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Pardo F, La Mattina AA, Diquattro E, Lucchini S, Viceconti M, Minerba A, Castagnini F, Traina F. Chronological Changes in Sagittal Femoral Bowing after Primary Cementless Total Hip Arthroplasty: A Comparative 3D CT Study. J Pers Med 2023; 13:1704. [PMID: 38138931 PMCID: PMC10744357 DOI: 10.3390/jpm13121704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 11/15/2023] [Accepted: 12/07/2023] [Indexed: 12/24/2023] Open
Abstract
Little is known about dynamic changes of femoral anatomy after total hip arthroplasty (THA), in particular about sagittal femoral bowing (SFB). A 3D CT study was designed to evaluate the chronological changes of SFB after cementless femoral stem implantation for primary THA. Ten patients who underwent unilateral primary THA with a cementless femoral stem, with 2 consecutive CT scans (extending from the fourth lumbar vertebra to the tibial plateaus), performed before THA and at least 3 years after THA, were enrolled. The 3D models of femurs were created using image segmentation software. Using the two CT scans, SFB values of the proximal and middle thirds were calculated on the replaced and untreated sides by two different observers. Eight anatomical stems and two conical stems were involved. The post-operative CT was performed at an average follow-up of 6.5 years after THA (range: 3-12.5). The measurements performed by the two observers did not differ in the proximal and middle regions. A significant difference between the pre-operative and post-operative SFB compared to the untreated side was found in the proximal femur segment (p = 0.004). Use of a cementless stem in THA induced chronological changes in SFB of the proximal femur, after a minimum timespan of 3 years.
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Affiliation(s)
- Francesco Pardo
- Orthopedics-Traumatology and Prosthetic Surgery and Hip and Knee Revision, IRCCS Istituto Ortopedico Rizzoli, 40136 Bologna, Italy
| | - Antonino Amedeo La Mattina
- Medical Technology Lab, IRCCS Istituto Ortopedico Rizzoli, 40136 Bologna, Italy
- Department of Industrial Engineering, Alma Mater Studiorum—University of Bologna (IT), 40136 Bologna, Italy
| | - Emanuele Diquattro
- Orthopedics-Traumatology and Prosthetic Surgery and Hip and Knee Revision, IRCCS Istituto Ortopedico Rizzoli, 40136 Bologna, Italy
| | - Stefano Lucchini
- Orthopedics-Traumatology and Prosthetic Surgery and Hip and Knee Revision, IRCCS Istituto Ortopedico Rizzoli, 40136 Bologna, Italy
| | - Marco Viceconti
- Medical Technology Lab, IRCCS Istituto Ortopedico Rizzoli, 40136 Bologna, Italy
- Department of Industrial Engineering, Alma Mater Studiorum—University of Bologna (IT), 40136 Bologna, Italy
| | - Andrea Minerba
- Orthopedics-Traumatology and Prosthetic Surgery and Hip and Knee Revision, IRCCS Istituto Ortopedico Rizzoli, 40136 Bologna, Italy
| | - Francesco Castagnini
- Orthopedics-Traumatology and Prosthetic Surgery and Hip and Knee Revision, IRCCS Istituto Ortopedico Rizzoli, 40136 Bologna, Italy
| | - Francesco Traina
- Department of Biomedical and Neuromotor Science-DIBINEM, University of Bologna, 40127 Bologna, Italy;
- Head of Ortopedia-Traumatologia e Chirurgia Protesica e dei Reimpianti d’Anca e di Ginocchio, IRCCS Istituto Ortopedico Rizzoli, Via Pupilli 1, 40136 Bologna, Italy
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Jahnke A, Harz T, Fonseca Ulloa CA, Ishaque BA, Rickert M. Development and Finite Element (FE) analysis of a novel short hip stem concept. J Orthop 2023; 46:117-123. [PMID: 37994362 PMCID: PMC10659989 DOI: 10.1016/j.jor.2023.09.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 09/22/2023] [Accepted: 09/29/2023] [Indexed: 11/24/2023] Open
Abstract
Introduction In order to improve the anchorage behavior of short hip stems, this development project aims at designing a short hip stem concept that preserves the femoral neck and minimizes interference with the physiological stress distribution of the femur. The new design will be evaluated according to ISO 7206-4 which is the standard for testing Implants for surgery. Methods Basic CAD models based on an established short stem prosthesis were created and evaluated using finite element analysis. The best design was further developed to achieve a more deformable stem while maintaining stability. The model was validated through in vitro testing. Results The "H-Beam" short stem showed a higher degree of deformation of approximately 142-144% compared to the established short stem. The FE model had a relative error of 0.98% and 1.07% compared to the in vitro tests. An operating procedure was outlined for this new short stem design. Discussion The FE model is deemed valid due to small differences in comparison to in vitro testing. The short-stem prosthesis is more flexible and can be easily adapted to individual anatomy during surgery. The prosthesis length is similar to conventional prostheses, but the new stem design could allow better and faster osteointegration while preserving the cancellous bone structure.
