Surgical Technique for Spine and Spinal Nerves
Vol.5 No.1(2003)

Main Theme－1：Minimally invasive spine surgery-Cervical spine
Cervical Expansive Open
－door Laminoplasty with Spinoplastic Hydroxyapatite Spacer－knack and Points
Shun－ichi KIHARA, et al.
Abstract We consider the following to be essential：1：minimally invasive surgery for the posterior cervical supporting component, including skin elasticity, 2：stability and symmetry in expanding the canal space and spinous process using a spinoplastic spacer, and 3：correction of cervical alignment by lever action of reconstructed spinous process and posterior cervical supporting component. The present author previously reported the short－term results of his original minimally invasive method of three centimeter skin incisional cervical expansive open－door laminoplasty. This paper reports a special knack and points to my original method. These are shown to be useful in the practical technique of the operation. It is considered that the operation can be established by accurate multi－steps.
Technique for Muscle Preserving Laminoplasty of the Cervical Spine
Yoshiyuki YATO, et al
Abstract We consider the following to be essential：1：minimally invasive surgery for the posterior cervical supporting component, including skin elasticity, 2：stability and symmetry in expanding the canal space and spinous process using a spinoplastic spacer, and 3：correction of cervical alignment by lever action of reconstructed spinous process and posterior cervical supporting component. The present author previously reported the short－term results of his original minimally invasive method of three centimeter skin incisional cervical expansive open－door laminoplasty. This paper reports a special knack and points to my original method. These are shown to be useful in the practical technique of the operation. It is considered that the operation can be established by accurate multi－steps.
Operative Results of Giant Neurogenic Tumors
Yurito Ueda, et al.
［Purpose］Giant spinal neurogenic tumors are relatively rare, and there are few reports about them. We investigated the operative results of giant neurogenic tumors that occurred in the thoraco-lumbo-sacral spine.
［Object and Method］There were 9 cases from 1991 to 2001. The mean age was 38.9 years and the mean postoperative period was 7 years 5 months. Five were males and 4 were females.
［Result］All the patients had dumbbell tumors. One was Eden type 1, 1 was type 2, 5 were type 3 and 2 were type 4. The anterior approach was selected in 2 cases, posterior approach in 4 cases and a combined anterior and posterior approach was needed in 3 cases. Spinal fusions were needed in 2 cases.
The average blood loss was 1335 ml and average operating time was 7 hours 27 minutes.
［Discussion and Conclusion］Subjective symptoms of neurogenic tumors that occur in the thoraco-lumbo-sacral spine are not always severe. In some cases they can become gigantic. In addition, their growing patterns vary, which makes the operative procedures very difficult. However, even if the size is so large, total resection is possible by using the proper approach and technique.
Main Theme－1：Minimally invasive spine surgery-
Thoracic spine Posterior Thoracic Herniotomy with Tubular Retractor System
in Microsurgical Technique-A Case Report-
Kunihiko SASAI, et al
Abstract 48－year－old man noticed spasticity and numbness in both legs approximately three months ago. Thereafter he gradually became unable to walk. MRI and CT－myelograms showed right dominant paracentral disk herniation at Th11/12. Under an approximately 2.5 cm transverse skin incision, the disk herniation was completely removed with a microscope and tubular retractor system. From the first postoperative day, he was able to walk with a soft corset. Though various surgical techniques for thoracic disk herniation have been reported, this method is the minimally invasive. This is the first case of microsurgical posterior thoracic herniotomy with a tubular retractor system.
Main Theme－1：Minimally invasive spine surgery
-Lumbar disc herniation
A Minimally Invasive Muscle Splitting Lumbar Microdiscectomy
Kiyoshi HIDAKA, et al.
Abstract The microscopic tubular retractor system(METRx system)is a minimally invasive technique for lumbar discectomy. Sequential soft tissue dilatation using dilators is less traumatizing for the paraspinal muscles. However, microdiscectomy through the tubular retractor may occasionally encounter difficulties in establishing microscopic visualization because of soft tissue interruption at the distal tip of the tubular retractor, and some surgeons do not feel comfortable with the limited working space within the tunnel shaped tubular retractor. We introduced sequential dilators for conventional microdiscectomy and developed specially designed specula fits for the An approximately 2.5 cm paramedian skin incision was made at the level of the appropriate disc space, followed by fascial incision. The muscle was sequentially dilated. After dilatation of the paraspinal muscles, a specially designed specula was placed over the largest dilator, extending down to the lamina. Microdiscectomy was then performed. This minimally invasive muscle splitting microdiscectomy was a less invasive but effective procedure for lumbar microdiscectomy.
Nishijima Spinal Retractor
Yuichiro NISHIJIMA
Abstract We developed a new spinal retractor, the Nishijima spinal retractor, for posterior lumbar surgery. The retractor originated from the Hohmann retractor. We modified the Hohmann retractor to have a detachable handle. In the case of microscopic posterior lumbar surgery, the tip of the retractor is inserted into the lateral aspect of the facet joint. In conventional posterior lumbar surgery, we inserted the retractor at the tip of the transverse process. After release of the detachable handle, the retractor was fixed to the skin with coarse surgical thread through the retractor hole. The advantage of this retractor is that it decreases the intramuscular pressure and prevents damage to retracted back muscles during posterior lumbar surgery. Another advantage is that it easily achieves free cranio－caudal space as compared with the conventional tubular retractor which is used in posterior lumbar microsurgery.
Radiographic Evaluation on the Height of Operated Intervertebral Disc Following MicroEndoscopic Discectomy(MED)for Lumbar Disc Herniation
Ryuichi SASAOKA,et al.
