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Garala K, Remtulla MA, Verma R, Lawrence T. Cemented acetabular components combined with trabecular metal augments provide excellent long-term survivorship for severe acetabular bone loss. Hip Int 2023; 33:833-838. [PMID: 35658637 DOI: 10.1177/11207000221102848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Acetabular bone loss is a challenging problem for revision hip surgeons. This study aimed to explore long-term outcomes of patients who have undergone cemented acetabular revision in conjunction with trabecular metal augmentation and impaction bone grafting in cases with significant segmental bone loss. METHODS All patients who underwent cemented acetabular revision requiring impaction bone grafting and trabecular metal augments with a minimum Paprosky score of 2B and minimum follow up of 5 years were identified. Pre- and postoperative WOMAC scores were compared. An assessment of pre- and postoperative hip centre of rotation was performed and compared to native centre of rotation. Immediate postoperative centre of rotation was then compared to radiographs at latest follow up to measure for migration of acetabular components. RESULTS 42 patients were identified. Mean age was 53 years old with 7 males and 35 female patients. Mean follow-up was 9.5 years. Preoperative WOMAC score was 30 and there was an increase to 90 (p < 0.01) at latest follow-up. No hips were revised for loosening or infection. There was a mean improvement in centre of rotation of 6.80 mm (CI, 4.57-9.03 mm) which was significant (p < 0.00002). There was no change of position of centre of rotation from immediate postoperative radiographs and those at latest follow up (p = 0.3). CONCLUSIONS Cemented acetabular components work well in conjunction with trabecular metal augments and impacted bone grafts in reconstructing complex acetabular defects. Together they provide immediate and long-term component stability, with excellent long-term clinical and radiological outcomes.
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Affiliation(s)
- Kanai Garala
- University Hospitals Birmingham - Solihull Hospital, Solihull, UK
| | | | - Raghav Verma
- University Hospitals Birmingham - Solihull Hospital, Solihull, UK
| | - Trevor Lawrence
- University Hospitals Birmingham - Solihull Hospital, Solihull, UK
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2
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Stiehler M, Günther KP, Goronzy J. [Strategies for cup revision]. ORTHOPADIE (HEIDELBERG, GERMANY) 2023; 52:12-20. [PMID: 35759041 DOI: 10.1007/s00132-022-04271-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 06/03/2022] [Indexed: 01/19/2023]
Abstract
Hip arthroplasty revision management can range from simple procedures using standard implants to complex surgical interventions requiring the combined use of revision cups, metal augments, bone grafts, and antiprotrusio cages. The adequate restoration of biomechanics and function of the hip joint with reconstruction of the original center of rotation can be challenging. We present an overview of various available techniques with the associated implant and anchoring strategies and the respective clinical results depending on the acetabular defect situation.
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Affiliation(s)
- Maik Stiehler
- UniversitätsCentrum für Orthopädie, Unfall- & Plastische Chirurgie, Universitätsklinikum Carl Gustav Carus, TU Dresden, Fetscherstr. 74, Haus 29, 01307, Dresden, Deutschland.
| | - Klaus-Peter Günther
- UniversitätsCentrum für Orthopädie, Unfall- & Plastische Chirurgie, Universitätsklinikum Carl Gustav Carus, TU Dresden, Fetscherstr. 74, Haus 29, 01307, Dresden, Deutschland
| | - Jens Goronzy
- UniversitätsCentrum für Orthopädie, Unfall- & Plastische Chirurgie, Universitätsklinikum Carl Gustav Carus, TU Dresden, Fetscherstr. 74, Haus 29, 01307, Dresden, Deutschland
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3
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Shen X, Qin Y, Li Y, Tang X, Xiao J. Trabecular metal versus non-trabecular metal acetabular components for acetabular revision surgery: A systematic review and meta-analysis. Int J Surg 2022; 100:106597. [DOI: 10.1016/j.ijsu.2022.106597] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 12/30/2021] [Accepted: 03/08/2022] [Indexed: 01/08/2023]
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Clinical Application and Biological Functionalization of Different Surface Coatings in Artificial Joint Prosthesis: A Comprehensive Research Review. COATINGS 2022. [DOI: 10.3390/coatings12020117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
With advances in materials science and biology, there have been continuing innovations in the field of artificial joint prostheses. Cementless prostheses have the advantages of long service life, easy revision, and good initial stability and are widely used in artificial joint replacement. Coatings are the key to cementless prostheses and are at the heart of their excellent functionality. This article mainly studies the clinical application of hydroxyapatite (HA) coating, standard porous coating represented by Porocoat coating, and new high-porosity coating represented by Gription coating. The clinical application and biological functionalization of different artificial joint prosthesis surface coatings are clarified, and it provides a reference for the clinical selection and development of different prosthesis surface coating materials.
