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Mjöberg B. Hip prosthetic loosening: A very personal review. World J Orthop 2021; 12:629-639. [PMID: 34631447 PMCID: PMC8472441 DOI: 10.5312/wjo.v12.i9.629] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 05/03/2021] [Accepted: 08/03/2021] [Indexed: 02/06/2023] Open
Abstract
Hip prosthetic loosening is often difficult to detect at an early stage, and there has been uncertainty for a long time as to when the loosening occurs and thus to the basic causes. By comparing different diagnostic methods, we found that loosening is best defined as prosthetic migration and measured by radiostereometric analysis. Convincing evidence indicates that poor interlock, poor bone quality, and resorption of a necrotic bone bed may initiate loosening during or shortly after surgery; this forms the basis of the theory of early loosening. Biomechanical factors do affect the subsequent progression of loosening, which may increase subclinically during a long period of time. Eventually, the loosening may be detected on standard radiographs and may be interpreted as late loosening but should to be interpreted as late detection of loosening. The theory of early loosening explains the rapid early migration, the development of periprosthetic osteolysis and granulomas, the causality between wear and loosening, and largely the epidemiology of clinical failure of hip prostheses. Aspects discussed are definition of loosening, the pattern of early migration, the choice of migration threshold, the current understanding of loosening, a less exothermic bone cement, cemented taper-slip stems, a new exciting computed tomography-based technique for simpler implant migration studies, and research suggestions.
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Affiliation(s)
- Bengt Mjöberg
- Department of Orthopedics, Lund University, Lund SE-221 00, Sweden
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van der Voort P, Pijls BG, Nieuwenhuijse MJ, Jasper J, Fiocco M, Plevier JWM, Middeldorp S, Valstar ER, Nelissen RGHH. Early subsidence of shape-closed hip arthroplasty stems is associated with late revision. A systematic review and meta-analysis of 24 RSA studies and 56 survival studies. Acta Orthop 2015; 86:575-85. [PMID: 25909455 PMCID: PMC4564780 DOI: 10.3109/17453674.2015.1043832] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
BACKGROUND AND PURPOSE Few studies have addressed the association between early migration of femoral stems and late aseptic revision in total hip arthroplasty. We performed a meta-regression analysis on 2 parallel systematic reviews and meta-analyses to determine the association between early migration and late aseptic revision of femoral stems. PATIENTS AND METHODS Of the 2 reviews, one covered early migration data obtained from radiostereometric analysis (RSA) studies and the other covered long-term aseptic revision rates obtained from survival studies with endpoint revision for aseptic loosening. Stems were stratified according to the design concept: cemented shape-closed, cemented force-closed, and uncemented. A weighted regression model was used to assess the association between early migration and late aseptic revision, and to correct for confounders. Thresholds for acceptable and unacceptable migration were determined in accordance with the national joint registries (≤ 5% revision at 10 years) and the NICE criteria (≤ 10% revision at 10 years). RESULTS 24 studies (731 stems) were included in the RSA review and 56 studies (20,599 stems) were included in the survival analysis review. Combining both reviews for the 3 design concepts showed that for every 0.1-mm increase in 2-year subsidence, as measured with RSA, there was a 4% increase in revision rate for the shape-closed stem designs. This association remained after correction for age, sex, diagnosis, hospital type, continent, and study quality. The threshold for acceptable migration of shape-closed designs was defined at 0.15 mm; stems subsiding less than 0.15 mm in 2 years had revision rates of less than 5% at 10 years, while stems exceeding 0.15 mm subsidence had revision rates of more than 5%. INTERPRETATION There was a clinically relevant association between early subsidence of shape-closed femoral stems and late revision for aseptic loosening. This association can be used to assess the safety of shape-closed stem designs. The published research is not sufficient to allow us to make any conclusions regarding such an association for the force-closed and uncemented stems.