Abstract To minimize operative invasion, since1999, we have started to perform MicroEndoscopic Discectomy(MED)for the operative therapy of lumbar disc herniation. This enables short bed rest and short hospital stay after operation. However, surgical stress to the operated intervertebral disc is similar to that following conventional procedures. No effect of early bedleaving has been proved before. In this study, we compared the changes of disc height radiographically in patients who had undergone MED or Microdiscectomy to evaluate the effects of early bed－leaving on the operated intervertebral disc after MED.
＜Patients and Methods＞
23 patients had MED and 19 had Microdiscectomy. All had more than a one－year follow－up period. The disc height was measured radiographically by Mochida's method. We compared the changes of disc height ratio between the MED and Microdiscectomy groups by age, gender, affected disc levels and operative procedure, and also evaluated the correlation between the total amount of removed disc material and disc height ratio.
＜Results＞
No significant differences of disc height ratio were observed between the MED and Microdiscectomy groups by age, gender, affected disc levels or operative procedure. There was a small correlation between total amount of removed disc material and disc height ratio.
＜Conclusion＞
No differences were seen in the changes of disc height ratio between the MED and Micro discectomy groups in the 1－year follow－up period. Long term follow－up(at least 2 years)is expected to evaluate more precisely.
Main Theme－1：Minimally invasive spine surgery-Lumbar spinal canal stenosis
New Applications of MicroEndoscopic Discectomy(MED)for Revision Discectomy and Decompression for Lumbar Spinal Canal Stenosis(LSCS)
Motonobu NATSUYAMA, et al.
Abstract
＜Introductions＞Smith and Foley developed a minimally invasive procedure for lumbar disc herniation(LDH), MED, in 1995. We started the same procedure from October 1998, operated 212 cases until March 2003, and had satisfactory results. This time we expanded the applications for revision discectomy and decompression for LSCS. The purpose of this study is to present the operative procedure, early clinical results, and complications.
＜Materials＞A)Seven cases of LDH patients who had undergone conventional Love procedure were operated by MED from May 2001 to November 2002. The mean age was 36, five patients were male, two, female, and the mean period from the first operation was 8 years. Infour, the operated level was in four, L4/5, in two, L5/S, and in one, L4/5/S. B)We operated on 35 patients of decompression by MED for LSCS from February 2000 to March 2003. Male were 25, female, ten, and mean age was 65year old. In 30, operated level was L4/5, in one, L5/S, in one, L3/4/5, in two, L4/5/S, in one, L2/3/4, L5/S.
＜Methods＞We investigated operation time, blood loss, period to begin to walk, the JOA recovery rate, and complications.
＜Results＞A)The mean operating time was 117 minutes. The mean blood loss was 17.0 ml.. All patients began to walk one day postoperation. The mean JOA score recovered from 11.3 preop. to 27.0, 3 M. postop., to 27.2, 6 M. postop. The JOA recovery rate was 89.9%3 M. postop, and 90.2%, 6 M. postop. In one case dura was damaged. B)The mean operating time was 120 minutes. The mean blood loss was 22.8 ml.. All patients began to walk one day postoperation. The mean JOA score recovered from 15.7 preop. to 26.6, 3 M. postop, 27.3, 12 M. postop.. The JOA recovery rate was 85.6% 3 M. postop, 86.5%, 12 M. postop.. In one case dura was damaged by airdrill, and in one case, there was muscle weakness in L5 area.
＜Conclusions＞Revision discectomy and decompression for LSCS were not considered to be a good candidate for MED because of adhesion. This time the author could overcome the difficulties by gentle and precise manipulation under blight and magnified operative field, and was satisfied with the results. We concluded that revision discectomy and decompression for LSCS could be a good candidate for MED.
Endoscopic Decompressive Laminotomy for Lumbarcanal Stenosis
-Bilateral Decompression from Lateral Approach-
Munehito YOSHIDA, et al.
Abstract From September 1998 to March 2002, 250 consecutive patients underwent posterior endoscopic surgery for lumbar radiculopathy. Among these patients, 27 were treated by endoscopic decompression for lumbar canal stenosis. There were 19 men and 8 women, and the average age was 60±12.8 years. The major preoperative symptoms were neurologic claudication, sometimes accompanied by sciatica. Clinical outcomes were evaluated by the Japanese Orthopedic Association scoring systems for lumbar disease. The average JOA score of the 27 patients was 13.7±3.8 preoperatively and improved to 26.4±2.8 postoperatively. The average operation time for one level was 56 minutes and the average blood loss was 46 ml. 18 patients had one level of decompression, 7 had two levels and two had 3 levels. There were no interoperative complications.
Contribution of Fenestration without Spinal Fusion for Lumbar Degenerative Spondylolisthesis with Spinal Stenosis to Symptoms in the Lower Extremities during a Long－term Postoperative Period
Tetsuro SATO, et al.
Abstract In order to clarify the necessity of spinal fusion, we investigated whether postoperative instability in the lumbar spine following fenestration contributes to deterioration of symptoms in the lower extremities during a long－term postoperative period. 42 patients showing cauda equina syndrome preoperatively were studied in this series. The follow－up period ranged from 5 to 11 years(Ave. 8). Neurologically, the JOA score for lumbar spine disorders was evaluated. Radiologically, slip－percentage and the range of slip angle from extension to flexion were evaluated. 42 patients were classified into neurologically deteriorated group(15 patients)and control group(27 patients). There were no differences in the scores of groups in the preoperative period or one year after operation, but there was a significant difference at the last visit. The average % slip significantly increased in both groups. The average range of slip angle decreased minimally in both groups. There were no differences in the % slip or the range of both groups in the preoperative period and at the last visit. Postoperative instability in the lumbar spine following fenestration for degenerative lumbar spondylolisthesis do not contribute to deterioration of symptoms in the lower extremities during the long－term postoperative period.
