Bicortical versus unicortical fixation of plated clavicular fractures: A biomechanical study

2020 ◽  
pp. 175857322091421
Author(s):  
Ezequiel E Zaidenberg ◽  
Michael Voor ◽  
Enrique Pereira ◽  
Luciano A Rossi ◽  
Carlos R Zaidenberg
Keyword(s):  
Screw Fixation ◽  
Plate Fixation ◽  
Clavicle Fracture ◽  
Axial Loading ◽  
Biomechanical Study ◽  
Combined Loading ◽  
Torsional Stiffness ◽  
Fourth Generation ◽  
Reconstruction Plate ◽  
Significant Difference

Purpose To compare the biomechanical properties of three plate stabilization techniques for midshaft clavicle fractures: anatomical bicortical locking construct, anatomical unicortical locking construct, and reconstruction bicortical locking construct. Methods We analyzed superior plating of the clavicle using an anatomical clavicle plate (Acumed) with both bicortical or unicortical screw fixation and a locking reconstruction plate (DePuy-Synthes). Twenty-one fourth generation composite clavicles were used for non-destructive stiffness testing in axial loading, bending, and torsion. Fifteen composite clavicles and 17 foam clavicles were used for cyclic failure testing using a combined loading method that included all three loading modes. Results No significant differences were found between the three constructs in torsional stiffness nor in vertical bending loading. In axial loading, the anatomical bicortical locking construct was significantly stiffer than either anatomical unicortical locking construct or the reconstruction bicortical locking construct. The unicortical fixation was also significantly stiffer than the reconstruction bicortical locking construct. Regarding failure testing, there was not a significant difference between the bicortical and unicortical anatomical locking constructs; however, both were significantly stronger than bicortical screw fixation in the reconstruction plate. Conclusion Based on the biomechanical performance of these constructs, unicortical locked plate fixation may be a reasonable option in the treatment of displaced midshaft clavicle fracture fixation.

Low-Profile Dual Small Plate Fixation Is Biomechanically Similar to Larger Superior or Anteroinferior Single Plate Fixation of Midshaft Clavicle Fractures

2019 ◽  
Vol 47 (11) ◽  
pp. 2678-2685 ◽  
Author(s):  
Connor G. Ziegler ◽  
Zachary S. Aman ◽  
Hunter W. Storaci ◽  
Hannah Finch ◽  
Grant J. Dornan ◽  
...  
Keyword(s):  
Plate Fixation ◽  
Bending Stiffness ◽  
Torsional Stiffness ◽  
Single Plate ◽  
Low Profile ◽  
Significant Difference ◽  
Dual Plating ◽  
Load To Failure ◽  
Clavicle Fractures ◽  
Cadaveric Model

Background: Limited biomechanical data exist for dual small plate fixation of midshaft clavicle fractures, and no prior study has concurrently compared dual small plating to larger superior or anteroinferior single plate and screw constructs. Purpose: To biomechanically compare dual small orthogonal plating, superior plating, and anteroinferior plating of midshaft clavicle fractures by use of a cadaveric model. Study Design: Descriptive laboratory study. Methods: The study used 18 cadaveric clavicle specimens (9 pairs total), and 3 plating techniques were studied: anteroinferior, superior, and dual. The dual plating technique used smaller diameter plates and screws (1.6-mm thickness) than the other, single plate techniques (3.3-mm thickness). Each of the 9 clavicle pairs was randomly assigned a combination of 2 plating techniques, and randomization was used to determine which techniques were used for the right and left specimens. Clavicles were plated and then osteotomized to create an inferior butterfly fracture model, which was then fixed with a single interfragmentary screw. Clavicle specimens were then potted for mechanical testing. Initial bending, axial, and torsional stiffness of each construct was determined through use of a randomized nondestructive cyclic testing protocol followed by load to failure. Results: No significant differences were found in cyclical axial ( P = .667) or torsional ( P = .526) stiffness between plating groups. Anteroinferior plating demonstrated significantly higher cyclical bending stiffness than superior plating ( P = .005). No significant difference was found in bending stiffness between dual plating and either anteroinferior ( P = .129) or superior plating ( P = .067). No significant difference was noted in load to failure among plating methods ( P = .353). Conclusion: Dual plating with a smaller plate-screw construct is biomechanically similar to superior and anteroinferior single plate fixation that uses larger plate-screw constructs. No significant differences were found between dual plating and either superior or anteroinferior single plating in axial, bending, or torsional stiffness or in bending load to failure. Dual small plating is a viable option for fixing midshaft clavicle fractures and may be a useful low-profile technique that avoids a larger and more prominent plate-screw construct. Clinical Relevance: Plate prominence and hardware irritation are commonly reported complaints and reasons for revision surgery after plate fixation of midshaft clavicle fractures. Dual small plate fixation has been used to improve cosmetic acceptability, minimize hardware irritation, and decrease reoperation rate. Biomechanically, dual small plate fixation performed similarly to larger single plate fixation in this cadaveric model of butterfly fracture.

