Minimally invasive stabilization (MISt) of the upper cervical spine via the posterolateral approach was developed and introduced. A posterolateral 4 cm skin incision was applied and the splenius muscles were split using fingers from C1, C2 or C3 lateral masses. Following this the great occipital nerve was detected behind obliquua capitis inferior (OCI). Blunt dissection was performed along the upper border of OCI laterally and cranially in the suboccipital triangle. VA(vertebral artery) was retracted cranially, and the great occipital nerve was medially retracted. The medial border of the OCI attachment of C1 was used as an entry point of C1 lateral mass screw and 1.4mm K-wire was inserted through a navigated guide tube. Cannulated pedicle screws were followed using the Iso-C 3D navigation system. 10 patients underwent this new method. Mean age at operation was 69.8 years old with the range of 34 to 87. The diagnoses were axis fractures in 8 patients, RA(rheumatoid arthritis) in 1 and tumor was found in 1. The average bleeding volume was 94.5ml and surgical time was 198.5 minutes. 17 screws were inserted in C1 lateral masses, 4 screws were inserted in C2 pedicles, 14 screws in C3 pedicles and 3 screws were in opposite transarticular C1/2. No complication and no LM screw misplacement occurred. This method provided direct oblique exploration of C1 lateral masses and also allowed the correct oblique angle of screw position which in turn results to less lateral deviation and subsequently reduces muscle damages and bleeding from the venous plexus.

There are two main types of electrodes used for spinal cord stimulation (SCS), the paddle type and the catheter type. When a catheter type electrode is inserted in cases with extensive spinal degeneration, the patient can experience intractable pain. We herein report two cases in which a catheter-type electrode was inserted by partial laminectomy under general anesthesia.

(Case 1) A 70-year-old male who had undergone SCS for advanced cervical-brachial syndrome one year before this admission. Since his neck and upper extremity pain relapsed due to a disconnection of the electrode, he was admitted to replace the electrode. To cope with future problems, such as a recurrent disconnection, catheter-type electrode was inserted by partial laminectomy.

(Case 2) A 70-year-old female who had undergone puncture trial for severe lumbago. Because pain relief was obtained, implantation surgery was planned. We planned to undergo the implantation surgery under general anesthesia due to the pain associated with the insertion of the lead during the puncture trial had been severe.

In both cases when the postion and angle of a 18-G touchy needle was fine-tuned into the epidural space, the electrode control became easier. Insertion of a catheter-type electrode by partial laminectomy under general anesthesia is a viable method in such cases where there is strong deformity of the vertebrae.

Purpose：To compare autologous bone graft with PEEK cage used for anterior cervical decompression fusion (ACDF) in more than 3 levels anterior cervical fusion (ACF).

Material and Methods：Patients who underwent hybrid method ACF in more than 3-levels from 2007 to 2013 were enrolled in this study. In the autologous group there were 21 cases and in the PEEK cage group there were 30 cases. Functional X-ray was taken after three months postoperatively to investigate the period until stabilization and bone union and the change of the fused angle. We also compared blood loss, operating time and clinical recovery rate.

Results：There was no difference in the period until union, but the period of stabilization was shorter and the fused angle was more lordotic in the autologous groups (p<0.01). There were no differences between the groups in clinical recovery rate, blood loss and operative time.

Discussion：Our results showed the stabilization was due to the property of the PEEK cage that meant bone ongrowth did not occur, and also that there was less of a fused angle in the PEEK cage group.

Conclusion：Both groups are almost equal except for the period until union and the fused angle. We concluded that additional use of a dynamic plate was mandatory for PEEK cages used in ACF for more than 3-levels.

