1
|
Kahmann SL, Sas A, Große Hokamp N, van Lenthe GH, Müller LP, Wegmann K. A combined experimental and finite element analysis of the human elbow under loads of daily living. J Biomech 2023; 158:111766. [PMID: 37633217 DOI: 10.1016/j.jbiomech.2023.111766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 08/06/2023] [Accepted: 08/11/2023] [Indexed: 08/28/2023]
Abstract
Elbow trauma is often accompanied by a loss of independence in daily self-care activities, negatively affecting patients' quality of life. Finite element models can help gaining profound knowledge about native human joint mechanics, which is crucial to adequately restore joint functionality after severe injuries. Therefore, a finite element model of the elbow is required that includes both the radio-capitellar and ulno-trochlear joint and is subjected to loads realistic for activities of daily living. Since no such model has been published, we aim to fill this gap. For comparison, 8 intact cadaveric elbows were subjected to loads of up to 1000 N, after they were placed in an extended position. At each load step, the displacement of the proximal humerus relative to the distal base plate was measured with optical tracking markers and the joint pressure was measured with a pressure mapping sensor. Analogously, eight finite element models were created based on subject-specific CT scans of the corresponding elbow specimens. The CT scans were registered to the positions of tantalum beads in the experiment. The optically measured displacements were applied as boundary conditions. We demonstrated that the workflow can predict the experimental contact pressure distribution with a moderate correlation, the experimental peak pressures in the correct joints and the experimental stiffness with moderate to excellent correlation. The predictions of peak pressure magnitude, contact area and load share on the radius require improvement by precise representation of the cartilage geometry and soft tissues in the model, and proper initial contact in the experiment.
Collapse
Affiliation(s)
- Stephanie L Kahmann
- University of Cologne, Faculty of Medicine and University Hospital Cologne, Center for Orthopedic and Trauma Surgery, Kerpener Str. 62, Cologne 50937, Germany; Biomechanics Section, Dept. of Mechanical Engineering, KU Leuven, Belgium.
| | - Amelie Sas
- Biomechanics Section, Dept. of Mechanical Engineering, KU Leuven, Belgium
| | - Nils Große Hokamp
- University of Cologne, Faculty of Medicine and University Hospital Cologne, Institute for Diagnostic and Interventional Radiology, Germany
| | - G Harry van Lenthe
- Biomechanics Section, Dept. of Mechanical Engineering, KU Leuven, Belgium
| | - Lars-Peter Müller
- University of Cologne, Faculty of Medicine and University Hospital Cologne, Center for Orthopedic and Trauma Surgery, Kerpener Str. 62, Cologne 50937, Germany
| | - Kilian Wegmann
- University of Cologne, Faculty of Medicine and University Hospital Cologne, Center for Orthopedic and Trauma Surgery, Kerpener Str. 62, Cologne 50937, Germany; OCM München, Steinerstr. 6, 81369, München, Deutschland
| |
Collapse
|
2
|
Kahmann SL, Rausch V, Plümer J, Müller LP, Pieper M, Wegmann K. The automized fracture edge detection and generation of three-dimensional fracture probability heat maps. Med Eng Phys 2022; 110:103913. [PMID: 36564138 DOI: 10.1016/j.medengphy.2022.103913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 09/29/2022] [Accepted: 10/22/2022] [Indexed: 11/06/2022]
Abstract
With proven impact of statistical fracture analysis on fracture classifications, it is desirable to minimize the manual work and to maximize repeatability of this approach. We address this with an algorithm that reduces the manual effort to segmentation, fragment identification and reduction. The fracture edge detection and heat map generation are performed automatically. With the same input, the algorithm always delivers the same output. The tool transforms one intact template consecutively onto each fractured specimen by linear least square optimization, detects the fragment edges in the template and then superimposes them to generate a fracture probability heat map. We hypothesized that the algorithm runs faster than the manual evaluation and with low (< 5 mm) deviation. We tested the hypothesis in 10 fractured proximal humeri and found that it performs with good accuracy (2.5 mm ± 2.4 mm averaged Euclidean distance) and speed (23 times faster). When applied to a distal humerus, a tibia plateau, and a scaphoid fracture, the run times were low (1-2 min), and the detected edges correct by visual judgement. In the geometrically complex acetabulum, at a run time of 78 min some outliers were considered acceptable. An automatically generated fracture probability heat map based on 50 proximal humerus fractures matches the areas of high risk of fracture reported in medical literature. Such automation of the fracture analysis method is advantageous and could be extended to reduce the manual effort even further.
