Kazuo Saita

Posterior Spinal Shortening for Paraplegia After Vertebral Collapse Caused by Osteoporosis

Study Design. Case report of a patient who underwent a new surgical procedure for paraplegia after vertebral collapse due to osteoporosis. Objectives. To propose a new approach to posterior spinal fusion surgery for osteoporotic patients. Summary of Background Data. Surgical treatment was performed on a paraplegic patient after vertebral collapse due to osteoporosis. However, the surgery was difficult because implants such as hooks and screws often dislodged during the treatment. The poor holding power of these implants to the osteoporotic spine is a challenging problem in this treatment. Methods. When a fractured vertebra is shortened by resecting the posterior part of the spine and the application of a compression force, a short vertebra is produced. As a result, the thoracic kyphosis decreases and the force pushing the upper thoracic spine inferio-ventrally also decreases. Results. A 74-year-old woman with T12 vertebral collapse was treated with this new method. Lateral Cobb angle (T10–L2) was reduced from 26 to 4° after surgery. The shortened vertebral body united, and after 33 months, the implant had not dislodged and no loss of correction was seen. Conclusion. The posterior spinal shortening can be a choice for treating delayed paraplegia after osteoporotic vertebral fracture.

Incidence and risk factors for mortality of vertebral osteomyelitis: a retrospective analysis using the Japanese diagnosis procedure combination database

Objective To examine the incidence of vertebral osteomyelitis (VO) and the clinical features of VO focusing on risk factors for death using a Japanese nationwide administrative database. Design Retrospective observational study. Setting Hospitals adopting the Diagnosis Procedure Combination system during 2007–2010. Participants We identified 7118 patients who were diagnosed with VO (International Classification of Diseases, 10th Revision codes: A18.0, M46.4, M46.5, M46.8, M46.9, M48.9 and M49.3, checked with the detailed diagnoses in each case and all other codes indicating the presence of a specific infection) and hospitalised between July and December, 2007–2010, using the Japanese Diagnosis Procedure Combination database. Main outcome measures The annual incidence of VO was estimated. Logistic regression analysis was performed to analyse factors affecting in-hospital mortality in the VO patients. Dependent variables included patient characteristics (age, sex and comorbidities), procedures (haemodialysis and surgery) and hospital factors (type of hospital and hospital volume). Results Overall, 58.9% of eligible patients were men and the average age was 69.2 years. The estimated incidence of VO increased from 5.3/100 000 population per year in 2007 to 7.4/100 000 population per year in 2010. In-hospital mortality was 6%. There was a linear trend between higher rates of in-hospital mortality and greater age. A higher rate of in-hospital mortality was significantly associated with haemodialysis use (ORs, 10.56 (95% CI 8.12 to 13.74)), diabetes (2.37 (1.89 to 2.98)), liver cirrhosis (2.63 (1.49 to 4.63)), malignancy (2.68, (2.10 to 3.42)) and infective endocarditis (3.19 (1.80 to 5.65)). Conclusions Our study demonstrates an increasing incidence of VO, and defines risk factors for death with a nationwide database. Several comorbidities were significantly associated with higher rates of in-hospital death in VO patients.

A report on the safety of unilateral vertebral artery ligation during cervical spine surgery.

Study Design This study retrospectively analyzed the outcome of unilateral vertebral artery ligation during cervical spine surgery. Objectives To examine the influence of unilateral vertebral artery ligation on the function of brain and spinal cord. Summary of Background Data There was little published information about the outcome of a vertebral artery ligation except for several reports from the field of neurosurgery. Methods Unilateral vertebral artery ligation was used in 15 patients with cervical tumors of the spine or the spinal cord (age range, 13-71 years; nine male patients and six female). The authors ligated the involved vertebral artery only when the tumor appeared on the minor or equal diameter artery side measured by preoperative angiogram. The patients condition was examined regarding signs of dysfunction of the brain stem, the cerebellum, or the spinal cord. Results Preoperative angiogram showed that the involved vertebral artery had a smaller diameter in four patients and had an equal diameter in 11 patients compared with the one not involved. The involved vertebral artery was severed at single site in four patients and was resected between two distant sites of ligation in 11 patients. Examination after surgery of the patients condition (follow-up periods ranged from 10 months to 7 years) revealed that unilateral vertebral artery ligation did not provoke any symptoms of damage resulting from ischemia of the brain stem, the cerebellum, or the spinal cord. Conclusion A vertebral artery could be ligated uneventfully when the diameter of the vertebral artery was not larger than the one not involved. Where vertebral artery ligation could not be avoided, it should be confirmed by preoperative angiogram that the other vertebral artery is large enough and that simultaneous occlusion testing of the involved vertebral artery is uneventful.