We describe the mid-term results of foraminotomy with muscle-preserving off-the-midline approach which preserves all muscular attachments to the spinous processes. Since 2009, 19 patients who were followed for more than 2 years underwent the foraminotomy due to radiculopathy. The mean follow-up period was 44 (range 25-61) months. Mean operation time was 138 minutes. Mean blood loss during operation was 36 grams. Improvement of radicular pain was identified in each patient. Post-operative persistent neck pain was not identified in any patient. Preand post-operative C2-7 angles averaged 8.9 and 10.7 degrees. Pre- and post-operative C2-7SVA averaged 22.5 and 19.7mm. Cervical curvature was well maintained after the surgery. Pre- and postoperative ROM of the neck averaged 35.2 and 47.0 degrees. ROM was significantly improved postoperatively. Pre- and post-operative cross sectional area of the deep extensor muscles at the affected area averaged 418 and 419mm². Considering our mid-term results, foraminotomy with musclepreserving off-the-midline approach through the intermuscular plane keeps muscle substance undamaged, thus diminishes the post-operative neck pain and preserves mobility and stability of the cervical spine while providing satisfactory improvement of the radicular pain.

Complete resection of spinal nerve sheath tumors (NSTs) does not always result in significant neurological deficit. The purpose of this retrospective case analysis was to discuss the optimal surgical strategy for spinal NST of the cervical spine. Twenty-nine patients with solitary cervical NST over the past decade were included. Twenty of 29 cases (69.0%) showed extradural dumbbell extension. Total removal of the tumor was achieved in 24 of 29 cases (82.8%). Staged surgery using combined anterior and posterior approaches was applied in 2 cases of extradural dumbbell extension. Tumor involvement with nerve root fibers critical for upper extremity function (C5-C8) was recognized in 8 of 29 cases (27.6%). Final assessment of neurological function revealed satisfactory or acceptable recovery in all 8 patients. Spinal NSTs with extradural dumbbell extension are a common condition in the cervical spine. Complete removal of spinal NST of the cervical spine may carry a risk of permanent neurological deficit, but such sequelae appeared to be the exception in the present case analysis. A radical and safe surgical strategy, including staged surgery combining anterior and posterior approaches, should be tailored to the individual case.

We investigated clinical outcomes of thirteen spinal meningiomas, operated on by one surgeon using the METRx microdiscectomy system to achieve a Simpson grade 2 operation with curettage of its dural attachment. Mean age at surgery was 68 years old(with a range of 51-86 years)and mean follow up periods was 90 months (with a range of 12-141 months).

In eleven cases out of 13, we could eradicate the meningioma completely through this system with no complications. No tumor recurrence was found on MRI in these 11 cases at the latest visit.

We concluded that it was not always necessary to excise tumor attachment of dura mater in patients over 50 years old.

Objective：The purpose of this retrospective study was to analyze surgical safety and usefulness of microsurgical hemilaminectomy in consecutive patients with intradural extramedullary spinal cord tumors, and to clarify the optimal surgical strategy.

Methods：A total of 53 cases of intradural extramedullary tumors were treated surgically in our institute over the past 3.5 years. There were 31 males and 22 females with a mean age of 56.6 years old. Surgical safety and usefulness of hemilaminectomy was analyzed in comparison with conventional laminotomy regarding the tumor pathology, tumor location/size, estimated blood loss during surgery, postoperative serum creatine kinase (CK) value or postoperative wound pain.

Results：Hemilaminectomy was applied in 25 of 36 cases of spinal nerve sheath tumors (69%) and in 8 of 17 cases of spinal meningiomas (47%). There was not a significant difference seen in either tumor removal, surgery-related complications, estimated blood loss during surgery or postoperative CK value between the hemilaminectomy group and conventional laminotomy group. On the other hand, postoperative wound pain was significantly less in hemilaminectomy group than in the conventional laminotomy group.

Conclusions：Hemilaminectomy for the removal of intradural extramedullary spinal cord tumors can be recognized as a less invasive and safe procedure, if applied appropriately.

Objective：We studied the method of recapping hemi-laminoplasty with preserving muscle (RecapL) to remove the lumbar intradural tumor, in 2012. The advantage of this procedure is to prevent muscular damage by preserving the muscular attachments of the lamina process. We assessed the clinical results of RecapL.