Collapse
Affiliation(s)
- Stephanie L Kahmann
- Faculty of Medicine and University Hospital, Center for Orthopedic and Trauma Surgery, University of Cologne, Kerpener Str. 62, Cologne 50937, Germany.
| | - Valentin Rausch
- Faculty of Medicine and University Hospital, Center for Orthopedic and Trauma Surgery, University of Cologne, Kerpener Str. 62, Cologne 50937, Germany
| | - Jonathan Plümer
- Faculty of Medicine and University Hospital, Center for Orthopedic and Trauma Surgery, University of Cologne, Kerpener Str. 62, Cologne 50937, Germany; Department of Orthopedic and Trauma Surgery, BG University Hospital Bergmannsheil, Bürkle-de-la-Camp-Platz 1, Bochum 44789, Germany
| | - Lars P Müller
- Faculty of Medicine and University Hospital, Center for Orthopedic and Trauma Surgery, University of Cologne, Kerpener Str. 62, Cologne 50937, Germany
| | - Martin Pieper
- University of Applied Sciences Aachen, Heinrich-Mußmann-Str. 1, Jülich 52428, Germany
| | - Kilian Wegmann
- Faculty of Medicine and University Hospital, Center for Orthopedic and Trauma Surgery, University of Cologne, Kerpener Str. 62, Cologne 50937, Germany
| |
Collapse
|
3
|
Rausch V, Harbrecht A, Kahmann SL, Fenten T, Jovanovic N, Hackl M, Müller LP, Staat M, Wegmann K. Osteosynthesis of Phalangeal Fractures: Biomechanical Comparison of Kirschner Wires, Plates, and Compression Screws. J Hand Surg Am 2020; 45:987.e1-987.e8. [PMID: 32499069 DOI: 10.1016/j.jhsa.2020.04.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 03/14/2020] [Accepted: 04/14/2020] [Indexed: 02/02/2023]
Abstract
PURPOSE The aim of this study was to compare several osteosynthesis techniques (intramedullary headless compression screws, T-plates, and Kirschner wires) for distal epiphyseal fractures of proximal phalanges in a human cadaveric model. METHODS A total of 90 proximal phalanges from 30 specimens (index, ring, and middle fingers) were used for this study. After stripping off all soft tissue, a transverse distal epiphyseal fracture was simulated at the proximal phalanx. The 30 specimens were randomly assigned to 1 fixation technique (30 per technique), either a 3.0-mm intramedullary headless compression screw, locking plate fixation with a 2.0-mm T-plate, or 2 oblique 1.0-mm Kirschner wires. Displacement analysis (bending, distraction, and torsion) was performed using optical tracking of an applied random speckle pattern after osteosynthesis. Biomechanical testing was performed with increasing cyclic loading and with cyclic load to failure using a biaxial torsion-tension testing machine. RESULTS Cannulated intramedullary compression screws showed significantly less displacement at the fracture site in torsional testing. Furthermore, screws were significantly more stable in bending testing. Kirschner wires were significantly less stable than plating or screw fixation in any cyclic load to failure test setup. CONCLUSIONS Intramedullary compression screws are a highly stable alternative in the treatment of transverse distal epiphyseal phalangeal fractures. Kirschner wires seem to be inferior regarding displacement properties and primary stability. CLINICAL RELEVANCE Fracture fixation of phalangeal fractures using plate osteosynthesis may have the advantage of a very rigid reduction, but disadvantages such as stiffness owing to the more invasive surgical approach and soft tissue irritation should be taken into account. Headless compression screws represent a minimally invasive choice for fixation with good biomechanical properties.
Collapse
Affiliation(s)
- Valentin Rausch
- Faculty of Medicine, University of Cologne, Center for Orthopedic and Trauma Surgery, University Hospital, Cologne, Germany
| | - Andreas Harbrecht
- Faculty of Medicine, University of Cologne, Center for Orthopedic and Trauma Surgery, University Hospital, Cologne, Germany; Department of Anatomy I, Faculty of Medicine, University of Cologne, Cologne, Germany.