Main Theme－2：Interbody fusion-Cervical spine
The Advantage of Anterior Cervical Plate on Anterior Cervical Multilevel Fusion
-The Prevention of Dynamic Canal Stenosis Adjacent to the Fusion-
Masatoshi SUMI, et al.
Abstract The advantage of the anterior cervical plate for anterior multilevel fusion(more than two discs)was assessed through comparative study of cases with or without plates. The radiograms of 99 cases with degenerative disease were analyzed for Cobb's angle at fusion level and dynamic spinal canal stenosis(DSCS)at adjacent disc level to fusion, at an average of 35 months(more than twelve months)after surgery. The Cobb's angles in the cases with plates at follow－up were preserved within the postoperative angles, whereas those without plates decreased. The cases with kyphotic fusion at follow－up after loss of more than five degrees were only 3.0% in the cases with plate, but 18.2% in those without plates. The alignment of fusion at follow－up was kyphosis in the cases with the aggravation of DSCS at the caudal－adjacent disc to fusion. The appearance rate of cases with aggravation of DSCS at the caudal－adjacent disc to fusion was higher in those without plates(33.3%) than in those with plates(7.4%). The anterior cervical plate for multilevel fusion in degenerative disease was proved to prevent the aggravation of DSCS at the caudal－adjacent disc to fusion by maintaining the postoperative alignment.
Correction of Alignment and Stable Fixation of the Cervical Spine with Bi－cortical Anterior Compression Plate System with Titanium Cage
-TFC reference-
Naoki ASAMＩ
Abstract The anterior compression plate system is very useful for correction and fusion by bi－cortical fixation to the cervical anterior body. With bi－cortical capability, stable physiological alignment is easily achieved after microsurgical decompression and removal of the disc and osteophytes. It has been considered that bi－cortical screw fixation carried a risk of damage to the cord. However, a low－profile titanium plate allows secure anchorage at the bone/plate interface and prevents screw backout or loosening, which could cause swallowing problems.
Main Theme－2：Interbody fusion-PLIF 1
Posterior Lumbar Interbody Fusion Via Unilateral Approach Using Local Autologous Bone and Single Cylindrical Threaded Cage
Taku OGURA, et al.
Abstract We have employed posterior lumbar interbody fusion(PLIF)as a surgical procedure for degenerative lumbar disease with preoperative instability in the spinal segment. We here report the surgical procedure and imaging findings of PLIF by unilateral approach using local autologous bone and a threaded cage. The subjects were 8 patients whose diagnoses were degenerative scoliosis(1 case), degenerative spondylolisthesis(4 cases), and spinal canal stenosis including unstable spinal segment(3 cases). We evaluated the chronological changes in disk height, the cage insertion angle, and the location of the cage on the roentgenogram and CT.
The disk height changed from 7.2 mm before to 11.5 mm after operation, and was 10.0 mm at the final follow－up examination. At this examination, 87.6% of the disk space was maintained. The cage insertion angle ranged from 20.0 to 30.0 degrees(mean value 25.1 degrees).
Although the insertion of the threaded cage resulted in well－maintained disk height, in spite of the short－term observation, great variations in the cage insertion angle and the location were found. Development of new surgical instruments and preoperative or intraoperative simulation may be necessary for stable cage insertion.
Posterior Lumbar Interbody Fusion Using Two Blocks of En
－bloc Resected Lamina as an Interbody Spacer
Shigeru HIRABAYASHI, et al.
Abstract We have performed PLIF in which two blocks of en－bloc resected lamina were used instead of bone grafted from the iliac bone as an interbody spacer in combination with rigid－type spinal instrumentation. There were 36 patients(18 M, 18 F, ages 21－78 years, mean 52.7 years；follow－up, 1 y 6 ms－6 ys 4 ms, mean 3 ys 10 ms). In 18 patients with spondylolitic spondylolisthesis and 2 patients with spondylolysis, a mid－line longitudinal split was made at the floating lamina and two blocks of lamina were resected. In 13 patients with degenerative spondylolisthesis and 3 with unstable spine, a mid－line longitudinal split was made at the lamina and a cleavage at the isthmus, and two blocks of complex of lamina and inferior articular process were then resected. Good bony union was obtained in all of the patients. The merits of our method are as follows： First, there are of course no complications at the iliac crest which is often used as a donor site；Second, the procedure for resecting lamina en bloc is to perform total facetectomy at the same time, resulting in a good visual field from the central to the extraforaminal zone for complete decompression of the dural sac and nerve root；Third, as the en－bloc resected laminae are circumferentially covered with cortical bone, it is strong and does not tend to collapse at the interbody space；Fourth, the combination of rigid－type spinal instrumentation is beneficial for obtaining good bony union, affording rigid fixation and reducting olisthesis.
Surgical Results of Posterior Lumbar Interbody Fusion Using the Brantigan I/F Cage
Tokumi KANEMURA, et al.
Abstract ＜Purpose＞The Brantigan I/F cage for posterior lumbar interbody fusion(PLIF)was designed to improve the success of fusion by separating the mechanical and biologic functions. The carbon fiber cage allows visualization of bony healing by normal radiographic methods. The aim of this study was to evaluate the surgical results of PLIF using the Brantigan I/F cage.