Method：Twelve consecutive patients were surgically treated by removing the tumor of conus or cauda equina using either the RecapL method (7 patients) or the non-RecapLmethod(5 patients). We evaluated each method using the following parameters：blood loss (g), operation time (min), improvement rate of JOA sore, preserving rate of paravertebral muscles, and the width of bony decompression at one year after surgery.

Result：There were no significant differences between the 2 groups (RecapL/non-RcapL) in blood loss (133/187ml), operation time (216/168min), improvement rate of JOA score (38/ 36%), preserving rate of paravertebral muscle (95/91%). However, there was a significant difference in the width of bony decompression (10.9/12.4mm) (p=0.05).

Discussion：RecapL is a minimally invasive surgery technique due to the tendency to preserve the muscular attachments of the spinous process. However, the main disadvantages of RecapL was that it was a slightly more complicated procedure and required a longer operating time.

In intradural extramedullary metastatic spinal cord tumors, neurological improvement can be expected by surgical extirpation of the tumor. Tumor hardness appeared to be strongly related to the degree of surgical excision and neurological result as well. We experienced three cases of surgically treated intradural extramedullary metastatic spinal cord tumor and examined excisional difficulty in relation to magnetic resonance imagings (MRIs) and pathological findings. A case of the tumor which displayed a low signal intensity using T2 MRI imaging was very hard, resulting in insufficient decompression. Pathologically, this tumor was verified to have much fibrous component by Masson trichrome stain. On the contrary, T2 high signal tumors having less fibrous tissue were removed with ease. MRI signals may predict tumor hardness as well as surgical difficulty.

Symptomatic spinal cavernous angioma (sSCA) is one of the diseases that usually may occur if there is an hemorrhagic state. Intramedullary SCA is relatively rare, and accounts for 5% of all spinal vascular abnormalities. Intramedullary SCA usually occurs at the thoracic levels and is rare at the conus medullaris. We reviewed one operative case of symptomatic SCA in the conus medullaris lesion. The case was of a 56-year-old male who developed sudden onset paraparesis and vesicorectal impairment. Emergency magnetic resonance imaging revealed intramedullary hemorrhage from Th9 to L1 level. This demonstrated the characteristic pattern of a cavernous angioma. Preoperative management included the administration of corticosteroid for edema in spinal cord. Because of slow progressive neurological deterioration following initial symptoms, an elective operation was performed for resection of tumor by selective dorsal midline myelotomy (depending on the abnormality of microscopic cord surface bia Th10-L2 laminoplastic laminotomy.) The patient was pathologically proven to have hemorrhagic spinal cavernous angioma after surgery, and underwent intensive postoperative rehabilitation and care.

We report the basic strategy of symptomatic spinal cavernous angioma management and the need for further research.

It is usual to perform foraminotomy using the posterior approach if conservative therapy has not been effective in treating refractory cervical radiculopathy. The advantage of the posterior approach is preservation of facet motion, but nerve root retraction is necessary for resection of the bone spurs. A high speed drill is usually used for resection of bone spurs, but its omnidirectional behavior can result in damage to tissues including nerve roots and the dural sac. The ultrasonic bone scalpel is a useful and safe tool for spine surgery such as resection of a bone spur which lies in front of the nerve root. The advantages of the ultrasonic bone scalpel include directionality and results in less damage to the surrounding soft tissue. For these reasons we often use this device in posterior approach foraminotomy for the treatment of cervical radiculopathy. This device could provide a safer alternative when retracting nerve roots during resection of bone spurs in foraminotomy for the treatment of cervical radiculopathy.

Background：Cervical laminoplasty became a worldwide standard operative procedure. There have been plenty of spacers to stabilize elevated laminae, however, ceramic spacers are the only ones available and covered by national health insurance in Japan.

Purpose：The purpose of this project was to introduce several processes in the development of a pure titanium spacer for it to be available in Japan.

