Effect of Zoledronic Acid on Early Osseointegration of Porous Implant in Rabbit / 대한정형외과연구학회지

PURPOSE: The purpose of this study was to determine whether intravenous injection of the zoledronic acid could promote osseointegration of the porous implant inserted into the rabbit medullary cavity. MATERIALS AND METHODS: A rabbit intramedullary osseointegration model was used. A specially designed porous nitinol implant (Bio-Smart, Sungnam, Gyeonggi-do, Korea) was inserted in the right distal femur of twenty six rabbits. They were randomized into the control or the experimental groups. In the control group, an intravenous injection of normal saline 2 ml/kg (Daihan Pharm, Seoul, Korea) was given at the end of the operation. In the experimental group, an intravenous injection of zoledronic acid 0.1 mg/kg (AclastaG(R) 2 ml/kg, Norvatis, Stein, Switzerland) was given at the end of the operation. Six weeks later, all animals were sacrificed and undecalcified histologic sections were prepared. Then, histomorphometric measurement of bone affinity index (%) and bone ingrowth area rate (%) was carried out. RESULTS: Six rabbits were excluded due to death and wound infection. Nine rabbits in the control group and eleven rabbits in the experimental group were included for the analysis. The bone affinity indices were 19.9+/-7.9% in the control group, and 28.4+/-7.2% in the experimental group. Although there was no statistical significance (p=0.056), the bone affinity index of the experimental group was higher than that of the control group. The bone ingrowth area rates were 8.7+/-3.7% in the control group, and 12.1+/-4.1% in the experimental group (p=0.046), indicating zoledronic acid had an positive effect on the promotion of bone ingrowth into the porous implant. CONCLUSION: In our rabbit intramedullary osseointegration model, intravenous injection of the zoledronic acid promoted early osseointegration of the porous implant. Zoledronic acid might be useful to promote the early osseointegration of the joint replacement implants.

The Results of Evisceration with Primary Porous Implant Placement in Patients with Endophthalmitis

PURPOSE: To assess the results and long-term prognosis of evisceration with primary porous implant placement in patients with endophthalmitis. METHODS: A retrospective study was conducted to review the files of 27 patients (29 eyes) with endophthalmitis who underwent evisceration with primary porous implant placement from January 1997 to December 2007 at St. Mary's Hospital and Kangnam St. Mary's Hospital. The mean follow-up period was 12.24 months (range, 3 to 89 months) and the mean age of the patients was 63.6 years (range, 33 to 89 years). RESULTS: During the surgical procedure, primary implant placement was successfully completed, and any postoperative infection or inflammation rapidly resolved in all 27 patients (29 eyes). One of two porous implant materials was used. Hydroxyapatite was inserted in 14 eyes and Medpor was inserted in 15 eyes. Delayed implant exposure was noted in 1 eye, which was treated by inserting a hydroxyapatite implant 18 months after the first surgery. This was well treated by a preserved scleral graft. Implant infection was noted in 1 other eye at 20 days after the first surgery. All other minor complications healed without sequelae. CONCLUSIONS: Evisceration with primary porous implant placement as the treatment for recalcitrant endophthalmitis resulted in rapid resolution of any infection and inflammation. Implant exposure and infection occurred in only 2 eyes, and these problems were well treated without long-term sequelae. Therefore, evisceration with primary porous implant placement is a treatment option for patients with endophthalmitis.

Study on the enhancing micro-roughness of porous surfaced dental implant through anodization / 대한치과보철학회지

STATEMENT OF PROBLEM: HA has been used as a coating material on Ti implants to improve osteoconductivity. However, it is difficult to form uniform HA coatings on implants with complex surface geometries using a plasma spraying technique. PURPOSE: To determine if Ti6Al4V sintered porous-surfaced implants coated with HA solgel coated and hydrothermal treated would accelerate osseointegration. MATERIALS AND METHODS: Porous implants which were made by electric discharge were used in this study. Implants were anodized and hydrothermal treatment or HA sol-gel coating was performed. Hydrothermal treatment was conducted by high pressure steam at 300 degrees C for 2 hours using a autoclave. To make a HA sol, triethyl phosphite and calcium nitrate were diluted and dissolved in anhydrous ethanol and mixed. Then anodized implant were spin-coated with the prepared HA sols and heat treated. Samples were soaked in the Hanks' solution with pH 7.4 at 37 degrees C for 6 weeks. The microstructure of the specimens was observed with a scanning electron microscope (SEM), and the composition of the surface layer was analyzed with an energy dispersive spectroscope (EDS). RESULTS: The scanning electron micrographs of HA sol-gel coated and hydrothermal treated surface did not show any significant change in the size or shape of the pores. After immersion in Hanks' solution, the precipitated HA crystals covered macro- and micro-pores. The precipitated Ca and P increased in Hanks' solution that surface treatment caused increased activity. CONCLUSION: This study shows that sol-gel coated HA and hydrothermal treatment significantly enhance the rate of HA formation due to the altered surface chemistry.