BACKGROUND:Various surface modification techniques have been utilized as an attempt to improve the osteointegration of Ti-based implants, which is a hotspot research concerning the artificial joint prosthesis. OBJECTIVE:To evaluate the effect of silicon doped zirconia film on the titanium surface on relevant factors of osteoblast-like MG63 cells. METHODS:Silicon doped zirconia and zirconia films were respectively prepared on the titanium surface by cathodic arc deposition. Osteoblast-like MG63 cells were cultured on silicon doped zirconia film, zirconia film and pure titanium, respectively. After 1, 4, 7, 10 days of incubation, samples were collected for assay. Osteoprotegerin (OPG) and receptor activator of nuclear factor κB ligand (RANKL) at mRNA and protein levels were detected using real-time PCR and ELISA, respectively. RESULTS AND CONCLUSION:(1) At 1 day of inoculation, there was no significant difference in the OPG mRNA and protein expression among the three groups. At 4 days of inoculation, the expression of OPG mRNA and protein in the silicon doped zirconia film and zirconia film groups was significantly higher than that in the pure titanium group (P<0.05), but there was no significant difference between the former two groups. At 7 and 10 days of inoculation, the expression of OPG mRNA and protein in the silicon doped zirconia film growp was highest among the three groups (P<0.05). (2) At 1 day of inoculation, there was no significant difference in the RANKL mRNA and protein expression among the three groups. At 4 and 7 days of inoculation, the expression of RANKL mRNA and protein in the silicon doped zirconia film group was significantly lower than that in the other two groups (P<0.05). At 10 days of inoculation, the expression of OPG mRNA and protein in the silicon doped zirconia film and zirconia film groups was significantly higher than that in the pure titanium group (P<0.05), but there was no significant difference between the former two groups. To conclude, silicon doped zirconia film fabricated by cathodic arc deposition can enhance the expression of OPG and reduce the expression of RANKL at the same time.

OBJECTIVETo compare the clinical effects of external fixator versus DVR system for the treatment of AO type C distal radius fractures.

METHODSThe clinical data of 52 patients with type C distal radial fractures treated with external fixator or DVR system respectively from January 2009 to December 2013 were analyzed retrospectively. In DVR system group, 31 patients were treated by open reduction and internal fixation with DVR system, involved 11 males and 20 females, with an average age of(47.3±10.9) years ranging from 24 to 65 years;according to AO/ASIF classification, 12 cases were type C1, 15 cases were type C2, 4 cases were type C3. In external fixator group, 21 patients were treated by closed reduction and cross wrist external fixation, involved 8 males and 13 females, with an average age of (48.1±12.1) years ranging from 26 to 69 years; according to AO/ASIF classification, 7 cases were type C1, 11 cases were type C2, 3 cases were type C3. The postoperative images, wrist joint functions and Gartland-Wetley scores were evaluated and compared.

RESULTSThirty-one patients in DVR system group were followed up for 20.4 months(ranged from 13 to 36 months) and in external fixator group 21 patients were followed up for 17.1 months (ranged from 11 to 33 months) respectively. X-rays showed all fractures healed. The palm dip and radial inclination in the DVR system group were significantly better than in the external fixator group(<0.05), while there was no significant difference in radial height and Gartland-Werley score(>0.05). There was 1 case of wrist stiffness in the DVR system group; 2 cases of pin tract infection, 1 case of fixator loosening and 2 cases of wrist stiffness in the external fixator group.

CONCLUSIONSClinical outcomes of DVR system fixation for type C distal radial fractures are better than that of external fixator fixation. However, DVR system fixation costs more and requires a secondary surgery to remove the internal fixation. The choices of surgical method depend on the clinical conditions of the patients.