ABSTRACT
Objective To explore the accuracy and clinical efficacy of advanced 3D printing navigation templates in assisting placement of atlantoaxial pedicle screw.Methods A retrospective analysis was carried out on 49 cases of patients with atlanto-axial vertebral fractures and dislocations between June 2013 and June 2016,and all of them were given posterior incision,reduction and internal fixation of atlantoaxial pedicle screw.The patients were divided into advanced 3D printing navigation template group (14 cases),early 3D printing navigation template group (16 cases),and routine pedicle screw placement group (19 cases).Atlantoaxial CT data of patients in advanced 3D printing navigation template group and early 3D printing navigation template group were input into Mimics 17.0,then advanced 3D printing navigation template group and early 3D printing navigation which were used in clinic surgery were designed and printed.The relationship between positions of pedicle screw with the pedicle and bone cortex in plain CT image was observed after operation.The quality of the screw position was assessed and the accuracy of three kinds of screwing methods was compared.The accuracy of the screwing angle was assessed by comparing with the differences between the preoperative designed channel inclination angle and postoperative actual screwing angle.Three groups were compared for differences between operation time,intraoperative blood loss,and scores of cervical nerve scale and visual analogue scale (VAS) of neck and shoulder pain by Japanese Orthopaedic Association (JOA).Results All 49 cases of patients successfully completed the surgery.Patients of the routine pedicle screw placement group,early 3D group and advanced 3D group correspond operation time for 141.2±20.7 min,112.5±12.1 min and 103.1±10.4 min,intraoperative blood loss for 314.0±81.4 ml,243.6±71.2 ml and 181.0+59.1 ml;total accuracy of screwing for 75.0％ (54/72),93.75 ％ (60/64) and 96.43 ％ (54/56).There were statistically significant differences among the routine group,3D group and advanced 3D group in the mentioned programs.There were no statistical differences between advanced 3D group and 3D group in the inclination angle and head tilt angle with the pre-designed values,while there was statistically significant difference between the routine group and the pre-designed value.The accuracy of the inclination angle and bead tilt angle screwing angle were obviously superior in the advanced 3D group and early 3D group to that of the routine group.There were statistically significant differences between preoperative with postoperative VAS scores and JOA scores in the same group,while there were no statistically significant differences among groups in JOA.But there was statistically significant difference between the routine group and the advanced 3D in VAS,and there was no statistically significant difference between the routine pedicle screw placement group and the early 3D in VAS.All three groups of patients had bony fusion of atlantoaxial vertebral body,without loosening,dislocation and fracture of the internal fixators.Conelusion Advanced 3D printing templates in assisting the surgical treatment for atlantoaxial fracture and dislocation can improve the accuracy of pedicle screwing and safety of the surgery,reduce the surgery risk,and obtain satisfied clinical curative effects.
ABSTRACT
Objective To investigate the olfactory function in patients with systemic lupus erythematosus (SLE) and to explore factors that may influence it.Methods The Connecticut Chemosensory Clinical Research Center (CCCRC) test was carried out in SLE patients and healthy controls for olfactory function testing.ELISA method was used to detect anti-ribosomal P protein antibody in the serum.The statistical methods used in this study including t test,ANOVA,LSD-t test,Pearson correlation analysis,multiple linear regression analysis,andx2 test.Results ① The CCCRC scores of the active,inactive group and healthy controls were compared,the difference was statistical significant (F=26.52,P=0.01).CCCRC score in active SLE group (62±16) was lower than that of the inactive group (80±13) the and the normal control group (83±12) (P＜0.01),while there was no statistical significant difference between the inactive group and the normal controls (P=0.226).② CCCRC score was lower in 16 ARPA positive SLE patients (61±17) than 49 negative patients (74±16) (t=2.681,P=0.009).③ In addition,CCCRC score showed a negative correlation with ARPA serum concentration (r=-0.327,P=0.008).There was no significant correlation between CCCRC score and disease course (r=0.141,P＞0.05).④ Multiple linear regression analysis indicated that CCCRC score was associated with age and ARPA.Conclusion SLE patients have olfactory dysfunction and the dys-function is associated with age and ARPA.
ABSTRACT
Objective:To test the effects of different preparation methods on the shear bond strength between porcelain veneers and the brackets.Methods:48 metal-porcelain veneers were randomly and evenly divided into two groups. The veneers in group 1 were grinded with stone, while others were intact. The veneers were bonded by acid etching,silicone coupler and acid etching combined with silicone coupler respectively.After bonding and 500 thermo cycle treatment, all veneers were submitted to shear bond strength test and the incidence of porcelain fracture was recorded.Results:The shear bond strength of the grinded samples was higher than that of the intact(P