Investigation of Bioabsorbable Screw Usage for Longbone Fracture Repair in the Horse: Biomechanical Features

1993 ◽  
Vol 06 (01) ◽  
pp. 42-46 ◽  
Author(s):  
T. C. Hearn ◽  
M. Arighi ◽  
J. R. Field
Keyword(s):  
Tensile Force ◽  
Testing Machine ◽  
Fracture Repair ◽  
Materials Testing ◽  
Bone Material ◽  
Bioabsorbable Screw ◽  
Axial Tensile ◽  
Metacarpal Bones ◽  
Significant Difference ◽  
Biomechanical Features

SummaryThe purpose of the study was to compare the biomechanical features of bioabsorbable, self-reinforced polyL-lactic acid (SR-PLLA) and stainless steel 4.5 mm ASIF screws. Paired extraction tests were conducted in matched third metacarpal bones and in a synthetic bone material composed of polyurethane foam. The tests were accomplished using a servohydraulic materials testing machine. From these tests the maximum value of tensile force, achieved during extraction, was recorded as the screw “holding strength‘.Comparison of holding strengths in horse cadaver bones revealed a significant difference (p = 0.0002) between screw types. The axial tensile strength of the SR-PLLA screws (878 Newtons) was much lower than that achieved by the ASIF screws (8513 N). Subsequent testing in synthetic material again reflected significant differences (p <0.0001) between the screw types. The results may be accounted for by differences in the thread-to-core ratio between the screw types. Other factors, such as elastic deformation of the bioabsorbable screw, may also contribute through differences in the mechanical interface between screw and media.

Investigation of Bioabsorbable Screw Usage for Long Bone Fracture Repair in the Horse: Interfragmentary Compression and Axial Load Response in Equine Cadaver Longbone Fractures

1995 ◽  
Vol 08 (04) ◽  
pp. 191-195 ◽  
Author(s):  
T. C. Hearn ◽  
M. Arighi ◽  
J. R. Field
Keyword(s):  
Stainless Steel ◽  
Axial Loading ◽  
Fracture Repair ◽  
Long Bone ◽  
Bioabsorbable Screw ◽  
Stainless Steel Screw ◽  
Metacarpal Bones ◽  
Significant Difference ◽  
Hybrid Configuration ◽  
Primary Fracture

SummaryThe purpose of the study was to compare biomechanical features of bioabsorbable, self-reinforced poly-L-lactic acid (SR-PLLA) and stainless steel (ASIF) 4.5 mm cortical screws. Tests were conducted in equine cadaver third metacarpal bones in which a simulated complete and displaced condylar fracture had been created by osteotomy.An evaluation of the amount of interfragmental compression achieved with each screw type was performed using electrical resistance strain gauges placed in proximity to the osteotomy. This revealed a substantial increase in interfragmental compression when ASIF screws were used compared to the SR-PLLA screw. A hybrid of the two screw types did however achieve adequate interfragmental compression. Comparison of the strength of fracture fixation through response to axial loading revealed significant difference between use of three ASIF screws and a hybrid of one SR-PLLA and two ASIF screws (p = 0.04) or two ASIF (p = 0.01) screws alone. It appeared that the hybrid configuration did have a mechanical advantage over the two ASIF screw arrangement.The results indicate that the SR-PLLA screw is inferior to the stainless steel screw as a means of primary fracture reduction in the horse. A less mechanically demanding role may yet enable usage of the bioabsorbable screws in equine fracture repair, although they proved inadequate in this testing environment.This study examined the inter-fragmental compression and response to axial loading of bioabsorbable and stainless steel 4.5 mm cortical screws in simulated condylar fractures in equine cadaver longbones. The stainless steel screw was superior in both compression and response to axial loading. It was concluded that the bioabsorbable screw did not possess characteristics that would allow it to bring about adequate primary fracture repair.