Expansive cervical laminoplasties – observations on comparative changes in spinous process lengths following longitudinal laminal divisions using autogenous bone or hydroxyapatite spacers

Expansive laminoplasty is devised to preserve the posterior structures, including the original length of the spinous process which anchors the nucheal muscles, in order to prevent the postoperative development of instability and cervical kyphosis due to structural loss and poor tone of the nucheal muscles, which can result in late neurological regression after laminectomy for cervical myelopathy.We retrospectively compared the length of the spinous process at the time of follow-up with that within 3 months postoperatively using CT images. The shortening was observed in 80% of 60 spinous processes in 13 patients, where a hydroxyapatite (HA) block was used as a spacer placed between the two sides of the split spinous process. The incidence was 9% of 22 spinous processes in six patients where auto bone graft (ABG) was used as a spacer, and the difference was significant (P<0.01, Chi-square test).Although the usage of HA has the advantage of being less invasive than ABG, it may jeopardize the biomechanical function of nucheal muscles due to reduction in the original length of the spinous process.

Removal of enterogenous cyst of the cervical spine through anterior approach.

Enterogenous cyst is a cause of spinal cord compression. The cyst has been treated surgically through a posterior approach in spite of the location ventral to the spinal cord. We saw two patients who had recurrence at 1 and 3 years after partial removal through this approach. We removed the cyst at the level of the cervical spine in four patients totally or subtotally through an anterior approach. All patients improved neurologically, and there were no signs or symptoms of recurrence at follow-up of from 2 to 13 years (average, 7 years 3 months). It is reasonable to approach the cyst located ventrally to the spinal cord through the anterior route, where the relationship between the cyst wall and the spinal cord can be viewed directly.

Bone Mineral Density in Patients With Ossification of the Posterior Longitudinal Ligament: Minimal Decrease of Bone Mineral Density With Aging

Study Design. Bone mineral density of individuals with ossification of the posterior longitudinal ligament and that of normal people was determined by dual‐energy x‐ray absorptiometry. Objectives. To determine whether bone mineral density in the people with ossification of the posterior longitudinal ligament is higher than that in normal individuals even in body parts other than the spine, and to evaluate the relation between bone mineral density and age in patients with ossification of the posterior longitudinal ligament. Summary of Background Data. It is unknown whether the bone mineral density of patients with ossification of the posterior longitudinal ligament is greater in body parts other than the spine. If so, it provides a basis for the theory that certain systemic factors are involved in the pathogenesis of ossification of the posterior longitudinal ligament. Because bone mineral density decreases physiologically after middle age, the influence of age must be considered in evaluating bone mineral density. Methods. In the rib area and upper and lower limb areas, which are not affected by ossification of the spinal ligament, bone mineral density of 45 men with ossification of the posterior longitudinal ligament of the cervical spine was compared with that of 25 men without ossification of the posterior longitudinal ligament (normal group). Results. Bone mineral density was higher in the group with ossification of the posterior longitudinal ligament in each part and significantly higher in the rib and lower limb areas (rib: P < 0.01, lower limb: P < 0.05). The age‐related decrease was significantly less in the group with ossification of the posterior longitudinal ligament (rib: P < 0.01, upper limb: P < 0.05, lower limb: P < 0.01). Conclusions. Systemic factors that increase bone mineral density appear to be involved in the pathogenesis of ossification of the posterior longitudinal ligament, and these factors may be activated after middle age.

Regional difference in the appearance of apoptotic cell death in the ligamentum flavum of the human cervical spine.

