Simulation of tissue differentiation around acetabular cups: the effects of implant-bone relative displacement and polar gap

Mukherjee, Kaushik,Gupta, Sanjay Techno-Press 2014 Advances in biomechanics & applications Vol.1 No.2

Peri-acetabular bone ingrowth plays a crucial role in long-term stability of press-fit acetabular cups. A poor bone ingrowth often results in increased cup migration, leading to aseptic loosening of the implant. The rate of peri-prosthetic bone formation is also affected by the polar gap that may be introduced during implantation. Applying a mechano-regulatory tissue differentiation algorithm on a two-dimensional plane strain microscale model, representing implant-bone interface, the objectives of the study are to gain an insight into the process of peri-prosthetic tissue differentiation and to investigate its relationship with implant-bone relative displacement and size of the polar gap. Implant-bone relative displacement was found to have a considerable influence on bone healing and peri-acetabular bone ingrowth. An increase in implant-bone relative displacement from $20{\mu}m$ to $100{\mu}m$ resulted in an increase in fibrous tissue formation from 22% to 60% and reduction in bone formation from 70% to 38% within the polar gap. The increase in fibrous tissue formation and subsequent decrease in bone formation leads to weakening of the implant-bone interface strength. In comparison, the effect of polar gap on bone healing and peri-acetabular bone ingrowth was less pronounced. Polar gap up to 5 mm was found to be progressively filled with bone under favourable implant-bone relative displacements of $20{\mu}m$ along tangential and $20{\mu}m$ along normal directions. However, the average Young's modulus of the newly formed tissue layer reduced from 2200 MPa to 1200 MPa with an increase in polar gap from 0.5 mm to 5 mm, suggesting the formation of a low strength tissue for increased polar gap. Based on this study, it may be concluded that a polar gap less than 0.5 mm seems favourable for an increase in strength of the implant-bone interface.

골신티그라피에 의한 Hydroxyapatite 안구삽입물로의 섬유혈관증식 평가

김지열(Ji Yeul Kim),범희승(Hee Seung Bom),송호천(Ho Chun Song),정상기(Sang Ki Jeong),박영걸(Young Kul Park) 대한핵의학회 1993 핵의학 분자영상 Vol.27 No.2

N/A Thirteen patients received a coralline hydroxyapatite sphere as a buried integrated ocular implant after enucleation surgery. The implant was modified by multiple drillings, 1 mm in diameter, to the center of the sphere to allow more rapid host tissue ingrowth. Tc-99m-MDP planar and tomographic bone scintigraphies were performed at various intervals after implantation (from 100 to 742 days after operation) to assess vascularization of the implant. All patients showed hot uptakes in the implants. These patients underwent a secondary drilling for the final motility peg application. The confirmation of vascular ingrowth was done by inspection of bleeding at the time of bleeding at the time of drilling from the center of the implant. Bleeding from the drilled implant was noted in all patients. In conclusion, hot uptake in the implanted ocular hydroxyapatite implant accurately reflect vascular ingrowth into the implant.

재치환술 시 얻어진 Harris-Galante Porous-Coated 비구컵에서의 골 내성장

장준동 ( Jun Dong Chang ),유제현 ( Je Hyun Yoo ),최용혁 ( Yong Hyuk Choi ),이창주 ( Chang Ju Lee ) 대한고관절학회 2006 Hip and Pelvis Vol.18 No.1

