Biomechanical models: key considerations in study design

Augat, Peter; Hast, Michael W.; Schemitsch, Emil H.; Heyland, Mark; Trepczynski, Adam; Borgiani, Edoardo; Rußow, Gabriele; Märdian, Sven; Duda, Georg N.; Hollensteiner, Marianne; Bottlang, Michael; Schemitsch, Emil H.

doi:10.1097/oi9.0000000000000099

Cited by 15 publications

(9 citation statements)

References 64 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Finally, limitations of this study should also be mentioned. As in most biomechanical studies, due to the absence of the limb, muscles, and other soft tissues, load application had to be abstracted [ 21 ] by the pull of the deltoid muscle realized through a testing machine. However, by using a template to place the scapula in the machine, special attention was paid to the physiological (and also reproducible) positioning of the scapula in the testing machine and also to the direction of muscle pull.…”

Section: Discussionmentioning

confidence: 99%

Single or Double Plating for Acromial Type III Fractures: Biomechanical Comparison of Load to Failure and Fragment Motion

Hollensteiner

Sandriesser

Rittenschober

et al. 2022

JCM

Self Cite

View full text Add to dashboard Cite

Background: Acromial Levy III fractures after inverse shoulder arthroplasty occur in up to 7% of patients. To date, it is not clear how these fractures should be treated as clinical outcomes remain unsatisfactory. The aim of this study was to evaluate the biomechanical performance of three different plating methods of type III acromion fractures. Methods: Levy III fractures in synthetic scapulae were fixed with three different methods. Angular stable locking plates were placed on the spina scapula to bridge the fracture either dorsally, caudally, or on both aspects by double plating. In a biomechanical experiment, the pull of the deltoid muscle at 40° abduction of the arm was simulated by cyclic loading with increasing load levels until failure. Failure load, cycles to failure, and fragment motions were evaluated. Results: The results showed that double plating (350 ± 63 N) withstood the highest loads until failure, followed by dorsal (292 ± 20 N) and caudal (217 ± 49 N) plating. Similarly, double plating showed significantly smaller fragment movement than the other two groups. Conclusions: Double plating appeared to provide the largest biomechanical stability in type III acromion fracture under arm abduction. Caudal plating in contract resulted in insufficient fracture stability and early failure and can thus not be recommended from a biomechanical point of view.

show abstract

Section: Discussionmentioning

confidence: 99%

Single or Double Plating for Acromial Type III Fractures: Biomechanical Comparison of Load to Failure and Fragment Motion

Hollensteiner

Sandriesser

Rittenschober

et al. 2022

JCM

Self Cite

View full text Add to dashboard Cite

show abstract

“…The results of FEM can be influenced by several factors, such as the software, the types of meshes and elements, the minimum differences in conditions, and the contours. On the other hand, the results of benchtop tests have not always matched the clinical experience and a computer simulation might be indicated instead of idealized, simple models often used in experimental tests [ 34 ]. Augat et al [ 34 ] stated that biomechanical studies typically have a higher sensitivity to detect a true difference between groups in a timely and cost-effective manner compared with clinical studies.…”

Section: Discussionmentioning

confidence: 99%

“…On the other hand, the results of benchtop tests have not always matched the clinical experience and a computer simulation might be indicated instead of idealized, simple models often used in experimental tests [ 34 ]. Augat et al [ 34 ] stated that biomechanical studies typically have a higher sensitivity to detect a true difference between groups in a timely and cost-effective manner compared with clinical studies. Moreover, “if research precedes implant design, the results can lead to innovative solutions in a systematic, evidence-based strategy” [ 34 ].…”

Section: Discussionmentioning

confidence: 99%

“…Augat et al [ 34 ] stated that biomechanical studies typically have a higher sensitivity to detect a true difference between groups in a timely and cost-effective manner compared with clinical studies. Moreover, “if research precedes implant design, the results can lead to innovative solutions in a systematic, evidence-based strategy” [ 34 ]. Nevertheless, although our findings look promising for the X-PIN system, especially when combined with an anti-rotation screw (X-PIN+P), we strongly recommend extrinsic comparison to make sure that the biomechanical characteristics of these implants are reproducible under different conditions, such as benchtop tests or even clinical application in P3 FNF.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Evaluation of a Locking Autocompression Screw Model in Pauwels Type-3 Femoral Neck Fracture: In Vitro Analysis