Headless Compression Screw Fixation for Proximal Phalanx Fractures: A Biomechanical Study

Hand ◽  
2020 ◽  
pp. 155894472092664
Author(s):  
Lauren Fader ◽  
Luke Robinson ◽  
Michael Voor
Keyword(s):  
Screw Fixation ◽  
Proximal Phalanx ◽  
Biomechanical Study ◽  
Materials Testing ◽  
Compression Screw ◽  
Headless Compression Screw ◽  
Screw Length ◽  
Significant Difference ◽  
Flexion Extension ◽  
Bending Load

Background: Proximal phalanx fractures are common injuries of the hand with multiple treatment options. Intramedullary (IM) screw fixation has become more widely used, and early outcomes are promising. However, biomechanical data regarding this type of fixation are sparse. Methods: Two methods of IM screw fixation of proximal phalanx fractures were tested in cadaver specimens. All specimens were treated with a single antegrade headless compression screw, with half getting the addition of a blocking screw. To test the most common deforming force of flexion-extension, each phalanx was subjected to apex volar 3-point bending using the Materials Testing System test frame. Results: There was no significant difference in the stiffness of 3-point bending with single antegrade screws alone and with a blocking screw (mean, 63.1 vs 52.2 N/mm; P = .27). When comparing smaller with larger specimens, stiffness of the small group was significantly greater than that of the large group when both fixation methods were included (85.3 vs 30.1 N/mm; P < .0002). When comparing stiffness with percent fill of the screw within bone, there was a moderately positive correlation (0.51). Conclusions: Addition of a blocking screw did not increase the stability of the IM screw fixation construct for proximal phalanx fractures. When comparing specimen size, the smaller bones were stiffer under 3-point bending load, regardless of the type of fixation. In addition, those specimens that had a larger longitudinal screw length to bone length ratio were stiffer. These findings provide valuable information as techniques for IM screw fixation of proximal phalanx fractures continue to evolve.

Stiffness of screw fixation and role of cortical hinge in the first metatarsal base osteotomy

1995 ◽  
Vol 85 (2) ◽  
pp. 73-82 ◽  
Author(s):  
JC Christensen ◽  
DN Gusman ◽  
AF Tencer
Keyword(s):  
Statistical Difference ◽  
Screw Fixation ◽  
Axial Loading ◽  
Torsional Stiffness ◽  
Axial Stiffness ◽  
Materials Testing ◽  
Metatarsal Osteotomy ◽  
First Metatarsal ◽  
Cantilever Bending

