Biomechanical Evaluation of Experimental Prostheses

2009 ◽  
pp. 103-122
Author(s):  
Mark R. Pitkin
Keyword(s):  
Biomechanical Evaluation

Topological design and biomechanical evaluation for 3D printed multi-segment artificial vertebral implants

2021 ◽  
pp. 112250
Author(s):  
Jianfeng Kang ◽  
Enchun Dong ◽  
Xiangdong Li ◽  
Zheng Guo ◽  
Lei Shi ◽  
...  
Keyword(s):  
Topological Design ◽  
3D Printed ◽  
Biomechanical Evaluation

Biomechanical Evaluation of a New Fixation Method for Stabilization of Sagittal Split Ramus Osteotomy After Mandibular Advancement

2021 ◽  
Vol 6 ◽  
pp. 247275122110192
Author(s):  
Karel Kuik ◽  
Jean Pierre T. F. Ho ◽  
Cornelis Klop ◽  
Maurits H. T. de Ruiter ◽  
Cornelis J. Kleverlaan ◽  
...  
Keyword(s):  
Hybrid Method ◽  
In Vitro Study ◽  
Mandibular Advancement ◽  
Fixation Method ◽  
Common Procedure ◽  
Sagittal Split Ramus Osteotomy ◽  
Fixation Methods ◽  
Biomechanical Evaluation ◽  
Monocortical Screws

Study Design: Biomechanical in vitro study. Mandibular advancement after sagittal split ramus osteotomy (SSRO) is a common procedure in orthognathic surgery. Several fixation methods are used for stabilization of SSRO. Objective: The aim of this study was to compare a new fixation method (gridplate) with more contemporary applied methods of fixation. Material and Methods: In this study, 50 polyurethane hemimandibles with a prefabricated SSRO were used as specimens. All hemimandibles were advanced by 8 mm and divided into 5 groups with different fixation methods: (A) one 4-hole miniplate with 4 monocortical screws; (B) two 4-hole miniplates with 8 monocortical screws; (C) one 4-hole miniplate with 4 monocortical screws and 1 bicortical screw in the retromolar area (hybrid method); (D) 3 bicortical screws in an inverted-L pattern; and (E) one 8-hole gridplate with 8 monocortical screws. Loads in newtons were recorded at displacements of the mandibular incisive edge at 1 mm, 3 mm and 5 mm. Results: Fixation with 3 bicortical screws and the gridplate presented the most stability, followed by two 4-hole miniplates. Fixation with the hybrid method or the single miniplate showed the least stability. Conclusion: According to the results of this study, the 8-hole gridplate design appears a sufficient fixation method regarding stabilization of SSRO with larger mandibular advancement.

No more rattling: biomechanical evaluation of a hexapod ring fixator free of play

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Markus Greinwald ◽  
Emily K. Bliven ◽  
Alex Trompeter ◽  
Peter Augat
Keyword(s):  
Mechanical Performance ◽  
Steel Frame ◽  
Ball Joint ◽  
Universal Joint ◽  
Ring Fixator ◽  
Low Weight ◽  
Biomechanical Evaluation ◽  
Axial Fracture ◽  
Ball Joints ◽  
Universal Joints

Abstract Hexapod-ring-fixators have a characteristic rattling sound during load changes due to play in the hexapod struts. This play is perceived as unpleasant by patients and can lead to frame instability. Using slotted-ball-instead of universal-joints for the ring-strut connection could potentially resolve this problem. The purpose of the study was to clarify if the use of slotted-ball-joints reduces play and also fracture gap movement. A hexapod-fixator with slotted-ball-joints and aluminum struts (Ball-Al) was compared to universal-joint-fixators with either aluminum (Uni Al) or steel struts (Uni Steel). Six fixator frames each were loaded in tension, compression, torsion, bending and shear and mechanical performance was analyzed in terms of movement, stiffness and play. The slotted-ball-joint fixator was the only system without measurable axial play (<0.01 mm) compared to Uni-Al (1.2 ± 0.1) mm and Uni-Steel (0.6 ± 0.2) mm (p≤0.001). In both shear directions the Uni-Al had the largest play (p≤0.014). The resulting axial fracture gap movements were similar for the two aluminum frames and up to 25% smaller for the steel frame, mainly due to the highest stiffness found for the Uni-Steel in all loading scenarios (p≤0.036). However, the Uni-Steel construct was also up to 29% (450 g) heavier and had fewer usable mounting holes. In conclusion, the slotted-ball-joints of the Ball-Al fixator reduced play and minimized shear movement in the fracture while maintaining low weight of the construct. The heavier and stiffer Uni-Steel fixator compensates for existing play with a higher overall stiffness.