et al. 2022

View full text Add to dashboard Cite

Femoral neck fractures in young adults are uncommon, resulting from high-energy trauma. Despite their infrequency in this population, there is higher rate of complications, especially in the more vertical fracture line, classified by Pauwels as a type-3 femoral neck fracture. The implant type is of paramount importance for maintaining anatomical reduction, since it must resist the deforming forces that act on the fracture. We comparatively evaluated two constructions of the novel locking autocompression implant (X-PIN and X-PIN+P) using the finite element method and previously established methods for treating Pauwels type-3 femoral neck fractures. Six fixation models were developed for the study: a dynamic hip screw (DHS), a DHS with an anti-rotation screw (DHS+P), the inverted triangle multiple cannulated screws construction (ASNIS), the multiple cannulated screws in an L-configuration (L), and the two models of the novel locking autocompression screw (X-PIN and X-PIN+P). Under the same conditions with a load of 2100 N, the following parameters were evaluated using SIMLAB® software: the main maximum (Max P), main minimum (Min P), localized maximum P1 (Max P1), localized maximum P2 (Max P2), total displacement, localized displacement, rotation displacement, and von Mises stress. Compared to the DHS+P and ASNIS models, the X-PIN+P model presented, respectively, increases of 51.6% and 64.7% for Max P, 85% and 247% for Min P, and 18.9% and 166.7% for von Mises stress. Max P1 did not differ between the models, but Max P2 was 55% and 50% lower for X-PIN+P than ASNIS and L, respectively. All displacement values were lower for X-PIN+P than the other models. In this FEM testing, the X-PIN+P was superior to the other models, which was due to improvement in all parameters of stress distribution, displacement, and von Mises stress compared to models using a lateral plate (DHS and DHS+P) or not (ASNIS and L).

show abstract

“…Our synthetic pelvic model had no ligaments or muscular attachments, and the load vectors would differ under real-life conditions. Nevertheless, synthetic bone models are established and well-accepted precursors to cadaver studies 36,59,60 . Screw and plate fixation in our study was performed without a drilling template that would otherwise improve conformity of the implantation 25,26 .…”

Section: Discussionmentioning

confidence: 99%

Development and preclinical evaluation of a cable-clamp fixation device for a disrupted pubic symphysis

et al. 2022

View full text Add to dashboard Cite

Background Traumatic separation of the pubic symphysis can destabilize the pelvis and require surgical fixation to reduce symphyseal gapping. The traditional approach involves open reduction and the implantation of a steel symphyseal plate (SP) on the pubic bone to hold the reposition. Despite its widespread use, SP-fixation is often associated with implant failure caused by screw loosening or breakage. Methods To address the need for a more reliable surgical intervention, we developed and tested two titanium cable-clamp implants. The cable served as tensioning device while the clamp secured the cable to the bone. The first implant design included a steel cable anterior to the pubic symphysis to simplify its placement outside the pelvis, and the second design included a cable encircling the pubic symphysis to stabilize the anterior pelvic ring. Using highly reproducible synthetic bone models and a limited number of cadaver specimens, we performed a comprehensive biomechanical study of implant stability and evaluated surgical feasibility. Results We were able to demonstrate that the cable-clamp implants provide stability equivalent to that of a traditional SP-fixation but without the same risks of implant failure. We also provide detailed ex vivo evaluations of the safety and feasibility of a trans-obturator surgical approach required for those kind of fixation. Conclusion We propose that the developed cable-clamp fixation devices may be of clinical value in treating pubic symphysis separation.

show abstract

Biomechanical models: key considerations in study design

Cited by 15 publications

References 64 publications

Single or Double Plating for Acromial Type III Fractures: Biomechanical Comparison of Load to Failure and Fragment Motion

Single or Double Plating for Acromial Type III Fractures: Biomechanical Comparison of Load to Failure and Fragment Motion

Evaluation of a Locking Autocompression Screw Model in Pauwels Type-3 Femoral Neck Fracture: In Vitro Analysis

Development and preclinical evaluation of a cable-clamp fixation device for a disrupted pubic symphysis

Contact Info

Product

Resources

About