Results：The main concept of the spacer includes：(1) high compatibility in shape with conventional ceramic spacers (2) high flexibility and universal design for unilateral and bilateral laminoplasties (3) chance of bone conduction in the spacer resulting in the reconstruction of the bony arch (4) avoidance of bony fusion to an adjacent lamina, along with conventional ceramic spacers. Following the preliminary clinical experience as well as certification in material safety and mechanical strength compared with conventional surgical procedures, a new Japan-made titanium spacer namedéLaminoplasty Basketêbecame commercially available in 2014.

Discussion：No apparent disadvantages in performing laminoplasty compared with ceramic spacers was found, and some merits of the developmental concepts have been recognized. Mechanical advantages compared with simple titanium plates have also been postulated. A proposal of a new titanium spacer will hopefully greatly aid the evolution of surgical techniques of Japanmade laminoplasty.

Introduction：In recent times posterior spinal decompression with instrumented fusion has changed greatly and the minimally invasive surgery (MIS) technique has been gradually established. The percutaneous pedicle screw (PPS) is one of these such methods. We developed a new cannulated pedicle probe, because there is currently no optimal probe for PPS.

Method：We reviewed 38 consecutive patients whom the same surgeon performed MIS using the PPS technique. In conjunction with the PPS implant we used；for the first 7 patients the Jamshidii needle was used, the next 18 cases used a conventional cannulated probe and next 13 cases used a custom-made cannulated probe (K probe) that we devised. We evaluated the precision of the PPS by these three methods and the implant appliance.

Results：The depth of probing can not be judged when using a Jamshidii needle and the conventional cannulated probe. The K probe has an intussuscipiens to allow for length adjustment and so we can understand the depth of probing.

Conclusions：The K probe that we developed is simple and appears to be a very useful surgical instrument.

We performed open-door laminoplasty by inserting hydroxyapatite (HA) spacers between the lamina and lateral mass without suturing. To maintain the strong restoring force of the hinge, we drilled only the dorsal cortex bone of the lamina with a diamond burr. In this presentation, we demonstrated a simple surgical technique and radiologically evaluated the results of spacer dislocations and hinge fractures 6 months after the surgery.

We analyzed retrospectively 84 consecutive cases of cervical spondylotic myelopathy performed using laminoplasty from January 2013 to December 2013 at our institute. The mean surgical time and mean intraoperative blood loss were 91±26 min and 93.6±63.5 ml, respectively. The mean preoperative C2-7 angle was 10.3±9.9°, while the mean postoperative C2-7 angle was 6.7±11.3°. Of the 344 HA spacers, one dislocated completely and five shifted partially, but there were no neurological deficits in any case. In all, patients with 19 (5.5%) hinge fractures developed asymptomatic hinge restenosis.

Our method enabled us to achieve satisfactory outcome through minimal exposure of the lateral mass, minimum blood loss, and minimal surgical time. The reason hinge fractures may have not

Background：TLIF using a rigid pedicle screw has become the gold standard in spinal fusion. But, do stronger instruments have advantages for bony union? Bone grafts in TLIF can undergo necrosis and the volume may decreases over time. If the disc height does not decrease accordingly, it will create some space between the grafted bone and both upper and lower vertebral bodies, which is disadvantageous for bony union. Thus, we considered that the pedicle screw with mobility would provide moderate compression force to the bone grafts in TLIF and would be better for bony union. Segmental Spinal Correction System (SSCS) was used for TLIF in this study.

Results：We investigated the clinical results of this method in 13 patients (6 male and 7 female, 56~79 y/o) with minimum 1 year follow up. The mean JOA score improved from 13. 5 preoperatively to 25.4 postoperatively. The mean Hirabayashi improvement rate was 76.8%. Bony union was observed for all patients.

Conclusion：TLIF using pedicle screw with mobility provides moderate compression force to the bone grafts in TLIF and bony union may be enhanced. This could be a new method in spinal fusion surgery.

Deep infection after spinal instrumentation surgery is a serious complication. We were able to treat almost all cases without removing spinal instruments by using negative pressure wound therapy (NPWT). We will introduce our treatment strategy of our department.