＜Materials and Methods＞We evaluated 231 consecutive patients who were treated by PLIF with the Brantigan I/F Cage and pedicle screw fixation. They were followed up for a minimum of 1 year. Fusion status was decided by lateral flexion－extension radiographs and CT scans with reconstruction.
＜Results＞The patients consisted of 107 men and 124 women with a mean age of 55.4 years. The successful fusion was achieved in 226(97.8%)of 231 patients. The average improvement rate in the JOA score was 76.4%. Although the intra－/post－operative complications occurred in 47 patients(20.3), there was no device－related complication.
＜Discussion and Conclusion＞The carbon fiber implant, Brantigan I/F Cage, is radiolucent so that normal radiographic methods can demonstrate bony healing without obscuring shadows of metal materials. Continuous radio－dense bone is seen in the center of the cages and between the cages bridging the interspaces, providing were defined radiographic evidence of fusion. The Brantigan I/F cage for PLIF is safe and effective for the management of lumbar disease.
A New Method of PLIF for Degenerative Lumbar Spondylolisthesis
Futoshi SUETSUNA, et al.
Abstract We have performed a new method of PLIF using LDS－Vigor(Lumbar Disc Spacer－Vigor), which can produce a reduction of listhesis, extension of the intervertebral space and lordosis of the fused segment by rotation of the LDS－Vigor in the disc space. 35 patients with an average age of 66 years were investigated. All patients underwent PLIF using LDS－Vigor and pedicle screw. The average follow－up period was 26 months. Radiographic evaluation was performed to examine the following：
1. fusion rate, 2. change of lordotic angle(LA), 3. change of % slip. Bony fusion was obtained in all cases except one in which there was infection. The average preoperative, postoperative and follow－up LA was－1.5 degrees, 12.0 degrees and 12.0 degrees respectively. The average preoperative, postoperative and follow－up % slip was 20.2%, 9.1% and 9.0%. The average preoperative and follow－up JOA score was 13.6 points and 25.6 points. Recovery rate was 78%. The usual methods of PLIF using threaded cages sometimes leave a gap between cage and vertebra and do not succeed in producing lordosis. Our method resolved these problems and gave a satisfactory radiographic and clinical outcome. LDS－Vigor is a new disc spacer for PLIF that is safe and simple.
Main Theme－2：Interbody fusion-PLIF 2
Changes in the Disc Height after Posterior Lumbar Interbody Fusion(PLIF)
-Comparison of Two Kinds of Intervertebral Spacers
Takahiro HOZUMI, et al.
Abstract To determine whether preservation of the vertebral bony endplate prevents subsidence of the posterior lumbar interbody fusion implant(PLIF implant), we retrospectively compared the postoperative intervertebral spaces radiographically after two kinds of PLIF procedures.
Ninety－three patients underwent two kinds of PLIF procedures, which were insertion of a threaded glass ceramic cylindrical spacer after drilling both the intervertebral disc and bony endplate(group A)(n=69 implants), and insertion of a titanium trapezoid spacer after curettage of the intervertebral disc and cartilaginous plate, leaving the bony endplate intact(group B)(n=24 implants). Both groups underwent total facetectomy and PLIF with pedicle screw fixation. Postoperative disc heights were measured serially by plain lateral radiography. Non－union was determined as a few degree of movement of the PLIF segment in flexion/extension radiography. Non－union was observed in four intervertebral spaces of group A(5.8%), and one intervertebral space of group B(4.2%). Subsidence of the PLIF implant was observed in 4 implants of group A(5.8%), but not in 23 implants of group B(0%).
The results showed that the procedure, in which the implant was inserted with preservation of the bony endplate, did not result in subsidence of the implant.
Evaluation of Our Surgical Treatment for Degenerative Lumbar Spondylolisthesis
Eikazu HIROFUJI, et al.
Abstract Surgical treatment for degenerative lumbar spondylolisthesis was selected at our hospital in consideration of age, occupation, stenosis at site of spondylolisthesis and elsewhere, and instability. Various kinds of surgical treatment were evaluated in this study.
Seventy－three patients were investigated, including 31 undergoing anterior fusion(A group), 10 receiving wide laminectomy(L group), 30 treated by wide laminectomy plus posterolateral fusion or posterior interbody fusion(F group)(5 patients received pedicle screws), and 2 undergoing partial posterior vertebral resection to correct lumar lordosis associated with fused and kyphotic spondylolisthesis(O group). The average follow－up period after surgery was 5.5 years. Each surgical procedure was evaluated according to the clinical outcome(JOA score：maximum=15 points)and X－ray findings. The relation between radiographic changes and clinical outcome was also investigated.
The average acquired JOA score at the latest visit was 3.1 points in A group, 3.6 in L group, 5.6 in F group and 11.0 in O group.
A significant relation between radiographic findings and clinical outcome was observed for scoliosis and the slip angle, i.e., the clinical outcome was worse when there was progression of scoliosis or an increased slip angle.
In our experience, multiple wide laminectomy with fusion seems to be essential for the treatment of degenerative lumbar spondylolisthesis.
However, the main issue concerning the surgical procedure is postoperative progression of the slip angle and scoliosis. Combined fusion surgery using pedicle screws can prevent the progression of scoliosis and slip angle. For fused and kyphotic spondylolisthesis, partial posterior vertebral resection for lumbar lordosis seems to be useful.
Surgical Results of PLIF with Additional Posterolateral Bone Graft for the Prevention of Adjacent Segments Disorder
Hitoshi IKEGAMI, et al.