목적: 인공 고관절 전치환술에서 미세포말 피복(porous-coated) 처리된 비구컵에서 골 내성장의 정도 및 골 내성장에 영향을 주는 요소들을 알아보고자 하였다. 대상 및 방법: 인공 고관절 전치환술 후 재치환술 시 얻어진 무시멘트 미세 포말형 비구컵인 Harris-Galante Porous-Coated (HGP) 비구컵 36예를 대상으로 하였다. 감염으로 재치환술을 시행한 예와 심하게 파괴된 예들은 제외하였다. 이 컵들을 대상으로 골 내성장의 정도를 육안적으로 측정하였고, 나이, 성별, 체중, 신장, 비구컵의 고정 기간, 비구컵의 크기, 고정 나사못의 수, 경사각, 전염각 등과의 상관성을 통계적으로 분석하였다. 결과: 전체 비구 표면에서 골 내성장이 있었던 부위의 평균 비율은 52.9±21.9%(2~90%)였으며, 3예(8.3%)에서만 30%이하의 골 내성장 비율을 보였다. 골 내성장의 양상과 부위는 일정하지 않았고, 골 내성장의 정도는 나이, 성별, 체중, 신장, 비구컵의 고정 기간, 비구컵의 크기, 고정 나사못의 수, 경사각, 전염각 등과 상관성이 없었다. 결론: 본 연구에서 HGP 비구컵은 환자의 인구학적 및 수술과 관련된 다양한 변수들과 상관없이 골 내성장의 측면에서 만족할 만한 결과를 보였다. 이러한 결과는 미세포말 표면 처리방법이 장기적인 관점에서도 무시멘트 비구컵의 고정을 위한 믿을만한 방법임을 시사한다. Purpose: To investigate the extent of bone ingrowth into the porous-coated acetabular cups as well as the factors that correlated with bone ingrowth in total hip arthroplasty. Materials and Methods: Thirty six Harris-Galante porous-coated acetabular cups that were retrieved through revision surgery were examined in this study. Acetabular cups retrieved due to infection or severely destroyed cups (ed note: severe what?) were excluded. The extent of bone ingrowth into the acetabular cups was grossly measured, and its correlation with the variables including age, gender, weight, height, the duration of fixation, size, number of screws, inclination and anteversion was statistically analyzed. Results: The mean proportion of bone ingrowth was 52.9 21.9%(2~90%) and less than 30% in three cups(8.3%). The pattern and the location of bone ingrowth were not consistent. There was no correlation between the extent of bone ingrowth and age, gender, weight, height, the duration of fixation, cup size, number of screws, size, inclination and anteversion. Conclusion: Harris-Galante porous-coated acetabular cups showed satisfactory bone ingrowth regardless of the variables associated with the demographic or surgical conditions. Surface treatments with a fiber-metal porouscoating appears to be suitable for cementless acetabular cups in terms of the long term results.

다공성 수산화인회석 혼합 골시멘트의 골내성장 효과

권순용 ( Soon Yong Kwon ),김용식 ( Yong Sik Kim ),김기원 ( Ki Won Kim ),이화성 ( Hwa Sung Lee ),이문홍 ( Moon Hong Lee ),우영균 ( Young Kyun Woo ) 대한고관절학회 1996 Hip and Pelvis Vol.8 No.1

The purpose of this study is to investigate the bone ingrowth effect of porous hydroxyapatite(HA) impregnated bone cement(polymethylmethacrylate, PMMA) through the histologic and biomechanical analysis. For this study, HA and PMMA were mixed in weight ratio 0:100, 10:90, 30:70, to make 0%, 10%, 30% mixture cylindrical rod shaped sample, sized about 4mm x 10mm. The halves of each sample as control were decalcified to make a comparative histologic and biomechanical analyses of bone ingrowth effect of HA impregnated PMMA. The histologic and biomechanical analyses in vitro and vivo were undertaken to evaluate the bone ingrowth effect of HA impregnated PMMA in several aspects to make a comparative analysis of the interfacial shear strength and a histologic analysis of HA impregnated PMMA in vivo. The comparative analysis of interfacial shear strength using hydraulically controlled machine(INSTRON) in vitro and histologic examination of HA impregnated PMMA in vivo were undertaken using each HA exposed samples(by grinding off and removing the surface coated PMMA) and those processed by surface decalcification, which were harvested from both sides of distal femurs of rabbit at 6 weeks after implantation, respectively. The following results were obtained; 1) In histologic observation using the hard tissue sectioning method with Villaneuva bone stain, there was peri-implant new bone formation in HA impregnated PMMA and more remakable in 30% samples, but an osseointegration into the HA was observed only in 30% sample. And in 10Po and 30% samples decalcifying off the surface HA, peri-implant new bone formation was observed also and more remakable in 30%. But there was no definite difference of bone ingrowth related periimplant new bone formation after and before decalcification about each 10% and 30% samples.