Biomechanical Evaluation of Intraosseous Distal Radioulnar Joint Prosthesis: A Prosthesis Designed Based on Sauvé-Kapandji Procedure

2021 ◽  
pp. 102975
Author(s):  
Ali Moradi ◽  
Reza Binava ◽  
Arya Hedjazi ◽  
Saeed Eslami Hasanabadi ◽  
Negar Taher Chaharjouy ◽  
...  
Keyword(s):  
Distal Radioulnar Joint ◽  
Joint Prosthesis ◽  
Radioulnar Joint ◽  
Biomechanical Evaluation

scholarly journals Posture and Health: Are the Biomechanical Postural Evaluation and the Postural Evaluation Questionnaire Comparable to and Predictive of the Digitized Biometrics Examination?

2021 ◽  
Vol 18 (7) ◽  
pp. 3507
Author(s):  
Giovanni Barassi ◽  
Edoardo Di Simone ◽  
Piero Galasso ◽  
Salvatore Cristiani ◽  
Marco Supplizi ◽  
...  
Keyword(s):  
Emotional Disorders ◽  
Healthy Subjects ◽  
Large Scale ◽  
Quantitative Investigation ◽  
Evaluation Questionnaire ◽  
Evaluation Form ◽  
Margin Of Error ◽  
Different Types ◽  
Biomechanical Evaluation ◽  
Postural Tone

Background: Postural tone alterations are expressions of myofascial and, therefore, of structural, visceral, and emotional disorders. To prevent these disorders, this study proposes a quantitative investigation method which administers a postural evaluation questionnaire and a postural biomechanical evaluation to 100 healthy subjects. Methods: The reliability of the method is studied by comparing both assessments with digitized biometrics. In addition, 50 subjects undergo the biomechanical evaluation form twice, by four different operators, to study the intraoperative repeatability. Results: The results show a satisfactory overlap between the results obtained with the postural evaluation questionnaire and the postural biomechanical evaluation compared to computerized biometrics. Furthermore, intraoperative repeatability in the use of the biomechanical evaluation form is demonstrated thanks to a minimal margin of error. Conclusions: This experience suggests the importance of undertaking this path in both the curative and the preventive sphere on a large scale and on different types of people who easily, and even unknowingly, may face dysfunctional syndromes, not only structural and myofascial but also consequently of the entire body’s homeostasis.

scholarly journals Biomechanical Evaluation of Tarsometatarsal Fusion Comparing Crossing Lag Screws and Lag Screw With Locking Plate

2021 ◽  
pp. 107110072110335
Author(s):  
Sarah Ettinger ◽  
Lisa-Christin Hemmersbach ◽  
Michael Schwarze ◽  
Christina Stukenborg-Colsman ◽  
Daiwei Yao ◽  
...  
Keyword(s):  
Locking Plate ◽  
Screw Fixation ◽  
Operative Procedure ◽  
Fixation Technique ◽  
Lag Screw ◽  
Group 15 ◽  
Fresh Frozen ◽  
Biomechanical Evaluation ◽  
The Stability ◽  
End Stage

Background: Tarsometatarsal (TMT) arthrodesis is a common operative procedure for end-stage arthritis of the TMT joints. To date, there is no consensus on the best fixation technique for TMT arthrodesis and which joints should be included. Methods: Thirty fresh-frozen feet were divided into one group (15 feet) in which TMT joints I-III were fused with a lag screw and locking plate and a second group (15 feet) in which TMT joints I-III were fused with 2 crossing lag screws. The arthrodesis was performed stepwise with evaluation of mobility between the metatarsal and cuneiform bones after every application or removal of a lag screw or locking plate. Results: Isolated lag-screw arthrodesis of the TMT I-III joints led to significantly increased stability in every joint ( P < .05). Additional application of a locking plate caused further stability in every TMT joint ( P < .05). An additional crossed lag screw did not significantly increase rigidity of the TMT II and III joints ( P > .05). An IM screw did not influence the stability of the fused TMT joints. For TMT III arthrodesis, lag-screw and locking plate constructs were superior to crossed lag-screw fixation ( P < .05). TMT I fusion does not support stability after TMT II and III arthrodesis. Conclusion: Each fixation technique provided sufficient stabilization of the TMT joints. Use of a lag screw plus locking plate might be superior to crossed screw fixation. An additional TMT I and/or III arthrodesis did not increase stability of an isolated TMT II arthrodesis. Clinical Relevance: We report the first biomechanical evaluation of TMT I-III arthrodesis. Our results may help surgeons to choose among osteosynthesis techniques and which joints to include in performing arthrodesis of TMT I-III joints.

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