plots according to ROC curve showed adequacy of previously demonstrated 2 cut-off points. For the purpose to screen the patients with high risk for myelopathy, 14 mm or less was recommended as a cut-off point of SAC.

The authors present two cases of synovitis, acne, pustulosis, hyperostosis, osteitis (SAPHO) syndrome with rapidly progressing destructive spondylitis treated surgically. The spinal lesions in SAPHO syndrome generally have a good prognosis and rarely cause the structural destruction or neurological deterioration. Case 1: a 63-year-old female had palmoplantar pustulosis for 2 years. At first, she only felt a pain in the nape with no inducing factor. Two months later, she had incomplete quadriplegia (ASIA scale C). Magnetic resonance imaging showed destruction of C4–C7, kyphotic deformity, and severe compression of the spinal cord. Decompression and reconstruction surgery using anterior and posterior approach improved her paralysis. Case 2: a 69-year-old female complained of persistent back pain. Magnetic resonance imaging revealed spondylitis of T7–T9. Although there were no typical skin lesions, we diagnosed SAPHO syndrome by hyperostosis of the sternocostoclavicular joint and sacral joint. Destruction with kyphotic deformity of the spine progressed gradually for 3 months. Curettage and reconstruction surgery using thoracic endoscope relieved her pain and prevented the destruction of the spine. The histopathology of the specimen obtained surgically showed non-specific inflammation in both cases. Spondylitis in SAPHO syndrome may cause severe destruction and kyphotic deformity followed by paralysis.

Study design Retrospective multi-institutional study Objective To describe the surgical outcomes in patients with ossification of the posterior longitudinal ligament in the thoracic spine (T-OPLL) and to clarify factors related to the surgical outcomes. Summary of background data Detailed analyses of surgical outcomes of T-OPLL have been difficult because of the rarity of this disease. Methods The subjects were 154 patients with T-OPLL who were surgically treated at 34 institutions between 1998 and 2002. The surgical procedures were laminectomy in 36, laminoplasty in 51, anterior decompression via anterior approach in 25 and via posterior approach in 29, combined anterior and posterior fusion in 8, and sternum splitting approach in 5 patients. Instrumentation was conducted in 52 patients. Assessments were made on (1) The Japanese Orthopedic Association (JOA) scores (full score, 11 points), its recovery rates, (2) factors related to surgical results, and (3) complications and their consequences. Results (1) The mean JOA score before surgery was 4.6 +/- 2.0 and, 7.1 +/- 2.5 after surgery. The mean recovery rate was 36.8% +/- 47.4%. (2) The recovery rate was 50% or higher in 72 patients (46.8%). Factors significantly related to this were location of the maximum ossification (T1-T4) (odds ratio, 2.43-4.17) and the use of instrumentation (odds ratio, 3.37). (3) The frequent complications were deterioration of myelopathy immediately after surgery in 18 (11.7%) and dural injury in 34 (22.1%) patients. Conclusion The factors significantly associated with favorable surgical results were maximum ossification located at the upper thoracic spine and use of instrumentation. T-OPLL at the nonkyphotic upper thoracic spine can be treated by laminoplasty that is relatively a safe surgical procedure for neural elements. The use of instrumentation allows correction of kyphosis or prevention of progression of kyphosis, thereby, enhancing and maintaining decompression effect, and its use should be considered with posterior decompression.

