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ABSTRACT: STUDY DESIGN:: A morphometric measurement of cortical bone trajectory (CBT) for the lumbar pedicle screw insertion using computed tomography (CT). OBJECTIVE:: The aim of this study is to conduct a detailed morphometric measurement of the CBT. SUMMARY OF BACKGROUND DATA:: The CBT is a novel lumbar pedicle screw trajectory which follows a caudocephalad path sagittally and a laterally directed path in the transverse plane. The advantage associated with this modified technique is increased cortical bone contact, providing enhanced screw purchase. However, little is known about the possible screw size or detailed direction of the trajectory. METHODS:: The CT scans of 100 adults who underwent examination for spinal problems were studied. A total of 470 lumbar vertebrae excluding spondylosis, malformation, and tumor were observed. In this trajectory, the starting point was supposed to be the junction of the center of the superior articular process and 1 mm inferior to the inferior border of the transverse process. CT images were analyzed using 3D reconstruction software. The diameter, length, lateral angle to the vertebral sagittal plane, and cephalad angle to the vertebral horizontal plane of the trajectory were measured. RESULTS:: The mean diameter gradually increased from L1 to L5 (from 6.2 mm at L1 to 8.4 mm at L5). The mean length from L1 to L5 were 36.8, 38.2, 39.3 39.8, and 38.3 mm, respectively. The lateral angle from L1 to L5 were 8.6, 8.5, 9.1, 9.1, and 8.8, respectively. The cephalad angle from L1 to L5 were 26.2, 25.5, 26.2, 26.0, and 25.8, respectively. CONCLUSIONS:: The morphology of the pedicle, such as shape and pedicle axis angle, differed over the lumbar levels, our measurements demonstrated similar data excluding the diameter of the trajectory. There were no significant differences between each level of the lateral and cephalad angles.
Journal of spinal disorders & techniques 02/2013; · 1.21 Impact Factor
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ABSTRACT: Retrospective study of new muscle-preserving exposure techniques and their application to posterior cervical spine surgery.
To describe muscle-preserving techniques for exposure of the posterior cervical spine, and to demonstrate how their application to a variety of posterior cervical spine surgeries for varying pathologies allows preservation of cervical mobility and stability.
Although surgical approaches through intermuscular planes have been applied to the extremities and anterior spinal column, to our knowledge, they have yet to be applied to the posterior cervical spine.
We have used our new exposure techniques since 2000, applying them to selective mono laminoplasty (73 patients) for cervical myelopathy, muscle-preserving intervertebral foraminotomy (30 patients) for radiculopathy, posterior atlantoaxial instrumentation with muscle preservation (6 patients) for upper cervical instability, and muscle-reserving unilateral posterior arch recapping technique (11 patients) for cervical spinal cord tumors. A total of 120 patients were enrolled in this study. To evaluate surgical outcomes, we reviewed all their clinical records and pre- and postoperative images.
In selective mono laminoplasty, recovery rate according to Japanese Orthopaedic Association (JOA) scores averaged 60.7%. In muscle-preserving intervertebral foraminotomy, the averaged visual analogue scale for radicular pain decreased from 2.53 preoperatively to 0.47 postoperatively. Of 120 patients, 119 showed neither loss of curvature nor neck motion according to a comparison of pre- and postoperative plain x-rays, with only 1 patient who underwent unilateral posterior arch recapping technique for intramedullary ependymoma showing both. No trace of damage to the deep muscles was observed in any of the 17 patients who underwent posterior atlantoaxial instrumentation with muscle preservation or unilateral posterior arch recapping technique on postoperative magnetic resonance imaging.
The muscle-preserving exposure techniques described here can be applied to a variety of posterior cervical spine surgeries for varying pathologies, with no adverse effect on cervical mobility or stability.
Spine 03/2012; 37(5):E286-96. · 2.08 Impact Factor
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ABSTRACT: A case report.