Abstract We report the surgical results of PLIF and study the effect of additional posterolateral bone graft to adjacent segments. 25 cases treated by PLIF were studied. We treated 10 cases of degenerative spondylolisthesis(DS), 8 of lumbar disc herniation(LDH), and 7 of spondylolytic olisthesis(SO). Causing of the cases such as existing disk degeneration or malalignments, we added posterolateral bone graft to each adjacent segment in order to prevent degeneration of the disk and instability. 2 of our cases of LCS had re－operations due to some adjacent segment disorder. Among the cases of LDH, no adjacent segment disorder was observed. Among SO, only one case had re－operation because of adjacent segment disorder；It was observed that in the group in which posterolateral bone graft was used the adjacent segment ROM decreased, and this had some effect in preventing adjacent segment disorder. It must be noticed that in all the cases which needed re－operation due to adjacent segments disorder, the cause was increment of instability in the adjacent segments. The cases which had the risk factors such as existing disk degeneration or malalignments, the addition of posterolateral bone graft to the adjacent segment was considered to be effective in preventing adjacent segment disorder and in improvement of long－term results.
Free papers
Anatomical and Clinical Study on Central Vessels and
the Anterior Median Septum in the Intramedullary Surgery
Kimihiko MII, et al.
Abstract ＜Purpose＞In intramedullary tumor surgery, management of the central vessels is most difficult in the ventral portion of the tumor. The authors will discuss the micro－surgical anatomy from work on cadavers and clinical cases.
＜Results & Discussion＞Central arteries derive from the anterior spinal artery and run through the ant. med. septum. they enter the substance of the spinal cord from the top of the septum at the bottom of the ant. med. fissure. Feeding arteries derive from central arteries at this point. A large tumor encroaches on the septum. Resection of this septum results in breaking of the spinal cord vessels. During operation under the ventral part of the tumor, the MEP often decreases. The anterior pia mater was exposed during surgery in 4 cases, and in 3 cases this resulted in complete paralysis. Unilateral position sense was retained in one case. This may suggest damage to the micro－circulation of the spinal cord.
＜Conclusion＞1. To maintain the micro－circulation of the spinal cord, the central vessels should not be cut, and tumor vessels should be cut selectively at the top of the septum, if possible. 2. Exposure of the anterior pia mater during surgery may be an unfavorable prognostic sign.
Cases Needed Multiple Operations for the Treatment of Intramedullary Cord Tumors
Hiroshi TAKAHASHI, et al.
Abstract ＜Purpose＞We present two cases with intramedullary cord tumors that needed multiple operations to improve their neurological state and to prevent rebleeding. A case with cavernous angioma at C1 level and a case with ependymoma from Th2 to Th5 accompanied by syrinx at the rostral and caudal side are reported.
As to cavernoma, residual tumor after the first operation at C1 level caused rebleeding and required a second operation. The residual tumor was located at the most caudal site of the operative field. This area was considered to be the part of the dead angle under the microscopic view with minimum myelotomy at the caudal site.
The other case, with ependymoma, showed cord swelling at the first operation and an intraoperative pathological report of malignant astrocytoma prevented further removal of the tumor. After the first operation, the neurological state of the patient deteriorated. However a second operation was performed after the final pathological report that the tumor was a piloid astrocytoma. We performed a total removal of the tumor, and the patient's condition improved. The pathological diagnosis at the second operation was ependymoma.
＜Conclusion＞Total or extensive removal is always needed in cases with ependymoma or cavernoma by a sufficient myelotomy to show the whole state of the intramedullary cord tumor. Though they sometimes result in temporary deterioration, long－term neurological recovery in these cases was much better than in those who underwent incomplete removal of the tumors.
Surgical Treatment for Dural Arteriovenous Fistulas
Shinichi OKA, et al.
Abstract We present a surgical treatment and clinical results for dural arteriovenous fistulas. Since 1996, a total of 7 patients with spinal arteriovenous fistulas were treated surgically. There were 4 men and 3 women with a mean age of 43 years. The mean follow－up period was 4.5 years. Pre－operative selective angiography was done to identify the feeding artery in all patients. The lamina at one level above and one below the lesion were removed widely. The dura was opened in the midline. The site of intradural penetration of the arterialized vein was identified adjacent to the nerve root. The arterialized vein was temporarily interrupted at the site of intradural penetration by vessel clip for fifteen minutes. Spinal cord monitoring was also checked during the temporary interruption. After removal of the clip, the arterialized vein was coagulated with bipolar forceps and resected where it entered the dura. In all patients, feeding arteries were identified and successfully interrupted. JOA scores improved from 3.4 to 5.9 points postoperatively. No recurrence was observed following this simple procedure. Clinical results were related to the duration of symptoms prior to operation and the severity of preoperative neurological impairment. Surgical therapy under spinal cord monitoring was a safe and effective treatment for spinal dural arteriovenous fistulas.
Diagnosis and Treatment of Non－neoplastic Intramedullary Lesions
Minoru HOSHIMARU, et al.
Abstract ＜Purpose＞It is important to make a correct differential diagnosis of intramedullary lesions. In this report, the clinical characteristics of non－neoplastic intramedullary lesions that mimicked an intramedullary tumor on MRI were studied.
＜Materials & Methods＞Between 1986 and 2001, 10 patients with a provisional diagnosis of intramedullary tumor underwent laminectomy and removal of the tumor. Total removal was performed in 3 patients and partial removal or biopsy in 7 patients. The seven women and three men had a mean age of 52.6 years(range, 27－83 yr).
＜Results＞Pathological diagnosis was granuloma in 4 patients, necrosis in 3, inflammatory change in 2, and multiple sclerosis in one. Surgery improved the neurological status in 2 cases, failed to change it in 4, and worsened it in 4. MRI demonstrated only slight bulging of the spinal cord in 6 patients, and remarkable bulging in 4 patients with granuloma. The lesion was contrast－enhanced with Gd in all cases.
