Tarsal tunnel syndrome is a not uncommon clinical condition. We have operated on 71 patients (125 feet) with tarsal tunnel syndrome over a two year period (2005-2006). During surgery we frequently found fine branches originating from the medial, lateral, or both plantar nerve within the tarsal tunnel. According to its origin and course we divided these into five patterns from 0 to 4 ; no fine branch, one fine branch from the medial plantar nerve, one fine branch from the lateral plantar nerve, two branches from the lateral and medial plantar nerve, two branches from the medial and lateral plantar nerve and forming an ansa, respectively. As a result our patients could be categorized as 51 (41%) group 0, 49 (39%) group 1, 3 (2%) group 2, 15 (12%) group 3, and 7 (6%) group 4. Although these fine branches presented in more than half of our cases we found that very little attention has been paid to this ahatomical feature's existence. To recognize the existence of anatomical variations is important in avoiding accidental nerve injury during operation.

  Object : To investigate hereditary disorders of connective tissue (HDCT) and Ehlers-Danlos syndromes (EDS) that can present with lower brain stem symptoms attributable to occipito-atlanto-axial hypermobility and cranial settling, and relationship to Chiari malformation type Ⅰ (CMI).

  Methods : The diagnostic criteria for EDS and related HDCT were prospectively met by 155 patients. Osseous structures comprising the craniocervical junction were investigated morphometrically using reconstructed 2D-CT and plain x-ray images in 135 patients with HDCT・EDS and the results were compared to those in patients with normal controls (n=55).

  Results : There were 124 cases (80%) in HDCT・EDS of CMI. The diagnostic features of HDCT・EDS with CMI had a greater incidence of lower brain stem symptoms and signs. The measured distances of the basion-dens interval (BDI), basion-atlas interval (BAI), atlas-dens interval (ADI), dens-atlas interval (DAI), clivus-atlas angle (CAA), clivus-axis angle (CXA), and atlas-axis angle (AXA) were the same in the supine and upright positions in normal controls. There was reduction of the BDI (3.3 mm), enlargement of the BAI (2.8 mm), and reduction of the CXA (10.8°), CAA (5.8°, p<0.001), and AXA (12.3°) upon assumption of the upright position. These changes were reducible by cervical traction.

  Conclusions : Morphometric evidence of cranial settling, posterior gliding of the occipital condyles in the HDCT・EDS cohort suggests hypermobility of the atlanto-occipital and atlanto-axial joints. This hypermobility induces more prominent brain stem symptoms in patients associated with CMI. The patients with CMI have greater hypermobility of occipito-atlanto-axial joints.

  Object : To examine that post-traumatic condition (PTC) can present with lower brain stem symptoms attributable to occipito-atlanto-axial hypermobility and cranial settling, and its relationship to Chiari malformation type Ⅰ (CMI).

  Methods : We defined the condition of continuous brain and neck symptoms after motor vehicle accidents or falling down with loss of consciousness as PTC and 56 patients met to the criteria. Osseous structures comprising the craniocervical junction were investigated morphometrically using reconstructed 2D-CT and plain x-ray images in 50 patients with PTC, and the results were compared to normal controls (n=55).

  Results : There were 28 cases (50%) in PTC of CMI. The diagnostic features of PTC with CMI had a greater incidence of lower brain stem symptoms and signs. We performed measurements of the basion-dens interval (BDI), basion-atlas interval (BAI), atlas-dens interval (ADI), dens-atlas interval (DAI), clivus-atlas angle (CAA), clivus-axis angle (CXA), and atlas-axis angle (AXA). They were the same in supine and upright positions in normal controls. In patients with PTC, there was reduction of the BDI (2.7 mm), enlargement of the BAI (2.8 mm), and reduction of the CXA (11.4°), CAA (6.6°, p<0.001), and AXA (11.0°) upon assumption of the upright position. These changes were reducible by cervical traction.

  Conclusions : Morphometric evidence in this cohort of cranial settling and posterior gliding of the occipital condyles in PTC suggests hypermobility of the atlanto-occipital and atlanto-axial joints. This hypermobility induces greater brain stem symptoms in patients associated with CMI. The patients with CMI have greater hypermobility of occipito-atlanto-axial joints.

  Object : Unilateral partial hemilaminectomy with bilateral ligamentectomy (UPBILIT) is one of the less invasive procedures for treating lumbar spinal stenosis. Optionally, this decompression technique can also be combined with inter-spinous process fixation (+F) for those patients with minimum instability. In this study, the surgical results of single-level UPBILIT were retrospectively evaluated.