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Affiliation(s)
- Paul van der Voort
- Department of Orthopaedics, Biomechanics and Imaging Group, Leiden University Medical Center, Leiden
| | - Bart G Pijls
- Department of Orthopaedics, Biomechanics and Imaging Group, Leiden University Medical Center, Leiden
| | - Marc J Nieuwenhuijse
- Department of Orthopaedics, Biomechanics and Imaging Group, Leiden University Medical Center, Leiden
| | - Jorrit Jasper
- Department of Orthopaedics, Biomechanics and Imaging Group, Leiden University Medical Center, Leiden
| | - Marta Fiocco
- Department of Medical Statistics and Bioinformatics, Leiden University Medical Center, Leiden
| | | | - Saskia Middeldorp
- Academic Medical Center, Department of Vascular Medicine, Amsterdam,Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, the Netherlands
| | - Edward R Valstar
- Department of Orthopaedics, Biomechanics and Imaging Group, Leiden University Medical Center, Leiden,Department of Biomechanical Engineering, Faculty of Mechanical, Maritime and Materials Engineering, University of Technology, Delft
| | - Rob G H H Nelissen
- Department of Orthopaedics, Biomechanics and Imaging Group, Leiden University Medical Center, Leiden
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Pijls BG, Nieuwenhuijse MJ, Fiocco M, Plevier JW, Middeldorp S, Nelissen RG, Valstar ER. Early proximal migration of cups is associated with late revision in THA: a systematic review and meta-analysis of 26 RSA studies and 49 survivalstudies. Acta Orthop 2012; 83:583-91. [PMID: 23126575 PMCID: PMC3555453 DOI: 10.3109/17453674.2012.745353] [Citation(s) in RCA: 121] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
BACKGROUND AND PURPOSE The association between excessive early migration of acetabular cups and late aseptic revision has been scantily reported. We therefore performed 2 parallel systematic reviews and meta-analyses to determine the association between early migration of acetabular cups and late aseptic revision. METHODS One review covered early migration data from radiostereometric analysis (RSA) studies, while the other focused on revision rates for aseptic loosening from long-term survival studies. Thresholds for acceptable and unacceptable migration were classified according the Swedish Hip Arthroplasty Register and the Australian National Joint Replacement Registry: < 5% revision at 10 years. RESULTS Following an elaborate literature search, 26 studies (involving 700 cups) were included in the RSA review and 49 studies (involving 38,013 cups) were included in the survival review. For every mm increase in 2-year proximal migration, there was a 10% increase in revision rate, which remained after correction for age, sex, diagnosis, hospital type, continent, and study quality. Consequently, proximal migration of up to 0.2 mm was considered acceptable and proximal migration of 1.0 mm or more was considered unacceptable. Cups with proximal migration of between 0.2 and 1.0 mm were considered to be at risk of having revision rates higher than 5% at 10 years. INTERPRETATION There was a clinically relevant association between early migration of acetabular cups and late revision due to loosening. The proposed migration thresholds can be implemented in a phased evidence-based introduction, since they allow early detection of high-risk cups while exposing a small number of patients.
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Affiliation(s)
- Bart G Pijls
- Department of Orthopaedics, Bio-Imaging Group, Leiden University Medical Center, Leiden, the Netherlands.
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Molt M, Ljung P, Toksvig-Larsen S. Does a new knee design perform as well as the design it replaces? Bone Joint Res 2012; 1:315-23. [PMID: 23610663 PMCID: PMC3626188 DOI: 10.1302/2046-3758.112.2000064] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Accepted: 10/09/2012] [Indexed: 11/17/2022] Open
Abstract
Objectives The objective of this study was to compare the early migration
characteristics and functional outcome of the Triathlon cemented
knee prosthesis with its predecessor, the Duracon cemented knee
prosthesis (both Stryker). Methods A total 60 patients were prospectively randomised and tibial
component migration was measured by radiostereometric analysis (RSA)
at three months, one year and two years; clinical outcome was measured
by the American Knee Society score and the Knee Osteoarthritis and
Injury Outcome Score. Results There were no statistically significant differences in rotation
or translation around or along the three coordinal axes, or in the
maximum total point motion (MTPM) during the two-year follow-up. Conclusions The Triathlon cemented knee prosthesis has similar early stability
and is likely to perform at least as well as the Duracon cemented
knee prosthesis over the longer term.
