Randomised Trial Comparing Bone Remodelling around Two Uncemented Stems Using Modified Gruen Zones

Broeke, René H.M. ten; Hendrickx, Roel P. M.; Leffers, Pieter; Jutten, Liesbeth M.C.; Geesink, R. G. T.

doi:10.5301/hip.2012.9103

Cited by 25 publications

(20 citation statements)

References 28 publications

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“…As illustrated from histomorphometry analyses of retrieval specimens, BONIT-HA coating results in osseointegration over a larger part of the coated stem surface [9, 14]. The highly bioactive biomimetic BONIT-HA coating results in both more extensive bone-implant contact and bone density in periprosthetic regions of interest compared to other currently known hydroxyapatite or porous-coated stems [9, 10]. Enhanced proximal fixation combined with reduced distal bone apposition, caused by the DOTIZE surface treatment, leaves space for relative ‘micromotion’ between the stiff distal stem and the more elastic bone [25].…”

Section: Discussionmentioning

confidence: 99%

“…BONIT-HA is a new generation, electrochemically deposited, biomimetic hydroxyapatite (HA) coating on top of a commercially pure titanium plasma spray (TPS) layer. It is deposited by low-temperature precipitation, is thin (10–20 μm), and has a 3D surface with high porosity (60%) and pore interconnectivity [9, 10, 12, 13]. The coating is fully resorbable and is known to be substituted by bone for about 99% [14].…”

Section: Methodsmentioning

confidence: 99%

“…The anodization surface treatment, DOTIZE, applied on the distal part of the stem, is an electrolytical conversion of the native oxide film on titanium surfaces into a thicker and denser titanium oxide. It shows anti-galling properties and reduces protein adsorption with 19% and bone apposition compared to untreated titanium alloy [9, 10, 15].

Fig.…”

Section: Methodsmentioning

confidence: 99%

“…Histological and histomorphometric analyses on retrieved implanted Symax hip stems have already proven early proximal ingrowth as a result of the new BONIT-hydroxyapatite (HA) coating (DOT GmbH, Rostock, Germany) and the distal DOTIZE surface treatment (DOT GmbH, Rostock, Germany) [9]. Furthermore, improved bone remodeling was already established in a 2-year follow-up dual-energy X-ray absorptiometry (DEXA) study compared to the Omnifit hip stem [10]. This international study is part of a stepwise clinical introduction of the Symax hip stem according to Malchau et al [11], illustrating the ‘phased innovation’ of this new implant.…”

Section: Introductionmentioning

confidence: 99%

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5-year clinical and radiographic follow-up of the uncemented Symax hip stem in an international study

et al. 2018

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BackgroundThe uncemented Symax hip stem is developed through optimization of the uncemented Omnifit hip stem. The Symax stem design combines an anatomical anteverted proximal geometry with a straight distal section. The proximal part is coated with a biomimetic hydroxyapatite (HA) coating for improved osseointegration to enhance load transfer and to minimize proximal bone loss. The distal part is treated with an anodization surface treatment in order to prevent distal bone apposition, which is expected to prevent distal loading and reduce proximal stress shielding. Aim of this study is to report mid-term clinical performance and evaluate whether the radiographic features are in line with the design principles of the Symax hip.MethodsThe biomimetic hydroxyapatite-coated uncemented Symax hip stem was evaluated in 80 patients during a 5-year prospective clinical international study. Harris Hip Score (HHS), Oxford Hip Score (OHS), and Western Ontario and McMaster Universities Arthritis Index (WOMAC) were performed preoperatively and postoperatively at 6 months and 1, 2, 3 and 5 years. Anteroposterior radiographs of the pelvis and axial radiographs of the operated hips were evaluated immediately postoperative and at follow-up 6 months and 1, 2, 3, and 5 years. Wilcoxon signed-rank test was used to analyse whether clinical outcome scores changed statistically significant over time. The overall percentage of agreement between two radiology assessment teams was used to evaluate observer agreement of radiology results. The Cohen’s Kappa was evaluated as a measure of reliability to quantify the agreement between raters, corrected for chance agreement.ResultsClinical outcome scores were excellent at 5 years with mean HHS of 98.1, mean OHS of 16.2 and mean WOMAC of 6.9. Only 2.7% of the patients had pain at rest or on weight-bearing, and mid-thigh pain was reported by 1.4% of the patients after 5 years. The percentage of agreement between radiology assessment teams was 94 to 100%, except for distal line formation (48%). Radiographic evaluation showed stable stems and signs of excellent progressive proximal fixation and favourable bone remodeling.ConclusionsThe excellent mid-term clinical and radiographic performances are in line with the design principles and coating properties of this new implant and earlier published results.Trial registrationhttp://ClinicalTrials.gov, NCT03469687. Registered 19 March 2018 – Retrospectively registered.

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Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Fig.…”

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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5-year clinical and radiographic follow-up of the uncemented Symax hip stem in an international study

et al. 2018

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“…This can possibly be attributed to a stress-shielding phenomenon but not to a bony integration of the distal part of the implant, as the BMD would not increase in R6 if the implant would buttress distally, which can sometimes be found after THA with other conventional straight stems [6,[35][36][37]. A recent DEXA study by Ten Broeke et al [38] compared two metaphyseal coated stems and observed only a small BMD increase in R4 after two years. However, BMD increase was only up to 3 % in R6 and a strong BMD decrease was seen in R7, indicating less load distribution to the calcar.…”

Section: Discussionmentioning

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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HA-Coated Implant: Bone Interface in Total Joint Arthroplasty

Daugaard

Bechtold

Søballé

2013

Bone-Implant Interface in Orthopedic Surgery

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Randomised Trial Comparing Bone Remodelling around Two Uncemented Stems Using Modified Gruen Zones

Cited by 25 publications

References 28 publications

5-year clinical and radiographic follow-up of the uncemented Symax hip stem in an international study

5-year clinical and radiographic follow-up of the uncemented Symax hip stem in an international study

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

HA-Coated Implant: Bone Interface in Total Joint Arthroplasty

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