＜Discussion and Conclusion＞It is difficult to make a correct differential diagnosis of intramedullary lesions with spinal MRI. Observation or systemic examination including brain MRI, gallium scintigraphy and lung CT may be helpful for the correct diagnosis.
Lumbar Extradural Granulation Due to Candida Grabrata
Eiichiro HONDA
Abstract Spinal epidural granuloma is rare, and is mainly due to infection, including chemical and allergic factors. Granuloma is caused by organisms such as tuberculosis, syphilis, candida or others. Furthermore, it may also be produced by foreign bodies such as the starch of surgical gloves and catheters. We here report lumbar epidural granuloma due to candida glabrata suspected by clinical evidence.
The patient was a 70－year－old, male with radicular pain in the left leg.. Neurological examination revealed straight leg raising test positive on the left side and severe radicular pain consistent with the L5 nerve root. Signs of infection such as WBC, CRP and RA were negative. MRI showed a mass lesion in the left lumbar canal of L4/5, consistent with iso on T1WI and low intensity on T2WI when enhanced homogeneously. The mass was removed through an enlarged interlaminar window. Discussion： Time of infection with granuloma varied from weeks to two years. In this case, the cause of the granuloma was considered to be the following：1)immuno－function impairment due to administration of anticancer agent 2)IVH administration for 7days after operation(venous infection)3)epidural anesthesia during operation(direct infection)4)localized anesthesia around facet joint with poor sterilization. In this case, the 4th cause was considered adequate, because the granulation around the L5 nerve root included the facet with an erosive lesion under operative view.
Treatment of Spinal Epidural Hematoma with the Multiple Operations： A Case Report
Kei YAMADA, et al.
Abstract A seventy－year－old woman developed paralysis on September 30. She did not have any history of hemodyscrasia or liver disease. The laboratory data showed no coagulation disorder. The plain X－ray did not show any abnormal finding. Magnetic resonance images(MRI)demonstrated a space－occupying lesion in the epidural space at levels Th8 to Th10, with compression of the spinal cord. As the neurological deficit showed no improvement after 24 hours, operative decompression was performed at the level of Th9. As progressive of anemia and a remarkable subcutaneous hematoma were observed after the operation, additional operative decompression was performed from Th6 to Th8. A vascular lesion was observed at the lateral dorsal side of the dura together with the remarkable hematoma. Four days after the operation, she suffered hemorrhagic shock resulting in disseminated intravascular coagulation. Her severe condition was managed with emergency transarterial embolization, and the vital signs became stable. However, intermittent bleeding continued, and a third operation for the resection of the hematoma was performed, which led to an improvement of the anemia.
［Discussion］There were various possible diagnoses for this case with the multiple operations. One was an epidural vascular lesion and another was some basic uncontrolled coagulation disorder.
Cerebrospinal Fluid Leakage with Meningitis by Enterococcus：A Case Report
Hiroshi ODA, et al.
Abstract We experienced a case of a patient in whom cerebrospinal fluid leakage occurred after multiple surgeries and the treatment was difficult because of complicated enterococcus meningitis.
The case was a 59－year－old female, who was diagnosed with degenerative L3 spondilolisthesis and underwent postero－lateral fusion from L3 to L5. Postoperatively, a pseudoarthrosis was found. Subsequently, a total of four instrumentations were performed. After the final surgery, because the spinal fluid leaked out and the condition of the wound site became worse, flap surgery of the gluteus maximus and a spinal drainage were conducted. Then, enterococcus meningitis occurred. We performed a repair of the dura mater and administered antibiotics and immunogloblin. The systemic condition recovered. Finally, wound healing and solid union of spinal fixation were obtained.
It is difficult not to have such cases at all. Treatments for complication after multiple spinal surgeries are important.
Intraoperative Radiation Therapy for Metastatic Spinal Tumors
-Technical Aspects-
Taiji KONDO, et al.
Abstract ＜Purpose＞To improve neurological recovery and local control of metastatic spinal tumors, we have performed posterior decompression and instrumentation combined with intraoperative radiation therapy(IORT). The aim of this report is to present the technical aspects of IORT.
＜IORT Procedure＞After conventional laminectomy, the patient was transferred to the radiotherapy room, where electron beam radiation was delivered to the metastatic lesions. Although the spinal cord was protected from the electron beam by a lead shield, simulation study showed that the beam could cover the posterior part of the vertebral body. The delivered dose was 20 Gy, equivalent to 50 Gy of external irradiation. After IORT, the patient was transferred back to the operating room, where spinal instrumentation was performed.
＜Results＞114 patients were treated with IORT in 1992－2002. Out of 96 cases with motor weakness, 71 cases(74%) improved by at least one level according to Frankel's classification. Out of 98 patients who survived more than three months after IORT, four(4%)showed local recurrence 12 to 36 months after IORT.
＜Conclusions＞Intraoperative radiotherapy is promising for neurological recovery and local control of spinal metastases.
The Experience of External Spinal Fixation Using Ilizarov Spinal Fixator for
Lumbar Burst Fracture
Masafumi UESUGI, et al.
Abstract
Between September 2001 and April 2002, two patients with lumbar burst fracture without any neurological deficitunderwent external spinal skeletal fixation with an Ilizarov Spinal Fixator.
The patients started walking two days after operation. No neurological deficit or severe back pain was noted during theobservation period.
Our results suggest that the Ilizarov Spinal Fixator can help early ambulation of the patient after lumbar burst fracture.