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Affiliation(s)
- M Molt
- Hässleholm Hospital, Orthopaedic Clinic Hässleholm - Kristianstad - Ystad, Box 351, 281 25 Hässleholm, Sweden
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Kostakos AT, Macheras GA, Frangakis CE, Stafilas KS, Baltas D, Xenakis TA. Migration of the trabecular metal monoblock acetabular cup system. J Arthroplasty 2010; 25:35-40. [PMID: 19056211 DOI: 10.1016/j.arth.2008.09.027] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2007] [Revised: 07/22/2008] [Accepted: 09/07/2008] [Indexed: 02/01/2023] Open
Abstract
Fifty-one primary total hip arthroplasties were performed using Trabecular Metal Monoblock Acetabular Cup System (Zimmer Inc, Warsaw, IN). In a 2-year prospective study, its behavior was closely monitored by clinical, radiologic, and component migration assessment by Ein-Bild-Röntgen-Analyse method. There were no complications. The mean Harris hip score was improved from 41 to 95. A polar gap at the postoperative radiograph was noted at 25% of the arthroplasties, most of which subsequently filled with bone within 6 months. The mean total absolute migration was 0.67 mm. The implant showed excellent early clinical and radiographic behavior. The 2-year migration rate study, as index of long-term survival and success, showed very good early implant stability and, in all cases except one, superior to the available studies for similar design acetabular cups.
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6
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Digas G. New polymer materials in total hip arthroplasty. ACTA ORTHOPAEDICA. SUPPLEMENTUM 2009. [DOI: 10.1080/17453674078540521] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Hernigou P, Daltro G, Lachaniette CHF, Roussignol X, Mukasa MM, Poignard A. Fixation of the cemented stem: clinical relevance of the porosity and thickness of the cement mantle. Open Orthop J 2009; 3:8-13. [PMID: 19516919 PMCID: PMC2687105 DOI: 10.2174/1874325000903010008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2008] [Revised: 01/09/2009] [Accepted: 01/13/2009] [Indexed: 11/26/2022] Open
Abstract
The aim of this review paper is to define the fixation of the cemented stem. Polymethyl methacrylate, otherwise known as “bone cement”, has been used in the fixation of hip implants since the early 1960s. Sir John Charnley, the pioneer of modern hip replacement, incorporated the use of cement in the development of low frictional torque hip arthroplasty. In this paper, the concepts of femoral stem design and fixation, clinical results, and advances in understanding of the optimal use of cement are reviewed. The purpose of this paper is to help understanding and discussions on the thickness and the porosity of the cement mantle in total hip arthroplasty. Cement does not act as an adhesive, as sometimes thought, but relies on an interlocking fit to provide mechanical stability at the cement–bone interface, while at the prosthesis– cement interface it achieves stability by optimizing the fit of the implant in the cement mantle, such as in a tapered femoral stem.
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Pérez MA, García-Aznar JM, Doblaré M. Does increased bone-cement interface strength have negative consequences for bulk cement integrity? A finite element study. Ann Biomed Eng 2008; 37:454-66. [PMID: 19085106 DOI: 10.1007/s10439-008-9616-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2008] [Accepted: 12/01/2008] [Indexed: 11/25/2022]
Abstract
Implant loosening is one of the most important modes of failure of cemented total hip replacement. It may be related to the cement strength, cement-prosthesis interface, cement-bone interface, surgical technique, or stem design. The main purpose of this study is to investigate the effect of bone-cement interface mechanical properties on cement degradation. The computational methodology proposed herein combines a previously developed bone-cement interface damage model and an accumulative damage model for bulk cement. This has been applied to a finite element model of an Exeter cemented hip implant. A higher strength of the bone-cement interface due to a higher amount of interdigitated bone results in faster cement deterioration. Over time, damage both at the bone-cement interface and in the cement mantle worsens. Also, a larger debonded area was predicted proximally, as observed in clinical practice. We conclude that the computational model proposed herein allows a realistic simulation of the bone-cement interface debonding and cement degradation, being a useful tool in the design of this kind of medical devices.
