Key Engineering Materials Vols. 361-363

Abstract: The biomaterial studied here is a composite associating a mineral phase of an intimate nanoscale melting of hydroxyapatite and beta tri calcium phosphate and an aqueous phase containing a synthetic polymer derived from cellulose HPMC (hydroxyl propyl methyl cellulose), marketed under name MBCP Gel (FDA approval, Biomatlante manufacturer). The present exploratory study aim was to study the safety of MBCP-gel, and to determine in the osseous healthy area the performance of MBCP gel. We expected to prove bone ingrowth into the osseous cavities created during drilling biopsy of the aseptic osteonecrosis of femoral head. The current results obtained in the first two patients with 1 year follow up demonstrate the resorption and bone ingrowth with trabecular bone architecture in the hole created into the femoral neck.

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.

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.

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.

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.

Abstract: The goal of hip arthroplasty is to restore the patient to an active and pain free life for ever. Unfortunately, prosthetic implants fail because of loosening, wear or infection. This study sets out to ascertain whether or not Hydroxyapatite hip arthroplasty (HA) will produce long-lasting function of at least ten years in unselected patients of all ages and all diagnoses. Cemented implants used in hip arthroplasty often loosen after ten or more years of use. This is partly mechanical but also associated with debris disease arising from plastic wear products. Cementing techniques have been improved and the Swedish Hip Register [1] demonstrates that the revision rates have been reduced with improved cementing techniques. Revision surgery after cemented arthroplasty is difficult and may be complicated by fracture of the host bone Bioactive materials are being used to secure joint implants [2,3] and this paper presents the results of a consecutive series of hip arthroplasties carried out over a total period of over 19 years using the Furlong Hydroxyapatite Ceramic Coated hip prosthesis.[4, 5]

Abstract: In this study, we report human clinical and histological data on the use of micromacroporous biphasic calcium phosphate wedges in combination with osteosynthesis with adjustable screws for open tibial osteotomy. 42 patients were operated for open tibial osteotomy for valgisation due to incipient medial gonarthrosis. The population was composed of 43 knees (25 right knees and 18 left knees) in 13 women and 29 men, with a mean age of 46 years. Radiological follow-up at D+1, D+90 and D+360, and 12 biopsies for histology were processed after the removal of the osteosynthesis. Consolidation was obtained in 100 % of cases (except one, because of failure of the osteosynthesis). Regular bone ingrowth was observed on X-ray, with maintain of the corrections at one year in 98.5 % of cases. Only 8 % of cases showed a radiolucent interface after D+360. Histological examinations demonstrated resorption of the MBCP and large bone ingrowth. Polarised microscopy confirmed the lamellar bone, and the X-rays and microscanner revealed well mineralised and organised newly-formed bone.

Abstract: We studied the role of cytokines (TNF-α, IL-6,IL-1β, TGF-β) as markers of osteolysis in patients who underwent to a hip prosthesis implantation subdivided in two groups: group A with an ultrahigh molecular weight polyethylene (UHMWPE) insert articulating against a metal ball head , and group B with an all alumina ceramic combination. Profibrogenic (TGF-β) and pro-inflammatory cytokines (TNF-α, IL-6,IL-1β) are secreted by the periprosthetic synovial-like fibrous membrane in hip artificial implants. They are secreted by inflammatory activated cells and trigger the cascade of biochemical events leading to the activation of osteoclasts and bone resorption. A statistically significant increase of TGF-β serum levels was observed between TGF-β values in implanted patients as compared to normal subjects and between TGF-β values after versus before implantation in Group A. A progressive decrease in TNF-α and IL-6 serum levels has been observed in both Groups, when compared with the initial values before the implantation. IL-1β levels decreased up to 60 months after the implantation Our data suggest that monitoring circulating cytokines could be a good indicator for the proliferation and activity of the periprosthetic synovial-like membrane and potential osteolysis. This could allow for an adequate early treatment.

Abstract: The aims of this study are to confirm the capacity of hard tissue induction by human demineralized dentin matrics (DDM) and calcified dentin matrics (CDM) in subcutaneous tissues of nude mice, and to report a human pioneering trial following the autotransplantation of DDM for bone augmentation in a case of the atrophied upper jaw. Human DDM and CDM particles were prepared from adult, extracted vital teeth, and were implanted into the subcutaneous tissues of 4-week-old nude mice. DDM induced bone and cartilage independently at 4 weeks after implantation, while CDM did not induce a hard tissue formation. Autogenous DDM prepared from the non-functional second molar of a 58-year-old female were grafted on the atrophied jaw and received to the host. Human dentin can be recycled as autogenous biomaterials for local bone engineering.

Abstract: This study analyzed the examination records and radiographs of 247 patients (144 male, 103 female) who received an OSSTEM Implant (Seoul, Republic of Korea) at the dental clinic at Chosun University, Korea, between January 2002 and December 2005. The overall success rate in patients who received an OSSTEM Implant from surgeons of the Department of Oral Surgery at our hospital was 93.1%, making the overall failure rate relatively low (6.9%). The failure rate for the maxillary molar tooth was slightly higher, at 9.95%, probably as a result of its relatively lower bone quality and reduced osteoid volume caused by pneumatization of the maxillary sinus. Thus, to determine appropriate treatment, it is necessary to accurately determine bone quality and volume. This can be achieved with implant placement analysis of computed tomography, precise preoperative planning, and sufficient technical experience.