  Methods : We conducted an analysis of data obtained in a consecutive series of 60 patients treated with single-level UPBILIT or UPBILIT+F over a 4-year period (April 2003-March 2007). Clinical outcome was measured using the Japan Orthopedic Association (JOA) score and JOA recovery rates. Prognostic factor and complicated cases were also evaluated.

  Results : Forty patients had undergone UPBILIT and twenty patients with spinal instability had undergone UPBILIT+F. On an average of 24.2 months postoperatively, 54 of 60 patients (90%) experienced clinical benefit. The JOA score significantly improved from 14.6 to 21.0 (p<0.0005) with an average JOA recovery rate of 44.9%. Longer duration of disease correlated with the fair outcome group.Two patients (3.3%) experienced dural tear intraoperatively, and postoperative complications occurred in 4 patients (6.7%).

  Conclusions : The favorable recovery rate and the low incidence of complication indicated that UPBILIT can be a useful decompression surgery for lumbar spinal stenosis. In addition, the procedure, by using inter-spinous process fixation, can also manage those patients with minimum spinal instability.

  Anterolateral partial vertebrectomy, a new operative technique which involves drilling into the anterolateral part of the vertebral bodies, enables radical resection of the lesion, without any fusion. The procedure, however, could possibly promote disc degeneration and, as a result, reduce disc height because of resection of the lateral part of the disc. The authors describe long-term results of disc height change after anterolateral vertebrectomy of the cervical spine.

  This study involved 11 patients (7 men and 4 women) ranging in age from 41 to 71 years. The follow-up period was from 4 to 13 years (average 6 years). Neurological findings were evaluated using NCSS before and after surgery and at the end of the follow-up period. The disc height was measured by using slide calipers before surgery and at the end of the follow-up period. In this study, 19 operated discs and 32 non-operated discs were used. The residual rate as represented by formula (disc height at the end of the follow-up period/disc height before surgery) was compared between operated discs and non-operated discs. The Student's t-test was used for comparison between the groups.

  In all but one case, NCSS was improved after operation and remained so during the follow-up period. In one patient who had complained of numbness in all 4 extremities due to cerebral palsy, NCSS was consistent during the follow-up period. The residual rate did not differ significantly in the operated group from the non-operated one (0.85±0.13 vs. 0.89±0.10). In the subgroup whose disc height was 5 mm or more, the residual rate did not differ significantly in the operated subgroup from non-operated one (0.82±0.13 vs. 0.88±0.12).

  This study suggests that the injury to the disc in anterolateral vertebrectomy does not influence on disc height. Anterolateral vertebrectomy seems to be a useful surgical option for degenerated cervical spinal disorders.

  Objective : Tethered cord syndrome (TCS) is an incompletely understood disorder that is characterized by symptoms attributable to downward traction of the caudal end of the spinal cord. We describe the clinical features and radiological findings of tethered cord syndrome, and the downward displacement of the hindbrain that mimics Chiari malformation type Ⅰ (CM-Ⅰ).

  Methods : This study comprised 105 patients who met the classical TCS criteria. Posterior cranial fossa size and volume were measured using reconstructed 2D computed tomography scans and magnetic resonance (MR) images. Results were compared to those in 75 year age-and sex-matched healthy control individuals. The relationships of neural and osseus structures at the craniocervical junction and thoracolumbar junction were investigated morphometrically using the MR images. For 47 patients whose symptoms had worsened or whose neurological findings had deteriorated, a section of the filum terminale was performed.

  Results : CM-Ⅰ was present in 81 patients with TCS (77%) and 24 patients without CM-Ⅰ (23%). The incidence of suboccipital headache was 58%, neck pain : 55% and dizziness : 43%, and nausea/vomiting 42%. The incidence of low back pain was 86%, leg pain : 74% and urinary urgency or incontinence : 67%. There were no significant differences in the size or volume of the posterior cranial fossa as compared to healthy control individuals. Morphometric measurements demonstrated an elongation of the brain stem (mean 6.4 mm, p<0.001) and a downward displacement of the medulla (mean 7.2 mm, p<0.001). Symptoms and signs which were related to TCS, were improved or resolved in 31 patients (66%), were unchanged in 14 patients (30%), and became worse in 2 patients (4%). Symptoms and signs which were related to CM-Ⅰ, were improved or resolved in 22 patients (47%), unchanged in 23 patients (49%), and became worse in 2 patients (4%). After the section of filum terminale, morphometric measurements demonstrated reduction of the brain stem length (mean 4.3 mm, p<0.001) and an improvement of downward displacement of the medulla (mean 3.9 mm, p<0.001).

