Biomedical subjects

Yohei Yuzawa

Publications and source records attributed to Yohei Yuzawa.

8 recordsLinked to original sources

PubMed2006

Posterior correction and fusion for severe cervical kyphosis in a patient with myotonic dystrophy: a case report.

STUDY DESIGN: A case report. OBJECTIVE: To report the first myotonic dystrophy case in which cervical kyphosis had been surgically corrected. SUMMARY OF BACKGROUND DATA: Myotonic dystrophy is an autosomal dominant disease that shows myotonia, progressive muscle atrophy, and other various symptoms. Instability of the neck is expected to cause disorders of the cervical spine; however, there are no detailed reports on deformity of cervical spine associated with this disease. METHODS: A 43-year-old man with cervical kyphosis due to myotonic dystrophy had undergone an occiput-T2 fusion with autogenous iliac bone using spinal instrumentation. RESULTS: The activity of daily life of the patient had improved markedly, and the good results continued to be preserved for 5 years. There were not any major perioperative complications. CONCLUSIONS: Surgical correction of cervical spine is not necessarily a contraindication for myotonic dystrophy.

Adult↗

PubMed2005

Magnetic resonance and computed tomography-based scoring system for the differential diagnosis of vertebral fractures caused by osteoporosis and malignant tumors.

BACKGROUND: Previous reports have described magnetic resonance imaging (MRI) findings alleged to be specific for vertebral fractures caused by malignant lesions. Using such findings for differential diagnosis is often difficult, especially during the early phase of the fracture. With the relative inaccuracy of any single imaging finding, a validated scoring system based on a combination of imaging findings might lead to enhanced diagnostic accuracy. The purpose of this study was to establish a diagnostic scoring system for discriminating osteoporotic vertebral fractures from those caused by malignant tumors on the basis of MRI and computed tomography (CT) findings. METHODS: Ten MRI and CT scan findings of 57 osteoporotic vertebral fractures and 43 neoplastic fractures were retrospectively evaluated for their ability to discriminate between malignant and benign vertebral fractures. RESULTS: The following four MRI and two CT findings were selected as the basis for the scoring system: pedicle or other posterior element involvement; extension into the paravertebral region; preservation of normal bone marrow signal; a continuous black line representing the posterior vertebral body margin on T2-weighted MRI images; osteolytic destruction; and distinct fracture lines on CT. CONCLUSION: By combining the findings common to MRI and CT scans of vertebral fractures, a simple scoring system was devised. This scoring system was found to enhance the accuracy of imaging diagnosis of fractures caused by benign or malignant spinal lesions.

Adult↗

PubMed2005

Surgical treatment with instrumentation for severely destructive spondyloarthropathy of cervical spine.

Nine patients with severely destructive spondyloarthropathy and marked neurologic deficits associated with dialysis-related amyloidosis underwent posterior decompression and fusion by means of instrumentation at our institute. All patients showed segmental kyphosis, six patients vertebral ankylosis, and eight patients spondylolisthesis. Spondylolisthesis at two levels was noted in three patients. Of the 11 levels of spondylolisthesis in all, 9 were proximally adjacent and 2 were distally adjacent to vertebral ankylosis. All patients underwent posterior decompression and multisegment fusion with autogenous iliac bone. From three to five spinal segments were fixed. Seven patients underwent posterior fusion by means of a pedicle or lateral mass screw between levels C3 and C7, one patient between C3 and C6, and one between C3 and T1. The clinical rate of improvement at the final follow-up was 74.3%. Though complete stability could not be achieved in three patients, the results were rated as good. No postoperative neurologic deterioration has been observed in this series, nor did any patients die immediately after surgery or during the postoperative follow-up period. As anterior long-span surgery might be too invasive for hemodialysis patients, we think that posterior decompression and fusion may well be a reasonable and effective strategy for severe hemodialysis-associated cervical spondyloarthropathy with neurologic deficits. To achieve complete stability, 360 degrees fusion with both anterior and posterior fixation with instrumentation may be required for these patients.

Aged↗

PubMed2005

Neurogenic bladder in patients with cervical compressive myelopathy.

