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Study Design: This is a retrospective review of 10 consecutive patients with spinal cord injury without radiographic evidence of abnormalities (SCIWORA) and 17 spinal cord injury patients without radiographic evidence of trauma (SCIWORET). Objectives: We wanted to assess the MRI and clinical findings, the prognosis and effect of anterior decompression of the spinal cord in SCIWORET patients. Summary of the Literature Review: SCIWORET is not uncommon among middle-age and elderly people. It is less reported in adults as compared with children. There are no studies on the method for the treatment or the effectiveness of anterior decompression of the spinal cord. Materials and Methods: From February 1994 to December 2005, this study included 27 patients who had cervical spinal cord injury without radiographic evidence of trauma on the plain roentgenography and MRI. Ten patients had no spinal cord compression (SCIWORA patients, group 1) and 17 had their spinal cord compressed from the anterior (SCIWORET patients, group 2), We conservatively treated the group 1 patients and 10 of the group 2 patients, and anterior decompression and fusion were done for 7 of the group 2 patients. Neurological evaluation was performed initial and at last follow up using an ASIA motor score and the Frankel grade. Results: The patients who had spinal cord edema on MRI had a better prognosis than those who had contusion (p=0.06). There is no statistical difference between the two groups for the neurologic changes at the initial period and the last follow up period (p=0.06, 0.61). Decompression of the spinal cord anteriorly was not effective for the neurologic recovery (p=0.25) and the involved segments were not related to the neurologic changes (p=0.34, 0.25). Conclusions: It was presumed that patients with edema of the spinal cord had a better prognosis than those with contusion of the spinal cord. There was no difference between the SCIWORA and SCIWORET groups for the neurologic changes and anterior decompression was not effective for the recovery of neurologic symptoms. This study was limited by its retrospective nature and the small number of patients, so a multi-center study is needed.

Study Design: This is a retrospective study Objectives: This study compared the clinical outcomes of posterior lumbar interbody fusion (PLIF) using hydroxyapatite blocks with PLIF using a metal or poly-ether-ether-ketone (PEEK) cage. Summary of the Literature Review: There are few reports on the clinical outcomes of PLIF using a hydroxyapatite block for treating lumbar degenerative disease. Materials and Methods: The 27 PLIF cases (62 units, HA block) that were followed up for 1-year were compared with 13 cases using a metal cage and 13 cases using a PEEK cage. Pedicle screw fixation was performed for all the cases. If the local bone is deficient, then an additional bone graft with autogeous iliac bone or bone substitute was used. The visual analog scale(VAS) for low back pain and radiating pain, the Oswestry disability index (ODI), the intervertebral height and the halo sign around the cages and pedicle screws were comparatively analyzed. Results: The mean VAS score for low back pain before PLIF and using the HA block, the metal cage and the PEEK cage was 7.5, 8.3 and 6.2, respectively, and this was 3.3, 2.9 and 4.8 after PLIF (P< 0.05 with using the HA block and the metal cage (Wilcoxon test). The mean VAS score for radiating pain before PLIF was 7.9, 8.3 and 8.5, respectively, and the VAS score was 3.5, 3.1 and 3.9, respectively, after PLIF (P< 0.05 for all cases, Wilcoxon test). For the ODI, the means before PLIF were 60.3, 51.2 and 53.8, respectively, and they changed to 30.5, 24.9 and 29.7, respectively, after PLIF (P< 0 .05 for all cases, Wilcoxon test). On the X-ray images, there was no halo sign greater than 2 mm near the pedicle screws or greater than 1 mm near the cages and no breakage of the HA block. No additional bone graft was needed for the PLIF using the HA block and local bone. There was no statistically significant differences among the groups (P > 0.05, One-way ANOVA). Conclusion: PLIF using a HA block showed improvements, including the back pain, and the ODI was satisfactory and this didn’t fall below those ODIs of using metal or PEEK cages. Although a HA block may have higher tendency to break, there was no breakage at the 1-year follow up.

Study Design: This is a retrospective study. Objectives: We wanted to analyze the frequency of instrument breakage and the long term reduction loss for patients who received pedicle screw fixation for thoracolumbar fractures. Summary of the Literature Review: A pedicle screw fixation system for thoracolumbar fractures has become popular since the late 1980s, but it is difficult to find articles mentioning its mid and long term results. Materials and Methods: Twenty-seven patients those received pedicle screw fixation for thoracolumbar fractures and dislocations and who were followed up more than 5 years were included. The average follow-up period was 139.0 months. We compared the anterior column height, the kyphotic angle and the local kyphotic angle on serial radiographs, and we measured the changes of the intervertebral disc height and the changes of the angle between screws. We also investigated the breakage and loosening of instruments. Results: The breakage of screws was observed in 11 cases (40.7%) and it had a statistical correlation with the loss of the lower intervertebral disc height and the loss of angles between the screws. During the follow-up, the kyphotic angle, the upper and lower disc height and the interscrew angle were decreased over time, whereas the anterior column height and wedge angle of the vertebra were maintained after the operation. There was no statistical correlation between the breakage of instruments and the degree of lower back pain. Conclusions: On the mid and long-term follow-up of the patients who were treated by pedicle screws for thoracolumbar fractures, the correction of the kyphotic angle was lost over time and breakage of screws may eventually occur. The loss of the kyphotic angle was mainly due to the continuous loss of the intervertebral disc height.