  Conclusions : TCS appeared to be a unique clinical entity that manifested an elongation and downward displacement of the hindbrain. TCS might occur as a continuum with CM-Ⅰand may be distinguished from generic CM-Ⅰ by the absence of a small posterior cranial fossa. There was preliminary evidence that section of filum terminale section could reverse a moderate degrees of the symptoms and signs, as well as reduce the elongation and downward displacement of the brain stem.

  Three-levels anterior cervical discectomy and fusion using titanium cages without plates were performed for five patients (4 male and 1 female). Mean age of the patients was 55 years (range : 34-62 years) with a mean follow-up interval of 21 months (range : 8-30 months). Three-levels anterior fusion was performed for cervical kyphosis, 3 level radiculopathy, and asymptomatic adjacent disc hernia or osteophyte. Of the 15 levels involved, 13 showed a stable fixation, in which 10 had bony fusion. Patients recovered significantly (p=0.009), by which mean NCSS scores were 11.4 and 13.2 pre-and postoperatively. Preoperative mean cervical lordosis C2-7 and range of motion (ROM) were 5.6° and 28.8° respectively, and postoperative mean lordosis and ROM were 14.4° and 19.8° respectively. There were no significant changes in these two parameters. There was no postoperative complications.

  As compared with the cervical laminoplasty group (24 patients, 23 males and 1 female, mean age 57 years), there were no significant differences in the pre-and postoperative NCSS scores, cervical lordosis, and ROM. In the laminoplasty group, however, there was transient C5 and C7 palsy.

  Neurological status, neuroradiological findings, and general condition of the patient should all be considered carefully, when three-level cervical anterior decompression and fusion is performed.

  Spontaneous spinal cerebrospinal fluid (CSF) leaks are an increasingly recognized cause of intracranial hypotension. Comprehensive diagnostic criteria encompassing the varied clinical and radiographic manifestations of spontaneous intracranial hypotension are not available. In this report the authors review the diagnosis of the point of cerebrospinal fluid leak. The major presenting symptoms include postural headaches, nausea, vomiting, and diplopia. Often, there is no history of traumatic injury. The most common cranial magnetic resonance (MR) imaging features include pachymeningeal gadolinium enhancement. MR myelography is a non invasive method to detect CSF leakage, however, extradural hyperintensity on MR myelography is non-specific for CSF. Fat-saturated T2-weighted imaging and post contrast T1-weighted imaging should be added to confirm CSF leakage. On spinal MR images, meningeal cysts and extradural venous plexus are frequently misdiagnosed as CSF leakage. In cases in which symptoms are severe and refractory to less invasive measures, surgical intervention is indicated. Recently, some authors reported the identification of upper cervical epidural fluid collections as a false localizing sign in patients with spontaneous intracranial hypotension (SIH) and this has provided significant insight into the selection of management options. However, herein we report on true C1-2 CSF leakage. We examined a group of consecutive patients with 25 SIH and 13 posttraumatic CSF hypovolemia and investigated clinical, MRI, CT myelography, and radioisotope findings and therapeutic outcomes of this syndrome.

  We analyzed the cases combined ventral and dorsal surgery were performed simultaneously for degenerative cervical spine disease. From January 2005 to May 2007, we experienced 206 cases of anterior fusion and 349 cases of laminoplasty. In those cases, 37 operations (7.3%) were performed using the combined approach. They consisted of 23 men and 14 women (mean age 62 years old, range 40-80 years old). All of the cases caused multilevel cervical spondylosis, accompanied with disc herniation in 18 cases, with kyphotic deformity in 10 cases, with spondylolisthesis in 5 cases, with osteophytes in 3 cases and ossification of the posterior longitudinal ligament (OPLL) in 1 case. There were no cases of neurological deterioration and reccurence postoperatively. For the preventation of recurrence in degenerative cervical spine desease, combined ventral and dorsal surgery is a viable option in the treatment of patients with multilevel canal stenosis (more than 3 vertebral levels or more), accompanying with unilaterally deviated disc herniation, osteophytes, and OPLL, with a kyphotic deformity of more than 10° in the neutral position and an angular deformity of more than 15° in flexion position, and with unstable spondylolisthesis.

  Objective : The purpose of this study was to evaluate radiological and clinical results in patients with lumbar spinal canal stenosis due to degenerative spondylolisthesis who had undergone posterior decompressive surgery without fusion. We report our findings in 31 patients who were followed for at least 3 years after surgery.