Platelet-activating antibodies, which recognize platelet factor 4 (PF4)/heparin complexes, induce spontaneous heparin-induced thrombocytopenia (HIT) syndrome or fondaparinux-associated HIT without exposure to unfractionated heparin (UFH) or low-molecular-weight heparin (LMWH). This condition mostly occurs after major orthopedic surgery, implying that surgery itself could trigger this immune response, although the mechanism is unclear. To investigate how surgery may do so, we performed a multicenter, prospective study of 2069 patients who underwent total knee arthroplasty (TKA) or hip arthroplasty. Approximately half of the patients received postoperative thromboprophylaxis with UFH, LMWH, or fondaparinux. The other half received only mechanical thromboprophylaxis, including dynamic (intermittent plantar or pneumatic compression device), static (graduated compression stockings [GCSs]), or both. We measured anti-PF4/heparin immunoglobulins G, A, and M before and 10 days after surgery using an immunoassay. Multivariate analysis revealed that dynamic mechanical thromboprophylaxis (DMT) was an independent risk factor for seroconversion (odds ratio [OR], 2.01; 95% confidence interval [CI], 1.34-3.02; P = .001), which was confirmed with propensity-score matching (OR, 1.99; 95% CI, 1.17-3.37; P = .018). For TKA, the seroconversion rates in patients treated with DMT but no anticoagulation and in patients treated with UFH or LMWH without DMT were similar, but significantly higher than in patients treated with only GCSs. The proportion of patients with ≥1.4 optical density units appeared to be higher among those treated with any anticoagulant plus DMT than among those not treated with DMT. Our study suggests that DMT increases risk of an anti-PF4/heparin immune response, even without heparin exposure. This trial was registered to www.umin.ac.jp/ctr as #UMIN000001366.

We report a case of syringomyelia assessed by magnetic resonance imaging (MRI) with a time-spatial labeling inversion pulse (Time-SLIP), which is a non-contrast MRI technique that uses the cerebrospinal fluid (CSF) as an intrinsic tracer, thus removing the need to administer a contrast agent. Time-SLIP permits investigation of flow movement for over 3 seconds without any limitations associated with the cardiac phase, and it is a clinically accessible method for flow analysis.We investigated an 85-year-old male experiencing progressive gait disturbance, with leg numbness and muscle weakness. Conventional MRI revealed syringomyelia from C7 to T12, with multiple webs of cavities. We then applied the Time-SLIP approach to characterize CSF flow in the syringomyelic cavities. Time-SLIP detected several unique CSF flow patterns that could not be observed by conventional imaging. The basic CSF flow pattern in the subarachnoid space was pulsatile and was harmonious with the heartbeat. Several unique flow patterns, such as bubbles, jumping, and fast flow, were observed within syringomyelic cavities by Time-SLIP imaging. These patterns likely reflect the complex flow paths through the septum and/or webs of cavities.Time-SLIP permits observation of CSF motion over a long period of time and detects patterns of flow velocity and direction. Thus, this novel approach to CSF flow analysis can be used to gain a more extensive understanding of spinal disease pathology and to optimize surgical access in the treatment of spinal lesions. Additionally, Time-SLIP has broad applicability in the field of spinal research.

The Japan Spine Research Society carried out a nationwide survey on complications of the spine, enrolling a total of 16 157 patients who had undergone spine surgery in 196 institutes in the 1-year period from January to December 2001. Diseases, surgical procedures, and complications were surveyed in detail. Forty-nine percent of patients were aged 60 years or older, which was remarkably increased in comparison with the percentage reported by the 1994 survey (37.3%). The number of cases with degenerative spinal diseases comprised 78.2% of the total number of spine surgery cases. The percentage of patients with stenosis was the greatest (38.5%), reflecting the increase in the elderly population undergoing spine surgery. Spinal instrumentation was used with 5497 patients (34.0%). The frequency of its use was much greater than that reported in 1994 (27.0%). The pedicle screw was the most frequently used instrument (54.6%). The use of spinal instrumentation greatly increased for spinal deformity, trauma, and tumors. Posterior lumbar interbody fusion has been increasingly used in cases of lumbar degenerative disease. Complications of spinal surgery were reported in 1383 patients (8.6%). The incidence of complications associated with instrumentation surgery was 12.1%, being twice as much as that associated with noninstrumentation surgery (6.8%).