Method：Immediately after the diagnosis of infection we thoroughly wash and debride the wound, and at this time do not perform closure of the wound. Instead the wound is closed using film material and filled with gauze. At the point where the bleeding lessens, NPWT is commenced. We make a simple NPWT system with equipment that is in the first ward in our hospital. To create a simple NPWT we use polyurethane foam, suction tube of 14Fr, gauze and film material. Every 2-3 days we change the NPWT system. We also perform wound cleaning when replacing. The instrument is covered in granulation tissue, and the NPWT is applied on the wound until epithelialization.

Result：There were 11 deep infection cases in January 2010 to June 2013. In eight cases, ?? instrumentation was prevented completely and in some cases it was only partially removed.

Discussion：It was possible to cover the instrument and eliminate dead space gradually by using NPWT. Avoiding the removal of the instrument is possible with NPWT.

Purpose：When Jehovahʼs Witnesses who refuse blood transfusions for religious reasons undergo surgery, ethical and medical problems may arise. We describe cases of spinal surgery in Jehovahʼs Witnesses.

Methods：Four patients (mean age, 38[15-60]years) underwent radical spinal surgery at our hospital during 2010-2013 for adolescent idiopathic scoliosis, cervical intramedullary tumor, atlantoaxial subluxation, or posterior longitudinal ligament ossification. We assessed the operation time, perioperative blood loss, and average decrease in postoperative hemoglobin level.

Results：The patients refused preoperative autologous blood donation, but consented to isovolemic hemodilution and salvage autologous blood transfusion. The mean operative time was 250 (231-328) min and perioperative blood loss was 390 (50-631) ml. The mean postoperative hemoglobin level decrease was 3.1g/dl；no allogeneic transfusions were necessary. All patients underwent surgery without blood transfusions or serious complications.

Discussion：When patients request for surgery without blood transfusion for religious reasons, we should obtain informed consent and document the blood transfusion denial. We should also ensure that blood loss and surgical time are reduced as much as possible under hypotensive anesthesia.

Conclusion：We successfully performed spinal surgery using isovolemic hemodilution and

Postoperative management of the patients with Parkinsonʼs disease (PD) can be difficult after spinal surgery. Reasons include the patient being unable to take L-dopa in the perioperative period, the symptoms of PD itself (especially akinesia leading to respiratory problems and thrombosis), disease progression and the development of Neuroleptic Malignant Syndrome.

We looked at 5 patients with postoperative deterioration of Parkinsonism after spinal surgery. We examined a number of variables which included：the cause of their spinal surgery, the Hoehn-Yahr (H-Y)classification, the dose and period of L-dopa administration, operative method, operative time, the presence of bleeding, the administration of L-dopa in the perioperative period, and compared them with the cases without postoperative deterioration of Parkinsonism after spinal surgery.

All cases with postoperative deterioration of Parkinsonism after spinal surgery, had Camptocormia, and H-Y classification was the average of 4 or more.

We found that to prevent the postoperative deterioration of Parkinsonism, oral administration of L-dopa on the morning of the operation day and also soon after surgery had been completed was effective. In addition, the the administration of intra-operative intravenous L dopa every 3 hours was also effective.

Thoracic disc herniations (TDH) are rare in comparison with their cervical or lumbar counterparts and are thought to comprise 0.1-4% of all disc herniation. TDH and OLF often coexist and occur at lower thoracic levels. A variety of methods using both anterior and posterior approaches to the thoracic disc space have been reported. Some authors however, have recently developed a transforaminal approach for thoracic disc decompression and interbody cage placement modified by the T-LIF technique. We have performed the TTIF approach uneventfully in two patients. The TTIF approach permits access to the anterior column of the thoracic spine and it allows for 270 degrees decompression. This technique not only effectively improves neurological function but also rectifies the sagittal alignment of the spine to avoid neural damage caused by the progression of thoracic kyphosis and micromotion after surgery. There may, however be difficulty in some cases depending on working space and disc height.