Study Design: This is a mechanical study of polymethylmetacrylate(PMMA) mixed with blood as a filler. Objective: We tried to change the properties of PMMA so that it is more suitable to use for percutaneous vertebroplasty (PVP). Summary of the Literature Review: The mechanical changes by adding a filler into PMMA were expected to decrease the Young’s modulus, the polymerization temperature and the setting time. These changes of PMMA were considered to be more suitable and adaptable conditions for PVP for treating osteoporotic vertebral compression fracture. Materials and Methods: Porous PMMA was produced by mixing 2 ml (B2), 4 ml (B4) and 6 ml (B6)-blood as a filler, and the mechanical properties were investigated in comparison with regular PMMA(R) in view of Young’s modulus, the polymerization temperature, the setting time and the optimal passing-time within the injectable viscosity (20~50N-needed) through a 2.8mm-diameter cement-filler tube. Porosity was inspected by performing microcomputated tomography (micro-CT). Results: Young’s modulus was decreased from 919.5 MPa (R) to 701 MPa (B2), 693.5 MPa (B4) and 545.6 MPa (B6) in each group. The polymerization temperature decreased from 74.2℃ (R) to 59.8℃ (B2), 54.2℃ (B4) and 47.5℃(B6), respectively. The setting time decreased from 1065sec (R) to 624sec (B2), 678sec(B4) and 606sec (B6), respectively, and the optimal passing-time decreased from 75.6sec (R) to 46.6sec (B2), 65.0sec (B4) and 79.0sec(B6), respectively. The porosity increased from 4.2%(R) to 27.6%(B2), 27.5%(B4) and 29.5%(B6), respectively. A homogenous microstructure with very fine pores was seen on inspection of all the blood-mixed PMMAs. Conclusion: Blood mixed with PMMA was considered as an excellent filler that was easy to make and had good biocompatibility. The 6ml blood-mixed PMMA (B6) showed more suitable mechanical properties, including a decreased elastic modulus due to more porosity, less heating and a retarded optimal passing-time by the serum barrier, which diminished the friction between the PMMA and a cement-filler tube.

Study Design: This is a retrospective radiologic study Objectives: The aim of this study is to analyze the signals and configurations of the MRI findings of osteoporotic vertebral fractures and the clinical consequences of each type of the MRI findings. Summary of the Literature Review: There have been some reports that have focused on the MR findings for the differentiation of osteoporotic and metastatic fractures, but there are few reports on the characteristics of the early stage of osteoporotic vertebral fractures. Materials and Methods: From July 2002 to April 2008, the MRI findings and medical records of 97 patients who were diagnosed with acute or subacute osteoporotic vertebral fractures and who were followed-up for more than 1 year were analyzed. The patients with minor trauma within 3 months before obtaining MRIs and they had decreased bone density were included in this study. Those with fractures due to severe trauma or pathologic causes or normal bone density were excluded. Three spine surgeons evaluated, at three times per each surgeon, the T1-weighted, T2-weighted and fat suppression T1-enhanced sagittal images for the signal of the vertebral body bone marrow and the type of the intravertebral body lesion shape. The relationships between the type of MRI findings and the time from the trauma and the follow up clinical consequences were analyzed. Results: The MRI patterns of 97 patients with 111 fractures of the vertebrae were divided into three types. There were 56 cases of type Ⅰ (50.5%), which was defined as diffuse typical signal intensity in the vertebral body, 39 cases (35.1%) of Type Ⅱ, which was defined as geographic low signal in the center of the vertebral body with typical signal changes, and 16 cases (14.4%). of type Ⅲ, which was defined as atypical signal intensity or a shape of lesion that did not correspond to type 1 nor type 2. The average time from trauma was 10.8±19.0days (0~90) for type Ⅰ, 19.1±24.9days (0~90) for type Ⅲ and 37.5±31.1days (0~90) for type Ⅲ, which showed differences among each types (p<0.001). Conclusions: The analysis of the relationship between the time from trauma and the signal intensity and the type of lesion on MRI examination revealed that the low signal intensity in the typical vertebral body signal or an atypical signal or shape were poor prognostic factors of osteoporotic vertebral fracture.