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5
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Bondarenko S, Filipenko V, Karpinsky M, Karpinska O, Ivanov G, Maltseva V, Badnaoui AA, Schwarzkopf R. Osseointegration of porous titanium and tantalum implants in ovariectomized rabbits: A biomechanical study. World J Orthop 2021; 12:214-222. [PMID: 33959485 PMCID: PMC8082506 DOI: 10.5312/wjo.v12.i4.214] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 02/01/2021] [Accepted: 03/11/2021] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Today, biological fixation of uncemented press-fit acetabular components plays an important role in total hip arthroplasty. Long-term stable fixation of these implants depends on the osseointegration of the acetabular cup bone tissue into the acetabular cup implant, and their ability to withstand functional loads.
AIM To compare the strength of bone-implant osseointegration of four types of porous metal implants in normal and osteoporotic bone in rabbits.
METHODS The study was performed in 50 female California rabbits divided into non-ovariectomized (non-OVX) and ovariectomized groups (OVX) at 6 mo of age. Rabbits were sacrificed 8 wk after the implantation of four biomaterials [TTM, CONCELOC, Zimmer Biomet's Trabecular Metal (TANTALUM), and ATLANT] in a 5-mm diameter defect created in the left femur. A biomechanical evaluation of the femur was carried out by testing implant breakout force. The force was gradually increased until complete detachment of the implant from the bone occurred.
RESULTS The breakout force needed for implant detachment was significantly higher in the non-OVX group, compared with the OVX group for all implants (TANTALUM, 194.7 ± 6.1 N vs 181.3 ± 2.8 N; P = 0.005; CONCELOC, 190.8 ± 3.6 N vs 180.9 ± 6.6 N; P = 0.019; TTM, 186.3 ± 1.8 N vs 172.0 N ± 11.0 N; P = 0.043; and ATLANT, 104.9 ± 7.0 N vs 78.9 N ± 4.5 N; P = 0.001). In the OVX group, The breakout forces in TANTALUM, TTM, and CONCELOC did not differ significantly (P = 0.066). The breakout force for ATLANT in the OVX group was lower by a factor of 2.3 compared with TANTALUM and CONCELOC, and by 2.2 compared with TTM (P = 0.001). In the non-OVX group, the breakout force for ATLANT was significantly different from all other implants, with a reduction in fixation strength by a factor of 1.9 (P = 0.001).
CONCLUSION TANTALUM, TTM, and CONCELOC had equal bone-implant osseointegration in healthy and in osteoporotic bone. ATLANT had significantly decreased osseointegration (P = 0.001) in healthy and in osteoporotic bone.