We examined the urinary disturbances in 56 consecutive patients with cervical compressive myelopathy using the latest International Continence Society classification. Of the 56 patients with cervical compressive myelopathy, 29 (52%) had some urinary subjective complaints, whereas the remaining 27 (48%) had none. Urologic examination indicated that 8 of these 29 (28%) patients with urinary complaints had urologic disorders other than neurogenic bladder. Of the remaining 21 patients, only 6 (25%) were judged to have neurogenic bladder on urodynamic study. Urodynamic study may be of limited value in diagnosing urinary disturbance in cervical myelopathy. Further, four cases (83%) showed underactive bladder activity in voiding phase, and only one case (17%) showed overactive bladder activity in filling phase. These results were contrary to those of previous studies indicating that cervical compressive myelopathy is associated with overactive bladder activity in filling phase. There were no significant differences in motor or sensory Japanese Orthopedic Association scores between the patients with and without urinary complaints. However, the patients with urinary complaints had significantly longer durations of myelopathy and delayed motor evoked potential latencies than those without urinary complaints. After surgery, 19 of the 21 (90%) patients with urinary complaints showed recovery from urinary disturbance. Operations in patients with cervical myelopathy were also effective against urinary disturbance. Urinary complaints may be an indication for surgical treatment despite the results of urodynamic study.

Cervical Vertebrae↗

PubMed2004

[Vertebroplasty].

Vertebroplasty for pseudoartrosis of vertebral fracture using PMMA (polymethylmetacrylate) or CPC (calcium phosphate cement) is a new less invasive surgical method providing sufficient pain relief and correction of kyphosis.

Calcium Phosphates↗

PubMed2003

Clinical outcome and survival after palliative surgery for spinal metastases: palliative surgery in spinal metastases.

BACKGROUND: The authors sought to identify treatment-related factors that influenced survival after surgical treatment for metastatic spinal tumors and to evaluate the relationship between survival and postoperative ambulation time as a factor related to quality of life. METHODS: The medical records of 81 patients with metastatic spinal tumors who underwent palliative surgery at the study institution were assessed. Univariate analysis for factors influencing survival used the Kaplan-Meier log rank statistic and multivariate analysis used the Cox proportional hazards model. The Spearman correlation test was used to analyze the relationship between postoperative ambulation and survival time. RESULTS: The patients had a median age of 59.9 years and a median survival of 10.6 months after surgery. For patients, postoperative ambulatory median survival was 16.5 months and median ambulation time was 13.8 months. By univariate analysis, anatomic site of the primary tumor, postoperative ambulation, and combined adjuvant therapy (chemotherapy plus radiotherapy) were associated with prolonged survival (P < 0.05). Multivariate analysis identified primary site and postoperative ambulatory function as independent predictors of prolonged survival (P < 0.0001). Significant correlations were found between ambulation time and survival time of patients who were able to walk after surgery (P < 0.0001), even in patients with liver (P < 0.05) or lung carcinoma (P < 0.05). CONCLUSIONS: The anatomic site of primary carcinoma and postoperative ambulation were associated with longer survival after palliative surgery for metastatic spinal tumor. When ambulation is attained after surgery, it can be preserved until late in remaining life even when the primary tumor is unfavorable. Palliative surgery for spinal metastasis can improve the quality and quantity of life.

Early Ambulation↗

PubMed2003

Multilevel subtotal corpectomy and interbody fusion using a fibular bone graft for cervical myelopathy due to ossification of the posterior longitudinal ligament.

A retrospective study of the outcomes of multilevel anterior decompression and interbody fusion for cervical myelopathy due to ossification of the posterior longitudinal ligament (OPLL) was performed to both investigate the long-term results and assess the cause of late deterioration. Twenty-seven patients (mean age, 58.1 years) underwent this procedure and were followed for at least 5 years. The severity of the clinical symptoms was described using the scoring system for cervical myelopathy proposed by the Japanese Orthopaedic Association (JOA score). The average preoperative JOA score was 7.7, and the score at final follow-up was 13.4 with a recovery rate of 62.0%. A delayed deterioration was attributed to a thoracolumbar lesion other than a compromising alteration of the cervical spine. Consequently, this method of treatment for OPLL could stop the progress of ossification and keep a physiological cervical alignment and thus provide good long-term results.

Adult↗

PubMed2002

Preoperative CT examination for accurate and safe anterior spinal instrumentation surgery with endoscopic approach.

The purpose of this article is to introduce a new procedure for the surgical planning of thoracic anterior spinal instrumentation via endoscopy. For accurate and safe anterior screw insertion via the endoscopic approach, we devised a surgical plan based on the preoperative chest computed tomography (CT) findings obtained with radiographic markers. Using this method, we performed endoscopic thoracic spinal instrumentation surgery in 14 patients. Nine patients underwent anterior endoscopic correction and fusion of idiopathic scoliosis by Cotrel-Dubousset instrumentation, and five patients underwent anterior endoscopic spinal fixation with instrumentation. The accuracy of screw insertion was evaluated postoperatively by CT scanning. One interbody fusion cage and 53 screws were inserted in the 14 patients using endoscopy. Postoperative CT scans revealed that the screws were all accurately inserted without any neurologic complications. In conclusion, using this novel procedure for surgical planning based on CT findings obtained with radiographic markers, anterior screws can be inserted safely and accurately via an endoscopic approach.

Adolescent↗