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Affiliation(s)
- M A Pérez
- Group of Structural Mechanics and Materials Modelling, Aragón Institute of Engineering Research (I3A), University of Zaragoza, Betancourt Building, c/ María de Luna, 50018 Zaragoza, Spain.
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Race A, Miller MA, Mann KA. A modified PMMA cement (Sub-cement) for accelerated fatigue testing of cemented implant constructs using cadaveric bone. J Biomech 2008; 41:3017-23. [PMID: 18774136 DOI: 10.1016/j.jbiomech.2008.07.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2008] [Revised: 06/26/2008] [Accepted: 07/16/2008] [Indexed: 02/01/2023]
Abstract
Pre-clinical screening of cemented implant systems could be improved by modeling the longer-term response of the implant/cement/bone construct to cyclic loading. We formulated bone cement with degraded fatigue fracture properties (Sub-cement) such that long-term fatigue could be simulated in short-term cadaver tests. Sub-cement was made by adding a chain-transfer agent to standard polymethylmethacrylate (PMMA) cement. This reduced the molecular weight of the inter-bead matrix without changing reaction-rate or handling characteristics. Static mechanical properties were approximately equivalent to normal cement. Over a physiologically reasonable range of stress-intensity factor, fatigue crack propagation rates for Sub-cement were higher by a factor of 25+/-19. When tested in a simplified 2 1/2-D physical model of a stem-cement-bone system, crack growth from the stem was accelerated by a factor of 100. Sub-cement accelerated both crack initiation and growth rate. Sub-cement is now being evaluated in full stem/cement/femur models.
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Affiliation(s)
- Amos Race
- Musculoskeletal Science Research Center, Institute for Human Performance (3217), SUNY Upstate Medical University, 750 East Adams Street, Syracuse, NY 13210, USA.
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11
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Dayton MR, Incavo SJ, Churchill DL, Uroskie JA, Beynnon BD. Effects of early and late stage cement intrusion into cancellous bone. Clin Orthop Relat Res 2002:39-45. [PMID: 12461354 DOI: 10.1097/00003086-200212000-00005] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Minimizing aseptic loosening of cemented femoral stems in total hip arthroplasty remains a goal. Recent investigation suggests that improved cement intrusion may result from elevated pressures shown to occur during stem placement into higher viscosity late stage polymethylmethacrylate cement when compared with low viscosity early stage cement. The hypothesis tested is that placement of a femoral stem in late stage cement can increase cement-bone contact as compared with placement in early stage cement. The variable tested in this experiment was cement viscosity. Radiographic analysis was done on nine paired femurs from cadavers that had placement of a cemented femoral stem with either early or late stage polymethylmethacrylate. Radiographs were assessed quantitatively by measuring the extent of radiolucency observed at the cement-bone interface. Specimens that had late stage cement had significantly less radiolucency in the middle zone region, corresponding to combined Gruen Zones 2 and 6. Similar trends were observed in the proximal and distal zone regions of the stem. Elevated stem insertion pressure associated with late stage cement can minimize void space between the cement and trabecular bone. These findings suggest that the surgeon should consider femoral stem placement later in the cement cure cycle, generating higher intramedullary pressure, and leading to improved cement intrusion into the surrounding bone.
