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Xiao G, Zhang X, Duan A, Li J, Chen J. Impact of augmentation strategy variations on the mechanical characteristics of patients with osteoporotic proximal humerus fractures with medial column instability. Front Bioeng Biotechnol 2024; 12:1463047. [PMID: 39386046 PMCID: PMC11461895 DOI: 10.3389/fbioe.2024.1463047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2024] [Accepted: 09/10/2024] [Indexed: 10/12/2024] Open
Abstract
Introduction Low bone density and lack of medial support are the two most important factors affecting the stability of locking plate fixation for osteoporotic proximal humeral fractures (PHFs). This study aimed to compare the biomechanical characteristics of PHILOS locking plates combined with calcar screws, bone cement, fibular allografts, and medial locking plate support strategies for treating osteoporotic PHFs with medial column instability. Methods A three-part osteoporotic PHF (AO 11-B3.2) model with metaphyseal loss was generated using 40 synthetic humeri and fixed via four distinct medial support strategies. All models were mechanically tested to quantify the mechanical characteristics. Subsequently, finite element models were created for each biomechanical test case. The stress distribution and displacement of the four different fixation structures were analyzed using finite element analysis. Results The results demonstrated that the PHILOS locking plate combined with the medial locking plate, exhibited the greatest stability when subjected to axial, shear, and torsional loading. Furthermore, the PHILOS locking plate combined with bone cement showed structural stability similar to that of the PHILOS locking plate combined with fibular allograft but with lower stress levels on the fracture surface. Discussion In conclusion, the PLP-MLP fixation structure showed superior biomechanical properties under axial, shear, and torsional loading compared to other medial support methods. Repairing the medial support when treating osteoporotic PHFs with medial column instability can enhance the mechanical stability of the fracture end in both the short and long term.
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Affiliation(s)
- Guoqing Xiao
- Sports Medicine Center, Department of Orthopedic Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan, China
- Department of Orthopedic Surgery, The Second Affiliated Hospital of Chengdu Medical College, China National Nuclear Corporation 416 Hospital, Chengdu, Sichuan, China
| | - Xiang Zhang
- Department of Orthopedic Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Alin Duan
- Department of Orthopedic Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Jian Li
- Sports Medicine Center, Department of Orthopedic Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Jialei Chen
- Department of Orthopedic Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan, China
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Zhelev D, Hristov S, Zderic I, Ivanov S, Visscher L, Baltov A, Ribagin S, Stoffel K, Kralinger F, Winkler J, Richards RG, Varga P, Gueorguiev B. Treatment of Metaphyseal Defects in Plated Proximal Humerus Fractures with a New Augmentation Technique-A Biomechanical Cadaveric Study. MEDICINA (KAUNAS, LITHUANIA) 2023; 59:1604. [PMID: 37763723 PMCID: PMC10536689 DOI: 10.3390/medicina59091604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2023] [Revised: 08/25/2023] [Accepted: 08/31/2023] [Indexed: 09/29/2023]
Abstract
Background and Objectives: Unstable proximal humerus fractures (PHFs) with metaphyseal defects-weakening the osteosynthesis construct-are challenging to treat. A new augmentation technique of plated complex PHFs with metaphyseal defects was recently introduced in the clinical practice. This biomechanical study aimed to analyze the stability of plated unstable PHFs augmented via implementation of this technique versus no augmentation. Materials and Methods: Three-part AO/OTA 11-B1.1 unstable PHFs with metaphyseal defects were created in sixteen paired human cadaveric humeri (average donor age 76 years, range 66-92 years), pairwise assigned to two groups for locked plate fixation with identical implant configuration. In one of the groups, six-milliliter polymethylmethacrylate bone cement with medium viscosity (seven minutes after mixing) was placed manually through the lateral window in the defect of the humerus head after its anatomical reduction to the shaft and prior to the anatomical reduction of the greater tuberosity fragment. All specimens were tested biomechanically in a 25° adduction, applying progressively increasing cyclic loading at 2 Hz until failure. Interfragmentary movements were monitored by motion tracking and X-ray imaging. Results: Initial stiffness was not significantly different between the groups, p = 0.467. Varus deformation of the humerus head fragment, fracture displacement at the medial humerus head aspect, and proximal screw migration and cut-out were significantly smaller in the augmented group after 2000, 4000, 6000, 8000 and 10,000 cycles, p ≤ 0.019. Cycles to 5° varus deformation of the humerus head fragment-set as a clinically relevant failure criterion-and failure load were significantly higher in the augmented group, p = 0.018. Conclusions: From a biomechanical standpoint, augmentation with polymethylmethacrylate bone cement placed in the metaphyseal humerus head defect of plated unstable PHFs considerably enhances fixation stability and can reduce the risk of postoperative complications.
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Affiliation(s)
- Daniel Zhelev
- AO Research Institute Davos, 7270 Davos, Switzerland; (D.Z.); (I.Z.); (L.V.); (R.G.R.); (P.V.)
- Department of Orthopedics and Traumatology, University Hospital for Active Treatment, 8018 Burgas, Bulgaria;
| | - Stoyan Hristov
- Department of Orthopedics and Traumatology, University Hospital for Active Treatment, 8018 Burgas, Bulgaria;
| | - Ivan Zderic
- AO Research Institute Davos, 7270 Davos, Switzerland; (D.Z.); (I.Z.); (L.V.); (R.G.R.); (P.V.)
| | - Stoyan Ivanov
- Department of Orthopaedics and Traumatology, Medical University of Varna, 9002 Varna, Bulgaria;
| | - Luke Visscher
- AO Research Institute Davos, 7270 Davos, Switzerland; (D.Z.); (I.Z.); (L.V.); (R.G.R.); (P.V.)
