Eiji Kawakita

A New Evaluation Method for Lumbar Spinal Instability: Passive Lumbar Extension Test

Background and Purpose. Although many studies have described clinical examination measures for the diagnosis of lumbar spinal instability, few of them have investigated the sensitivity and specificity of the measures that were used. The authors devised a passive lumbar extension (PLE) test for assessing lumbar spinal instability. The purpose of this study was to investigate the sensitivity, specificity, and positive likelihood ratio of this test. Subjects and Methods. The PLE test as well as the instability catch sign, painful catch sign, and apprehension sign tests were done for 122 subjects with lumbar degenerative diseases. The subjects were divided into 2 groups—instability positive and instability negative—on the basis of findings on flexion-extension films of the lumbar spine. The sensitivity, specificity, predictive values, and positive likelihood ratio of each test were investigated. Results. The sensitivity and specificity of the PLE test were 84.2% and 90.4%, respectively. These values were higher than those of other signs. The positive likelihood ratio of the PLE test was 8.84 (95% confidence interval=4.51–17.33). Discussion and Conclusion. The PLE test is an effective method for examining patients for lumbar spinal instability and can be performed easily in an outpatient clinic.

Thoracic myelopathy with alkaptonuria.

Study Design. A case of thoracic myelopathy with alkaptonuria (ochronotic spondyloarthropathy) is presented. Objective. To present and review the first reported case of an alkaptonuric patient with concomitant thoracic myelopathy. Summary of Background Data. Alkaptonuria, a rare hereditary metabolic disease, is characterized by accumulation of homogentistic acid, ochronosis, and destruction of connective tissue resulting in degenerative spondylosis and arthritis. Despite the high incidence of intervertebral disc diseases among patients with alkaptonuria, neurologic symptoms caused by spinal disease are rare. Thoracic myelopathy in a patient with alkaptonuria has not been previously reported. Methods. The clinical course, radiologic features, pathology, and treatment outcome of an alkaptonuria patient with thoracic myelopathy was documented. Results. Myelopathy of the patient was caused by rupture of a thoracic intervertebral disc. The neurologic symptoms of the patient were markedly improved after surgery. Conclusion. We have reported for the first time, that an alkaptonuria patient showed thoracic myelopathy caused by rupture of a thoracic intervertebral disc. Decompression followed by the instrumented fusion of the thoracic spine was effective for improving the neurologic symptoms.

Cordectomy for post-traumatic syringomyelia

SummaryWe performed cordectomy, a surgical technique that is infrequently used at present, for a patient with post-traumatic syringomyelia (following complete paraplegia of both lower limbs due to dislocation fracture of the 9th thoracic vertebra), yielding a favourable result. We recommend cordectomy as a surgical technique to which spinal surgeons should give utmost consideration for patients with post-traumatic syringomyelia demonstrating progressive symptoms assumed to be attributable to the syrinx and with an anatomically transected spinal cord of the mid-to-lower thoracic vertebral level.

Direction of the formation of anterior lumbar vertebral osteophytes

BackgroundX-ray images of lumbar degenerative diseases often show not only claw osteophytes, but also pairs of osteophytes that form in a direction away from the adjacent disc. We have investigated the direction of the formation of anterior lumbar vertebral osteophytes across the lumbar vertebrae using a sufficient number of lumbar radiographs, because osteophytes images can provide essential information that will contribute to the understanding of the pathology and progress of lumbar spine degeneration.MethodsThe direction of the formation of 14,250 pairs of anterior lumbar vertebral osteophytes across the adjacent intervertebral discs in 2,850 patients who were all over 60 years old was investigated. Anterior lumbar vertebral osteophytes were distributed into six groups based on the direction of extension of each pair of osteophytes across the intervertebral disc space.ResultsIn L1–L2 and L2–L3, the number of patients classified into groups B (the pair of osteophytes extended in the direction of the adjacent disc) and C (almost complete bone bridge formation by a pair of osteophytes across the intervertebral disc space) was larger than that classified into group D (the pair of osteophytes extended in a direction away from the adjacent disc). In L3–L4, L4–L5 and L5-S1, the number of patients in group D was greater than that of patients belonging to groups B and C.ConclusionOur study showed that pairs of osteophytes frequently formed in the direction of the adjacent disc in the upper lumbar vertebrae (L1–L2 and L2–L3) and in the direction away from the adjacent disc in middle or lower lumbar vertebrae (L3–L4, L4–L5, and L5-S1).

Primary Ewing sarcoma of the spine mimicking a psoas abscess secondary to spinal infection.

Study Design. A case of primary Ewing sarcoma of the lumbar spine is presented. Objective. To present and review a rare case of primary Ewing sarcoma of the lumbar spine that required differentiation from spinal infection. Summary of Background Data. Primary Ewing sarcoma originating from the spinal column is very rare. Because Ewing sarcoma is one of the most aggressive bone tumors with high proliferative and invasive potential, its clinical symptoms and variety of imaging manifestations can mimic the pathologic findings of other diseases, including infectious diseases. Methods. The clinical course, radiologic features, pathology and treatment outcome of a patient with primary Ewing sarcoma of the lumbar spine was documented. Results. The magnetic resonance imaging findings showed an abnormal marrow signal at the L2 vertebra and significant enlargement of the unilateral iliopsoas muscle. Immunologic and molecular analysis of the surgical specimen provided a diagnosis of Ewing sarcoma. Laminotomy followed by multidisciplinary therapy including chemotherapy and radiation therapy was effective for treating this case. Conclusion. We report a case of Ewing sarcoma that mimicked a psoas abscess secondary to spinal infection. Abnormal magnetic resonance imaging images, as well as a confusing clinical course, made diagnosis difficult. When enlargement of the iliopsoas with a vertebral lesion is detected in a child with low back pain, Ewing sarcoma should be included in the differential diagnosis.