  Patients and methods : We evaluated 31 consecutive patients who underwent posterior decompressive surgery without fusion between 2001 and 2005. The mean follow-up was 62.3 months. Clinical results were evaluated using the Japanese Orthopaedic Association (JOA) score and the recovery rate. The radiographic parameters we assessed were the change in % slip and the slip angle on lateral neutral films, and translation and dynamic angulation on lateral flexion and extension films obtained before and after surgery.

  Results : The symptom recovery rate assessed with the JOA scoring system was 76.6%. There was no statistically significant difference between pre- and postoperative measurements with respect to the slip angle, translation, and dynamic angulation. The postoperative % slip was statistically larger than the preoperative value (p<0.01), although the progression of slippage and instability after surgery did not affect the clinical results. We performed reoperation in 2 patients (6.5%) ; they underwent posterior decompression. None of the 31 patients required secondary fusion.

  Conclusion : In the mid-term we obtained good operative results in patientswho had undergone decompression without fusion to treat lumbar spinal canal stenosis due to degenerative spondylolisthesis. Our findings suggest that posterior decompression wide enough to reach the lateral recesses but performed without damage to the articular processes does not routinely require spinal fusion and provides satisfactory clinical results.

  Objective : Spontaneous spinal epidural hematoma (SSEH) is still a rare entity, in spite of the recent advances in diagnostic radiology. We will summarize the treatment outcomes of our 9 cases of SSEH.

  Patients and methods : We retrospectively analyzed 9 cases (4 men and 5 women) of SSEH treated in our facility. The patients' age were ranged from 65 to 84 years (averaged 71.9±8.2 years). All patients were diagnosed by MRI and evaluation of their past medical history, neurological symptoms, radiographical findings (distribution of hematoma, rate of intra-spinal occupation), treatment procedure (surgical, conservative), clinical status, and outcome. We used the NCSS (Neurosurgical Cervical Spine Scale) for the estimation of neurological symptoms.

  Results : All patients were suffered from painful complaints (3 in the neck, 3 in the shoulder, 2 in the back and 1 headache) at the onset of SSEH. There were no patients with coagulopathy in their initial examination of blood coagulation. Six patients were demonstrated epidural hematoma in the cervical and 3 in the cervico-tholacic region. Surgical removal of the hematomas was performed in 6 (emergently in 5) and conservatively treated in 3 of the patients with rapid clearance of the hematoma. Patients treated conservatively had a tendency of long distribution of hematoma and low rate of intra-spinal occupation of hematoma, compared to others treated surgically. Finally, all patients experienced a significant recovery in their neurological deficits.

  Conclusion : Treatment outcomes of patients with SSEH were quite good. Surgical indication should be decided carefully with reference of the intra-spinal distribution and rate of occupation of the hematoma.

  Objective : In the basic management of spinal cord injury, systematic evaluation and support take precedence. Accordingly, the authors focus on the respiratory and circulatory failure that often follows cervical spine injury.

  Methods : Sixty-one cases of cervical spine injury treated over the past 5 years were analyzed retrospectively. All cases received a comprehensive and systematic examination as an initial evaluation, followed by neurological and radiological assessment. Five cases were further classified as Frankel A, 4 cases and B, 1 case. These patients were 3 males and 2 females with a mean age of 48.6 years old.

  Results : Three cases of Frankel A and 1 case of Frankel B were accompanied by either respiratory or circulatory failure resulting from spinal cord injury at the initial evaluation. The sinus bradycardia due to the sympathetic denervation of neurogenic shock was found in 3 of these 4 cases. Four patients received surgical stabilization of their cervical spine. At the late follow-up 1 case died of cardiac failure, and 1 case died of respiratory arrest due to pulmonary embolism.

  Conclusion : It is vitally important to attempt to differentiate neurogenic shock from hypovolemic shock in these injured cases. We emphasize the importance of a comprehensive and systemic management of the accompanying respiratory and circulatory failure after severe cervical spine injury.

  Microscopic posterior herniotomy (MPH) is a surgical option for postero-lateral cervical disc herniation (PLCDH). It can remove the herniated nucleus pulposus while preserving mobility at the operated disc level. In this report, we performed MPH on two men with PLCDH, and then evaluated the surgical outcomes. A 38-year-old man (Case 1) and a 43-year-old man (Case 2) suffered from severe pain in their right arms. MR images showed right PLCDH at C6-7 in Case 1 and at C5-6 in Case 2. Conservative treatments were ineffective, and we then performed MPH. The patients were relieved of their radicular pain immediately after the operation. They took analgesics for a week to reduce the wound pain, but none were needed after that. Case 1 returned to work on post-operative day 30, and Case 2 did the same on day 12. The preoperative Japanese Orthopedic Association scores (possible highest score, 14) of Case 1 and 2 were 11 and 10, respectively, and were improved to 14 in both patients from 3-months to the last follow-up check over a year later. The preoperative Visual Analogue Scale scores for pain (possible worst score, 10) of Case 1 and 2 were 7.0 and 10.0, respectively. These scores decreased to 1.4 in Case 1 and 0.5 in Case 2 at 1-month, and 0 in Case 1 and 0.3 in Case 2 at the last follow-up. Dynamic radiographs showed that the patients maintained a good range of motion and were free of instability in the cervical spine at the last follow-up. We conclude that MPH can provide excellent surgical outcomes for PLCDH.