Study Design: This is a retrospective preparative study and prospective study Objective: We instituted and verified the precautions against postoperative spinal infection. Summary of the Literature Review: Postoperative infection comes from contamination during the operation and various strategies have been recommended to prevent it. Materials and Methods: 583 cases that underwent instrumented posterior spinal fusion during two years (group Ⅰ), were reviewed to discover the risk factors, and intraoperative cultures were done to detect the contamination routes and the causative microorganisms for the next 4 months. Six precautions, based on the results, were instituted. We analyzed 354 cases that underwent operation in the following year (group Ⅱ) using the precautions. Results: Twenty cases (3.4%) were infected in group I and the types of infection were superficial wound infection (4 cases), deep wound infection (4 cases), osteomyelitis around the interbody space (7 cases), osteomyelitis around the pedicle screws (4 cases) and a combination of wound infection and osteomyelitis around the pedicle screws (1 case). Infections happened more frequently in the cases of interbody fusion (p=0.034), revision (p=0.087) and those done in the summer season (p=0.025). S. epidermidis, as the causative bacteria, was cultured from both the operation environments and wounds. Six precautions based on the preliminary results were instituted as follows; irrigation method reformation, delayed opening of instruments, turning-off local air conditioners, changing of gowns before instrumentation, local bone irrigation and limited indications for interbody fusion. After implementation, two cases (0.6%) of infection developed in group II (p=0.002, odds ratio=0.160; 95% confidence interval = 0.037 to 0.688). Conclusion: Wounds, grafted bones or instruments can be contaminated under longer-time exposure to operating room air and so produce interbody or pedicle osteomyelitis without wound infection. The precautions were effective to decrease the postoperative infection rates following posterior spinal fusion.

Survival after traumatic atlanto-occipital dislocation is rare. Severe persistent neurological deficits are common in the survivors, but early resuscitation and the use of the newer diagnostic techniques have contributed to improved outcomes. We present here the case of a 42 year old man with traumatic atlanto-occipital dislocation combined with a dens fracture, and the patient obtained good clinical results after we applied a Halo-vest and performed posterior fusion.

A 36-year old man with neck pain developed an acute cervical prevertebral hematoma after acupuncture therapy at an oriental medicine hospital. MR imaging demonstrated a fluid collection, and this suggested a diagnosis of retropharyngeal hematoma, and the patient was managed conservatively. We report here on a case of a retropharyngeal hematoma following acupuncture therapy and we review the relevant literature.

Ossifying fibromyxoid tumor is rare soft tissue neoplasm of an uncertain histogenesis, and this was first described in 1989. The majority of the reported cases have involved the soft tissue of the extremities. We present here on a case of atypical ossifying fibromixoid tumor that had invaded the spine and we report on its management and outcome. We also review the relevant literature.

Most of intradural tumors are primary tumors and few of them are metastatic tumors. Especially, spinal intradural metastatic tumors which are derived from renal cell carcinoma are rarer. Even though such tumors occur, it accompany with brain metastasis in many cases. And there was no report regarding isolated intradural metastasis, without metastasizing on brain or other central nervous system organs, in domestic. The purpose of this research is to report the excellent clinical results regarding solitarily intradural metastasized renal cell carcinoma. Researchers found out renal cell carcinoma which was solitarily metastasized intradural of the third lumbar of 63 years old man who has renal cell carcinoma and underwent nephrectomy 2 years before. tumor extirpation was performed after total laminectomy. And after keeping watching it for 2 years, we could get favorable results and would like to report it with review of literature.

Lumbosacral fixation or spinopelvic fixation is frequently required for the surgical treatment of neuromuscular scoliosis and degenerative lesions, trauma and tumor in the lumbosacral vertebrae. However, the establishment of stable fixation with these procedures is difficult due to the anatomic characteristics of the sacrum and this is even more problematic for the cases with long segmental fixation, severe instability and bone defects. Although the emergence of pedicle screws makes spinal fixation easier and more rigid, S1 pedicle screws alone do not provide enough stability for lumbosacral fixation. For the purposes of reinforcing lumbosacral fixation, procedures using rods or screws can be used: the procedures using rods include the Galveston method, the McCarthy S-rod and the Jackson intrasacral rod, and the procedures using screws include sacral alar screws, transdiscal screws and iliac screws. The purpose of this study was to ascertain the proper fixation methods, according to each indication, for spinopelvic fixation and we analyzed the advantages and drawbacks of each fixation method. In addition, the fixation method of iliac screws, which has recently become more popular, is presented in detail to enhance the availability and reduce the complication of this technique.