Remodeling of Spinal Canal After Thoraco－Lumbar Burst Fracture
Masaaki MURATA
Abstract Posterior fusion without direct decompression was chosen in a case of complete paraplegia due to instability following thoraco－lumbar burst fracture. This report concerns examination of the remodeling of the spinal canal in these cases. Among 20 patients who underwent pedicle screw fixation for thoraco－lumbar burst fracture, and were observed for six months or more after operation, 19 patients(15 men, four women)were studied by means of CT scan. Average observation period was 16.1 months. Results showed that in thoraco－lumbar burst fracture treated by this method, good remodeling of the spinal canal was obtained irrespective of age, grade of damage before operation and postoperative alignment. Moreover, the time needed for remodeling was less than 6 months after operation. This corresponded the time of bony union of the fracture, and when firm fixation was obtained, it was considered that the spinal cord was remodeled by the time of bony union.
Posterior Instrumentation with Transpedicular Bone Graft for the Osteoporotic Vertebral Collapse
Yukimasa NISHIMURA, et al.
Abstract We report the surgical results of posterior instrumentation with transpedicular anterior decompression and intravertebral bone graft for osteoporotic vertebral collapse. 8 cases of posttraumatic osteoporotic vertebral collapse were treated using posterior instrumentation with transpedicular anterior decompression, intravertebral bone graft and interbody fusion.There were one male and seven females. The average age at the operation was 74 years and the mean follow－up period was 37 months. The collapsed vertebra was Th12 in 6 cases and L1 in 2cases. The patients were studied clinically and radiologically at follow－up. All had complete relief of their back pain and showed good neurological improvement. Radiologically, the average local kyphotic angle was 33.9°before surgery, and was corrected to 14.3°immediately after surgery. At follow－up, the kyphotic angle was maintained at 15.8°with little less of correction. Good bony union of the collapsed vertebra was achieved in all patients, and there was no instrumentation failure. We consider that posterior instrumentation with transpedicular anterior decompression, intravertebral bone graft and interbody fusion is a useful treatment for osteoporotic vertebral collapse.
Reconstruction Surgery for the Late Collapse of Thoracolumbar Vertebrae
Yuji MATSUBARA, et al.
Abstract
＜Purpose＞The purpose of this study is to evaluate the surgical management of late collapse of thoracic and lumbar vertebrae.
＜Materials and methods＞Eleven cases were operated for late collapse of thoracic and lumbar vertebrae. There were 2 males and 9 females. The average age was 65 years, ranging from 57 to 76 years. 8 cases underwent posterior correction and anterior fusion, and 3 cases underwent posterior osteotomy and fusion.
＜Results＞The operation time was an average of 369 minutes, ranging from 257 to 425 minutes. The estimated blood loss was an average of 1404 ml ranging from 560 to 3274 ml. The local kyphosis changed from 37.1°to 11.1°. The fusion rate was 90.9% and pseudoarthrosis was seen in one case. Instrument failure and fibula strut fracture were seen in another case.
＜Discussion and conclusions＞We think that solid fusion of the fracture site is needed in cases of osteoporosis. We have selected combined fusion. Recently we have selected vertebrectomy and anterior strut graft by posterior approach only. This method is less invasive and useful for late collapse of thoracolumbar vertebrae.
Posterior Microendoscopic Surgical Approach for The Cervical Spine
Takamichi YUGUCHI, et al.
Abstract To evaluate the feasibility and the advantage of a minimally invasive microendoscopic technique for posterior decompression in cervical degenerative disease, cervical foraminotomy and/or hemi－laminectomy and contralateral laminadoming were performed in cadavers and in clinical cases.
The posterior approach has advantages in selected cases. However, the standard posterior approach requires extensive paraspinous muscle dissection, and is, therefore, subject to several postoperative problems. This minimally invasive endoscopic technique needs only a small surgical route, thus reducing damage to the paraspinous muscles. It also provides a clear view of drilling points, because of the oblique view angle of the endoscope. Posterior cervical decompression with this system is technically feasible and will reduce postoperative morbidity. This study deals with cases of cervical radiculopathy and segmental canal stenosis operated on with this system, as well as the key points of the surgical procedure.
Trans－sternoclavicular Approach with Elevation of the Osseomuscular Flap to the Upper Thoracic Spine
Shoyo MIZUTANI, et al.
Abstract We describe a method of trans－sternoclavicular approach to the upper thoracic spine invaded by metastatic tumor, with elevation of an osseomuscular flap. The method of exposure is reported by Birch(1990).
(Case)A twenty－seven year old man was admitted with chief complaints of difficulty in walking and dysuria. One year ago he had undergone extended resection of a liposarcoma of his right thigh. Magnetic resonance imaging and CT scan studies revealed a Th1－Th2 spinal tumor which severely compressed the spinal cord, with invasion of the surrounding soft tissue. The diagnosis was recurrence of liposarcoma. The first operation was posterior decompression of the spinal cord and spinal instrumentation. At the second operation, we performed vertebrectomy of T1 and T2, and then replaced the titanium cylinder by the anterior approach. The exposure was by the transclavicular approach；the manubrium sterni and the medial third of the clavicle with a pedicle of the sternocleidomastoid muscle was divided and elevated upward.
(Conclusion)This approach gives a wide view of the operative field, and the osseomuscular flap can then be re－attached to restore normal anatomy.
Circumferential Decompression for Thoracic Myelopathy Due to
Severe Kyphosis Combined with Ossification of Ligamentum Flavum
Masashi SAITO, et al.
