Biomedical subjects

Sadahiko Konishi

Publications and source records attributed to Sadahiko Konishi.

10 recordsLinked to original sources

PubMed2006

Endoscopic vertebroplasty for the treatment of chronic vertebral compression fracture. Technical note.

The authors describe a new vertebroplasty technique for the treatment of chronic painful vertebral compression fractures (VCFs). A urinary balloon catheter is introduced into the vertebral body (VB) via a bilateral transpedicular approach and inflated with contrast medium to obtain sufficient space for endoscopic observation. The granulation tissue occupying the VB is then removed using a punch or curette inserted through one pedicle, with the guidance of an endoscope introduced through the contralateral pedicle. After endoscopic resection of granulation tissue in the fractured VB, vertebroplasty is performed by injecting calcium phosphate cement (CPC) into the VB. Fourteen patients in whom chronic painful VCFs were diagnosed underwent surgery involving the aforementioned technique. In all cases, intractable pain and ambulatory function improved after surgery, and there were no significant systemic complications. On radiological evaluation in eight cases in which the follow-up period exceeded 1 year, the mean height of the fractured VB improved from 38% of that of adjacent intact VBs to 85%. Although a slight loss of correction was routinely observed at 1 month postoperatively, an additional loss of VB height was not noted up to 1 year later. Bone formation was commonly seen along the anterior wall of the involved vertebrae in all cases. Vertebroplasty involving the endoscopic removal of granulation tissue proved to be an efficacious procedure for the treatment of chronic painful VCFs. The osteoconductive capacity of CPC facilitated callus formation and ultimately restoration of vertebral bone structure.

Aged↗

PubMed2005

Objective assessment of reduced invasiveness in MED. Compared with conventional one-level laminotomy.

Microendoscopic discectomy (MED) has been accepted as a minimally invasive procedure for lumbar discectomy because of the small skin incision and short hospital stay required for this surgery. However, there are few objective laboratory data to confirm the reduced systemic responses in the early phase after this procedure. In order to substantiate the reduced invasiveness of MED compared to microdiscectomy (MD) or procedures involved in one-level unilateral laminotomy, the invasiveness of each surgical procedure was evaluated by measuring serum levels of biochemical parameters reflective of a post-operative inflammatory reaction and damage to the paravertebral muscles. Thirty-three patients who underwent lumbar discectomy or one-level unilateral laminotomy (MED in 15 cases, MD in 11 cases and one-level unilateral laminotomy in 7 cases with lumbar spinal canal stenosis) were included in this study. The serum levels of C-reactive protein (CRP) and creatine phosphokinase (CPK) were measured at 24 h after operation. Interleukin-6 (IL-6) and Interleukin-10 (IL-10) were measured at 2, 4, 8 and -24 h following the surgery to monitor the inflammatory response to the respective surgery. The post-operative serum CRP levels from both the MD and MED groups were significantly lower than those from the open laminotomy group. However, there was no significant difference in these serum levels between the MED and MD groups. The levels of IL-6 and IL-10 in the MED group during the first post-operative day were also significantly lower than those in the laminotomy group. When the MED and MD groups were compared, the IL-6 levels in the MED group were lower than in MD group at 2, 4 and 8 h after surgery, but the differences were not statistically significant. However, the level was significantly lower in the MED group at 24 h after surgery. In terms of IL-10, no significant difference was noted between the MED and MD groups over the study period. The changes in serum levels of post-operative inflammatory: markers (CRP, IL-6 and IL-10) in the early phase indicated reduced inflammatory reactions in MED as well as in MD when compared with classical open unilateral laminotomy. These data draw a direct link between the lower level of the inflammatory response and reduced invasiveness of MED. However, an indicator for muscle damage (CPK) appeared not to be affected by the type of surgical procedure used to correct disc herniation.

Adult↗

PubMed2004

Does chronic cervical myelopathy affect respiratory function?