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Affiliation(s)
- Michael R Dayton
- McClure Musculoskeletal Research Center, Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, VT 05405, USA
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12
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Ornstein E, Franzén H, Johnsson R, Sundberg M. Radiostereometric analysis in hip revision surgery--optimal time for index examination: 6 patients revised with impacted allografts and cement followed weekly for 6 weeks. ACTA ORTHOPAEDICA SCANDINAVICA 2000; 71:360-4. [PMID: 11028883 DOI: 10.1080/000164700317393349] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
We revised the hip (6 stems and 5 sockets) with impacted morselized allografts and cement in 6 patients. We followed prosthetic migration by roentgen radiostereometric analysis (RSA) every 7th day for 6 weeks after the first (index) examination performed on the first postoperative day before mobilization. Most of the migration occurred during the first 2 weeks. In most cases more than half of the distal stem migration was seen between the 1st and 14th days. In all cases, the stem and socket migrations slowed down gradually and several prosthetic components had become stable after 5 weeks. We conclude that it is essential to perform the index RSA examination on the 1st or 2nd day after surgery and to state when and how weight bearing should be permitted. Otherwise it will be difficult to compare prosthetic migration in various studies and define normative values for migration predicting survival.
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Affiliation(s)
- E Ornstein
- Department of Orthopedics, Hässelholm-Kristianstad County Hospital, Sweden
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Abstract
A total of 156 ceramic versus ultra-high-molecular-weight polyethylene hip prostheses were followed for a minimum of 10 years to compare the outcome of the femoral component in 2 groups: those with and those without radiologically detectable voids in the cement mantle. No significant difference was observed. In this series, voids with a 5-mm diameter had no effect on loosening of the femoral component over a 10-year period.
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Affiliation(s)
- P Hernigou
- Department of Orthopaedic Surgery, Henri Mondor Hospital, Creteil, France
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14
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Wang JS, Franzén H, Lidgren L. Interface gap after implantation of a cemented femoral stem in pigs. ACTA ORTHOPAEDICA SCANDINAVICA 1999; 70:234-9. [PMID: 10429597 DOI: 10.3109/17453679908997799] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We studied the interface gap around cemented femoral stems. Fresh pig femora were used. Bone cement mixed under vacuum or at atmospheric pressure was injected into the femoral canal and a cobalt chrome stem was then implanted. The femora were sectioned transversely from the minor trochanter and distally by using a high-pressure water cutter. Most of the interfaces had intimate contact. However, in all specimens, small gaps were found at the bone-cement and cement-stem interfaces. The gaps at the interfaces between the bone and cement and the cement and stem were measured, using a computerized video digital system. They occupied about 10% of the circumference at the bone-cement interface and about 15% of the circumference at the cement-stem interface, irrespective of the mixing procedures. Most gaps were less than 100 mu at the interfaces. In conclusion, cemented implants in the animal model showed that small gaps are found at the interfaces directly after implantation. These gaps may be weak points and initiate debonding when loading the prostheses.
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Affiliation(s)
- J S Wang
- Department of Orthopedics, Lund University Hospital, Sweden.