We report a novel case of torticollis disorder because of a congenital split atlas after minor trauma.
Torticollis experienced after minor trauma in childhood is usually because of atlantoaxial rotatory fixation, which is a common disorder in pediatric patients and is usually diagnosed with computed tomography (CT). CT scanning with 3-dimensional reconstruction, however, showed a unique rotation of split atlas, a congenital anomaly that presented with torticollis.
A female child aged 3 years and 11 months presented to the orthopedic clinic with torticollis after a fall. CT imaging showed no rotatory dislocation of C1-C2. On the 3-dimensional CT reconstruction images, however, anterior and posterior defects in the atlas, the so-called split atlas, and an atypical rotation with malalignment of the posterior arch and asymmetry of the atlantoaxial facet joint were noted. The child was treated with closed reduction using skull traction under general anesthesia.
Repositioning of the atlas rotation was confirmed using intraoperative 3-dimensional scanning, and open reduction therapy was avoided. The patient was treated with halo vest for 8 weeks and had full recovery of neck motion with resolution of the torticollis.
We present a novel torticollis disorder caused by C1 rotation of a split atlas with closed reduction treatment.
Spine 06/2010; 35(14):E672-5. · 2.08 Impact Factor
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ABSTRACT: Outcomes of muscle-preserving interlaminar decompression (MILD) for the lumbar spine are reported.
To verify the clinical findings of lumbar MILD.
A preliminary short-term follow-up study of lumbar MILD demonstrated satisfactory neural recovery and reduced invasiveness. METHODS.: The initial 105 consecutive patients with lumbar spinal canal stenosis were included in this study. A total of 210 intervertebral levels were decompressed. There were 48 women and 57 men, and the mean patient age was 68.8 years. The postoperative follow-up period ranged from 8 to 44 months (mean 21.3 months). Eighty-one patients showed cauda equina claudication, and 75 patients complained of radicular pain. Preoperative imaging studies demonstrated that all patients had moderate-to-severe spinal canal stenosis, 75 patients had degenerative spinal canal stenosis, and the remaining 30 had degenerative spondylolisthesis. Pre- and postoperative Japanese Orthopedic Association scores, intraoperative blood loss, surgical complications, and postoperative ambulation were recorded. RESULTS.: One hundred five patients underwent lumbar MILD procedure for 210 interspinous levels, 42 patients for 2 levels, 37 patients for 1 level, 17 for 3 levels, 7 for 4 levels, and 2 for 5 levels. Cerebrospinal fluid leakage due to dural tear occurred in 2 patients. Expansion of the operative field was not necessary to repair the dura mater. The mean operation time was 104.9 minutes per level, and mean intraoperative blood loss was 29.4 g per level. Neurologic improvement was demonstrated in all patients. The mean recovery rate calculated with pre- and postoperative Japanese Orthopedic Association scores was 64.9%. Patients started to stand or walk an average of 2.5 days after surgery. None of the patients presented with wound infection. There was no neurologic complication in this series.
In MILD for the lumbar spine, damage to the posterior stabilizing structures such as the intervertebral facet joints, paravertebral muscles, thoracolumbar fascia, supra- and interspinous ligaments, can be minimized, while preserving the function of the spinous processes as lever arms for lumbar extension.
Spine 05/2009; 34(8):E276-80. · 2.08 Impact Factor
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ABSTRACT: The authors report a case of spontaneous resorption of intradural disc material in a patient with recurrent intradural lumbar disc herniation and review magnetic resonance (MR) imaging and histopathological findings. Intradural lumbar disc herniation is rare, and most patients with this condition require surgical intervention due to severe leg pain and vesicorectal disturbance. In the present case, however, the recurrent intradural herniated mass had completely disappeared by 9 months after onset. Histological examination of intradural herniated disc tissue demonstrated infiltrated macrophages and angiogenesis within the herniated tissue, and Gd-enhanced MR images showed rim enhancement not only at the initial presentation, but also at recurrence. The authors conclude that when rim enhancement is present on Gd-enhanced MR images, there is a possibility of spontaneous resorption even though the herniated mass may be located within the intradural space. Moreover, when radiculopathy is controllable and cauda equina syndrome is absent, conservative therapy can be selected.
