Papers by Keyword: Total Hip Arthroplasty (THA)

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Authors: Laurent Sedel, Agnes Raould, Frederic Zadegan, Didier Hannouche, Remy Nizard
Abstract: The experience of Alumina ceramic liner fixed in a metallic shell is not new ; From 1983 to 1999 , 555 components of this type with a titanium screw in shell design were implanted . Recently a review of the first 117 cases with a mean follow up of 12 years were presented. No ceramic fracture were recorded. In 1989 a new press fit shell fixation system replaced the screw in design; This material was implanted from 1989 to 1997. The shape of the liner was an angle of 5°40’ , a liner in excess of 2 mm .A centraliser to insure the correct setting. The shell thickness was limited in order to allow the grid fixation One fracture of the rim (Shipping) was discovered during revision surgery performed elsewhere for acetabular loosening; This revision was performed 4 years after a trauma with fracture of the patella in a fore board trauma. No other fracture was recorded with this design (over more than 1500 implanted). Starting in 1997 a new press fit socket was introduced with a sand blasted surface covered with HA. To be able to retain the same liners , the thickness of the shell were increased resulting in a thin Alumina component for the small sizes (50 mm for a 32 mm head.) . In 1999 a slight modification of the design were made. Recessed liner of 1 mm , ancillary material with a system to insure as well polyethylene or alumina liner fixation. At the moment 5 fractures of this design were recorded (one coming from another institution).
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Authors: S.M. Kurtz, S. Srivastav, K. Dwyer, J.L. Ochoa, S.B. Brown
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Authors: Ryoichi Suetoshi, Dorian Cretin, Shinji Ogawa, Takayoshi Nakano
Abstract: Following artificial hip joint implantation, a stress inhibition, applied to bone in the surroundings of implants, causes a structural change in bone called bone loss. To evaluate the bone mechanical characteristics, it is essential to investigate the elastic properties of cortical bone. In this article a pair of donor femora was investigated, one with an implant and the other without. Differences in Speed of Sound (SOS), a parameter reflecting elastic properties, were measured in both femora by ultrasound transmission. As a result, in almost all areas, the femur that was implanted showed significantly lower cortical SOS. Our results indicated that the change in the mechanical function of bone, due to the introduction of femoral implants, could be evaluated by the measurement of SOS.
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Authors: Clifford W. Colwell, J.A. D'Antonio, W.N. Capello, M.E. Hardwick
Abstract: Alumina ceramic is an excellent material for biologic implantation. Decreased particulate wear debris should increase implant longevity. The purpose of this study is to examine clinical and radiological results of ceramic-on-ceramic hip implants compared to cobalt chrome on polyethylene. Four cementless systems were compared, three alumina-on-alumina bearing systems: System I, porous coated cup; System II, hydroxyapatite-coated cup; Trident system, hydroxyapatite-coated cup with metal sleeve backing on ceramic cup liner; and System III (control), porous-coated cup with polyethylene and cobalt chromium bearing system. Patients were randomized to receive System I, II, or III. Trident patients were not randomized. Examinations are performed at 6 months, 1 year and yearly thereafter including x-rays, clinical exam and Harris Hip Score (HHS). Minimum 24-month followup was performed in 562 ceramic hips and 154 control hips. Age, height, weight, gender and diagnosis were similar in all groups. HHS was rated good/excellent by 95 percent of ceramic hips and 97 percent of control hips. Radiographic results demonstrated radiolucency in Femoral Gruen Zone 1 in 3.8 percent (18/474) of ceramic hips and in 8 percent (10/128) of control hips. Unstable acetabular components were reported in none of ceramic hips and in 3.2 percent (5/154) of control hips. Revision was performed in 7 (1.2 percent) ceramic hips, none due to failure of ceramic materials, and in 9 (5.8 percent) control hips. Alumina ceramic materials show promise, but continued evaluation of long-term clinical results is needed.
