Papers by Author: Hiroyuki Oonishi Jr.

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Authors: Hironobu Oonishi, Hiroyuki Oonishi Jr., Sok Chol Kim, Hirotsugu Ohashi, Satoshi Ojima
Abstract: To augment cement-bone bonding, hydroxyapatite (HA) granules were interposed at cement-bone interface (IBBC technique). HA granules were smeared on the bone surface just before cementing components. Porous HA granules of 300 to 500μm in diameter and 100 to 300μm in diameter were used from 1986 to 1988(first generation) and 1989 to 1991(second generation), respectively. 222 hips of 151 patients in the first generation and 252 hips of 170 patients in second generation could be followed. After 16 to 21 year follow up, radiolucent line (space), less than 1mm, was observed in 4 hips(1.8%) in the first generation and in 15 hips(6.2%) in the second generation(p<0.01). osteolysis was observed in 1 hip(0.5%) and 6 hips (1.6%), respectively. Loosening (separation) was observed only 2 cups (0.8%) in the second generation.
1299
Authors: Hironobu Oonishi, Hiroyuki Oonishi Jr., Shigekazu Mizokawa, Hirotsugu Ohashi, Masaru Ueno, Mikio Iwamoto
Abstract: To improve the fixation of bone and bone cement in THA we used Interface Bioactive Bone Cement technique (IBBC) since 1982. For prostheses 28 mm-alumina head with polyethylene socket (Kyocera Co.) were used. In IBBC not-resorbable pure crystalline HA granules (0.3– 0.5 mm) were smeared on the bone surface in one to three layers just before packing bone cement. Group 1: IBBC was used in six joints in 1982. Group 2: In 25 patients, conventional bone cement technique (non-IBBC) in the one hip (in 1985 to 1986) and IBBC technique in the other hip (in 1986) were performed in the same patients. Group 3: In 65 patients (71 joints) IBBC were performed. Neither radiolucent line nor osteolysis appeared in all case in group 1. In group 2 in Non-IBBC the appearance rate of radiolucent line and osteolysis were rather high, however in IBBC they were extremely low. In Non-IBBC loosening were seen in 5 joints in the acetabulum and in 2 joints in the femur. However, in IBBC there was no loosening. In group 3 the radiolucent line and the osteolysis appeared extremely low. There was no loosening. In Non-IBBC the appearance rate of radiolucent line and the osteolysis was very high and the rate of loosening was 20%. However, in IBBC, radiolucent line and osteolysis will be prevented eternally.
366
Authors: Hiroyuki Oonishi Jr., Tomonori Arita, Akira Tachibana, Toshizumi Tanabe, Shigekazu Mizokawa, Hironobu Oonishi
Abstract: Antibiotics release impregnated in HA granules, which were used in IBBC to prevent infection after total joint arthroplasty, was measured. For antibiotics, Flumarin, Vancomycin, Pansporin and Firstcin were used. Two models of antibiotics release were assumed; Model [I]: antibiotics release from surroundings of HA granules immediately after surgery and Model [II]: antibiotics release loaded on HA after antibiotics release from surroundings of HA granules as follows; (1) loading in normal pressure and (2) loading in reduced pressure. The amount of antibiotics loaded on HA is higher when loading is conducted under reduced pressure than that under normal pressure. Firstcin showed the highest loaded amount and the most desirable sustained release pattern. The antibiotics release from HA are varid depending on the antibiotics used.
361
Authors: Sok Chol Kim, Hironobu Oonishi, Hiroyuki Oonishi Jr., Masayuki Kyomoto, Mikio Iwamoto, Masaru Ueno, Hirotsugu Ohashi
Abstract: In the late 1970s, based on good clinical results in total hip prostheses, the use of a combination of alumina ceramics and ultra-high molecular weight polyethylene (UHMWPE) was begun for total knee prostheses (TKPs) in order to reduce UHMWPE wear. In this study, to examine the in vivo efficacy of the alumina ceramic bearing surfaces of TKPs, we compared retrieved alumina ceramic TKPs with cobalt-chrome (Co-Cr) alloy TKPs by surface observations and linear wear measurements. In scanning electron microscopic observations, many scratches due to clinical use were observed only on the retrieved Co-Cr alloy femoral components. The damage in the form of scratches on the articulating surface was linear and was produced by rubbing against the Co-Cr alloy surface. The linear wear rate of the retrieved Co-Cr alloy TKPs was 0.027–0.358 mm/year. In contrast, the wear of the retrieved alumina ceramic TKPs was stably low and linear; the linear wear rate was estimated to be 0.026 mm/year. The lower wear rate and milder nature of wear observed in the TKPs with the combination of UHMWPE inserts and alumina ceramic femoral components suggest the possibility of the retention of high performance even during prolonged clinical use.
1287
Authors: Hironobu Oonishi, Sok Chol Kim, Hiroyuki Oonishi Jr., Masayuki Kyomoto, Mikio Iwamoto, Masaru Ueno, Hirotsugu Ohashi
Abstract: In the late 1970s, we started the clinical use of total knee prostheses (TKPs) composed of alumina ceramic. In this study, we investigated the long-term clinical performance of ceramic TKPs. First-generation ceramic TKPs were used between 1981 and 1985; second-generation TKPs, between 1990 and 1996 and third-generation TKPs, between 1993 and 1998. We examined the findings of clinical radiographic observation. A total of 137 first-generation ceramic TKPs were followed up for 20–23 years after implantation. All the rates of loosening, sinking and revision were higher with cementless fixation than with cemented fixation. In the second- and third-generation TKPs, all the components were implanted using bone cement. In 249 joints that were followed up for 6–14 years, neither loosening nor sinking was observed. No osteolysis was observed in any case. We compared the wear of metal TKPs and ceramic TKPs that were retrieved after long-term use. Metal TKPs exhibited a higher wear rate than ceramic TKPs, and they also exhibited scratched surface damages. The lower wear rate and considerably less surface damage observed in our previous study suggest the long-term durability and performance of ceramic TKPs.