Journal of Neurosurgery Spine 07/2007; 6(6):574-8. · 1.53 Impact Factor
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ABSTRACT: Posterior cervical spinal cord shifting after selective single laminectomy associated with partial laminotomies was compared with that after bilateral open-door laminoplasty between the C3 and C7 levels in relation to the clinical results of each procedure.
To investigate the clinical significance of posterior spinal cord shifting after extensive cervical laminoplasty.
Current techniques used for cervical laminoplasty for multisegmental cervical spondylotic myelopathy (CSM) are consecutively performed between the C3 and C6 or C7 levels with expectation that the spinal cord will shift backward to keep it clear of anterior compression. However, the clinical significance of the posterior spinal cord shifting remains controversial, and there has been no report verifying it by comparing limited posterior decompression procedures with conventional extensive ones.
Twenty-six patients with consecutive 2- to 3-level CSM who underwent selective laminoplasty (Group A) were enrolled in the study, and among 56 CSM patients who underwent bilateral open-door laminoplasty between the C3 and C7 levels, 25 who had consecutive 2- or 3- level stenosis identified by preoperative magnetic resonance imaging were used as controls (Group B). The recovery rate was calculated using preoperative and postoperative Japanese Orthopedic Association (JOA) scores for each patient, and for each patient's magnetic resonance imaging, the postoperative cervical curvature index was obtained according to Ishihara's method and the magnitude of postoperative backward shifting of the spinal cord was measured.
There was no significant difference between the subjects in Groups A and B with respect to the spinal curvature index, preoperative JOA scores, and recovery rate, but the magnitude of the postoperative posterior shifting of the spinal cord was greater for those in Group B than for those in Group A. There was no correlation between the recovery rate and posterior shifting of the spinal cord for each group, and no correlation was also found between the curvature index and posterior shifting of the spinal cord.
The outcome of posterior decompression surgery for multisegmental CSM is not correlated with the magnitude of postoperative backward shifting of the spinal cord. Extensive and consecutive decompression performed in conventional cervical laminoplasties is therefore not always necessary for multisegmental CSM.
Spine 12/2005; 30(21):2414-9. · 2.08 Impact Factor
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ABSTRACT: There is no well-established treatment for osteoporosis in male patients with leprosy, because no clinical trials have examined the efficacy of treatment on bone mineral density (BMD) or fracture incidence in patients with leprosy. In this study, we report a case of osteoporosis in a man with leprosy, treated by oral administration of risedronate and alfacalcidol. An 82-year-old man with leprosy presented to our hospital with chronic back pain, due to osteoporosis, in July 2002. To prevent the progression of osteoporosis, oral administration of risedronate and alfacalcidol was started for this patient. An increase in forearm BMD and a decrease in the level of urinary crosslinked N-telopeptides of type I collagen (NTx) were observed in January 2003. The patient suffered a trochanteric fracture of the proximal femur at the end of March 2003. Surgical treatment with a sliding-screw plate was performed 5 days after the injury. Complete bony union of the right proximal femur was confirmed by radiography in July 2003. The above findings suggested that the treatment with risedronate and alfacalcidol contributed to the increase in BMD; however, the treatment did not prevent fracture due to osteoporosis in this male patient with leprosy.
Journal of Bone and Mineral Metabolism 02/2005; 23(1):90-4. · 2.27 Impact Factor
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ABSTRACT: The authors report on two patients undergoing long-term hemodialysis in whom cervical myelopathy was caused by calcification related to the cervical dural sac. The lesions were demonstrated on plain computerized tomography (CT) scans as dotted curvilinear bands outlining the dural sacs in almost the whole of their cervical spines. During posterior decompressive surgery in both cases, the CT scanning--documented curvilinear bands were identified as calcified plaques infiltrating the fibrous membranes beneath the ligamenta flava, constricting the cervical dural tube. In each case, the spinal cord could not be decompressed by merely enlarging the osseous spinal canal; rather, it required removal of the calcified membrane from the posterior surface of the dura. Based on the operative findings, the lesion should be described as cervical peridural calcification.