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Authors: Juan C. Hermida, Darryl D. D'Lima, Nikolai Steklov, Clifford W. Colwell
Abstract: Hydroxyapatite (HA) coatings for femoral stems have been successful in short- to intermediate-term follow up. However, the outcomes of HA-coated cups have not been as successful as comparable non-HA-coated designs. This has been attributed to component design and to poor quality HA-coating processes. This is a clinical outcome study of a newer generation acetabular design with an improved plasma-sprayed HA-coat. Ninety consecutive primary total hip replacements implanted with a HA-coated metal-backed cup were prospectively followed up for 2–5 years after surgery. Mean age was 69 years, male:female ratio was 36:47; mean-weight was 77 kg. Polyethylene wear was measured on digitized images. Component position, component migration, and implant-bone interface radiolucent lines were analyzed by computerized image analysis. Hip-scores improved from preoperative mean 59(±12) to a final follow-up mean of 91(±12). One hip was revised for recurrent dislocation. No hips were revised for aseptic loosening. Mean acetabular abduction angle was 46°(±8.5) and anteversion was 18°(±8.7). Incomplete lucent lines were noted on early postoperative radiographs in 5% of the cases. With ongoing follow up radiolucent line thickness decreased by mean 13% and radiolucent line density increased by 11%. No cup had complete continuous radiolucent lines or lysis. Mean polyethylene linear and volumetric wear rates were 0.14(± 0.15) mm/year and 73(± 70) mm3/year respectively. Wear rates were higher in males (p<0.03). No other factor (age, body weight, cup abduction or anteversion angle) correlated significantly with wear rate. This study presents encouraging short-term results. The improvement in radiolucent lines suggests a beneficial effect of the HA-coat on bone ingrowth. None of the cups loosened or migrated. Wear rates were comparable to published reports of successful non-HA-coated cups. Long-term follow up is ongoing to corroborate these early findings.
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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.
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Authors: Taishi Sato, Yasuharu Nakashima, Mio Akiyama, Takuaki Yamamoto, Taro Mawatari, Takashi Itokawa, Masanobu Ohishi, Goro Motomura, Masanobu Hirata, Yukihide Iwamoto
Abstract: The purpose of this study was to examine the effects of ceramic femoral head material on the wear of annealed, crosslinked ultra-high molecular weight polyethylene (UHMWPE) (XLPE) in total hip arthroplasty compared to non-crosslinked conventional UHMWPE (CPE). XLPE was fabricated by crosslinking with 60 kGy irradiation and annealing. Femoral heads made from zirconia and alumina ceramics, and cobalt-chrome (CoCr) of 22 mm or 26 mm diameter were used. In this study, the femoral head penetration into the cup was measured digitally on radiographs of 70 hips with XLPE and 50 hips with CPE. The average follow-up periods were 6.1 and 12.7 years, respectively. The steady wear rate of XLPE was significantly lower than those of CPE (0.002 versus 0.08 mm/year, respectively). Zirconia displayed increased wear rates compared to alumina in CPE; however, there was no difference among head materials in XLPE (0.0028, 0.011 and 0.009 mm/year for zirconia, alumina and CoCr, respectively). Neither head size or implantation period impacted XLPE wear. In contrast to CPE, XLPE displayed low wear rates surpassing the effects of varying femoral head material, size, implantation period and patient demographics.
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Authors: R. Schmidt, R. Petzold, Lutz Müller, Rocco Paolo Pitto
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Authors: Dong Song Li, Shu Qiang Li, Bo Cai, Wei Feng, Jian Guo Liu
Abstract: Objective To construct three-dimensional models of individualized femoral prosthesis by using computer-aided design and to verify whether individualized femoral prosthesis is superior to popular femoral prosthesis via simulating and contrasting mechanical study. Methods Two-dimensional images of fresh femurs were obtained by using total-length CT scanning and processed with computer edge recognition and three-dimensional contour extraction software to identify outer and inner contour of pulp cavity, extract contour data of pulp cavity and prosthesis, and construct three-dimensional models of femur and individualized femoral prosthesis. SolidWorks software was used to establish three-dimensional prosthetic models in common biological and bone cement types; moreover, bone-cement, biological, and individualized femoral prosthesis were replaced via simulating clinical surgery. Results Edge extracting was replaced by Canny operator, characterizing by stable running, credible outcome, and consistent with the primary request. Stress, femoral stress, interface stress, and primary micro-motion of individualized femoral prosthesis were significantly lower than biological and bone-cement femoral prosthesis (P Conclusion The computer-aided design is reliable to perform the assistant design of prosthesis; furthermore, biomechanical properties of the individualized femoral prosthesis are superior to those of popular femoral prosthesis.
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Authors: Nuno Eduardo Dias Gueiral, Elisabete Maria da Silva Marques Nogueira, Antonio Manuel de Amaral Monteiro Ramos
Abstract: One the mechanisms of failure in total hip arthroplasty in cemented prosthesis is cement fatigue. The main objective of this work is to use Acoustic Emission (AE) as a non-destructive and non-intrusive monitoring test in a cemented prosthesis. The femoral component was sinusoidally loading in a fatigue machine. Experimental data collected during acoustic emission test was treated and analysed by Wavelet Transform and allowed to locate a crack in cement mantle of femoral component. Other complementary diagnostic tests were used to confirm the existence of a fault (crack). One of them was penetrating liquids in different cut sections of femoral component. The other one was microscopic analysis that allowed observing the existence of a crack which location is pointed out by the results of AE answer. The AE sources locations are situated inside the crack observed in the optical microscope. The Wavelet Transform (WT) AE signals demonstrated the accuracy of damage location in bone cement and thus becoming useful in other orthopedics studies.
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