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Affiliation(s)
- Alexander Jahnke
- Laboratory of Biomechanics, Justus-Liebig-University Giessen, Klinikstrasse 29, 35392, Giessen, Germany
| | - Torben Harz
- Laboratory of Biomechanics, Justus-Liebig-University Giessen, Klinikstrasse 29, 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
| | - 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
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Schamberger CT, Tuffs C, Suda AJ, Grossner T, Schmidmaier G, Stein S. Association of Chondrolabral Lesions with Ultrasound-Guided Detection of Pathological Head-Neck Contour. Diagnostics (Basel) 2023; 13:3334. [PMID: 37958230 PMCID: PMC10649636 DOI: 10.3390/diagnostics13213334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 10/25/2023] [Indexed: 11/15/2023] Open
Abstract
OBJECTIVE This study aimed to investigate whether the asphericity of the neck-head junction of the femur confirmed via ultrasound is associated with further pathology due to femoro-acetabular impingement (FAI). METHODOLOGY After a clinical examination with positive FAI tests, an ultrasound examination of the hip was performed. In the case of asphericity, a quantitative ultrasound-assisted assessment of the hip was performed, followed by contrast-enhanced arthro-MRI with the question of cartilage or labral damage. RESULTS AND CONCLUSIONS We included 51 patients with a mean age of 35.25. According to the examination algorithm, asphericity was present in all patients via ultrasonography. The average anterior alpha angle (AAA) determined in ultrasonography was 43.49°. The average AAA on the arthro-MRI was 44.19°. The mean anterior head neck offset (AHNO) in ultrasound was 5.27 mm, and in arthro-MRI, it was 5.36 mm. Arthro-MRI confirmed a bump in 47 patients and a talization disorder in 4 patients. In 49 patients, a labral lesion was found, with one being a re-rupture. Furthermore, in one patient, labral degeneration was identified. Cartilage damage to the hip joint was found in 25 patients. Two patients had neither labral nor cartilage damage in the arthro-MRI. In our study, sonographically confirmed asphericity of the head-neck junction was found in 49 cases, which was associated with further pathology and, according to the current doctrine, was attributable to the FAI and required surgical intervention. This study shows that the detection of a pathologic head and neck contour via ultrasound in combination with positive clinical signs, as present in FAI, is associated with chondrolabral lesions detected via arthro-MRI in 96.1% of cases.