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Affiliation(s)
- Stanislav Bondarenko
- Department of Joint Pathology, Sytenko Institute of Spine and Joint Pathology, Kharkiv 61124, Ukraine
| | - Volodymyr Filipenko
- Department of Joint Pathology, Sytenko Institute of Spine and Joint Pathology, Kharkiv 61124, Ukraine
| | - Michael Karpinsky
- Department of Biomechanics, Sytenko Institute of Spine and Joint Pathology, Kharkiv 61124, Ukraine
| | - Olena Karpinska
- Department of Biomechanics, Sytenko Institute of Spine and Joint Pathology, Kharkiv 61124, Ukraine
| | - Gennadiy Ivanov
- Department of Experimental Pathology, Sytenko Institute of Spine and Joint Pathology, Kharkiv 61124, Ukraine
| | - Valentyna Maltseva
- Morphology of Connective Tissue Department, Sytenko Institute of Spine and Joint Pathology, Kharkiv 61124, Ukraine
| | - Ahmed Amine Badnaoui
- Department of Joint Pathology, Sytenko Institute of Spine and Joint Pathology, Kharkiv 61124, Ukraine
| | - Ran Schwarzkopf
- Department of Orthopedic Surgery, NYU Langone Orthopedic Hospital, Hospital for Joint Diseases, New York, NY 10003, United States
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Morosato F, Cristofolini L, Castagnini F, Traina F. Effect of cup medialization on primary stability of press-fit acetabular cups. Clin Biomech (Bristol, Avon) 2020; 80:105172. [PMID: 32927407 DOI: 10.1016/j.clinbiomech.2020.105172] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 08/31/2020] [Accepted: 09/01/2020] [Indexed: 02/07/2023]
Abstract
BACKGROUND Appropriate restoration of the native centre of rotation is of paramount importance in total hip arthroplasty. Reconstruction of the centre of rotation depends on reaming technique: conventional approaches require more cup medialization than anatomical preparations. To date, the influence of cup medialization on socket stability in cementless implants is still unknown. METHODS Ten cadaveric hemipelvises were sequentially reamed using anatomical technique (only subchondral bone removal with restoration of the native centre of rotation) and conventional preparation (reaming to the lamina and medializing the cup). A biomechanical test was performed on the reconstructions. Implant motions were measured with digital image correlation while a cyclic load of increasing magnitude was applied. FINDINGS No significant difference was measured between the two implantation techniques in terms of permanent cup migrations. The only significant difference was found for the cup inducible rotations, where the conventional technique was associated with larger rotations. INTERPRETATION Conventional reaming and cup medialization do not improve initial cup stability. Beyond the recently questioned concerns about medialization and hip biomechanics, this is another issue to bear in mind when reaming the acetabulum.
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Affiliation(s)
- Federico Morosato
- Department of Industrial Engineering, School of Engineering and Architecture, Alma Mater Studiorum - Università di Bologna, Bologna, Italy
| | - Luca Cristofolini
- Department of Industrial Engineering, School of Engineering and Architecture, Alma Mater Studiorum - Università di Bologna, Bologna, Italy.
| | | | - Francesco Traina
- Chirurgia Protesica, IRCCS Rizzoli Orthopaedic Institute, Bologna, Italy; Department of Biomedical and Neuromotor Sciences, Università di Bologna, Italy
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Chacko V, Agrawal P, Porter ML, Board TN. Early results of a high friction surface coated uncemented socket in revision hip arthroplasty. Hip Int 2020; 30:739-744. [PMID: 31272233 DOI: 10.1177/1120700019863002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Revision hip arthroplasty with high friction trabecular metal sockets has resulted in good medium-term results. Many manufacturers have therefore introduced higher friction coatings to their implants to meet a growing demand for similar implants. The Pinnacle Gription was introduced in 2007 as an evolution of the standard Pinnacle socket. This study aimed to assess the early results of this socket in a revision setting. METHODS Between August 2009 and December 2016, the Gription socket was used in 146 revision hip replacements. The mean age was 63 (19-88) years. Defects were classified as Paprosky Grade 2 in 71(2A [28], 2B [19], 2C [24]) and grade 3 in 20 (3A [18], 3B [2]). Bearing combinations were ceramic-on-ceramic in 23, metal-on-polyethylene in 71, ceramic-on-polyethylene in 52. Screws were used in 112 cases, impaction bone grafting in 34 and metal augments in 1 case. Radiographs were analysed for progressive radiolucent lines and migration. RESULTS Mean follow-up was 43.5 (range 25-62) months. There were 6 re-revisions (2 for deep infection, 2 for recurrent dislocation and 2 for aseptic loosening). None of the other cases had evidence of socket migration or progressive radiolucent lines. There were no intraoperative or postoperative periprosthetic fractures. The crude survivorship for all-cause failure was 95.8% and the survivorship for aseptic loosening was 98.6%. at 43.5 months follow-up. CONCLUSIONS This is the largest reported series of Gription socket use in revision arthroplasty and demonstrates encouraging early results. We therefore advocate the continued cautious use of this implant.