The authors investigated various factors that affect stiffness of screw fixation in the oblique first metatarsal osteotomy. One screw versus two screw fixation with intact medial cortical hinge, and two screw fixation without hinge were tested on the same metatarsal specimen. Mechanical properties of the fixation patterns were measured on a materials testing apparatus. Each metatarsal was tested at below failure threshold for stiffness within the elastic range of the specimen. Load versus displacement curves and fixation stiffness values were generated for axial loading, valgus torque, and plantar-to-dorsal cantilever bending. Osteotomies with an intact hinge demonstrated superior stiffness in most parameters as compared to osteotomies without a hinge. Two screw fixation with intact hinge showed significantly increased axial stiffness as compared to one screw fixation. There was no statistical difference between one and two screws in cantilever bending and torsional stiffness with an intact hinge. The major stabilizing factor of the first metatarsal base osteotomy is the medial cortical hinge.

scholarly journals Cannulated iliac screw fixation combined with reconstruction plate fixation for Day type II crescent pelvic fractures

2020 ◽  
Vol 48 (1) ◽  
pp. 030006051989612 ◽  
Author(s):  
Ming Li ◽  
Dichao Huang ◽  
Hailin Yan ◽  
Haiyang Li ◽  
Liping Wang ◽  
...  
Keyword(s):  
Screw Fixation ◽  
Plate Fixation ◽  
Pelvic Fractures ◽  
Type Ii ◽  
Reconstruction Plate ◽  
Iliac Screw

Screw Fixation Compared to H-Locking Plate Fixation for First Metatarsocuneiform Arthrodesis: A Biomechanical Study

2005 ◽  
Vol 26 (11) ◽  
pp. 984-989 ◽  
Author(s):  
David A. Cohen ◽  
Brent G. Parks ◽  
Lew C. Schon
Keyword(s):  
Locking Plate ◽  
Mechanical Design ◽  
Screw Fixation ◽  
Plate Fixation ◽  
Biomechanical Study ◽  
Maximal Load ◽  
Load To Failure ◽  
Fresh Frozen ◽  
The Mean ◽  
Eden Prairie

Background: Several different techniques have been used for fixation of first metatarsocuneiform (MTC) joint arthrodesis, a standard treatment for arthritis, instability, and deformity of the MTC joint. Improved plating systems using locking designs are now available, but no studies have yet compared this construct with other methods. We compared load to failure with a locking plate design versus standard crossed-screw fixation. Methods: Ten matched pairs of fresh frozen cadaver feet were used. The bone density of each pair was measured with DEXA scanning. One foot of each pair was randomly assigned to have a dorsomedial Normed H titanium locking plate (Normed Medizin-Technik Vertriebs-GmbH, D-78501 Tuttlingen, Germany) applied to the first MTC joint. On the other foot of the pair, fixation of the first MTC joint was done with crossed ACE DePuy 4.0 (DePuy/Ace, Warsaw, IN) titanium cannulated screws. The first metatarsal and first cuneiform were then isolated and planted in an epoxy resin. The specimens were loaded to failure in a four-point bending configuration using a MTS Mini Bionix test frame (MTS Systems Corp., Eden Prairie, MN). Failure was defined as displacement of more than 3 mm at the arthrodesis site. The Student t-test was used to determine any observed differences, with significance set at p ≤ 0.05. Results: The mean maximal load to failure was 140.08 N (SD ± 77.1) for screw fixation alone and 58.09 N (SD ± 11.86) for the H-locking plate. This difference was statistically significant ( p = 0.008). The mean stiffness of the construct for screw fixation alone was 83.10 N/mm (SD ± 49.8) and 19.96 N/mm for the H-locking plate. This difference also was statistically significant ( p = 0. 004). Conclusion: Screw fixation for first MTC arthrodesis created a stronger and stiffer construct than did the H-locking plate. This was likely due to the mechanical design of the implants. Compression across the MTC joint could be applied with the screws, but the plate relied on a fixed angle design with no compression.