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15
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Havelin LI, Espehaug B, Vollset SE, Engesaeter LB. The effect of the type of cement on early revision of Charnley total hip prostheses. A review of eight thousand five hundred and seventy-nine primary arthroplasties from the Norwegian Arthroplasty Register. J Bone Joint Surg Am 1995; 77:1543-50. [PMID: 7593063 DOI: 10.2106/00004623-199510000-00009] [Citation(s) in RCA: 123] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
We studied the survival of 8579 Charnley prostheses, in 7922 patients, according to the different types of cement that had been used. All of the patients had had a primary total hip replacement for primary coxarthrosis. The mean duration of follow-up was 3.2 years (range, zero to 6.4 years). The data were collected from the national Norwegian Arthroplasty Register. The duration of survival was defined as the time to revision due to aseptic loosening. The Kaplan-Meier estimate of survival at 5.5 years for the 1226 femoral components that had been implanted with low-viscosity cement was 94.1 per cent (95 per cent confidence interval, 92.1 to 96.2 per cent), compared with 98.1 per cent (95 per cent confidence interval, 97.5 to 98.6 per cent) for the 6589 components that had been implanted with high-viscosity cement (p < 0.0001). The remaining 764 femoral components had been implanted with Boneloc cement, which was classified as neither high nor low-viscosity, and these components were considered as a separate group in the analyses. The Boneloc cement had been used for only three years, and the two-year survival rate of these prostheses was 95.5 per cent (p < 0.0001). The cement contained an antibiotic in 2801 (42 per cent of the hips in which the femoral component had been implanted with high-viscosity cement, compared with only thirty (2 per cent) of those in which it had been implanted with low-viscosity cement.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- L I Havelin
- Department of Orthopaedics and Traumatology, Haukeland University Hospital, Bergen, Norway
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Mjöberg B. Theories of wear and loosening in hip prostheses. Wear-induced loosening vs loosening-induced wear--a review. ACTA ORTHOPAEDICA SCANDINAVICA 1994; 65:361-71. [PMID: 8042497 DOI: 10.3109/17453679408995473] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The observation of perioprosthetic granulomas containing wear debris around apparently well-fixed as well as around loose-fitting prosthetic components has led to the development of the hypothesis of wear-induced loosening. However, the hypothesis of wear-induced loosening can neither explain the rapid early prosthetic migration detected by roentgen stereophotogrammetry nor the epidemiology of clinical failure without supplementary ad hoc-assumptions. By contrast, apart from explaining the rapid early prosthetic migration detected by roentgen stereophotogrammetry, the theory of early loosening can explain the development of wear granulomas as well as to a great extent the epidemiology of clinical failure.
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Affiliation(s)
- B Mjöberg
- Department of Orthopedics, Uppsala University Hospital, Sweden
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Abstract
The accuracy of the Nunn method in measuring acetabular component migration was compared with 3 other radiological methods and with roentgen stereophotogrammetry in 34 pelvic radiographs. The Nunn method seems to have the same or better accuracy than the other non-computerized methods, but less accuracy than the computerized EBRA method.
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Affiliation(s)
- T Ilchmann
- Department of Orthopedics, Lund University Hospital, Sweden
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Abstract
Studies using roentgen stereophotogrammetry and bone scintigraphy support a narrow definition of prosthetic fixation (viz., nonmigration), and consequently a broad definition of loosening. Roentgen stereophotogrammetric research indicates that if loosening occurs, it is initiated at an early stage; insufficient initial fixation or loss of fixation by resorption of a layer of heat-injured bone may cause prosthetic instability and progressive bone resorption. Migration of one or both prosthetic components can be revealed by roentgen stereophotogrammetry in many asymptomatic hips during the first postoperative year--some of these components will probably fail in the future. The femoral component is exposed to greater shear stresses than the acetabular component, and it is uncertain whether fixation of the femoral component can be achieved more than occasionally without the use of bone cement.
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Affiliation(s)
- B Mjöberg
- Department of Orthopedics, Uppsala University Hospital, Sweden
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Franzén H, Mjöberg B. Wear and loosening of the hip prosthesis. A roentgen stereophotogrammetric 3-year study of 14 cases. ACTA ORTHOPAEDICA SCANDINAVICA 1990; 61:499-501. [PMID: 2281755 DOI: 10.3109/17453679008993570] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Fourteen patients were followed by roentgen stereophotogrammetry for 3 years after hip arthroplasty. In 11 of the 14 acetabular components, definite wear was identified. The mean wear rate was 0.13 mm per year. There was no correlation between the wear and loosening of either the acetabular or the femoral component. Our findings indicate that products of wear do not initiate prosthetic loosening.
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Affiliation(s)
- H Franzén
- Department of Orthopedics, Lund University Hospital, Sweden
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