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8
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Morosato F, Traina F, Schierjott RA, Hettich G, Grupp TM, Cristofolini L. Primary Stability of Revision Acetabular Reconstructions Using an Innovative Bone Graft Substitute: A Comparative Biomechanical Study on Cadaveric Pelvises. MATERIALS 2020; 13:ma13194312. [PMID: 32992567 PMCID: PMC7579522 DOI: 10.3390/ma13194312] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 09/23/2020] [Accepted: 09/24/2020] [Indexed: 11/16/2022]
Abstract
Hip implant failure is mainly due to aseptic loosening of the cotyle and is typically accompanied by defects in the acetabular region. Revision surgery aims to repair such defects before implantation by means of reconstruction materials, whose morselized bone graft represents the gold standard. Due to the limited availability of bone tissue, synthetic substitutes are also used. The aim of this study was to evaluate if a synthetic fully resorbable tri-calcium phosphate-based substitute can provide adequate mechanical stability when employed to restore severe, contained defects, in comparison with morselized bone graft. Five cadaveric pelvises were adopted, one side was reconstructed with morselized bone graft and the other with the synthetic substitute, consisting of dense calcium phosphate granules within a collagen matrix. During the biomechanical test, cyclic load packages of increasing magnitude were applied to each specimen until failure. Bone/implant motions were measured through Digital Image Correlation and were expressed in terms of permanent and inducible translations and rotations. The reconstruction types exhibited a similar behavior, consisting of an initial settling trend followed by failure as bone fracture (i.e., no failure of the reconstruction material). When 2.2 Body Weight was applied, the permanent translations were not significantly different between the two reconstructions (p = 0.06–1.0) and were below 1.0 mm. Similarly, the inducible translations did not differ significantly (p = 0.06–1.0) and were below 0.160 mm. Rotations presented the same order of magnitude but were qualitatively different. Overall, the synthetic substitute provided adequate mechanical stability in comparison with morselized bone graft, thus representing a reliable alternative to treat severe, contained acetabular defects.
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Affiliation(s)
- Federico Morosato
- Department of Industrial Engineering, Alma Mater Studiorum, Università di Bologna, 40131 Bologna, Italy;
| | - Francesco Traina
- Chirurgia Protesica, IRCCS Rizzoli Orthopaedic Institute, 40136 Bologna, Italy;
- Department of Biomedical and Neuromotor Sciences, Università di Bologna, 40126 Bologna, Italy
| | - Ronja A. Schierjott
- Aesculap AG, Research & Development, Am Aesculap-Platz, 78532 Tuttlingen, Germany; (R.A.S.); (G.H.); (T.M.G.)
- Department of Orthopaedic Surgery, Physical Medicine and Rehabilitation, Campus Grosshadern, Ludwig Maximilian University, 81377 Munich, Germany
| | - Georg Hettich
- Aesculap AG, Research & Development, Am Aesculap-Platz, 78532 Tuttlingen, Germany; (R.A.S.); (G.H.); (T.M.G.)
| | - Thomas M. Grupp
- Aesculap AG, Research & Development, Am Aesculap-Platz, 78532 Tuttlingen, Germany; (R.A.S.); (G.H.); (T.M.G.)
- Department of Orthopaedic Surgery, Physical Medicine and Rehabilitation, Campus Grosshadern, Ludwig Maximilian University, 81377 Munich, Germany
| | - Luca Cristofolini
- Department of Industrial Engineering, Alma Mater Studiorum, Università di Bologna, 40131 Bologna, Italy;
- Correspondence:
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Schierjott RA, Hettich G, Ringkamp A, Baxmann M, Morosato F, Damm P, Grupp TM. A method to assess primary stability of acetabular components in association with bone defects. J Orthop Res 2020; 38:1769-1778. [PMID: 31944372 DOI: 10.1002/jor.24591] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 01/13/2020] [Indexed: 02/04/2023]
Abstract
The objectives of this study were to develop a simplified acetabular bone defect model based on a representative clinical case, derive four bone defect increments from the simplified defect to establish a step-wise testing procedure, and analyze the impact of bone defect and bone defect filling on primary stability of a press-fit cup in the smallest defined bone defect increment. The original bone defect was approximated with nine reaming procedures and by exclusion of specific procedures, four defect increments were derived. The smallest increment was used in an artificial acetabular test model to test primary stability of a press-fit cup in combination with bone graft substitute (BGS). A primary acetabular test model and a defect model without filling were used as reference. Load was applied in direction of level walking in sinusoidal waveform with an incrementally increasing maximum load (300 N/1000 cycles from 600 to 3000 N). Relative motions (inducible displacement, migration, and total motion) between cup and test model were assessed with an optical measurement system. Original and simplified bone defect volume showed a conformity of 99%. Maximum total motion in the primary setup at 600 N (45.7 ± 5.6 µm) was in a range comparable to tests in human donor specimens (36.0 ± 16.8 µm). Primary stability was reduced by the bone defect, but could mostly be reestablished by BGS-filling. The presented method could be used as platform to test and compare different treatment strategies for increasing bone defect severity in a standardized way.