Atlantoaxial fusion by transarticular screw fixation provides firm fixation, and good results have been reported. However, there are also problems, such as injury of the vertebral artery at the time of screw insertion. For accurate facet fusion, we developed a new hole-in-one guide for screw fixation and obtained good results with its use. In 60 adult subjects. we measured the antero-posterior and transverse axes and determined the center of the atlantoaxial surface and the insertion point of the screw in three dimensions on computed tomography scans. Based on these values, we measured the optimum screw insertion angle on sagittal and coronal planes, and the distance between the center and the posterior margin of the joint surface; our new hole-in-one guide was produced with these data. When the guide tip is determined to be located at the center posterior margin of the axial joint surface, and the guidewire insertion point is determined to be located at the center of the axial inferior facet immediately above the C2/3 joint, the guidewire is passed through the axial pedicle and the center of the atlantoaxial joint. Since April 1997, we have used this hole-in-one guide technique in eight patients with atlantoaxial instability. The screws passed the pars interarticularis and the center of the atlantoaxial joint in all patients with safety and accuracy. No complications associated with this technique occurred.

Ossification of the posterior longitudinal ligament of the spine (OPLL) is a common musculoskeletal disease among people after middle age. The OPLL presents with serious neurological abnormalities due to compression of the spinal cord and nerve roots. The OPLL is caused by genetic and environment factors; however, its etiology and pathogenesis still remain to be elucidated. To determine the susceptibility loci for OPLL, we performed a genome-wide linkage study using 214 affected sib-pairs of Japanese. In stratification analyses for definite cervical OPLL, we found loci with suggestive linkage on 1p21, 2p22–2p24, 7q22, 16q24 and 20p12. Fine mapping using additional markers detected the highest non-parametric linkage score (3.43, P = 0.00027) at D20S894 on chromosome 20p12 in a subgroup that had no complication of diabetes mellitus. Our result would shed a new light on genetic aspects of OPLL.

Study design Retrospective multi-institutional study. Objective To investigate the incidence of neurological deficits after cervical laminoplasty for ossification of the posterior longitudinal ligament (OPLL). Summary of background data According to analysis of long-term results, laminoplasty for cervical OPLL has been reported as a safe and effective alternative procedure with few complications. However, perioperative neurological complication rates of laminoplasty for cervical OPLL have not been well described. Methods Subjects comprised 581 patients (458 men and 123 women; mean age: 62 ± 10 years; range: 30-86 years) who had undergone laminoplasty for cervical OPLL at 27 institutions between 2005 and 2008. Continuous-type OPLL was seen in 114, segmental-type in 146, mixed-type in 265, local-type in 24, and not judged in 32 patients. Postoperative neurological complications within 2 weeks after laminoplasty were analyzed in detail. Cobb angle between C2 and C7 (C2/C7 angle), maximal thickness, and occupying rate of OPLL were investigated. Pre- and postoperative magnetic resonance imaging was performed on patients with postoperative neurological complications. Results Open-door laminoplasty was conducted in 237, double-door laminoplasty in 311, and other types of laminoplasty in 33 patients. Deterioration of lower-extremity function occurred after laminoplasty in 18 patients (3.1%). Causes of deterioration were epidural hematoma in 3, spinal cord herniation through injured dura mater in 1, incomplete laminoplasty due to vertebral artery injury while making a trough in 1, and unidentified in 13 patients. Prevalence of unsatisfactory recovery not reaching preoperative level by 6-month follow-up was 7/581 (1.2%). Mean occupying rate of OPLL for patients with deteriorated lower-extremity function was 51.2 ± 13.6% (range, 21.0%-73.3%), significantly higher than the 42.3 ± 13.0% for patients without deterioration. OPLL thickness was also higher in patients with deterioration (mean, 6.6 ± 2.2 mm) than in those without deterioration (mean, 5.7 ± 2.0 mm). No significant difference in C2/C7 lordotic angle was seen between groups. Conclusion Although most neurological deterioration can be expected to recover to some extent, the frequency of short-term neurological complications was higher than the authors expected.