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Affiliation(s)
- Christian T. Schamberger
- Clinic for Trauma and Reconstructive Surgery, University Hospital Heidelberg, 69118 Heidelberg, Germany
| | - Christopher Tuffs
- Department of General, Visceral and Transplantation Surgery, University Hospital Heidelberg,
69120 Heidelberg, Germany
| | - Arnold J. Suda
- Department of Orthopaedics and Trauma Surgery, AUVA Trauma Center Salzburg, 5010 Salzburg, Austria
| | - Tobias Grossner
- Clinic for Trauma and Reconstructive Surgery, University Hospital Heidelberg, 69118 Heidelberg, Germany
| | - Gerhard Schmidmaier
- Clinic for Trauma and Reconstructive Surgery, University Hospital Heidelberg, 69118 Heidelberg, Germany
| | - Stephan Stein
- Clinic for Trauma and Reconstructive Surgery, University Hospital Heidelberg, 69118 Heidelberg, Germany
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Fonseca Ulloa CA, Schreynemackers S, Harz T, Lang FW, Fölsch C, Rickert M, Jahnke A, Ishaque BA. Acoustical determination of primary stability of femoral short stem during uncemented hip implantation. Clin Biomech (Bristol, Avon) 2023; 109:106079. [PMID: 37651899 DOI: 10.1016/j.clinbiomech.2023.106079] [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] [Received: 04/24/2023] [Revised: 08/17/2023] [Accepted: 08/21/2023] [Indexed: 09/02/2023]
Abstract
BACKGROUND Preparing the medullary space of the femur aims to create an ideal form-fitting of cementless implants to provide sufficient initial stability, which is crucial for osseous integration, ensuring good long-term results. Hammering the implant into the proximal femur creates a press-fit anchoring of the endoprosthesis in the medullary space. Implanting the optimal size of the shaft for best fitting should avoid damage to the bone. Modified acoustic signals in connection with implantation are being detected by surgeons and might be related to the primary stability of the implant. METHODS This study aims to explore the relationship between frequency sound patterns and the change in stem stability. For this purpose, n = 32 Metha® short stems were implanted in a clinical setting by the same surgeon. During implantation, the sounds were recorded. To define a change in the acoustic system response during the operation, the individual blows of the implantation sequence were correlated with one another. FINDINGS An algorithm was able to subdivide through sound analysis two groups of hammer blows (area 1 and area 2) since the characteristics of these groups showed significant differences within the frequency range of 100 Hz to 24 kHz. The edge between both groups, detected by the algorithm, was validated with expert surgeons' classifications of the same data. INTERPRETATION In conclusion, monitoring, the hammer blows sound might allow quantification of the primary stability of the implant. Sound analysis including patient parameters and a classification algorithm could provide a precise characterization of implant stability.
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Affiliation(s)
- Carlos A Fonseca Ulloa
- Laboratory of Biomechanics, Justus-Liebig-University Giessen, Klinikstrasse 29, 35392 Giessen, Germany.
| | - Simon Schreynemackers
- Laboratory of Biomechanics, Justus-Liebig-University Giessen, Klinikstrasse 29, 35392 Giessen, Germany; Faculty of Health Sciences, University of Applied Sciences (THM), Wiesenstraße 14, 35390 Giessen, Germany
| | - Torben Harz
- Laboratory of Biomechanics, Justus-Liebig-University Giessen, Klinikstrasse 29, 35392 Giessen, Germany
| | - Frieder W Lang
- Laboratory of Biomechanics, Justus-Liebig-University Giessen, Klinikstrasse 29, 35392 Giessen, Germany
| | - Christian Fölsch
- 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
| | - 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
| | - Alexander Jahnke
- Laboratory of Biomechanics, Justus-Liebig-University Giessen, Klinikstrasse 29, 35392 Giessen, Germany
| | - Bernd A 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
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Fonseca Ulloa CA, Seeger A, Hagedorn FS, Harz T, Fölsch C, Ishaque BA, Rickert M, Jahnke A. Development and validation of an algorithm to determine the minimal factors needed for non-invasive measurement of the in vivo primary stability of cementless hip implants. Med Eng Phys 2023; 111:103932. [PMID: 36792236 DOI: 10.1016/j.medengphy.2022.103932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 11/17/2022] [Accepted: 11/23/2022] [Indexed: 12/05/2022]
Abstract
Aseptic loosening is a frequent cause for revision of endoprosthesis. X-ray examinations like Radio-Stereometry-Analysis (RSA) are among the most widely used in vivo methods for its detection. Nevertheless, this method is not used routinely because of bone marker and related radiation exposure. This work aims at creating a new in vivo concept to detect implant stability measuring micromotions without x-ray and to develop a corresponding algorithm. Based on the assumption of contactless measurement, the input parameters for the algorithm are the distances of each ultrasound sensor to the object (prosthesis and bone) and its position. First, the number of parameters necessary for a precise reconstruction and measurement of micromotions between objects had to be defined. Therefore, the algorithm has been tested with simulations of these parameters. Two experimental measurements, either using contact sensors or ultrasound, were used to prove the accuracy of the algorithm. Simulations indicate a high accuracy with three distances as initial parameters for each object. Contact measurements show precise representation of micromotion, and the contactless measurements show the possibility of detecting various materials with a high resolution. This work lays the foundations for non-invasive detection of micromotions between the implant-bone interface.