| | - Stephanie L Kahmann
- Faculty of Medicine, University of Cologne, Center for Orthopedic and Trauma Surgery, University Hospital, Cologne, Germany; Institute of Bioengineering, FH Aachen University of Applied Sciences, Jülich, Germany
| | - Thomas Fenten
- Faculty of Medicine, University of Cologne, Center for Orthopedic and Trauma Surgery, University Hospital, Cologne, Germany
| | - Nebojsa Jovanovic
- Department of Trauma and Orthopedics, Hand and Microsurgery Unit, Rashid Hospital, Dubai Health Authority, Oud Metha, Dubai
| | - Michael Hackl
- Faculty of Medicine, University of Cologne, Center for Orthopedic and Trauma Surgery, University Hospital, Cologne, Germany
| | - Lars P Müller
- Faculty of Medicine, University of Cologne, Center for Orthopedic and Trauma Surgery, University Hospital, Cologne, Germany
| | - Manfred Staat
- Institute of Bioengineering, FH Aachen University of Applied Sciences, Jülich, Germany
| | - Kilian Wegmann
- Faculty of Medicine, University of Cologne, Center for Orthopedic and Trauma Surgery, University Hospital, Cologne, Germany
| |
Collapse
|
4
|
Rausch V, Kahmann SL, Baltschun C, Staat M, Müller LP, Wegmann K. Pressure Distribution to the Distal Biceps Tendon at the Radial Tuberosity: A Biomechanical Study. J Hand Surg Am 2020; 45:776.e1-776.e9. [PMID: 32151407 DOI: 10.1016/j.jhsa.2020.01.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 11/05/2019] [Accepted: 01/07/2020] [Indexed: 02/02/2023]
Abstract
PURPOSE Mechanical impingement at the narrow radioulnar space of the tuberosity is believed to be an etiological factor in the injury of the distal biceps tendon. The aim of the study was to compare the pressure distribution at the proximal radioulnar space between 2 fixation techniques and the intact state. METHODS Six right arms and 6 left arms from 5 female and 6 male frozen specimens were used for this study. A pressure transducer was introduced at the height of the radial tuberosity with the intact distal biceps tendon and after 2 fixation methods: the suture-anchor and the cortical button technique. The force (N), maximum pressure (kPa) applied to the radial tuberosity, and the contact area (mm2) of the radial tuberosity with the ulna were measured and differences from the intact tendon were detected from 60° supination to 60° pronation in 15° increments with the elbow in full extension and in 45° and 90° flexion of the elbow. RESULTS With the distal biceps tendon intact, the pressures during pronation were similar regardless of extension and flexion and were the highest at 60° pronation with 90° elbow flexion (23.3 ± 53.5 kPa). After repair of the tendon, the mean peak pressure, contact area, and total force showed an increase regardless of the fixation technique. Highest peak pressures were found using the cortical button technique at 45° flexion of the elbow and 60° pronation. These differences were significantly different from the intact tendon. The contact area was significantly larger in full extension and 15°, 30°, and 60° pronation using the cortical button technique. CONCLUSIONS Pressures on the distal biceps tendon at the radial tuberosity increase during pronation, especially after repair of the tendon. CLINICAL RELEVANCE Mechanical impingement could play a role in both the etiology of primary distal biceps tendon ruptures and the complications occurring after fixation of the tendon using certain techniques.
Collapse
Affiliation(s)
- Valentin Rausch
- Center for Orthopedic and Trauma Surgery, University of Cologne, Faculty of Medicine and University Hospital, Cologne, Germany.
| | - Stephanie L Kahmann
- Center for Orthopedic and Trauma Surgery, University of Cologne, Faculty of Medicine and University Hospital, Cologne, Germany
| | - Christoph Baltschun
- Biomechanics Laboratory, Institute of Bioengineering, F.H. Aachen University of Applied Sciences, Jülich, Germany
| | - Manfred Staat
- Biomechanics Laboratory, Institute of Bioengineering, F.H. Aachen University of Applied Sciences, Jülich, Germany
| | - Lars P Müller
- Center for Orthopedic and Trauma Surgery, University of Cologne, Faculty of Medicine and University Hospital, Cologne, Germany
| | - Kilian Wegmann
- Center for Orthopedic and Trauma Surgery, University of Cologne, Faculty of Medicine and University Hospital, Cologne, Germany
| |
Collapse
|
5
|
Abel A, Kahmann SL, Mellon S, Staat M, Jung A. An open-source tool for the validation of finite element models using three-dimensional full-field measurements. Med Eng Phys 2020; 77:125-129. [PMID: 31952915 DOI: 10.1016/j.medengphy.2019.10.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 07/19/2019] [Accepted: 10/14/2019] [Indexed: 10/25/2022]
Abstract
Three-dimensional (3D) full-field measurements provide a comprehensive and accurate validation of finite element (FE) models. For the validation, the result of the model and measurements are compared based on two respective point-sets and this requires the point-sets to be registered in one coordinate system. Point-set registration is a non-convex optimization problem that has widely been solved by the ordinary iterative closest point algorithm. However, this approach necessitates a good initialization without which it easily returns a local optimum, i.e. an erroneous registration. The globally optimal iterative closest point (Go-ICP) algorithm has overcome this drawback and forms the basis for the presented open-source tool that can be used for the validation of FE models using 3D full-field measurements. The capability of the tool is demonstrated using an application example from the field of biomechanics. Methodological problems that arise in real-world data and the respective implemented solution approaches are discussed.
Collapse
Affiliation(s)
- Alexander Abel
- Institute of Bioengineering, FH Aachen University of Applied Sciences, Heinrich-Mußmann Straße 1, 52428 Jülich, Germany
| | - Stephanie L Kahmann
- Institute of Bioengineering, FH Aachen University of Applied Sciences, Heinrich-Mußmann Straße 1, 52428 Jülich, Germany; Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Windmill Road, Oxford OX3 7LD, United Kingdom
| | - Stephen Mellon
- Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Windmill Road, Oxford OX3 7LD, United Kingdom
| | - Manfred Staat
- Institute of Bioengineering, FH Aachen University of Applied Sciences, Heinrich-Mußmann Straße 1, 52428 Jülich, Germany
| | - Alexander Jung
- Institute of Bioengineering, FH Aachen University of Applied Sciences, Heinrich-Mußmann Straße 1, 52428 Jülich, Germany; Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Windmill Road, Oxford OX3 7LD, United Kingdom.
| |
Collapse
|