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Affiliation(s)
- Ronja A Schierjott
- Research & Development, Aesculap AG, Am Aesculap-Platz, Tuttlingen, Germany.,Department of Orthopaedic Surgery, Physical Medicine & Rehabilitation, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Georg Hettich
- Research & Development, Aesculap AG, Am Aesculap-Platz, Tuttlingen, Germany
| | - Alexandra Ringkamp
- Department of Biomechatronics, Faculty of Mechanical Engineering, Technische Universität Ilmenau, Ilmenau, Germany
| | - Marc Baxmann
- Research & Development, Aesculap AG, Am Aesculap-Platz, Tuttlingen, Germany
| | - Federico Morosato
- Department of Industrial Engineering, School of Engineering and Architecture, Università di Bologna, Bologna, Italy
| | - Philipp Damm
- Julius Wolff Institute, Joint Loading & Musculoskeletal Analysis, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Thomas M Grupp
- Research & Development, Aesculap AG, Am Aesculap-Platz, Tuttlingen, Germany.,Department of Orthopaedic Surgery, Physical Medicine & Rehabilitation, Ludwig-Maximilians-University Munich, Munich, Germany
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10
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Beckmann NA, Bitsch RG, Bormann T, Braun S, Jaeger S. Titanium Acetabular Component Deformation under Cyclic Loading. MATERIALS 2019; 13:ma13010052. [PMID: 31861893 PMCID: PMC6981461 DOI: 10.3390/ma13010052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 12/15/2019] [Accepted: 12/17/2019] [Indexed: 12/30/2022]
Abstract
Acetabular cup deformation may affect liner/cup congruency, clearance and/or osseointegration. It is unclear, whether deformation of the acetabular components occurs during load and to what extent. To evaluate this, revision multi-hole cups were implanted into six cadaver hemipelvises in two scenarios: without acetabular defect (ND); with a large acetabular defect (LD) that was treated with an augment. In the LD scenario, the cup and augment were attached to the bone and each other with screws. Subsequently, the implanted hemipelvises were loaded under a physiologic partial-weight-bearing modality. The deformation of the acetabular components was determined using a best-fit algorithm. The statistical evaluation involved repeated-measures ANOVA. The mean elastic distension of the ND cup was 292.9 µm (SD 12.2 µm); in the LD scenario, 43.7 µm (SD 11.2 µm); the mean maximal augment distension was 79.6 µm (SD 21.6 µm). A significant difference between the maximal distension of the cups in both scenarios was noted (F(1, 10) = 11.404; p = 0.007). No significant difference was noted between the compression of the ND and LD cups, nor between LD cups and LD augments. The LD cup displayed significantly lower elastic distension than the ND cup, most likely due to increased stiffness from the affixed augment and screw fixation.