Volar Plating versus Headless Compression Screw Fixation of Scaphoid Nonunions: A Meta-analysis of Outcomes

2021 ◽  
Author(s):  
Duncan S. Van Nest ◽  
Michael Reynolds ◽  
Eugene Warnick ◽  
Matthew Sherman ◽  
Asif M. Ilyas
Keyword(s):  
Screw Fixation ◽  
Plate Fixation ◽  
Meta Analysis ◽  
Volar Plate ◽  
Scaphoid Nonunion ◽  
Compression Screw ◽  
Treatment Groups ◽  
Headless Compression Screw ◽  
Significant Difference ◽  
Volar Plate Fixation

Abstract Background Headless compression screw fixation with bone grafting has been the mainstay of treatment for scaphoid nonunion for the past several decades. Recently, locked volar plate fixation has gained popularity as a technique for scaphoid fixation, especially for recalcitrant or secondary nonunions. Purpose The purpose of this meta-analysis was to compare union rates and clinical outcomes between locked volar plate fixation and headless compression screw fixation for the treatment of scaphoid nonunions. Methods A literature search was performed for studies documenting treatment outcomes for scaphoid nonunions from 2000 to 2020. Inclusion criteria consisted of (1) average age > 18 years, (2) primary study using screw fixation, plate fixation, or both, with discrete data reported for each procedure, and (3) average follow-up of at least 3 months. Exclusion criteria consisted of studies with incomplete or missing data on union rates. Data from each study was weighted, combined within treatment groups, and compared across treatment groups using a generalized linear model or binomial distribution. Results Following title and full-text review, 23 articles were included for analysis. Preoperatively, patients treated with plate fixation had significantly longer time from injury to surgery and were more likely to have failed prior surgical intervention. There was no significant difference between union rates at 92 and 94% for screw and plate fixation, respectively. However, plate fixation resulted in longer time to union and lower modified Mayo wrist scores. Conclusion Patients treated with locked volar plate fixation were more likely to be used for recalcitrant or secondary nonunions. There was no statistically significant difference in union rates between screw and plate fixation. The results from this meta-analysis support the select use of locked volar plate fixation for scaphoid nonunion, especially recalcitrant nonunions and those that have failed prior surgical repair.

scholarly journals An In Vitro Biomechanical Evaluation of a Lateral Lumbar Interbody Fusion Device With Integrated Lateral Modular Plate Fixation

2020 ◽  
pp. 219256822090561
Author(s):  
Ryan DenHaese ◽  
Anup Gandhi ◽  
Chris Ferry ◽  
Sam Farmer ◽  
Randall Porter
Keyword(s):  
Range Of Motion ◽  
Pedicle Screw ◽  
Screw Fixation ◽  
Plate Fixation ◽  
Axial Rotation ◽  
Pedicle Screw Fixation ◽  
Biomechanical Study ◽  
Flexion Extension ◽  
Bilateral Pedicle Screw

Study Design: In vitro cadaveric biomechanical study. Objective: Biomechanically characterize a novel lateral lumbar interbody fusion (LLIF) implant possessing integrated lateral modular plate fixation (MPF). Methods: A human lumbar cadaveric (n = 7, L1-L4) biomechanical study of segmental range-of-motion stiffness was performed. A ±7.5 Nċm moment was applied in flexion/extension, lateral bending, and axial rotation using a 6 degree-of-freedom kinematics system. Specimens were tested first in an intact state and then following iterative instrumentation (L2/3): (1) LLIF cage only, (2) LLIF + 2-screw MPF, (3) LLIF + 4-screw MPF, (4) LLIF + 4-screw MPF + interspinous process fixation, and (5) LLIF + bilateral pedicle screw fixation. Comparative analysis of range-of-motion outcomes was performed between iterations. Results: Key biomechanical findings: (1) Flexion/extension range-of-motion reduction with LLIF + 4-screw MPF was significantly greater than LLIF + 2-screw MPF ( P < .01). (2) LLIF with 2-screw and 4-screw MPF were comparable to LLIF with bilateral pedicle screw fixation in lateral bending and axial rotation range-of-motion reduction ( P = 1.0). (3) LLIF + 4-screw MPF and supplemental interspinous process fixation range-of-motion reduction was comparable to LLIF + bilateral pedicle screw fixation in all directions ( P ≥ .6). Conclusions: LLIF with 4-screw MPF may provide inherent advantages over traditional 2-screw plating modalities. Furthermore, when coupled with interspinous process fixation, LLIF with MPF is a stable circumferential construct that provides biomechanical utility in all principal motions.