Journal of Neurosurgery 04/2004; 100(3 Suppl Spine):284-6. · 2.96 Impact Factor
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ABSTRACT: Results of skip laminectomy and open-door laminoplasty for cervical spondylotic myelopathy were compared.
To verify that skip laminectomy is less invasive to the posterior extensor mechanism of the cervical spine including the deep extensor muscles than conventional laminoplasty and is effective in preventing postoperative problems often seen after conventional laminoplasty of the cervical spine such as persisting axial pain, restriction of neck motion, and loss of cervical lordosis.
A preliminary short-term follow-up study on skip laminectomy demonstrated that the procedure successfully prevented such postoperative problems, while achieving adequate decompression of the spinal cord.
Since December 1998, more than 100 patients with cervical spondylotic myelopathy underwent skip laminectomy, and 43 who were followed for more than 2 years (average of 2 years and 6 months) (Group A) were included in this study. Fifty-one patients who underwent open-door laminoplasty (Group B) in the authors' institutes before December 1998 served as controls. Japanese Orthopaedic Association scores and incidence of newly developed or deteriorated axial pain were recorded. Preoperative and postoperative ranges of neck motion were measured on lateral flexion and extension radiographs. Preoperative and postoperative cervical curvature indices were calculated according to Ishihara's method. For quantitative analysis of damage to the posterior cervical muscles, atrophy rates were calculated from cross-sectional areas of the deep extensor muscles on preoperative and postoperative axial magnetic resonance images.
Using Japanese Orthopaedic Association scores, the average recovery rates were 59.2% for Group A and 60.1% for Group B. Only one patient (2%) in Group A had newly developed axial pain, whereas 33 patients (66%) in Group B had postoperative development or deterioration of axial pain. Postoperative range of neck motion averaged 98% of the preoperative measurement in Group A and 61% in Group B. There was no significant difference between preoperative and postoperative cervical curvature index in Group A, whereas the mean value of postoperative index (16.0) was significantly smaller than that of preoperative one (11.8) in Group B (P < 0.05). The atrophy rate of the deep extensor muscles in Group A averaged 13%, whereas that in Group B was 59.9%.
Skip laminectomy was less invasive to the posterior extensor mechanism including the deep extensor muscles than open-door laminoplasty. This new procedure was effective in preventing postoperative morbidities often seen after conventional laminectomy and laminoplasty with adequate decompression of the spinal cord.
Spine 01/2004; 28(24):2667-72. · 2.08 Impact Factor
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ABSTRACT: A 66-year-old man on long-term hemodialysis for chronic renal failure presented with progressing disabilities due to cervical myelopathy. On computerized tomography (CT), bright, dotted curvi-linear bands outlined the cervical spinal dura. At operation, these bands on CT were identified as calcified plaque impregnated in fibrous membrane, constricting the dura and the spinal cord in almost the whole cervical spine. Spinal cord decompression was incomplete by merely enlarging the bony spinal canal but was accomplished by removing the calcification from the dura. A cross-sectional study on CT in a single dialysis unit disclosed that the prevalence of this pathological CT finding was 26%. Plain CT of the cervical spine, focusing on the upper cervical vertebrae in particular, was the most helpful in detecting the lesion. Based on the findings at operation, cervical peridural calcification seemed an adequate term for the lesion. This pathology should be recognized as an important complication of dialysis therapy because it is not unusual and potentially causes cervical myelopathy.Un homme g de 66 ans, trait depuis plusieurs annes par dialyse pour insuffisance rnale, consulte pour des symptmes de mylopathie cervicale progressive. Sur le scanner l''on constate la prsence de bandes claires curvilignes entourant la dure-mre. Lors de l''intervention, ces bandes sont identifies comme tant des plaques calcifies au sein d''une membrane fibreuse, enserrant la dure-mre au long de pratiquement toute la moelle cervicale. La dcompression de la moelle, incomplte par la seule libration osseuse, ne fut effective qu''aprs ablation de ces plaques calcifies depuis la dure-mre. Une tude croise par scanner dans une unit de dialyse rvla que la prvalence de ces anomalies scanographiques tait de 26%. Un scanner de tout le rachis cervical, en particulier centr sur le rachis cervical suprieur, constitue le meilleur moyen diagnostique de la lsion. En se fondant sur les constatations opratoires, c''est la prsence de calcifications pridurales qui est considrer comme pathognomonique. Cette pathologie est considrer comme une importante complication de la dialyse, non rare et responsable potentiellement de mylopathie cervicale.