OBJECT: Although respiratory function is often impaired by acute cervical spinal cord injury, changes in respiratory function in patients with chronic cervical myelopathy (CCM) are not well documented. The purpose of this study was to evaluate the respiratory function of patients with CCM. METHODS: Spirometric parameters were measured in 94 patients with CCM before they underwent expansive laminoplasty. These measurements were compared with those obtained in age- and sex-matched control group patients without myelopathy. The study patients were also subdivided into two groups: those with spinal compressive lesions above or below the C3-4 disc level were compared in terms of respiratory function. The vital capacity values measured in patients with CCM were significantly lower than those in the control group. In patients in whom spinal cord compression was present above C3-4, vital capacity values were lower than in patients in whom the compression level was below C3-4. The resting respiratory rate per minute was elevated in the CCM group. Peak expiratory flow rate was significantly decreased, and expiratory velocities at 50 and 25% of vital capacity were significantly increased in the CCM group. CONCLUSIONS: The results indicated that expiratory flow may be impaired or incomplete in patients with CCM. An underlying subclinical respiratory dysfunction appears to be associated with CCM.

Adult↗

PubMed2003

High serum levels of menatetrenone in male patients with ossification of the posterior longitudinal ligament.

STUDY DESIGN: This work was performed to investigate the role of vitamin K (VK) in the pathogenesis of ossification of posterior longitudinal ligament (OPLL), by analyzing the biochemical markers of the blood samples of OPLL patients and responses of ligament cells derived from OPLL lesion to VK2. OBJECTIVES: The pathogenesis of OPLL, classified as a form of diffuse idiopathic skeletal hyperostosis, is still unclear. In this study, we investigated the role of menaquinone (VK2) in patients with OPLL (OPLL patients) and the effects of VK2 on ligament cells isolated from OPLL lesion. METHODS: Serum levels of intact osteocalcin, glu-osteocalcin, MK-4, -7 (VK2 variants) and other minerals in spot blood samples were measured in 24 OPLL patients and in 24 age-matched control patients (non-OPLL patients). The cultured cells isolated from an OPLL patient were treated with MK-4. Alkaline phosphatase (Al-p) activity and osteocalcin release were measured after 2 weeks of culture. RESULTS: In the clinical study, the serum MK-4 in male OPLL patients was significantly higher than that in male non-OPLL patients. However, among female patients, the difference was not significant. Although the serum osteocalcin in females was significantly higher than that in males, there was no significant difference between the OPLL and non-OPLL groups. In in vitro study, MK-4 did not increase Al-p activity in the ligament cells isolated from nonossified region of OPLL patient. Osteoblastic activity of the cultured cells was not stimulated by MK-4. CONCLUSION: From these results and previous reports, we propose the possibility of the impediment in VK2 metabolism in OPLL patients. The results also implicate the gender tendency in OPLL, because the difference of serum level of MK-4 in OPLL patients was significant only in male.

Aged↗

PubMed2003

Palsy of the C5 nerve root after midsagittal-splitting laminoplasty of the cervical spine.