scholarly journals Comparative Biomechanical Study of Screw Fixation Techniques in Periacetabular Osteotomy

Biomechanics ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 131-144
Author(s):  
Mahsan Bakhtiarinejad ◽  
Amirhossein Farvardin ◽  
Ryan J. Murphy ◽  
Robert B. Grupp ◽  
John E. Tis ◽  
...  
Keyword(s):  
Screw Fixation ◽  
Periacetabular Osteotomy ◽  
Developmental Dysplasia ◽  
Biomechanical Study ◽  
Pelvic Bone ◽  
Optimal Method ◽  
Yield Load ◽  
Acetabular Fragment ◽  
Significant Difference ◽  
Fixation Techniques

Periacetabular osteotomy (PAO) is a common surgical treatment for developmental dysplasia of the hip. To obtain the optimal method of fixation during PAO, different screw fixation techniques have been proposed for stabilizing the acetabular fragment. This study assesses the biomechanical performance of two popular 3-screw fixation techniques: iliac (IS) and transverse (IT) configurations, through finite element simulations. Additionally, different 2-screw combinations are simulated to investigate the biomechanical significance of each screw of the fixation configurations. The study findings show that yield load of the pelvic bone subject to gait loading for IT configuration is on average 7% higher compared to that of the IS. Although the yield load of the IT is predicted to be slightly higher, no significant difference in bone stiffness and displacement of the acetabular fragment are found between two configurations. Simulation results, therefore, do not demonstrate a significant biomechanical advantage of the IT configuration over the IS. Furthermore, the biomechanical comparison between the 2-screw combinations of IS and IT fixations demonstrates that the most anterior screw in IS, located at the iliac crest, and the most medial screw in the IT are the most critical elements in providing sufficient stability and support for acetabular fragment.

A biomechanical study comparing plate fixation using unicortical and bicortical screws in transverse metacarpal fracture models subjected to cyclic loading

2011 ◽  
Vol 37 (5) ◽  
pp. 396-401 ◽  
Author(s):  
R. Afshar ◽  
T. S. Fong ◽  
M. Hadi Latifi ◽  
S. R. Kanthan ◽  
T. Kamarul
Keyword(s):  
Cyclic Loading ◽  
Static Loading ◽  
Screw Fixation ◽  
Plate Fixation ◽  
Biomechanical Study ◽  
Metacarpal Fracture ◽  
Three Point Bending ◽  
Load To Failure ◽  
Fracture Models ◽  
The Mean

The use of bicortical screws to fix metacarpal fractures has been suggested to provide no added biomechanical advantage over unicortical screw fixation. However, this was only demonstrated in static loading regimes, which may not be representative of biological conditions. The present study was done to determine whether similar outcomes are obtained when cyclic loading is applied. Transverse midshaft osteotomies were created in 20 metacarpals harvested from three cadavers. Fractures were stabilised using 2.0 mm mini fragment plates fixed with either bicortical or unicortical screw fixation. These fixations were tested to failure with a three-point bending cyclic loading protocol using an electromechanical microtester and a 1 kN load cell. The mean load to failure was 370 N (SD 116) for unicortical fixation and 450 N (SD 135) for bicortical fixation. Significant differences between these two constructs were observed. A biomechanical advantage was found when using bicortical screws in metacarpal fracture plating.

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