Study design Retrospective multicenter study. Objective To review the clinical characteristics of traumatic cervical spinal cord injury (SCI) associated with ossification of the posterior longitudinal ligament (OPLL). Summary of background data Despite its potentially devastating consequences, there is a lack of information about acute cervical SCI complicated by OPLL. Methods This study included consecutive patients with acute traumatic cervical SCI (Frankel A, B, and C) who were admitted within 48 hours of injury to 34 spine institutions across Japan. For analysis of neurologic outcome, patients who had completed at least a 6-month follow-up were included. Neurologic improvement was defined as at least one grade conversion in Frankel grade. Results A total of 453 patients were identified (367 men, 86 women; mean age, 59 years). OPLL was found in 106 (23%) patients (87 men, 19 women; mean age, 66 years). Most of the patients with OPLL (94 of 106) were without bone injury, presenting with incomplete SCI. The prevalence of OPLL reached 34% in SCI without bone injury. The cause of SCI was predominantly falls (74%). Only 25% of the patients were aware of OPLL. Half of the OPLL patients reported gait disturbance before injury. Forty-eight (52%) OPLL patients without bone injury underwent surgery (median, 13.5 days after injury), mostly laminoplasty. Overall, no significant difference was noted in neurologic improvement between surgery group and conservative group. However, further stratification showed that surgery was associated with greater neurologic recovery in patients who had gait disturbance before injury (P = 0.04). Conclusion Prevalence of OPLL among cervical SCI was alarmingly high, especially in those without bone injury. Most of cervical SCI associated with OPLL were incomplete, without bone injury, and caused predominantly by low-energy trauma. The majority of the patients were unaware of OPLL. Surgery produced better neurologic recovery in patients who had gait disturbance before injury.

Eighty-eight autopsy specimens from L4-5 lumbar discs of cadavers with an average age of 77.6 years were examined radiologically and histopathologically. They were classified into three groups by the height of intervertebral disc space: slightly degenerated (57 cases), moderately degenerated (25 cases), and severely degenerated (6 cases). Cartilaginous end-plate rupture was found most commonly in the severely degenerated group. Reverse orientation of the anulus fibrosus was found in one third of all specimens. End-plate was separated from vertebral body in 45 cases (51.1%) of 88 specimens. From the findings it is suggested that the end-plate is avulsed from the vertebral body under the precondition of separation and then herniated with anchoring anulus fibrosus. This type of herniation occurs more often than herniation of the nucleus pulposus in the elderly.

Eleven patients treated surgically for lumbar spinal canal stenosis associated with lumbar spondylolysis were reviewed to investigate the pathogenesis of the lumbar nerve root involvement in spondylolysis. In accordance with the location of neural compression, spinal canal stenosis was divided into three categories; subarticular recess stenosis(five patients), central and subarticular recess stenosis (two patients) and stenosis at the pars defect (four patients). Stenosis in more than half of the patients was found to be degenerative, as it is in usual cases, rather than due to spondylolysis.

We describe a case of Down's syndrome associated with progressive extradural neuroblastoma. Postmortem aspiration of the bone marrow revealed diffuse infiltration by tumor cells, in which trisomy 21 was found by fluorescence in hybridization in situ.

The concept of synovitis, acne, pustulosis, hyperostosis, osteitis (SAPHO) syndrome has been well clarified, after Chamot et al. suggested this peculiar disorder in 1987. The most commonly affected site in SAPHO syndrome is the anterior chest, followed by the spine. However, the clinical course and taxonomic concept of SAPHO spinal lesions are poorly understood. This study was performed to analyze: (1) the detailed clinical course of spinal lesions in SAPHO syndrome, and (2) the relationship between SAPHO syndrome with spinal lesions and seronegative spondyloarthropathy. Thirteen patients with spondylitis in SAPHO syndrome were analyzed. The features of spinal lesions were a chronic onset with a slight inflammatory reaction, and slowly progressing non-marginal syndesmophytes at multi spinal levels, besides the coexistence of specific skin lesions. SAPHO syndrome, especially spinal lesions related to palmoplantar pustulosis, can be recognized as a subtype of seronegative spondyloarthropathy.

