OBJECTIVE: Two-dimensional fluoroscopy-based computerized navigation for the placement of pedicle screws offers the advantage of using stored patient-specific imaging data in providing real-time guidance during screw placement. The study aimed to describe the accuracy and reliability of a fluoroscopy-based navigation system for pedicle screw insertion. METHODS: A total of 477 pedicle screws were inserted in the lower back of 96 consecutive patients between October 2007 and June 2012 using fluoroscopy-based computer-assisted surgery. The accuracy of screw placement was evaluated using a sophisticated computed tomography protocol. RESULTS: Of the 477 pedicle screws, 461 (96.7%) were judged to be inserted correctly. Frank screw misplacement [16 screws (3.3%)] was observed in 15 patients. Of these, 8 were classified as minimally misplaced (< or =2 mm); 3, as moderately misplaced (2.1-4 mm); and 5, as severely misplaced (>4 mm). No complications, including nerve root injury, cerebrospinal fluid leakage, or internal organ injury, were observed in any of the patients. CONCLUSION: The accuracy of pedicle screw placement using a fluoroscopy-based computer navigation system was observed to be superior to that obtained with conventional techniques.
Cerebrospinal Fluid ; Humans ; Surgery, Computer-Assisted

Vertebroplasty (VP) is a well-known therapeutic modality used to treat pain associated with vertebral compression fractures. Major complications such as cord or root compression, epidural and subdural hematomas (SDH) and pulmonary emboli, occur in less than 1% of patients who undergo VP after compression fracture. Spinal SDH is an extremely rare complication that usually happens a few hours after the procedure. We report a case of spinal SDH that developed at two weeks after a successful VP. We also reviewed related literatures and discussed its possible pathogenesis.
Fractures, Compression ; Hematoma, Subdural ; Hematoma, Subdural, Spinal ; Humans ; Spine ; Vertebroplasty

BACKGROUND: We performed the study on the changes of beta2-microglobulin(beta2M) clearance and urea reduction ratio after reuse of dialyzers with three different membranes. METHODS: 9 patients who had received regular hemodialysis more than five years were enrolled. Three kinds of dialyzer membrane were used; i.e. : Two of them were high-flux and the other was low-flux. Dialyzer reprocessing was performed by an automated machine using glutaraldehyde and bleach. Each dialyzer was reused 10 times. Solute clearance was determined for each dialyzer after the 1st, 5th, 8th and 10th reuse. RESULTS: Urea clearance was well maintained after reuse with both high-flux and low-flux membrane but beta2M clearance was significantly greater with high-flux dialyzers than low-flux dialyzer. Effects of each dialyzer reuse on beta2M clearance showed no significant decrease until the 10th reuse and no significant difference in beta2M clearance between the two high-flux dialyzers(polyamide vs PEPA membrane, p= 0.197). CONCLUSION: Reuse of dialyzers was cost-effective. After reuse of dialyzer, clearance of solute was maintained in both small and large solutes until the 10 th reuse. Further study is needed regarding the maintenance of solute clearance with increased number of reuses.
Blood Urea Nitrogen* ; Cellulose ; Glutaral ; Humans ; Membranes* ; Nylons ; Renal Dialysis ; Urea

The use of erythropoietin for correction of anemia in maintenance hemodialysis patients affects dialyzer reuse, dialysis efficacy and other clinical parameters. This study showed the change of Kt/Vurea, nPCR, pre-dialysis BUN, body weight, ultrafiltration volume, pre-dialysis blood pressure, heparin dosage, the number of dialyzer reuse caused by the administration of erythropoietin in reuse(n=11) and first use(n=9) patients who were started erythropoietin since January, 1995. 1) In 20 all patients, hematocrit increased significantly after EPO treatment 20.7+/-0.8%, 27.8+/-0.7%, ultrafiltration volume increased from 2.0+/-0.3L to 2.5+/-0.2L(P<0.05). However no significant changes were noted in Kt/Vurea, nPCR and other parameters 2) In patients of dialysis reuse, the number of reuse was not affected by EPO treatment(8.4+/-1.7, 9.6+/-1.5, P=0.67). No significant differences were observed in all parameters except hematocrit in case of first use and reuse. 3) Entire patients were reclassified into low baseline protein intake group(nPCR<1.0g/kg/day) and high baseline protein intake group(nPcR>1.0/kg/ day) and then pretreatment versus posttreatment nPCR, pre-dialysis BUN and ultrafiltration volume were compared. In low baseline protein intake group, significant increases of ultrafiltration volume, nPCR were observed. However, pre-dialysis BUN were not changed significantly. In high protein intake group, nPCR, pre-dialysis BUN, ultrafiltration volume were changed without significance. In conclusion, EPO treatment did not affect Kt/Vurea, dialyzer reuse, nPCR, predialysis blood pressure, heparin dosage. But ultrafiltration volume increased significantly after EPO treatment. Maybe increased appetite in low baseline protein intake group caused the increased posttreatment ultrafiltration volume.
Anemia ; Appetite ; Blood Pressure ; Body Weight ; Dialysis* ; Erythropoietin* ; Hematocrit ; Heparin ; Humans ; Renal Dialysis ; Ultrafiltration

Renal transplantation is the optimal treatment for end stage renal disease and it has been improved through the development of operative methods and immunosuppressants. However some patients must receive dialysis or undergo retransplantation after a loss of the primary graft due to rejection or other causes. Recently the frequency of retransplantation has begun to increase gradually. Some articles have reported that retransplantation results do not significantly differ in comparison with initial transplantation results when living related donor kidneys are used. Our study focused on the outcome of 445 first transplantation and 12 retransplantation cases. The sex distribution of retransplanted patients was 11 male and 1 female. The mean age (yrs) for recipients was 32.3 at the first transplantation and 39.1 at the retransplantation. The underlying causes of end stage renal disease were presumed to be chronic glomerulonephritis in all retransplantion patients; the mean duration of graft survival (mo) for first transplantation was 77.92. The causes of previous graft failure were as follows: 10 due to chronic rejection, 1 due to recurrent glomerulonephritis, 1 resulted from a graft rupture due to a motorcar accident. The interval (mo) between graft failure and retransplantation averaged 6.7 and 9 out of 12 patients underwent regrafting within 1 year of their previous graft loss. Recipient-donor relationships in first transplantations were as follows: 9 were living related and 3 were living non-related. Recipient-donor relationships in second transplantations were as follows: 4 were living related and 8 were living non-related. Acute rejection within 1 month of transplantation occurred in 4 primary transplantation patients and 2 retransplantation patients. The incidence of acute rejection within 1 month was as follows: 23% of 445 first renal transplantation patients, 16.7% of 12 second transplantation patients. The 1 year and 2 year graft survival rate was 100% and the mean survival duration (mo) was 33 for retransp
Dialysis ; Female ; Glomerulonephritis ; Graft Survival ; Humans ; Immunosuppressive Agents ; Incidence ; Kidney Failure, Chronic ; Kidney Transplantation ; Kidney* ; Male ; Rupture ; Sex Distribution ; Tissue Donors ; Transplants