Abstract In children who have had tuberculosis involving the thoracic spine, the kyphotic deformity may progress after a solid anterior spinal fusion. Severe thoracic kyphosis is a possible cause of progressive myelopathy in adults. We have had the opportunity to treat a 54－year－old male surgically by circumferentiall decompression for myelopathy due to severe angular thoracic kyphosis combined with ossification of the ligamentum flavum. The site of kyphosis and ossification of ligamentum flavum was the thoracolumbar region. Our approach consisted of two surgical procedures. The first procedure was laminectomy and pediclectomy of both sides with posterior approach. The second was anterior decompression of the apical vertebra with costotransversectomy approach. This report describes the surgical procedures and shows the operative results of this complicated case.
Far－out syndrome-Report of Four Cases
Kenichi WATANABE, et al.
Abstract Four cases of Far－out syndrome described by Wiltse(Spine, 1984)were presented, in which L5 vertebra tilting were characteristically shown on pain x－ray films and lateral marginal spurs were demonstrated on either L5 or sacral body by MCT and 3D－CT. By coronal view of MRI Compression to the 5th lumber nerve root was not clearly demonstrated but by selective radiculography of L5 nerve root, clear indentation toward the caudal derection was well visualized on the L5 nerve root in all cases. Pathologies found in surgeries were as followed：In one case, L5 nerve root was impinged by ligaments attached on transverse process and impingement was relieved by sectioning this ligament. In one case impingement was relieved by sectioning bone spurs around bodies, In two cases L5 nerve roots were found relieved from pressure by restoring intervertebral height using PLIF, TLIF technique.
＜Discussion＞It was reported pathologies of far－out syndrome were either lumbosacral ligaments by Olsewski, 1991 and Transfeldt, 1993 or bone spurs by Abe, 1997 and Dezawa, 1998 and Matumoto, 2002. In our cases direct pressure to the nerve root were either ligaments or bone spurs were found as described by Wiltze, 1984. But it was found interesting that these anatomical structure became pathological by L5 vertebral tilting. Indentation to nerve root from above downwards goes well with this finding. Therefore restoring intervertebral height using PLIF and/or TLIF technique should be considered in one of surgical management of Far－out syndrome.
Microscopic Nerve Root Decompression for L5 Spondylysis
Junichi OSUMI
Abstract The purpose of this study is to introduce microscopic nerve root decompression for L5 spondylolysis. Subjects were 6 patients(5 males and 1 female aged 45 in average)with L5 spondylolysis. Their chief symptoms were leg pain rather than low back pain.
A 2－3 cm median incision was made special muscle retractors were used for exposure of the operation site. Under a microscope laminotomy was carried out to release the exiting L5 nerve root which was compressed by the loose lamina. The pedicular spur was resected. Walking was allowed on the first postoperative day, and one week after surgery patients went back to normal life.
The mean JOA scores of the patients were 16.0 preoperatively and improved to 24.7 postoperatively.
In patients with spondylolysis whose chief complaints are radicular leg pain, nerve root decompression takes priority over fixation surgery. In decompression not only the loose lamina but the pedicular spur should be resected. Our method is minimally invasive and gives a clear operation field and adequate decompression.
Lumbosacral Correction by Intrasacral Fixation
-Cantilever and In Situ Contouring Technique-
Tokumi KANEMURA, et al.
Abstract ＜Purpose＞The aim of this study was to evaluate the surgical effects of spinal correction for degenerative lumbar kyphosis and flatback syndrome using intrasacral fixation(ISF)with cantilever and in situ contouring technique.
＜Material and Method＞We evaluated 16 consecutive patients with degenerative lumbar kyphosis and flatback syndrome who were treated by ISF with cantilever and in situ contouring technique. They were followed up for a minimum of 6 months.
＜Results＞The patients consisted of 5 men and 11 women with a mean age of 50 years(11－80). Thirteen patients underwent by PLIF with ISF, two patients PLF and staged ALIF, and one patient PLF only. There were statistically significant differences between mean measurements before surgery and at the last follow－up for lumbar lordosis, －10.3°versus－34.8°(p＜0.05). At the last follow－up, pseudarthrosis occurred in one patient who underwent PLF only.
＜Discussion＞ISF with cantilever and in situ contouring technique for degenerative lumbar kyphosis and flatback syndrome provided increased lumbar lordosis, improved sagittal alignment and rigid lumbosacral fixation.
＜Conclusions＞We evaluated 16 patients with degenerative lumbar kyphosis and flatback syndrome who were treated by ISF. We obtained successful surgical results, and the technique was concerned to be effective for degenerative lumbar kyphosis and flatback syndrome.
A Novel Method of Posterior Iliac Crest Bone Harvesting to
Prevent Superior Cluneal Nerve Injury
Yohichi AOTA, et al.
Abstract Superior cluneal nerve injury is a well－known cause of chronic pain complicating bone graft harvesting from the posterior iliac crest for spinal fusion. Familiarity with the pelvic anatomy and awareness of the possibility of this complication may prevent this. The medial branch of the superior cluneal nerve crosses over the iliac crest through an osteofibrous tunnel, which is in the outer table of the crest. The superior cluneal nerves are at risk when a surgeon does a subperiosteal dissection in the outer table. Although the literature is full of the procedures for outer table and/or intracortical harvesting, no documentation of inner table harvesting is available. The infrafascial approach was developed to avoid superior cluneal nerve injury. Inner table harvesting by the new approach carries significant advantages over other approaches to the posterior iliac crest. It inflicts the least trauma to the superior cluneal nerve. The results were excellent in 18 cases(2 of which underwent bilateral harvesting). In conclusion, inner cortex harvesting by the infra－fascial approach is feasible and is likely to prevent pain at the bone graft donor site.