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Affiliation(s)
- Nicholas A. Beckmann
- Clinic for Orthopedics and Trauma Surgery, Heidelberg University Hospital, Heidelberg University, 69118 Heidelberg, Germany
- Department of Orthopaedic Surgery and Traumatology, Inselspital, Bern University Hospital, 3010 Bern, Switzerland
- Correspondence: or
| | - Rudi G. Bitsch
- National Joint Center, ATOS Clinics, 69115 Heidelberg, Germany;
| | - Theresa Bormann
- Laboratory of Biomechanics and Implant Research, Clinic for Orthopedics and Trauma Surgery, Heidelberg University Hospital, Heidelberg University, 69118 Heidelberg, Germany; (T.B.); (S.B.); (S.J.)
| | - Steffen Braun
- Laboratory of Biomechanics and Implant Research, Clinic for Orthopedics and Trauma Surgery, Heidelberg University Hospital, Heidelberg University, 69118 Heidelberg, Germany; (T.B.); (S.B.); (S.J.)
| | - Sebastian Jaeger
- Laboratory of Biomechanics and Implant Research, Clinic for Orthopedics and Trauma Surgery, Heidelberg University Hospital, Heidelberg University, 69118 Heidelberg, Germany; (T.B.); (S.B.); (S.J.)
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Jahnke A, Bott CC, Fonseca Ulloa CA, Jahnke GW, Rickert M, Ishaque BA, Ahmed GA. In vitro examination of the primary stability of three press-fit acetabular cups under consideration of two different bearing couples. Med Eng Phys 2019; 67:49-54. [PMID: 30902521 DOI: 10.1016/j.medengphy.2019.03.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 01/09/2019] [Accepted: 03/10/2019] [Indexed: 12/21/2022]
Abstract
BACKROUND For preclinical statements about the anchoring behavior of prostheses, the primary stability of the prosthesis is of special importance. It was the aim of this study to examine and compare the relevant relative micromotions of three different acetabulum prostheses by introducing three-dimensional torques. METHODS The cups were implanted under standard conditions into an anatomical artificial bone model. Three-dimensional torques were applied to the acetabular cups. Taking into account the resulting frictional moments of two different bearing couples, ceramic-on-ceramic and ceramic-on-polyethylene, the relative micromotions of the cups were recorded as maximum total micromotion, translational and rotational micromotion, and the primary stability values of the three cups were compared. RESULTS Relative micromotion of all cup models was always significantly smaller with the CoC bearing couples than with the CoP bearing couples (p < 0.001). The rotational micromotion was always lower (p < 0.001) than the translational micromotion, and the rotational as well as the translational micromotions were each always lower than the maximum total micromotion (p < 0.001, p < 0.010). The thinnest-walled cup system always showed the largest relative micromotions. CONCLUSION The results of our study can be interpreted as indicating that the low relative micromotions of all cups - irrespective of the use of CoC or CoP bearing couples - are within an acceptable range favoring secondary osseointegration of the implants. Furthermore, we were able to show that the cup wall thickness and the surface quality of the cup systems have an influence on the primary stability and the elastic deformability of the examined cup systems.
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Affiliation(s)
- Alexander Jahnke
- Laboratory of Biomechanics, Justus-Liebig-University Giessen, Klinikstrasse 29, 35392 Giessen, Germany.
| | - Catharina Chiara Bott
- Laboratory of Biomechanics, Justus-Liebig-University Giessen, Klinikstrasse 29, 35392 Giessen, Germany
| | | | - Gerhard Walter Jahnke
- Laboratory of Biomechanics, Justus-Liebig-University Giessen, Klinikstrasse 29, 35392 Giessen, Germany
| | - Markus Rickert
- Laboratory of Biomechanics, Justus-Liebig-University Giessen, Klinikstrasse 29, 35392 Giessen, Germany; Department of Orthopaedics and Orthopaedic Surgery, University Hospital Giessen and Marburg (UKGM), Klinikstrasse 33, 35392 Giessen, Germany
| | - Bernd Alexander Ishaque
- Laboratory of Biomechanics, Justus-Liebig-University Giessen, Klinikstrasse 29, 35392 Giessen, Germany; Department of Orthopaedics and Orthopaedic Surgery, University Hospital Giessen and Marburg (UKGM), Klinikstrasse 33, 35392 Giessen, Germany
| | - Gafar Adam Ahmed
- Laboratory of Biomechanics, Justus-Liebig-University Giessen, Klinikstrasse 29, 35392 Giessen, Germany; Department of Orthopaedics and Orthopaedic Surgery, University Hospital Giessen and Marburg (UKGM), Klinikstrasse 33, 35392 Giessen, Germany
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