European Journal of Orthopaedic Surgery & Traumatology 01/2003; 13(3):133-136. · 0.10 Impact Factor
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ABSTRACT: Cervical malalignment occurring after conventional laminectomy or laminoplasty is caused by intraoperative injuries to the posterior extensor mechanism, including the deep extensor muscles. To minimize such injuries, we developed a technique for muscle-preserving double-door laminoplasty below C2 (TEMPL) and TEMPL for the axis (TEMPLA) in treating patients with multisegmental cervical myelopathy. In these procedures, the posterior arches, which were sagittally split in the midline, can be opened. This leaves untouched the semispinalis cervicis and multifidus muscle attachments to each split half of the spinous process below C2, and of all five muscles to each split half of the C2 spinous process. In review of short-term surgical outcomes from 41 patients who underwent the procedures, neurological improvement was demonstrated in each patient. Postoperative kyphosis development was identified in one patient only, in whom delayed fracture occurred at the bilateral C2 laminar hinge. TEMPL and TEMPLA, in which the deep extensor musculature is preserved as an important stabilizer of the cervical spine, are effective procedures to prevent postoperative cervical malalignment. Rsum. Les laminectomies et les laminoplasties du rachis cervical se compliquent souvent de dformations en rapport avec le traumatisme musculaire opratoire. Dans le traitement des mylopathies cervicales par ossification du ligament longitudinal postrieur, les auteurs ont dvelopp une technique de laminoplastie dite e double door f pour prserver les muscles de la rgion. La technique est diffrente pour C2 (TEMPLA) et au-dessous de C2 (TEMPL). Dans cette technique, l'arc postrieur de la vertbre coup en son milieu peut tre ouvert, laissant intacte l'attache musculaire. La revue court terme de 41 patients oprs par cette technique a montr une amlioration neurologique constante. Aucune cyphose post-opratoire n'a t remarque sauf chez un patient o une fracture diffre des lames de C2 a t mise en vidence. La technique TEMPLA et TEMPL, qui prserve les muscles extenseurs du cou est efficace et prvient des dformations post-opratoires du rachis cervical.
European Journal of Orthopaedic Surgery & Traumatology 11/2002; 12(4):175-180. · 0.10 Impact Factor
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ABSTRACT: To prevent the occurrence of postoperative cervical malalignment, which is often a complication of conventional axial laminectomy or laminoplasty, the authors developed a new double-door laminoplasty procedure in which the C-2 spinal canal is expanded while all the muscular attachments to each split half of the spinous process remain undisturbed. In conjunction with laminoplasties at other levels, this procedure was performed in five patients with ossification of the posterior longitudinal ligament and cervical myelopathy. Neurological improvement was demonstrated in each patient, and there was no radiological evidence of cervical malalignment. The technique for this procedure is described and its usefulness in preventing postoperative spinal malalignment is discussed.
Neurosurgical FOCUS 02/2002; 12(1):E9. · 2.87 Impact Factor