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Affiliation(s)
- Carlos A Fonseca Ulloa
- Laboratory of Biomechanics, Justus-Liebig-University Giessen, Klinikstrasse. 29, 35392 Giessen, Germany.
| | - Anja Seeger
- Laboratory of Biomechanics, Justus-Liebig-University Giessen, Klinikstrasse. 29, 35392 Giessen, Germany
| | - Frederike S Hagedorn
- Department of Pathology, University Hospital Giessen and Marburg (UKGM), Langhansstrasse, 10, 35392 Giessen, Germany
| | - Torben Harz
- Laboratory of Biomechanics, Justus-Liebig-University Giessen, Klinikstrasse. 29, 35392 Giessen, Germany
| | - Christian Fölsch
- 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 A 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
| | - 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
| | - Alexander Jahnke
- Laboratory of Biomechanics, Justus-Liebig-University Giessen, Klinikstrasse. 29, 35392 Giessen, Germany
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Jahnke A, Müller F, Fonseca Ulloa CA, Rickert M, Werner BS, Gohlke F. Press-fit reverse shoulder arthroplasty in case of advanced humeral bone loss - Is additional distal fixation necessary for primary stability? Clin Biomech (Bristol, Avon) 2021; 82:105283. [PMID: 33524845 DOI: 10.1016/j.clinbiomech.2021.105283] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 12/24/2020] [Accepted: 01/22/2021] [Indexed: 02/07/2023]
Abstract
BACKGROUND Revision reverse shoulder arthroplasty (RSA) poses considerable surgical challenges. We hypothesized that a newly developed press-fit stem, which is modeled on the medullary canal of the supracondylar region of the distal humerus by a slight distal bend, achieve both correct fit and sufficient primary stability and that additional distal fixation by interlocking screws is favorable in case of advanced humeral bone loss. METHODS A modular tapered press-fit stem was implanted in 16 Sawbone humeri in three consecutively created defect situations (200 mm (experimental group type 3°), 160 mm (type 4°) and 120 mm (type 5°) bone length above the epicondylar line. In experimental groups type 4° and 5°, additional distal interlocking screw fixation with one to three screws was tested. Primary stability was investigated by measuring micromotions with a high-precision rotational setup. FINDINGS Highest relative micromotions were noted at the proximal end in experimental groups type 3° and type 4°, whereas in type 5° highest micromotions could be seen at the distal end. Overall micromotions were significantly lower in type 3° and increased with extended defect size. In experimental group type 5°, micromotions increased with reduced additional distal screw fixation. INTERPRETATION The examined press-fit stem did not provide sufficient primary rotational stability in all constructs without additional support. Advanced distal humeral bone loss had a strong impact on primary fixation. In experimental group type 5° with 120 mm bone remaining, it might be beneficial to use three distal interlocking screws in the supracondylar region in order to neutralize torque and to avoid early loosening.