Axial pull-out strength of 3.5 cortical and 4.0 cancellous bone screws placed in canine proximal tibias using manual and power tapping

2008 ◽  
Vol 21 (04) ◽  
pp. 323-328 ◽  
Author(s):  
M. E. Soniat ◽  
S. Elder ◽  
R. McLaughlin ◽  
J. L. Demko
Keyword(s):  
Cancellous Bone ◽  
Testing Machine ◽  
Bone Screws ◽  
Materials Testing ◽  
Pull Out ◽  
Cortical Width ◽  
Bone Width ◽  
Significant Difference ◽  
Pull Out Strength

SummaryAn in vitro experimental cadaveric mechanical testing study was performed using 20 radiographically mature dogs, weighing between 18–33 kg. The aim of the study was to compare the axial pull-out strength of 3.5 mm cortical and 4.0 mm cancellous bone screws inserted in the canine proximal tibia using manual and power tapping techniques. 3.5 cortical and 4.0 cancellous bone screws were inserted in canine cadaver proximal tibiae using a manual or power tapping technique. The screws were extracted using a servohydraulic materials testing machine in order to measure axial pullout strength. Axial pull-out strength was recorded relative to the total bone width and total cortical width of each tibia. The mean axial pull-out strength for all constructs was 717.8±56.5 N without any statistically significant difference among groups (p=0.4183). The groups were equal in animal body weight, cortical width and total bone width (p=0.2808). The axial pull-out strength in proportion to cortical and total bone width was not significantly different among groups (p=0.5318). Axial pull-out strengths of 3.5 mm cortical and 4.0 mm cancellous bone screws inserted in the proximal tibial metaphysis were not significantly different. Axial pull-out strength was not affected by the use of power tapping in either screw type.

STRUCTURAL PROPERTIES OF THE SUPRASPINATUS TENDON IN TWO JOINT POSITIONS

2001 ◽  
Vol 05 (02) ◽  
pp. 105-112
Author(s):  
Andreas M. Halder ◽  
Mark E. Zobitz ◽  
Fred Schultz ◽  
Kai-Nan An
Keyword(s):  
Rotator Cuff ◽  
Structural Properties ◽  
Ultimate Load ◽  
Tensile Force ◽  
Testing Machine ◽  
Supraspinatus Tendon ◽  
Rotator Cuff Tears ◽  
Anterior Portion ◽  
Arm Position ◽  
Significant Difference

The supraspinatus tendon is frequently involved in rotator cuff tears. It has been suggested that joint position affects the structural mechanics of the tendon–bone complex. The purpose of this study was to determine regional variations in structural properties of the supraspinatus tendon in two glenohumeral positions. Supraspinatus tendons from 17 fresh frozen cadavers were divided into three strips of equal width and tested with a material-testing machine. The arm orientation was either in hanging position or 60 degrees glenohumeral abduction corresponding to 90 degrees arm abduction assuming 30 degrees scapular rotation. Tensile force, tendon elongation and failure mode were recorded. Overall, there was no significant difference in structural properties between hanging arm position and 60 degrees of glenohumeral abduction (p>0.05). However, the mean ultimate load (385 N, SD 56 N) and mean ultimate stress (14 MPa, SD 3 MPa) of the anterior tendon section with the arm in glenohumeral abduction were lower in 60 degrees abduction than in the hanging arm position (611 N, SD 276 N; 24 MPa, SD 10 MPa). In hanging arm position, the anterior tendon portion had a significantly greater ultimate load and stiffness than the middle and posterior portions (p<0.05). The regional variation in structural properties substantiates the clinical finding that rotator cuff ruptures easily extend posteriorly. Our study suggests that glenohumeral abduction reduces the failure strength of the supraspinatus tendon, specifically of its anterior portion. In our study, the maximum load of the anterior portion was substantially higher than predicted maximum loads transmitted physiologically through the entire tendon.

Effects of Tapping on the Holding Strength of Cancellous Bone Screws

1992 ◽  
Vol 05 (01) ◽  
pp. 10-12 ◽  
Author(s):  
J. F. Surowiak ◽  
J. Schatzker ◽  
T. C. Hearn
Keyword(s):  
Cancellous Bone ◽  
Material Properties ◽  
Tensile Force ◽  
Testing Machine ◽  
Bone Screws ◽  
The Other ◽  
Materials Testing ◽  
Host Medium ◽  
Pilot Hole ◽  
Maximum Value