The case of a patient with progressive paraparesis due to first thoracic disc herniation is reported. He was treated successfully with anterior interbody fusion by the Smith-Robinson approach. An anterior approach is desirable for surgical treatment of T1/2 disc herniation, and up to this level the Smith-Robinson approach, without thoracotomy, is entirely possible.

Though there are several methods of instrumental surgery for scoliosis, we tried Luque Spinal Segmental Instrumentation (L-S. S. I.) on two cases of neuromuscular scoliosis. One is a spinal deformity caused by cerebral palsy, and the other is a case of the cervical cord injury with tetraplegia. Both cases got better condition than that before operation. L-S. S. I. provides secure internal fixation and correction force over conventional Harrington Instrumentation, so no external fixation is needed after surgery. Even if the patient has sensory disturbance, this instrumentation makes its maintenance easy. Spasticity with neuromuscular disease causes hook-bone stress or fracture and rod migration easily in Harrington Instrumentation. But in L-S. S. I. such cases are few. Compared with Harrington Instrumentation, loss of correction, ocurrence of pseudarthrosis are less in L-S. S. I.. And some reports mention that L-S. S. I. does not require bone graft. Selection of the length of spine to be instrumented, control for head decompensation, trunk shift and pelvic obliquity are other problems. But taking all things into consideration, we think that L-S. S. I. is a useful method for neuromuscular scoliosis.

Cervical Discography has been performed on 5 cases of traumatic myelopathy. These cases have no fracture, dislocation and disc degeneration in X-P. All of them have negative myelogram.In discography contrast medium leaked into the spinal canal and all patients complained of nape pain, arm pain, when disc was injected.In two patients the pain spread downward into abdomen and extremities.All of them were performed anterior body fusion of cervical spine, neurological recovery were excellent.

The purposes of surgical treatment for fracture-dislocations of cervical spine are stabilization of cervical spine and the expectation of recovery of neurological functions. We prefer the anterior interbody fusion for these cases after pre-operative reduction of cervical spine achieved by means of skull traction. However, in old cases it is very difficult to reduce the injured spine by means of skull traction. In addition, because of neck pain, restriction of mobility of cervical spine and possibility of delayed myelopathy it is desired to do anterior interbody fusion in reduced position.We have treated 7 cases of such old fracture-dislocations of middle or lower cervical spine. All cases had neck pain, restriction of mobility of cervical spine and mild neuological symptoms. We performed anterior interbody fusion in these 7 cases and the results were excellent.

This is a report on four cases of delayed myelopathy following compression fractures of the thoraco-lumbar spine. Cases 1, 2, and 3 developed myelopathy in a relatively short period of time of 6, 2 and 3 months following the fractures respectively. Although these three cases showed stable fractures on radiographs immediately after the injury, there were bulging features on the posterior margin of the vertebral body. Correction of kyphotic deformity, decompression and anterior fusion were indicated for the cases with destruction of anterior stabilizing mechanism. We obtained excellent result in these three cases through this method. Case 4. showed compression myelopathy caused by ossification of yellow ligament (OYL) with occurred at the site of compression fracture. In this case, the kyphotic deformity after fracture secondarily caused the neurological symptoms due to OYL.

A report is made in 6 cases of thoracic spondylotic myelopathy. Their age ranges from 28 years to 68 years old. Of them two cases are male and 4 are female. Generally the site of this disease is said to be most frequent at the lower thoracic vertebra, but this myelopathy can be also observed in the upper thoracic vertebra. As for the clinical symptoms sensory disturbances of the legs, disturbances of movement, and rectovesical disturbances can be pointed out, that gradually progress in some cases, while in others this myelopathy is induced by sternomutator or by fall, that aggravates by degree. X-ray picture reveal the narrowing of the inervertebral disc space, the calcification of inervetebral disc and sclerosis of the posterior margin of vertebral body in some cases, but these changes seem to be aging phenomena, that cannot at once be concsidered necessarily as the direct cause of myelopathy. There are cases where no abnomality of humoral findings, that symptoms are not always consistent. At the present stage myeography is most useful for the diagnosis. As long as the case be definititly diagnosed as myelopathy due to the disturbance of intervertebral disc, anterior decompression proves to be most rational, but there are cases difficult of diagnosis. We have performed laminectomy in five cases and obtained favorable results in all of them.

