The Bicontact cementless primary total hip arthroplasty: long-term results

Short stem hip arthroplasties with predominantly metaphyseal fixation, such as the METHA® stem (Aesculap, Tuttlingen, Germany), are recommended because they are presumed to allow a more physiologic load transfer and thus a reduction of stress-shielding. However, the hypothesized metaphyseal anchorage associated with the aforementioned benefits still needs to be verified. Therefore, the METHA short stem and the Bicontact® standard stem (Aesculap, Tuttlingen, Germany) were tested biomechanically in synthetic femora while strain gauges monitored their corresponding strain patterns. For the METHA stem, the strains in all tested locations including the region of the calcar (87% of the non-implanted femur) were similar to conditions of synthetic bone without implanted stem. The Bicontact stem showed approximately the level of strain of the non-implanted femur on the lateral and medial aspect in the proximal diaphysis of the femur. On the anterior and posterior aspect of the proximal metaphysis the strains reached averages of 78% and 87% of the non-implanted femur, respectively. This study revealed primary metaphyseal anchorage of the METHA short stem, as opposed to a metaphyseal-diaphyseal anchorage of the Bicontact stem.

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“…Swamy et al . reported a survivorship for aseptic loosening of 100% after 12.9 years for 201 prosthesis 32 . Ochs et al .…”

Section: Discussionmentioning

confidence: 99%

Changes in strain patterns after implantation of a short stem with metaphyseal anchorage compared to a standard stem: an experimental study in synthetic bone

et al. 2014

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“…This can be assessed by direct acquisition of bone remodelling data via dual-energy X-ray absorptiometry (DEXA), which is the gold standard in evaluating redistribution of mechanical forces and femur remodelling around the THA implant [3]. Although good long-term results with the Bicontact® stem have been published [1,2,4], it is questionable whether the implant provides the criteria for a state-of-the-art stem regarding proximal bone stock preservation. The aim of our study was to monitor the periprosthetic bone mineral density (BMD) after implantation of the Bicontact® stem in a prospective two-year follow-up DEXA study.…”

Section: Introductionmentioning

confidence: 99%

The cementless Bicontact® stem in a prospective dual-energy X-ray absorptiometry study

Lerch

Kurtz

Bouguecha

et al. 2012

International Orthopaedics (SICOT)

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Purpose The cementless Bicontact® total hip arthroplasty (THA) system (AESCULAP AG, Tuttlingen, Germany) was introduced in 1986/1987 and has been in successful clinical use in an unaltered form up to today. Although good longterm results with the Bicontact® stem have been published, it is questionable whether the implant provides the criteria for a state-of-the-art stem regarding proximal bone stock preservation. The purpose of the study was to monitor the periprosthetic bone mineral density (BMD) in a prospective two-year follow-up dual-energy X-ray absorptiometry (DEXA) study. Methods After power analysis, a consecutive series of 25 patients with unilateral Bicontact® stem implantation was examined clinically and underwent DEXA examinations. Scans of seven regions of interest were taken preoperatively and at one week, six months, and one and two years. Results One patient required stem revision due to a deep infection. The Harris Hip Score increased significantly by 44 points. The most significant bone loss was observed in the calcar region (R7) in the first six months (−19.2 %). It recovered in the following 18 months to −8.5 %. The BMD in the greater trochanter dropped significantly after six months and remained stable at this level. BMD exceeded baseline values in distal regions and even more in the lesser trochanter region after two years. Conclusions We conclude that the Bicontact® stem provides adequate proximal bone stock preservation. We observed some signs of stress shielding at the tip of the stem, which is inevitable to some degree in THA with cementless straight stems. However, in this prospective DEXA investigation, we showed that proximal off-loading does not occur after THA with the Bicontact® system. Thus, we believe that this stem is still a state-of-the-art implant.

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“…To compare the in situ protein adsorption onto two different surface structures in the same patient and for safety purposes, the Bicontact stem (Braun Aesculap, Tuttlingen, Germany) was chosen, a long‐term established Ti‐6Al‐4V implant which is characterized be a large anchoring distance and high implant survival rates . The proximal part of the implant is covered by a 0.35 mm plasma spray layer of commercial pure Ti (cpTi) and has a microrough surface structure (Plasmapore, porosity 35%, pore size 50–200 µm).…”

Section: Methodsmentioning

confidence: 99%

Intrasurgical Protein Layer on Titanium Arthroplasty Explants: From the Big Twelve to the Implant Proteome

Jäger

Jennissen

Haversath

et al. 2019

Proteomics Clinical Apps

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Purpose: Aseptic loosening in total joint replacement due to insufficient osteointegration is an unsolved problem in orthopaedics. The purpose of the study is to obtain a picture of the initial protein adsorption layer on femoral endoprosthetic surfaces as the key to the initiation of osseointegration. Experimental design: The paper describes the first study of femoral stem explants from patients for proteome analysis of the primary protein layer. After 2 min in situ, the stems are explanted and frozen in liquid nitrogen. Proteins are eluted under reducing conditions and analyzed by LC-MS/MS. Results: After exclusion of proteins identified by a single peptide, the implant proteome is found to consist of 2802 unique proteins. Of these, 77% are of intracellular origin, 9% are derived from the plasma proteome, 8% from the bone proteome, and four proteins with highest specificity score could be assigned to the bone marrow proteome (transcriptome). The most abundant protein in the adsorbed total protein layer is hemoglobin (8-11%) followed by serum albumin (3.6-6%). Conclusions: A detailed knowledge of the initial protein film deposited onto the implants, as demonstrated here for the first time, may help to understand and predict the response of the osseous microenvironment to implant surfaces.

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The Bicontact cementless primary total hip arthroplasty: long-term results

Cited by 20 publications

References 26 publications

Changes in strain patterns after implantation of a short stem with metaphyseal anchorage compared to a standard stem: an experimental study in synthetic bone

Changes in strain patterns after implantation of a short stem with metaphyseal anchorage compared to a standard stem: an experimental study in synthetic bone

The cementless Bicontact® stem in a prospective dual-energy X-ray absorptiometry study

Intrasurgical Protein Layer on Titanium Arthroplasty Explants: From the Big Twelve to the Implant Proteome

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