1311
Authors: Hiroyuki Oonishi Jr., Hironobu Oonishi, Sok Chol Kim, Shingo Masuda, Masaru Ueno, Hirotsugu Ohashi
Abstract: In total hip prosthesis (THP), we have been using alumina ceramic femoral heads to reduce polyethylene debris and the modified cementing technique, which was named “interface bioactive bone cement (IBBC)” method to improve implant fixation. In this study, we investigated the long-term clinical performance of THPs with an alumina ceramic head and IBBC method. From 1986 to 1988, 285 joints (215 patients) were operated on by a senior surgeon, and 265 joints (192 patients) could be followed up. The presence of radiolucent lines, loosening, osteolysis and ultrahigh-molecular-weight polyethylene (UHMWPE) socket wear were observed. In IBBC, a radiolucent line appeared as a ’space’, and loosening appeared as a ’separation’ between the HA layer and the cement. A ‘space’ appeared in 3 joints (1.4%) on the acetabulum and in 4 joints (1.8%) on the femur, while a ‘separation’ appeared in 3 joints (1.4%) on the acetabulum. Osteolysis was noted in 1 joint (0.5%) on the acetabulum and in 2 joints (0.9%) on the femur. No revision surgery was required. In our previous study, we reported that the thickness of the socket affected its clinical wear rate and that the wear rate of sockets with an alumina ceramic head was 20% lower than that of sockets with a metal head. By reducing wear debris through the use of ceramic heads, osteolysis could be reduced. Long-term fixation of THPs to the bone has been achieved by using IBBC. Thus, the long-term clinical results of THPs with an alumina head that were fixed using IBBC were excellent.
1303
Authors: Sok Chol Kim, Hironobu Oonishi, Hiroyuki Oonishi Jr., Hirotsugu Ohashi
Abstract: Improved cement technique by interposing less than two layers of hydroxyapatite (HA) granules between bone and bone cement at the cementing (Interface Bioactive Bone Cement : IBBC) have been performed in total knee arthroplasty (TKA). 140 knees (120 patients) could be followed up clinically and radiologically. As a control, clinical results of TKA with conventional cementing (Non-IBBC) were used. In IBBC cases, the appearance rate of the radiolucent lines on the tibial components and the periprosthetic osteolysis of the tibial components were significantly low. In IBBC, bone cement bound to HA mechanically immediately after surgery and HA granules bound to the bone physicochemically after bone ingrowth into the spaces around the HA granules. Thus, we believe that IBBC is a method combining the advantage of cementless HA coating and bone cement.
819
Authors: Shigekazu Mizokawa, Tomonori Arita, Akira Tachibana, Toshizumi Tanabe, Hiroyuki Oonishi Jr., Hironobu Oonishi
Abstract: Since 1985, HA granules were interposed on the interface between bone and bone cement at the cementation (Interface Bioactive Bone Cement : IBBC) in THA to prevent generation of connective tissue and osteolysis. To prevent infection, β-TCP impregnated with antibiotics along with HA granules was used. As TCP is resorbable, antibiotic release can be controlled. β-TCP granules were impregnated with antibiotics of folmoxef sodium (F), Vancomycine hydrochloride (V) cefortiam dihydrochloride (C) and cefozopran hydrochloride (CE). Three models of antibiotic release were assumed. Model [1] was antibiotic release from surroundings of β-TCP granules. Model [2] was the condition loaded under normal and reduced pressure. In Model [3], β-TCP was dissolved gradually in EDTA, as the model in the living body. In model [1], the amount of release of F, V and C was 3280, 300 and 3 µg, respectively and completed in 30 hours. In model [2], the amount of release of F, V, C and CE was 16, 8, 0 and 8000 µg in reduced pressure, respectively. The release of F, V and C completed within 24 hours and that of CE was in 6 days. In model [3], released amount of C and CE was 116 and 7100 µg, respectively and completed in 19 days.
186
Authors: Sok Chol Kim, Hironobu Oonishi, Hiroyuki Oonishi Jr., Hirotsugu Ohashi
Abstract: Improved cement technique by interposing less than two layers of hydroxyapatite (HA) granules between bone and bone cement at the cementing (Interface Bioactive Bone Cement : IBBC) have been performed in total knee replacement (TKR). Results of TKRs of the rheumatoid arthritis (RA) who used IBBC were evaluated. 54 knees of the RA could be followed up clinically and radiologically. As a control, clinical results of TKR with conventional cementing (Non-IBBC) were used. In IBBC cases, the appearance rate of the radiolucent lines on the tibial components and the periprosthetic osteolysis of the tibial components were significantly low. In IBBC, bone cement bound to HA mechanically immediately after surgery and HA granules bound to the bone physicochemically after bone ingrowth into the spaces around the HA granules. Thus, we believe that IBBC is a method combining the advantage of cementless HA coating and bone cement.
1307
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