To date, there have been no prospective, objective studies comparing the accuracy of the MRI, myelo-CT and myelography. The purpose of this study is to compare the diagnostic and predictive values of MRIs, myelo-CTs, and myelographies. Myelographies with dynamic motion views, myelo-CTs, MRIs and exercise treadmill tests were performed in 35 cases. The narrowest AP diameter of the dural sac was measured by myelography. At the pathologic level, dural cross-sectional area (D-CSA) was calculated in the MRI and Myelo-CT. The time to the first symptoms (TAF) and the total ambulation time (TAT) were measured during the exercise treadmill test and used as the standard in the comparison of correlation between radiographic parameters and walking capacity. The mean D-CSA by CT was 58.3 mm2 and 47.6 mm2 by MRI. All radiographic parameters such as AP diameters and D-CSA have no correlation to TAF or TAT (p>0.05). Our data showed no statistically significant differences in the correlation of the patients' walking capacity to the severity of stenosis as assessed by myelography, myelo-CT and MRI.

PurposeTo identify the incidence of new vertebral compression fractures in women after kyphoplasty and to analyze influential factors in these patients.Materials and MethodsOne hundred and eleven consecutive female patients with osteoporotic vertebral compression fractures (VCFs) underwent kyphoplasty at 137 levels. These patients were followed for 15.2 months postoperatively. For the survey of new vertebral compression fractures, medical records and x-rays were reviewed, and telephone interviews were conducted with all patients.ResultsDuring that time 20 (18%) patients developed new VCFs. The rate of occurrence of new VCFs in one year was 15.5% using a Kaplan-Meier curve. Body mass index (BMI), symptom duration and kyphoplasty level were the statistically significant factors between the patient groups both with and without new VCFs after kyphoplasty. In the comparison between the adjacent and remote new VCF groups, the adjacent new VCF group showed a larger amount of polymethyl methacrylate (PMMA) use during kyphoplasty (p < 0.05). Before kyphoplasty, 9.9% of the patients had been prescribed medication for osteoporosis, and 93.7% of the patients started or continued medication after kyphoplasty. The development of new VCFs was affected by the number of vertebrae involved in the kyphoplasty. However, the lower incidence rate (15.5%) of new compression fractures might be due to a greater percentage (93.7% in our study) of patients taking anti-osteoporotic medication before and/or after kyphoplasty.ConclusionWhen kyphoplasty is planned for the management of patients with osteoporotic VCFs, the application of a small amount of PMMA can be considered in order to lower the risk of new fractures in adjacent vertebrae. The postoperative use of anti- osteoporotic medication is recommended for the prevention of new VCFs.

Study DesignRetrospective study.PurposeFirst, to examine the association between bone mineral density (BMD) and the halo phenomenon, and second, to investigate risk factors predisposing to the halo phenomenon and its correlation with clinical outcomes.Overview of LiteratureThe few in vivo studies regarding the relationship between pedicle screw stability and BMD have shown conflicting results.MethodsForty-four female patients who underwent spine fusion surgery due to spinal stenosis were included in this study. The halo phenomenon and fusion state were evaluated through plain radiographs performed immediately after surgery and through the final outpatient follow-up examination. BMD, osteoarthritis grade in the hip and knee joints, and surgical outcome were also evaluated.ResultsBMD was not related to the halo phenomenon, but age, absence of osteoarthritis in the knee, and non-union state were found to be significant risk factors for the halo phenomenon. However, the radiological halo phenomenon did not correlate with clinical outcome (visual analogue scale for back pain and leg pain).ConclusionsThe halo phenomenon is a simple phenomenon that can develop during follow-up after pedicle screw fixation. It does not influence clinical outcomes, and thus it is thought that hydroxyapatite coating screws, expandable screws, cement augmentation, and additional surgeries are not required, if their purpose is to prevent the halo phenomenon.