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Affiliation(s)
- Alexander Jahnke
- Laboratory of Biomechanics, Justus-Liebig-University Giessen, Klinikstrasse 29, 35392 Giessen, Germany.
| | - Felizia Müller
- Laboratory of Biomechanics, Justus-Liebig-University Giessen, Klinikstrasse 29, 35392 Giessen, Germany
| | - Carlos A Fonseca Ulloa
- 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
| | - Birgit S Werner
- Department of Shoulder Surgery, Rhoen Clinics, Bad Neustadt, Germany
| | - Frank Gohlke
- Department of Shoulder Surgery, Rhoen Clinics, Bad Neustadt, Germany
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How do the geometries of the broach handles relate to the distribution of force and moments in a femoral model? Med Eng Phys 2020; 86:122-127. [PMID: 33261725 DOI: 10.1016/j.medengphy.2020.11.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 11/02/2020] [Accepted: 11/06/2020] [Indexed: 11/21/2022]
Abstract
The continuous improvement of minimally invasive hip endoprostheses surgery comes with a change in geometries of surgery instruments like the broach handles. Consequently, depending on the handles' curvature this results in a deviation between handle and femoral axis. Therefore, this study aimed to prove the influence of different handles' curvatures on the preparation of implant site and acting forces and moments in this process. Five femoral models attached to different handles (double-curved, single-curved, straight) were locked in a drop-weight device with standardize implantation forces and moments and five strokes were measured for each possible combination. Distribution of force and moment components was dependent on the handle's curvature, where the lowest variation from the standard force values was by the straight one (av:15.2% ± 0.5%) and the strongest discrepancies were exhibit by the double-curved one (av:54.3% ± 0.1%.). Moment values have also shown this trend with the lowest variation (12.4%-23.3%) by the straight one and the highest discrepancies (56,6%-90.9%) by the double-curved one. Results show that unguided axial impact introduces unwanted transverse forces and moments into the femur. Therefore, broach handles should be modified accordingly so that minimally invasive surgery remains feasible but unwanted forces or moments can still be compensated.
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Jahnke A, Ghandourah S, Fonseca Ulloa CA, Seeger JB, Rickert M, Ishaque BA, Ahmed GA. Comparison of Short Stems Versus Straight Hip Stems: A Biomechanical Analysis of the Primary Torsional Stability. J Biomech Eng 2020; 142:124502. [PMID: 32601705 DOI: 10.1115/1.4047659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Indexed: 11/08/2022]
Abstract
Cementless straight stems show very good survival rates. However, the more distal force application of straight stems may lead to release-related proximal stress-shielding. Nevertheless, this technical brief had the objective of conducting a biomechanical in vitro analysis comparing short stems with established straight stems with respect to their primary torsional stability. Two cementless short hip stems and three cementless straight hip stems were implanted in n = 5 synthetic femora each. Torsional torques were applied into the hip stems at a continuous interval of ±7 Nm. Micromotions were measured by six inductive extensometers on four different measurement levels. At the proximal measuring point, significantly smaller relative micromotions of the CLS® prosthesis could be detected compared to all other stem models (p < 0.05). In all stem models, smallest relative micromotions were found at the metaphyseal/diaphyseal measuring point. Only at the measuring point of the distal tips of the straight stems, statistically significantly lower relative micromotion of the CLS® stem compared to the Trendhip® stem could be found (p < 0.01). All the investigated stems generally display a rather comparable anchoring pattern and an almost physiological force application. Since the comparatively long straight stems present an anchoring pattern nearly identical to that of the examined short stems, a shortening of the established straight stems could be taken into consideration. This would offer the advantage of minimally invasive surgery and bone-saving resection as well as preservation of cancellous bone in case a revision would become necessary.