144 cases of cervical myelopathy (123 spondylotic, 21 traumatic) and 23 cases of incomplete cervical spinal cord injury without vertebral fracture and/or dislocation were surgically treated and followed for more than one year. 137 cases were treated by anterior interbody fusion and the remaining cases by laminectomy. The indications for these procedures were outlined. Successful operative results were obtained in 86 per cent of cervical myelopathy cases and 52 per cent of spinal cord injury cases. In contrast with the former cases the rate of recovery in the latter was markedly lowered as the duration of the disease became prolonged.These facts suggest that the rate of postoperative recovery in the spinal cord injury refflects the natural course of recovery rather than the effect of surgery, and that the existence of trauma history to the cervical spine does not have so much influence on the rate of recovery in cervical myelopathy as in spinal cord injury.

Seventy three patients with upper cervical spine injuries are reviewed. These 73 consisted of 2 atlanto-occipital dislocations, 8 fractures of atlas, 17 hangman's fractures, 33 fractures of dens, 6 fractures of axis-body and 10 atlantoaxial subluxations. Five cases of them had died when carried to our clinic.In acute stage most of them showed occipitalgia, nape pain, knock pain on C2 spinous process and limitation of neck movement. In some cases we could observe occipital neuralgia, hypelgesia or hypesthesia which were considered of upper cervical root symptomes. Twenty six of them showed cervical cord symptomes.In acute stage most of them were treated conservatively. Some cases of hangman's fractures, old fractures of dens and atlantoaxial subluxations needed operative procedures.

25 cases out of about 270 cervical cord injuries are found in our clinic. Ossification patterns can be divided in to hyperostotic type (17 cases) and spondylotic type (8 cases) clinically. Inducing force is weaker than other cervical cord injury. Injuried level is often at disc level especially in spondylotic type. Prognosis is related to inducing force, ossification type and narrowing rate.Histology shows compressed and degenerated cord. So, we have not done the early decompressive laminectomy because of further damage to fragile cord by operation. But, we think that anterior spinal fusion is sometime indicated. Anterior spinal fusion should be done in the cases with myelographic interruption at the disc level.

To study the influence of anterior body fusion on the adjacent vertebral discs, the radiographs of 101 patients with cervical spondylotic myelopathy (CSM) were analysed, and cervical mobility and intersegmental mobility were determined. Single level fusions were carried out in 29 patients, double level fusions in 45 patients and triple level fusions in 27 patients. Cervical mobility after surgery was inversely proportional to the number of fused discs. Angles were reduced by fusion in proportion to the number of fused discs. The compensatory increase in motion at the disc adjacent to the fusion was slight, and the number of fused discs had little influence on the compensatory increase in motion. Regarding cervical motion, extension and flexion were limited to the same extent in single level fusions, flexion was more limited in double level fusions and limitation of extension was much larger in triple level fusions. Seven patients underwent a second operation after a double level fusion, and one patient underwent a second operation after a single level fusion. In all five patients whose radiographs before the second operation were available, flexion was adequately limited, but extension was not limited at all. These results suggest that the failure to limit extension is responsible for the recurrence of CSM.

Operative treatment was performed in nine patients with cervical spondylotic myelopathy complicating athetoid cerebral palsy. The first two patients were treated by laminectomy, and the other seven by anterior interbody fusion. The symptoms in both the laminectomy patients improved after operation, but became worse again when cervical instability developed; they then had to have an anterior fusion in addition. In six of the seven patients who had primary anterior fusion a halo-cast (or a halo-vest) was used to keep the cervical spine immobile, and good bony fusion was obtained with satisfactory results. However, in one patient no halo apparatus was used, bony union did not occur and the radiculopathy reappeared. In cervical myelopathy complicating athetoid cerebral palsy laminectomy is contra-indicated; anterior fusion combined with a halo apparatus is, however, satisfactory.