Ossification or calcification of the ligamentum flavum (LF) is relatively common in the middle and lower cervical, thoracic, and lumbar spine but extremely rare in the upper cervical region. This clinical fact suggests that there exist local factors promoting or preventing ossification or calcification of LF. However, little is known about the differences in the ultrastructure and cellular alterations of the LF between the different spinal levels, even in the cervical spine. With electron microscopy, we examined samples of LF collected surgically from the upper and lower cervical spine regions; we then studied the apoptotic appearance of ligament cells using a preferential labeling method. We found direct evidence of apoptosis of ligament cells in the LF. Apoptosis was more apparent in the upper region samples than in the lower region samples. The spaces around the normal fibroblasts were filled with thick collagen fibrils, but the collagen fibrils disappeared around the apoptotic bodies and thin fibrils were formed. The difference of the level of apoptosis may correlate to the ultrastructual difference of LF, and our data will benefit further investigations seeking to clarify the mechanism of various pathological conditions in the human LF.

Risk factors for incidental durotomy during posterior open spine surgery for degenerative diseases in adults: A multicenter observational study

Incidental durotomy (ID) is a common intraoperative complication of spine surgery. It can lead to persistent cerebrospinal fluid leakage, which may cause serious complications, including severe headache, pseudomeningocele formation, nerve root entrapment, and intracranial hemorrhage. As a result, it contributes to higher healthcare costs and poor patient outcomes. The purpose of this study was to clarify the independent risk factors that can cause ID during posterior open spine surgery for degenerative diseases in adults. We conducted a prospective multicenter study of adult patients who underwent posterior open spine surgery for degenerative diseases at 10 participating hospitals from July 2010 to June 2013. A total of 4,652 consecutive patients were enrolled. We evaluated potential risk factors, including age, sex, body mass index, American Society of Anesthesiologists physical status classification, the presence of diabetes mellitus, the use of hemodialysis, smoking status, steroid intake, location of the surgery, type of operative procedure, and past surgical history in the operated area. A multivariate logistic regression analysis was performed to identify the risk factors associated with ID. The incidence of ID was 8.2% (380/4,652). Corrective vertebral osteotomy and revision surgery were identified as independent risk factors for ID, while cervical surgery and discectomy were identified as factors that independently protected against ID during posterior open spine surgery for degenerative diseases in adults. Therefore, we identified 2 independent risk factors for and 2 protective factors against ID. These results may contribute to making surgeons aware of the risk factors for ID and can be used to counsel patients on the risks and complications associated with open spine surgery.

An Unusual Presentation of Adult Tethered Cord Syndrome Associated with Severe Chest and Upper Back Pain

Adult tethered cord syndrome (ATCS) is a rare entity that usually presents with multiple neurological symptoms, including lower extremity pain, backache, lower extremity muscle weakness, and bowel/bladder disturbances. Prompt surgical treatment is often necessary to avoid permanent sequelae. We report a 63-year-old man with sudden-onset severe right chest and upper back pain, followed by urinary retention. His initial workup included computed tomography of the abdomen and pelvis, which showed a presacral mass. His symptom-driven neurological workup focused on the cervical and thoracic spine, the results of which were normal. Pelvic radiographs and magnetic resonance imaging of the lumbosacral spine showed spina bifida occulta, meningocele, and presacral masses consistent with a teratomatous tumor. His symptoms, except for urinary retention, improved dramatically with surgical treatment. The excised specimen contained a teratomatous lesion plus an organized hematoma. Hematoma formation was suspected as the trigger of his sudden-onset right chest and upper back pain.

Patella dislocation following distal femoral replacement after bone tumour resection.

We report the case of a 16-year-old girl with patella dislocation following distal femur replacement for a malignant tumour. We performed a medial plication and lateral release procedure to treat her persistent patellar dislocation after distal femur replacement following malignant tumour resection. This treatment improved the patients gait ability dramatically. A distal femur reconstruction with a total knee arthroplasty (TKA) system for tumour resection is a frequently performed procedure. The reported incidence of patella dislocation following distal femur reconstruction with a TKA is 2.3%. However, treatment procedures for patella dislocation following a distal femur replacement after malignant tumour resection have not been studied extensively. To the best of our knowledge, this is the first English case report about patella dislocation following distal femoral replacement focusing on surgical treatment. Our experience suggests that treatment for patella dislocation following distal femur reconstruction with a TKA should be considered positively.