SummaryThe purpose of the study was to determine whether tapping affects the holding strength of cancellous bone screws in soft material. Paired extraction tests were conducted using 6.5 mm cancellous bone screws in porous polyurethane foam. One member of each pair had a pre-tapped pilot hole, the other was inserted in a self-tapping manner. The maximum value of tensile force during extraction with a servohydraulic materials testing machine was recorded as the screw holding strength.Comparison of the holding strengths between the pre-tapped and self-tapping groups revealed a lower mean holding strength for the pre-tapped group (p <0.05). This result contrasts with previous studies which showed that pre-tapping increases the holding strength of bone screws in relatively stronger materials. The effect of tapping on the holding strength of bone screws is therefore dependant on the material properties of the host medium.This study examined the effect of tapping the pilot hole on the extraction strength of 6.5 mm cancellous bone screws in soft, synthetic cancellous material. In contrast with previous studies in stronger materials, it was found that tapping significantly reduces the holding strength of bone screws. The effects of tapping depend on the material properties of the host medium.

scholarly journals Effect of Alternative Palatal Root Access Technique on Fracture Resistance of Root Canal Treated Maxillary Fourth Premolar Teeth in Dogs

2020 ◽  
Vol 7 ◽  
Author(s):  
Jennifer Matelski ◽  
Aaron Rendahl ◽  
Stephanie Goldschmidt
Keyword(s):  
Root Canal ◽  
Fracture Resistance ◽  
Testing Machine ◽  
Maximum Force ◽  
Treatment Modalities ◽  
Control Group ◽  
Materials Testing ◽  
Treatment Technique ◽  
Treatment Groups ◽  
Significant Difference

A biomechanical study was performed to identify the effect of different treatment methods for difficult to instrument palatal roots on the fracture resistance of root canal treated maxillary fourth premolar teeth in dogs. Forty maxillary fourth premolar teeth with surrounding alveolar bone were harvested from beagle cadavers. Inclusion criteria included maxillary fourth premolars with no evidence of disease and similar distal root canal volumes on radiographic evaluation. The teeth were randomly divided into a control group and three treatment groups based on the endodontic treatment technique for the palatal root. The control group had a single 2 mm transcoronal access on the mesiobuccal aspect of the tooth to allow instrumentation of both the mesiobuccal and palatal root through a single small access. Alternative treatment modalities that are described for difficult to instrument palatal roots investigated in this study included enlarging the transcoronal mesiobuccal access to 4 mm, making an additional access directly over the palatal root (2 mm), and hemisection with extraction of the palatal root. All teeth had the same distal root access size (2 mm) and relative location. After access, all teeth were filed, shaped, obturated, and restored in the same fashion. Axial compression testing was performed at an angle of 60 degrees to the long axis of the tooth using a universal materials testing machine. The maximum force prior to fracture was determined for each tooth based on a force vs. deflection curve. The mean maximum force prior to fracture for all teeth was 831 N. No significant difference in mean fracture resistance was identified between the control group and treatment groups or between the different treatment groups themselves. Thus, when faced with a difficult to instrument palatal root, the treatment method chosen should be based on operator preference and experience.

Static Evaluation of Distraction Associated With Axial Rotation of the CerviCore® Intervertebral Disc Prosthesis

2010 ◽  
Author(s):  
Kathryn A. Stascavage ◽  
Morgan L. Brophy ◽  
Alexandra F. Lisi ◽  
Antonio Valdevit ◽  
Thomas Errico
Keyword(s):  
Linear Regression ◽  
Intervertebral Disc ◽  
Rotation Angle ◽  
Testing Machine ◽  
Axial Rotation ◽  
Materials Testing ◽  
Disc Prosthesis ◽  
Intervertebral Disc Prosthesis ◽  
Significant Difference ◽  
Intact Condition