Analysis of Intracellular Bone Ingrowth Characteristics on Trabecular-like Porous Structure according to Alteration of Pore size

이용경,정아라,반훈영,권보미,임도형 대한기계학회 2021 대한기계학회 춘추학술대회 Vol.2021 No.4

The first two authors contributed equally to this study. † Corresponding authors Previous studies have reported that different pore size of implants can lead to different bone ingrowth capacity. Recently, it also has been reported that the trabecular-like porous structure can improve bone ingrowth capacity, however the optimal pore size to induce bone growth are still unclear. This study was to confirm the bone ingrowth characteristics according to the pore size of the 3D printed implant. Specimens with pore sizes of 400 µm, 600 µm, 800 µm, and 1000 µm were fabricated by powder bed fusion (PBF) method. Human osteosarcoma cells (SaOS-2) were used to measure bone growth characteristics. Cellular proliferation was measured using cell counting kit-8 (CCK-8) and osteogenic differentiation was analyzed through alkaline phosphatase (ALP) activity. The CCK-8 results showed that the small pore size had more cells than the large pore size in a short incubation period, however it was confirmed that the proliferation of the cells was higher in the large pore size as the incubation period increased. Based on the results, we confirmed that the optimal structure for bone ingrowth need to be determined in consideration of both the bone growth time and the pore size.

Effects of a p38 MAP kinase inhibitor on bone ingrowth and tissue differentiation in rabbit chambers

Goodman, S.B.,Ma, T.,Spanogle, J.,Chiu, R.,Miyanishi, K.,Oh, K.,Plouhar, P.,Wadsworth, S.,Smith, R.L. Wiley Subscription Services, Inc., A Wiley Company 2007 Journal of biomedical materials research. Part A Vol.a81 No.2

<P>The effects of an oral p38 mitogen-activated protein kinase (MAPK) inhibitor and polyethylene particles separately and together on tissue differentiation in the bone harvest chamber (BHC) in rabbits over a 3-week treatment period were investigated. The harvested tissue was analyzed histomorphometrically for markers of bone formation (percentage of bone area), osteoblasts (alkaline phosphatase staining), and osteoclasts (CD51, the α chain of the vitronectin receptor). Polyethylene particles decreased the percentage of bone ingrowth and staining for alkaline phosphatase. The p38 MAPK inhibitor alone decreased alkaline phosphatase staining. When the oral p38 MAPK inhibitor was given and the chamber contained polyethylene particles, there was a suppression of bone ingrowth and alkaline phosphatase staining. In contrast to oral non-steroidal anti-inflammatory drugs (NSAIDs) and local Interleukin-1 receptor antagonist (IL-1ra) administration, the oral p38 MAPK inhibitor alone did not suppress bone formation when given during the initial phase of tissue differentiation. Particle-induced inflammation and the foreign body reaction were not curtailed when the p38 MAPK inhibitor was given simultaneously with particles. Additional experiments are needed to establish the efficacy of p38 MAPK inhibitor administration on mitigating an established inflammatory and foreign body reaction that parallels the clinical situation more closely. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res 2007</P>

백서에서 Medpor^® 매식후 조직반응에 관한 실험적 연구

김수관,여환호,Kim, Su-Gwan,Yeo, Hwan-Ho 대한악안면성형재건외과학회 1998 Maxillofacial Plastic Reconstructive Surgery Vol.20 No.2

$Medpor^{(R)}$(porous polyethylene) Surgical Implants are used for the augmentation or restoration of bony contour in craniofacial defects. The purpose of this study is to evaluate the ingrowth of soft tissue and bone after application in calvaria of rats. The experiment was carried out in 60 rats. The reflected periosteum was resutured after implantation of $Medpor^{(R)}$ as a experimental site, while in the calvarial bone the reflected periosteum resutured without implantation as a control site. The histologic examination was performed after 1-, 2-, 4-, 8-, 12-, 24-weeks implantation in calvaria of rats. I concluded that there was abundant ingrowth of soft tissue and bone without any adverse tissue response and that it shows good stability.

백서에서 Medpor(R) 매식후 조직반응에 관한 실험적 연구

김수관(Su Gwan Kim),여환호(Hwan Ho Yeo) 대한악안면성형재건외과학회 1998 Maxillofacial Plastic Reconstructive Surgery Vol.20 No.2

MedporR(porous polyethylene) Surgical Implants are used for the augmentation or restoration of bony contour in craniofacial defects. The purpose of this study is to evaluate the ingrowth of soft tissue and bone after application in calvaria of rats. The experiment was carried out in 60 rats. The reflected periosteum was resutured after implantation of MedporR as a experimental site, while in the calvarial bone the reflected periosteum resutured without implantation as a control site. The histologic examination was performed after 1-, 2-, 4-, 8-, 12-, 24-weeks implantation in calvaria of rats. I concluded that there was abundant ingrowth of soft tissue and bone without any adverse tissue response and that it shows good stability.