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Affiliation(s)
- Alexander Jahnke
- Laboratory of Biomechanics, Justus-Liebig-University, Klinikstrasse 29, Giessen 35392, Germany
| | - Suleiman Ghandourah
- Department of Orthopaedics and Orthopaedic Surgery, University Hospital Giessen, Klinikstrasse 33, Giessen 35392, Germany
| | - Carlos A Fonseca Ulloa
- Laboratory of Biomechanics, Justus-Liebig-University, Klinikstrasse 29, Giessen 35392, Germany
| | - Jörn Bengt Seeger
- Department of Orthopaedics and Orthopaedic Surgery, University Hospital Giessen, Klinikstrasse 33, Giessen 35392, Germany
| | - Markus Rickert
- Department of Orthopaedics and Orthopaedic Surgery, University Hospital Giessen, Klinikstrasse 33, Giessen 35392, Germany
| | - Bernd Alexander Ishaque
- Department of Orthopaedics and Orthopaedic Surgery, University Hospital Giessen, Klinikstrasse 33, Giessen 35392, Germany
| | - Gafar Adam Ahmed
- Department of Orthopaedics and Orthopaedic Surgery, University Hospital Giessen, Klinikstrasse 33, Giessen 35392, Germany
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Modeling and computing of stress and strain distribution in UHMW polyethylene elements of chosen artificial human joints. POLISH JOURNAL OF CHEMICAL TECHNOLOGY 2020. [DOI: 10.2478/pjct-2020-0021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
The aim of the study was to present numerical strength analysis of the virtual knee and hip joints for the most popular tribological pairs used in prosthetic arthroplasty based on the Finite Elements Method. FEM makes it possible to calculate the stress in particular elements of the tested models. The research was dedicated to elucidate abrasive wear mechanisms during surface grinding of a polyethylene UHMW and a metal elements of endoprostheses. Strong adhesion was found between the abrasives and workpieces, which might be attributed to the chemical bonding between the abrasives and workpieces in synovial liquid. Therefore, the wear of UHMWPE is both chemical and physical. Abrasive wear effect, as a result of the abrasive wear process, is associated with material loss of the element surface layer due to the separation of particles by fissuring, stretching, or micro-cutting.
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Ahmed GA, Auge L, Loke J, Fonseca Ulloa CA, Fölsch C, Rickert M, Ishaque BA, Jahnke A. How screw connections influence the primary stability of acetabular cups under consideration of different bone models. J Orthop 2020; 21:302-308. [PMID: 32581456 DOI: 10.1016/j.jor.2020.05.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 05/31/2020] [Indexed: 10/24/2022] Open
Abstract
Introduction Good osteointegration of implants requires sufficient primary stability. Aim of this study was to examine the influence of screw fixation on the primary stability of press-fit cups. Methods Two press-fit acetabular cups were tested with regard to the influence and number of screws and their primary stability. Results For the relatively thin-walled Allofit®-S cup, an influence of the number of screws on the different forms of movement could be demonstrated. Conclusions We see a clear influence of the cup wall thickness on the elastic deformability and accordingly on the primary stability of the examined cups.
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Affiliation(s)
- Gafar Adam Ahmed
- Laboratory for 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
| | - Linda Auge
- Laboratory for Biomechanics, Justus Liebig University Giessen, Klinikstrasse 29, 35392, Giessen, Germany
| | - Jessica Loke
- Laboratory for Biomechanics, Justus Liebig University Giessen, Klinikstrasse 29, 35392, Giessen, Germany
| | | | - Christian Fölsch
- Laboratory for 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
| | - Markus Rickert
- Laboratory for 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 for 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
| | - Alexander Jahnke
- Laboratory for Biomechanics, Justus Liebig University Giessen, Klinikstrasse 29, 35392, Giessen, Germany
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Outcome of short- to medium-term migration analysis of a cementless short stem total hip arthroplasty using EBRA-FCA: a radiological and clinical study. Arch Orthop Trauma Surg 2020; 140:247-253. [PMID: 31786645 DOI: 10.1007/s00402-019-03315-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Indexed: 02/09/2023]
Abstract