  Unlike lumbar canal stenosis of the central portion, nerve root tunnel stenosis cannot be diagnosed by myelography or magnetic resonance imaging (MRI), resulting in failed back surgery syndrome. We report a case of 60-year-old male who presented with severe right leg pain. A bilateral partial laminectomy and microdiscectomy of L4/5 was performed three years ago, and the patient's left leg pain and low back pain disappeared completely.

  MRI showed no recurrence of the obvious lumbar canal stenosis of the central portion of the spinal canal or disc herniation so he only received conservative therapy with non-steroidal anti-inflammatory drugs in the other hospital. We suspected right L4/5 foraminal stenosis by parasagittal MRI and diagnosed with L4 nerve root block. We performed L4/5 lateral fenestration and foraminotomy using the right extraforaminal approach.

  The extracanalicular L4 nerve root was subtotally covered with bony components (L4 transverse process, accessory process, and pars interarticularis, and L5 ascending joint), so we removed them carefully with an air drill. After that, L4 root was released completely. The patients symptoms disappeared immediately after surgery. Postoperative 3-dimensional computed tomography revealed sufficient preservation of the L4/5 facet joint and pars interarticularis.

  Although long-term follow-up is necessary, microsurgical lateral decompression without spinal fusion can be a useful surgical option for patients with nerve root tunnel stenosis after same level bilateral partial laminectomy.

  Calcification is extremely rare in spinal ependymomas. We report a case of cervical intramedullary ependymoma with remarkable calcification.

  A 45-year-old-male presented with weakness and muscle atrophy of his right upper extremity. Magnetic resonance imaging (MRI) of the cervical spine demonstrated a slightly enhanced solid lesion at the level of C4-5 with a large multilobulated cystic lesion from C2 through C6. Computed tomography (CT) demonstrated a distinct calcification at the caudal and right side of the solid lesion. The patient underwent C3-7 open-door laminoplasty, and the tumor was totally removed. The histopathological diagnosis was cellular ependymoma with psammoma bodies.

  Tumor cysts, syrinx and hemorrhage are common in spinal ependymomas. Whereas calcification occurs far less frequently in spinal ependymomas than in intracranial ependymomas. Our case and previously reported cases suggest that calcifications tend to occur in the rim of the cervical ependymomas. We hypothesize that the cause of the calcification is calcium deposition in previous occult peritumoral hemorrhage.

  A series of 9 patients with spinal extradural schwannomas (1 neurofibroma and 8 schwannomas) was surgically treated during a 2-year period. The purpose of this article is to present some pointers for the surgical management of spinal extradural schwannomas. The tumors were more prevalent in women (6 of 9 cases). The patients' median age was 46.4 years. The tumor was located in the cervical region in 7 patients (78%) and in the lumbosacral region in 2 cases (22%). The clinical syndromes produced by the tumors were nonspecific because of their spinal levels and their epidural position. Data pertaining to tumor characteristics and the results of surgery were analyzed. After confirming that stimulation of the distal part of the root of the tumor produced no response, the root giving rise to the tumor was sacrificed. Complete resection was achieved in all patients. Worsening of preoperative neurological deficits was observed in 2 patients : one patient, in whom the tumor capsule and surrounding connective tissues tightly adhered to the C5-7 nerves, and another patient, in whom the tumor capsule was very thin. Although their motor impairments have been improving over the 2 years since their operations, their neurological impairment continues to be worse than it was preoperatively. However, no recurrence was observed in all cases at 2-year follow-up. Based on our series of 9 surgically treated cases of spinal extradural schwannoma, it can be seen that sacrifice of the nerve root is often required to achieve total removal of the tumor, and that resection does not always result in a postoperative neurological deficit. Intraoperative stimulation can help the surgeon decide whether the root may be divided without incurring a postoperative deficit. With respect to tumor recurrence, complete resection of the tumor, including the tumor capsule, is preferred over intracapsular enucleation alone.