Introduction: The spine displays coupled motion. In the cervical spine this may be partly attributed to the oncovertberal joints which act as rails to guide vertebral motion. In axial rotation, a vertical distraction is observed and increases until additional structures are engaged to restrain motion. The purpose of this study was to measure and compare distraction under axial rotation between the intact disc and the CerviCore® Intervertebral Disc prosthesis. Material and Methods: Six caprine functional spinal units (FSUs) were embedded in sleeves with a displacement transducer secured laterally across the disc space. The FSU was placed on the load cell of a materials testing machine and a 100N compressive load applied. Through the use of a rotary table, the inferior body was rotated relative to the superior body to angles of 0, 3, 6, and 9 degrees and distraction recorded at each position. The FSU was then implanted with the CerviCore® Intervertebral Disc prosthesis (without removal of the transducer) and the rotation sequence repeated. Statistical comparisons between the intact and implanted conditions were performed using a repeated measures ANOVA and a Tukey post-hoc test for comparisons between angle configurations. Further comparisons between the intact and implanted conditions at specific angle orientations were performed using a paired t-test. Results: No significant differences were found in axial distraction between the intact and CerviCore® implanted conditions regardless of rotation angle applied (P>0.4 for all). With respect to the effects of rotation angle upon distraction, a significant difference between the 0 versus the 6 and 9 degree conditions (P<0.05 for both) was found for the intact condition. In the case of the CerviCore® implanted condition a significant difference was found between the 0 and 9 degree rotation condition (P<0.05). A linear regression of vertical distraction versus applied rotation resulted in a vertical distraction rate that was not significantly different between the intact and implanted conditions (P>0.08). Discussion: No significant differences were detected for distraction heights at angles of 0, 3, 6, and 9 degrees under intact and implanted conditions. Further, a linear regression of measured distraction versus applied rotation angle indicated that the rate of distraction between intact and implanted conditions was not significantly different. Noteworthy is that in the regression analysis, the confidence bands associated with the implanted device are considerably narrower that those for the intact condition, indicating a more predictable response to applied rotation in the case of the implanted condition.

scholarly journals Biomechanical comparison of a novel castless arthrodesis plate with T-plate and cross pin techniques for canine partial carpal arthrodesis

2013 ◽  
Vol 26 (03) ◽  
pp. 165-171 ◽  
Author(s):  
A. W. Miles ◽  
P. Pollintine ◽  
N. J. Burton
Keyword(s):  
Ultimate Strength ◽  
Ex Vivo ◽  
Plate Fixation ◽  
Testing Machine ◽  
Carpal Bone ◽  
Metacarpal Bones ◽  
Significant Difference ◽  
Clinical Benefits ◽  
Biomechanical Comparison ◽  
Ultimate Displacement

SummaryObjectives: To describe a novel canine castless partial carpal arthrodesis plate (par-CA) and its ex vivo biomechanical comparison with T-plate and cross pinning techniques for canine partial carpal arthrodesis.Methods: The three implant systems were applied to three cohorts of six forelimbs from Greyhounds euthanatized for reasons unrelated to the study. Intercarpal and carpometacarpal palmar fibrocartilage and ligaments were sectioned. Potentiometers were applied between the radial carpal and third metacarpal bones to measure micromotion, and limbs were loaded at 30% of bodyweight at 1 Hertz for 10,000 cycles on a servo-hydraulic universal testing machine. Following assessment of micromotion, limbs were loaded to failure at 20 mm/s and ultimate strength, ultimate displacement, and stiffness were measured.Results: The T-plate (p <0.01) and par-CA (p <0.01) had reduced micromotion relative to the cross pin constructs but there was no significant difference between the control, T-plate and par-CA constructs. There was no significant difference in ultimate strength between constructs. Ultimate displacement was reduced in the plated constructs. Stiffness did not differ between constructs.Clinical significance: The novel par-CA construct was biomechanically similar to the T-plate and both were superior to cross pins in resisting micromotion. There was no difference in load at failure between constructs. The par-CA plate permits radial and ulnar carpal bone compression, a more distal location of the plate to limit impingement, and placement of screws in two metacarpal bones; features which may offer clinical benefits over T-plate fixation.

scholarly journals The comparative biomechanics of the reinforced interdental crossover and the Stout loop composite splints for mandibular fracture repair in dogs

2013 ◽  
Vol 26 (06) ◽  
pp. 461-468 ◽  
Author(s):  
A. M. Kitshoff ◽  
H. de Rooster ◽  
S. M. Ferreira ◽  
D. Burger ◽  
G. Steenkamp
Keyword(s):  
Young Adult ◽  
Total Energy ◽  
Testing Machine ◽  
Mandibular Fracture ◽  
Fracture Repair ◽  
Second Molar ◽  
Time Of Application ◽  
Total Displacement ◽  
Significant Difference ◽  
Mandibular Segment