Basic Research on a Cylindrical Implant Made of Shape-Memory Alloy for the Treatment of Long Bone Fracture

The internal fixing materials made from shape-memory alloys (SMAs) have recently been reported for long bone fracture. We present a new internal fixation technique using a cylindrical SMAs implant in a rat femoral fracture healing. The implant was designed in a shape to circumferentially fix the fractured bone using resilient SMA claws. To evaluate the fixing ability of the implant, three-point bending and rotation tests were performed. Fifteen female Wister rats were treated surgically as an experimental model. All rats were killed at 16 weeks postoperatively, and the radiological and histological evaluations were performed. In biomechanical test, the good fixation ability of the implant was demonstrated. In animal model, no cases of postoperative infection or death were encountered and postoperative gait was stable in all cases. Radiological examination at 16 weeks postoperatively demonstrated the implant firmly fixed to the fractured part, endosteal healing, and no callus formation in all cases. In Histological evaluation, bone union in all cases was characterized by endochondral ossification from within the medullary cavity. In conclusion, our cylindrical SMA implant provided good fixation in biomechanical tests, and achieved bone union in all 15 rats. If a larger size is designed in the future, our implant will be a clinically applicable, useful fixing material for fracture of the human long bones.

Low back pain and cervical spondylotic myelopathy

Purpose. To determine characteristics responsible for improvement of low back pain after cervical laminoplasty for cervical spondylotic myelopathy. Methods. 18 men and 10 women aged 38 to 88 (mean, 71) years who had a low back pain visual analogue scale (VAS) score of 5 or more before cervical laminoplasty were included. In 12 patients the VAS score improved to ≤1 after surgery and remained so at 2 years, but in 16 it remained unimproved. Patient characteristics of the 2 groups were compared. Results. Preoperatively 11 of the 12 patients with improved VAS score had continuous low back pain all day, compared to 3 of the 16 who remained unimproved (p<0.01). Conclusion. In some patients, low back pain may be improved following cervical laminoplasty.

Clinical profile of long-term survivors of breast or thyroid cancer with metastatic spinal tumours

Patients with breast or thyroid cancer with metastatic spinal tumours are expected to survive relatively longer than patients with other cancers with metastatic spinal tumours. The purpose of this study was to determine the clinical characteristics of long-term survivors of breast or thyroid cancer with metastatic spinal tumours. We studied the clinical profile of long-term survivors by comparing the characteristics of nine patients who had survived for at least 5 years after a spinal operation with the characteristics of 16 patients who had not. Our results showed that the longer the time from the diagnosis of the primary cancer to the spinal operation, the longer patients with breast or thyroid cancer and metastatic spinal tumours would survive. Six of the eight patients (75.0%) who had undergone the spinal operation at least 5 years after the diagnosis of the primary cancer survived especially long. In conclusion, the duration from the diagnosis of the primary cancer to the spinal operation is very useful for predicting a prognosis in patients with breast or thyroid cancer and metastatic spinal tumours.

Intraosseous lipoma of the third lumbar spine: a case report

IntroductionIntraosseous lipoma is a benign bone tumor, and the tumor occurs more frequently in the lower extremities. We present a very rare case of intraosseous lipoma occurring in the lumbar vertebral arch and spinous process.Case presentationA 54-year-old Japanese man presented with a three-month history of lumbar pain. Magnetic resonance imaging of the L3 vertebral arch and spinous process revealed high intensity on T1- and T2-weighted imaging, and it was suppressed on fat-suppression imaging and no enhancement showed on gadolinium contrast-enhanced imaging. Computed tomography imaging revealed an osteolytic change accompanied by marginal osteosclerosis in his third lumbar vertebral arch and spinous process, as well as a thinned and bulging bone cortex. An analgesic had been administered prior to his visit, but low back pain had persisted, so we performed curettage and filled the defect with hydroxyapatite bone. His low back pain was improved immediately after surgery, and no recurrence of tumor has been observed on computed tomography imaging as of three years postoperatively.ConclusionsSymptomatic intraosseous lipoma of spine is very rare, but the patient may be surgically well-treated by curettage and reconstruction of the benign tumor.

Suicide during hospitalization in patients with spinal disease

Study Design. A retrospective study. Objective. To examine the frequency and current status of the incidence of deaths by suicide of patients with spinal diseases during hospitalization. Summary of Background Data. It was reported that most cases of deaths by suicide during hospitalization were patients admitted to the psychiatric ward. There were no reports to the incidence of death by suicide during hospitalization in patients with spinal diseases. Methods. Of 69,861 patients admitted to the Department of Orthopedics of 28 affiliated hospitals of our university between September 1997 and August 2002, 14,987 patients with spinal diseases were targeted for this study. We examined the number of deaths by suicide during hospitalization. Results. Of the 14,987 patients with spinal diseases, there were 5 deaths (0.03%) by suicide during hospitalization. There were no deaths by suicide in 54,874 patients with orthopedic diseases other than spinal diseases. Conclusion. In the treatment of patients with spinal diseases, it seemed important for spinal surgeons to provide comprehensive treatment for the whole patient by paying attention to the relationship between a patient and a physician, in particular, by carefully observing the psychologic status of a patient.