STUDY DESIGN: The imaging characteristics of postoperative C5 nerve root palsy after midsagittal-splitting laminoplasty for cervical myelopathy, including those observed on plain radiography, computed tomography, and magnetic resonance imaging, were analyzed. OBJECTIVE: To investigate the imaging findings that predict occurrence of C5 nerve root palsy after midsagittal-splitting laminoplasty. SUMMARY OF BACKGROUND DATA: There have been several reports on imaging findings for postoperative nerve root palsy after open-door laminoplasty. However, there have been no detailed reports on imaging characteristics that predict the occurrence of nerve root palsy after midsagittal-splitting laminoplasty. METHODS: The study included 45 consecutive patients undergoing midsagittal-splitting laminoplasty with sufficient pre- and postoperative imaging examinations: 27 patients with cervical spondylotic myelopathy (CSM), 14 patients with ossification of the posterior longitudinal ligament (OPLL), and 4 patients with cervical disc herniation. Characteristics of pre- and postoperative plain radiographs, computed tomography scans, and magnetic resonance images were compared between the patients with and those without C5 nerve root palsy. RESULTS: Palsy of the C5 nerve root developed in 4 patients, and did not develop in 41 patients. Of the four patients with C5 nerve root palsy, one had CSM and the other three had OPLL. The incidence of C5 nerve root palsy involved 3 of 14 patients with OPLL patients (21.4%) and 1 of 31 patients without OPLL (3.2%) (P = 0.08). For both diseases, the patients with palsy tended to have increased postoperative cervical lordosis (P = 0.21). As for anterior compression on the spinal cord at C3, the P value for the comparison between the group with and the group without palsy was 0.07 for preoperative compression and 0.01 for postoperative compression. CONCLUSIONS: The preliminary data suggest that patients who have OPLL with marked anterior compression on spinal cord at C3 can be at risk for postoperative C5 nerve root palsy after midsagittal-splitting laminoplasty. Also, a postoperative increase in cervical lordosis may be the cause of postoperative nerve root palsy.

Adult↗

PubMed2003

Piriformis syndrome diagnosed by cauda equina action potentials: report of two cases.

STUDY DESIGN: Evaluation of recorded potentials from the lumbar spine after stimulation of the peroneal nerve in patients with piriformis syndrome is reported. OBJECTIVES: To report a new method of diagnosis of piriformis syndrome. SUMMARY OF BACKGROUND DATA: Clinically, the Freiberg and Pace signs were used to diagnose this entity. Among imaging examinations, computed tomography and magnetic resonance imaging have been used. An electrophysiological method using H reflex has also been reported. However, the best method for diagnosis of piriformis syndrome has yet to be clearly established. METHODS: After having an epidural electrode inserted into the lumbar spine, patients lay on their back. Cauda equina action potentials were recorded with the epidural electrode at L3/4 after stimulation of the peroneal nerve at the fibular head. As a control, the potentials were recorded with the hip and knee extended. Potentials were then also recorded with the hip flexed, and then with the hip flexed and internally rotated to stress the sciatic nerve by the piriformis muscle. RESULTS: We observed changes in amplitudes and latencies of recorded potentials. Amplitude decreased to about 70% of the control value in one case and to 67% in the other. On the nonaffected side, however, this amplitude did not decrease below 90%. The latency was also delayed on the affected side, but not on the nonaffected side. CONCLUSIONS: Recording of evoked potentials from the lumbar spine with stress to the affected leg was useful for diagnosing piriformis syndrome.

Action Potentials↗

PubMed2002

Dumbbell-shaped meningioma with cystic degeneration in the thoracic spine: a case report.

STUDY DESIGN: A case report of dumbbell-shaped meningioma in the thoracic spine with cystic degeneration for which a combined posterior microscopic and anterior thoracoscopic approach was used is described. OBJECTIVES: To report a rare case of dumbbell-shaped meningioma, and to describe a thoracoscopic surgical approach for paravertebral tumor. SUMMARY OF BACKGROUND DATA: Dumbbell-shaped tumors arising from nerve root sheaths are very common. However, a dumbbell-shaped meningioma is relatively rare, and reports on thoracoscopic resection of dumbbell and paravertebral tumors are still very few in number. METHODS: The dumbbell meningioma was managed surgically. Because of the paravertebral tumor's intrathoracic expansion, a combined posterior and anterior approach was used. With the posterior approach, microscopic resection using hemilaminotomy was performed, whereas with the anterior approach, the thoracoscopic approach was used instead of thoracotomy. RESULTS: Complete resection of the tumor was performed successfully. The patient regained his functional ability to walk soon after surgery because of less pain than with thoracotomy. CONCLUSIONS: With combined microscopic and thoracoscopic surgery, dumbbell-shaped meningioma could be completely resected. The thoracoscopic approach for the removal of a paravertebral tumor can be a good alternative to thoracotomy.