INTRODUCTION Stress shielding may lead to aseptic loosening which is a common reason for implant failure. An established method to identify implants with risk of implant failure caused by aseptic loosening is to measure early migration of the stem with the "Ein Bild Roentgen Analyse" femoral component analysis (EBRA-FCA). Therefore, the aim of this study was to measure the migration of a cementless short stem prosthesis via EBRA-FCA to predict the future performance. MATERIALS AND METHODS A total collective of 71 patients were treated with a cementless short hip stem prosthesis. Indications for surgery were primary coxarthrosis, dysplasia coxarthrosis or femoral head necrosis. After surgery, the patients were followed-up immediately after 3, 6, 12, 24, 36, and 48 months and X-ray images for EBRA-FCA measurements were taken. Axial caudal migration as well as the varus/valgus tilting of the prosthesis was determined. Possible influencing factors like BMI, age, diagnosis, gender or Harris Hip Score (HHS) on the migration of the stem were assessed. RESULTS HHS increased significantly direct postoperatively (p < 0.001). At the second follow-up the average caudal migration was 0.42 ± 0.52 mm (range: 0.00-2.85 mm) (p < 0.001). A total of 14 patients underwent a caudal migration greater than 1.5 mm until 48 months. The initial varus and valgus tilts within the first 3 months were significant (p < 0.001). No correlations between BMI, age, diagnosis, gender or HHS and the migration as well as the tilting of the cementless short hip stem prosthesis were found. CONCLUSIONS Although initial axial caudal migration as well as tilting tendencies in varus or valgus position can be detected, there is no marked migration of the examined prosthesis after the first 48 months. Likewise, no aseptic early loosening was detected throughout the study period, which indicates good osseointegration of the short stem prosthesis.
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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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Jahnke A, Schroeder S, Fonseca Ulloa CA, Ahmed GA, Ishaque BA, Rickert M. Effect of bearing friction torques on the primary stability of press-fit acetabular cups: A novel in vitro method. J Orthop Res 2018; 36:2745-2753. [PMID: 29744927 DOI: 10.1002/jor.24041] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 04/27/2018] [Indexed: 02/04/2023]
Abstract
Aseptic loosening is the main reason for revision of total hip arthroplasty, and relative micromotions between cementless acetabular cups and bone play an important role regarding their comparatively high loosening rate. Therefore, the aim of the present study was to analyze the influence of resulting frictional torques on the primary stability of press-fit acetabular cups subjected to two different bearing partners. A cementless press-fit cup was implanted in bone-like foam. Primary stability of the cup was analyzed by determining spatial total, translational, and rotational interface micromotions by means of an eddy current sensor measuring system. Torque transmission into the cup was realized by three synchronous servomotors considering resultant friction torques based on constant friction for ceramic-on-ceramic (CoC: μ = 0.044; max. resultant torque: 1.5 Nm) and for ceramic-on-polyethylene (CoP: μ = 0.063; max. resultant torque: 1.9 Nm) bearing partners. Rotational micromotion of CoC was 8.99 ± 0.85 µm and of CoP 13.39 ± 1.43 µm. Translational micromotion of CoC was 29.93 ± 1.44 μm and of CoP 39.91 ± 2.25 μm. Maximum total relative micromotions were 37.10 ± 1.07 μm for CoC and 51.64 ± 2.18 μm for CoP. Micromotions resulting from CoC were statistically lower than those resulting from CoP (p < 0.05). The described 3D-measuring set-up offers a novel in vitro method of measuring primary stability of acetabular cups. We can therefore conclude, that primary stability of acetabular cup systems can be observed using either the lower friction curve (CoC) or the higher friction curve (CoP). In future studies different cup designs or cup fixation mechanisms may be tested and compared in vitro and assessed prior to implantation. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2745-2753, 2018.
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Affiliation(s)
- Alexander Jahnke
- Laboratory of Biomechanics, Justus-Liebig-University Giessen, Klinikstrasse 29, 35392, Giessen, Germany
| | - Stefan Schroeder
- Laboratory of Biomechanics, Justus-Liebig-University Giessen, Klinikstrasse 29, 35392, Giessen, Germany
| | - Carlos A Fonseca Ulloa
- Laboratory of Biomechanics, Justus-Liebig-University Giessen, Klinikstrasse 29, 35392, Giessen, Germany
| | - Gafar A 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
| | - Bernd A 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
| | - 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
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