- School of Medicine, Queensland University of Technology, Brisbane 4000, Australia
| | - Asen Baltov
- Department of Trauma Surgery, University Multiprofile Hospital for Active Treatment and Emergency Medicine ‘N. I. Pirogov’, 1606 Sofia, Bulgaria;
| | - Simeon Ribagin
- Department of Health Pharmaceutical Care, Medical College, University ‘Prof. Dr. Asen Zlatarov’, 8010 Burgas, Bulgaria;
| | - Karl Stoffel
- Department of Orthopaedics and Traumatology, University Hospital Basel, 4031 Basel, Switzerland;
| | - Franz Kralinger
- Department of Trauma Surgery, Medical University of Vienna, 1090 Vienna, Austria;
- Trauma and Sports Department, Ottakring Clinic, Teaching Hospital, Medical University of Vienna, 1160 Vienna, Austria
| | - Jörg Winkler
- Cantonal Hospital Graubuenden, 7000 Chur, Switzerland;
| | - R. Geoff Richards
- AO Research Institute Davos, 7270 Davos, Switzerland; (D.Z.); (I.Z.); (L.V.); (R.G.R.); (P.V.)
| | - Peter Varga
- AO Research Institute Davos, 7270 Davos, Switzerland; (D.Z.); (I.Z.); (L.V.); (R.G.R.); (P.V.)
| | - Boyko Gueorguiev
- AO Research Institute Davos, 7270 Davos, Switzerland; (D.Z.); (I.Z.); (L.V.); (R.G.R.); (P.V.)
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Gueorguiev B, Lenz M. [Cement augmentation and bone graft substitutes-Materials and biomechanics]. Unfallchirurg 2022; 125:430-435. [PMID: 35486124 DOI: 10.1007/s00113-022-01182-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/06/2022] [Indexed: 10/18/2022]
Abstract
BACKGROUND Materials with different characteristics are used for cement augmentation and as bone graft substitutes. OBJECTIVE Cement augmentation and bone graft substitutes are the subject of current research. The evaluation of new knowledge allows its specific application. MATERIAL AND METHODS Selective literature search and outline of experimental research results on cement augmentation and bone graft substitutes. RESULTS Augmentation and bone graft substitutes are essential components of current trauma surgical procedures. Despite intensive research all materials have specific disadvantages. Cement augmentation of implants enhances not only the anchorage but also influences the failure mode. CONCLUSION Cement augmentation has large potential especially in osteoporotic bone. In load-bearing regions acrylic-based cements remain the standard of choice. Ceramic cements are preferred in non-load-bearing areas. Their combination with resorbable metals offers still largely unexplored potential. Virtual biomechanics can help improve the targeted application of cement augmentation.
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Affiliation(s)
- Boyko Gueorguiev
- AO Forschungsinstitut Davos, Clavadelerstraße 8, 7270, Davos, Schweiz.
| | - Mark Lenz
- AO Forschungsinstitut Davos, Clavadelerstraße 8, 7270, Davos, Schweiz.,Klinik für Unfall‑, Hand- und Wiederherstellungschirurgie, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena, 07747, Jena, Deutschland
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RUSPI MARIALUISA, MARRAS DANIELE, CRISTOFOLINI LUCA. DOES CEMENT CURING CAUSE CONCERNING INCREASE OF THE TEMPERATURE WHEN DELIVERED IN THE HUMAN HUMERUS? J MECH MED BIOL 2021. [DOI: 10.1142/s0219519421500603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
For the treatment of humeral fractures, numerous strategies exist to improve the clinical outcome of the reconstruction and to reduce the incidence of fixation failure. Injection of acrylic-based cements to reinforce the bone and/or augment the screws is one option. The heat generated during cement polymerization raises some concerns, as it could cause tissue damage. The first aim of this study was to measure the temperature over time during polymerization when acrylic cements are delivered inside the bone to treat fracture. The second aim was to assess if the ISO-5833:2002 standard can predict what happens in a real bone. Different tests were performed using two acrylic-based cements (Mendec and Cal-Cemex): (i) the ISO-5833:2002 standard (Annex C); (ii) tests on human bones (humeral diaphysis and humeral head) injected with cement to simulate fracture treatment. In the humeri, the highest temperature was measured in the diaphysis (68.6∘C for Mendec, 62.7∘C for Cal-Cemex). These values are comparable with the temperature reached in other consolidated applications (vertebroplasty). Exposure to high temperature was shorter for the diaphysis than for the head. For both cements, in both the diaphysis and the head, temperatures exceeded 48∘C for less than 10[Formula: see text]min. This is within the threshold for tissue necrosis. The ISO-5833:2002 yielded significantly different results in terms of maximum temperature (difference exceeding 15∘C) and exposure to temperature above 48∘C and 45∘C. This discrepancy is probably due to a combination of factors affecting the amount of heat produced and dissipated (e.g., amount and shape of the cement, thermal conductivity).
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Affiliation(s)
- MARIA LUISA RUSPI
- Department of Industrial Engineering, School of Engineering and Architecture, Alma Mater Studiorum, University of Bologna, Via Umberto Terracini 24-28, 40131 Bologna, Italy
| | - DANIELE MARRAS
- Department of Industrial Engineering, School of Engineering and Architecture, Alma Mater Studiorum, University of Bologna, Via Umberto Terracini 24-28, 40131 Bologna, Italy
| | - LUCA CRISTOFOLINI
- Department of Industrial Engineering, School of Engineering and Architecture, Alma Mater Studiorum, University of Bologna, Via Umberto Terracini 24-28, 40131 Bologna, Italy
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