Humans↗

PubMed2002

Single-stage excision of hemivertebrae via the posterior approach alone for congenital spine deformity: follow-up period longer than ten years.

STUDY DESIGN: Evaluation of the long-term results for single fully segmented hemivertebrae were subjected to single-stage excision via posterior approach alone. OBJECTIVES: To describe the long-term results of this procedure. SUMMARY OF BACKGROUND DATA: In the case of congenital spinal deformity caused by a single, full hemivertebra, excision of the hemivertebra is ideal for obtaining a good correction percentage even in short segments. Recently, single-stage excision of a hemivertebra using a combined anterior and posterior approach has been reported. METHODS: Five patients with a hemivertebra underwent surgery. The hemivertebra involved the thoracolumbar region in three cases and the lumbosacral region in two cases. After removal of a lamina of the hemivertebra, the body of the hemivertebra was visualized easily because the spinal cord had deviated to the concave side of the curve. The vertebral body, along with its cranial and caudal discs, was curetted with this approach. Thereafter, bone chips were grafted into the defect created by vertebrectomy. The results of this surgical procedure, especially those observed during long-term follow-up evaluation, were investigated. RESULTS: For patients with a thoracolumbar hemivertebra, scoliosis improved from 49 degrees +/- 6 degrees to 22.3 degrees +/- 3.5 degrees, for a 54.3% correction. The correction ratio for kyphosis was 67.4%. Over an average 12.8-year follow up period, loss of scoliotic curvature correction was only 3.7 degrees. In contrast, the hemivertebral correction ratio for patients with a lumbosacral hemivertebra remained 32.5% because of difficulty using internal fixation associated with patient age. At the most recent follow-up assessment, one patient exhibited deterioration of coronal spinal balance. CONCLUSION: The described procedure was less invasive because it avoided an anterior approach, yet it yielded satisfactory long-term results for thoracolumbar hemivertebrae.

Adolescent↗

PubMed2002

Hydroxyapatite granule graft combined with recombinant human bone morphogenic protein-2 for solid lumbar fusion.

The purpose of this study was to evaluate the availability of recombinant human bone morphogenetic protein-2 (rhBMP-2) combined with hydroxyapatite (HA) and autogenous bone. Posterolateral intertransverse fusion between the fifth and sixth lumbar vertebrae was performed in 27 adult Japanese white rabbits. These 27 rabbits were classified into three groups: the autogenous bone group, the HA group, and the bone morphogenic protein (BMP) group. In the HA group, HA (0.5 g) mixed with iliac bone was grafted. In the BMP group, HA (0.5 g) soaked with rhBMP-2 (100 mg) and iliac bone was grafted. At 6 weeks after the procedure, bone union was evaluated. In the BMP group, all cases showed solid bone union, and fusion masses were stiffer than the masses obtained in the other group. Biomechanically and histologically, grafts of HA soaked with rhBMP-2 and iliac bone was clearly effective in obtaining a solid intertransverse arthrodesis.

Animals↗

PubMed2002

Analysis of the spastic gait caused by cervical compression myelopathy.

We evaluated the spastic gait of patients with cervical myelopathy with a three-dimensional gait analysis system. Fifteen patients with cervical myelopathy (S group) were investigated. The results obtained were compared with those of normal volunteers (N group). The S group exhibited significant reduction of gait velocity and step length (p < 0.01). In the knee flexion-extension curve, two peaks were observed in the N group. In the S1 group (symptomatic period <1 year), the anterior peak was not smooth, whereas in the S2 group (symptomatic period >1 year), no peak was observed. The pelvis tilted to the side of the standing leg in the N group. However, in the S1 group, this tilting was much less pronounced, and in some patients tilting toward the nonsupporting leg was observed. In the S2 group, the pelvis again tilting toward the supporting side was observed.

Adult↗