Purpose：We have performed semi-rigid posterior fixation using dynamic connector (DC) and sublaminar taping (ST) to prevent adjacent segment disorder (ASD) and instrumentation failure. The purpose of this study was to evaluate the short-term efficacy of this procedure.

Methods：We retrospectively analyzed 18 patients (3 male, 15 female, mean age：77.9 years old, mean follow-up period：19 months) who underwent posterior decompression fusion for lumbar osteoporotic vertebral fracture (OVF). Mean fused level was 3.8. DCs were used in 10 cases (Group D+), and static connectors were used in 8 cases (Group D−). STs were applied in 15 cases(Group S+), while the other 3 cases (Group S−) were treated without STs. Radiographs and clinical findings preoperatively, immediately after surgery, and at the final follow-up were evaluated.

Results：Clear zones around PSs were observed in 6 cases (60%) in Group D+ and 7 cases (88%) in Group D−. Postoperative vertebral fractures were observed in 6 cases (40%) in Group S + and 2 cases (67%) in Group S−. Surgical revisions were necessary in 4 cases.

Conclusions：DC and ST are useful options in posterior fixation for the treatment of OVF to prevent ASD and instrumentation failure.

97 adult scoliosis patients that underwent spinal deformity surgery using iliac screws were studied. Penetration of the outer or inner iliac table were assessed by postoperative CT. The screw was considered misplaced if the screw penetrated the iliac table or inserted into the sacroiliac joint. The iliac opening angle was measured using preoperative pelvic CT. Sagittal projection of the iliac screws was also assessed by postoperative lateral lumbar radiographs. The accuracy between surgeries performed before and after 2013 was compared. Among the 194 iliac screws, 162 iliac screws (83.5%) were inserted correctly. The rate of correct insertion in the group performed after 2013 was higher than in the group performed previously (90.2% vs. 77.5%). The iliac opening angle in the lateral penetration group was smaller than that of the correct insertion group, and the sagittal screw angle in the medial penetration group was smaller than the correct insertion group. Screw penetration of the outer iliac table occurred possibly in patients with a narrower iliac opening angle. Also the iliac screw should be inserted approximately parallel to the sacral slope in order to avoid penetration of the inner iliac table. The accuracy of free-hand iliac screw insertion will improve with reference to these points.

Sacral pedicle fracture following spinal instrumentation is an extremely rare complication. We report five cases of insufficient S1 pedicle fracture after spinal instrumentation. All patients developed lower limb and lower back pain several days after instrumentation. In X-rays image, the back out of cages were found in three cases. However S1 pedicle fracture was not found using CT, but with MRI in the all cases. The S1 pedicle screw was significantly loose because of S1 pedicle fracture in all cases. We perfomed reinsertion in three cases and switched to alar screw in two cases. During follow-up, we needed to reoperate on lumbopelvic fixation in one case and considered reoperation in one case because of the presence of low back pain. Where lower limbs and low back pain after spinal instrumentation occurs, we should consider the possibility of the S1 pedicle fracture and be vigilant to the need of rectifying this problem.

Occurrence of spinal epidural hematoma after microendoscopic decompressive laminotomy (MEDL)　is not rare, and it can be due to a poorly functioning drain. The urokinase immobilization antithrombogenic drain which is available with only a large diameter, and only until recently, was made with a small diameter and was used for MEDL in this study. The urokinase immobilized antithrombotic drains prevented thrombotic occlusion, and moreover, short slits, on contralateral side of the dura, and the external-cylinderless endoscopic drain installation method was effective in reducing the formation of hematoma by performing together.

A 71-year-old man who underwent cervical laminectomy experienced two symptomatic epidural hematomas. Drain obstruction was the predominant cause. Congenital Protein S deficiency was diagnosed postoperatively. Protein S is a natural anticoagulant which is essential for inhibiting thrombosis. The present case suggests that not only a bleeding disorder, but also a hypercoagulable state could be a risk factor for postoperative symptomatic epidural hematoma.