Summary Objectives: To describe a new technique, the reinforced interdental crossover composite splint (RIC), for transverse mandibular fracture repair in dogs. This technique was compared biomechanically with the established reinforced interdental Stout loop composite splint (RIS) technique. Methods: Six pairs of mandibles from young adult small breed dogs were used for the study. Osteotomies were created in a standardized fashion and fixed with either RIC or RIS. All composite splint constructs were tested biomechanically with a cantilever bending force, using a single column testing machine at a rate of 2 mm/min. The time of application, amount of composite used, ultimate force, stiffness, total displacement, and total energy absorbed during displacement of the rostral mandibular segment were calculated and compared between the two groups. Results: No significant difference was found when comparing the time of application of the RIC and the RIS techniques. All implants failed by either composite resin fracture over the region of the osteotomy or by fracture between the first and second molar followed by detachment of the resin from the lingual enamel surface of the first molar. Differences between the RIC and RIS in force (80.5 N ± 40.3 and 51.8 N ± 27.4. respectively) and stiffness (16.2 N/mm ± 4.4 and 10.1 N/mm ± 4.1 respectively) were significant (p = 0.03). However differences between the two techniques in displacement and total energy absorbed were not significant. Clinical significance: In experimentally fractured mandibles of young adult dogs there is evidence that RIC is biomechanically similar to RIS.

scholarly journals Influence of Resin Cements on the Tension Force of Cast Frameworks Made by the Technique of Framework Cemented on Prepared Abutments

2015 ◽  
Vol 26 (4) ◽  
pp. 390-392
Author(s):  
Ana Paula Perroni ◽  
Érica Alves Gomes ◽  
Amália Machado Bielemann ◽  
Bruna Baseggio ◽  
Leonardo Federizzi ◽  
...  
Keyword(s):  
Tensile Force ◽  
Testing Machine ◽  
Acrylic Resin ◽  
Tension Force ◽  
Polymerization Process ◽  
Resin Cements ◽  
Universal Testing ◽  
Significant Difference ◽  
Positive Results ◽  
One Way Anova

<p>This study evaluated the tension force of cast frameworks made by the technique of framework cemented on prepared abutments using two different resin cements. Forty multi-unit abutment analogs were individually fixed with chemically cured acrylic resin inside PVC cylinders using a parallelometer. Brass cylindrical abutments were tightened to the multi-unit abutments to be used as spacers and then castable UCLA abutments were positioned above. These abutments were cast with Ni-Cr and then divided into 4 groups (n=10): cemented with RelyX U100(r); cemented with RelyX U100(r) and simulation of acrylic resin polymerization process; cemented with Multilink(r); and cemented with Multilink(r) and simulation of acrylic resin polymerization process. Abutments were cemented according to manufacturers' instructions. In a universal testing machine, tensile strength was applied in the direction of the long axis of the abutments at 1 mm/min crosshead speed until displacement of the luted abutments was obtained. The values of maximum tensile force (N) required for the displacement of the luted abutments were tabulated and analyzed statistically by one-way ANOVA with a 95% confidence level. No statistically significant difference was found among the groups (p>0.05). There was an increase in mean tension force when the specimens were subjected to the simulation of acrylic resin polymerization process, but the results did not differ statistically. Both resin cements presented positive results as regards the retention of luted abutments on their respective multi-unit abutments. Both materials may be indicated for the technique of framework cemented on prepared abutments when professionals pursuit better adaptation of implant-supported frameworks.</p>

The Palmar Locking Compression Plate is Biomechanically Comparable to the Dorsal PI Plate for Dorsally Comminuted, Intraarticular Wrist Fractures

2007 ◽  
Vol 32 (4) ◽  
pp. 388-393 ◽  
Author(s):  
A. J. HART ◽  
T. SEEPAUL ◽  
R. J. HEWITT ◽  
S. ANG ◽  
U. HANSEN ◽  
...  
Keyword(s):  
Permanent Deformation ◽  
Testing Machine ◽  
Absolute Difference ◽  
Control Group ◽  
Materials Testing ◽  
Wrist Fractures ◽  
Significant Difference ◽  
The Mean ◽  
Clinically Significant ◽  
Experimental Group

A clinically appropriate fracture model and testing regimen were used to test the null hypothesis that a palmarly applied locking plate was inferior to a dorsally applied Pi plate in the stabilisation of dorsally comminuted intraarticular wrist fractures. Sixteen standardised fractures of Synbone models of the radius were stabilised using either a palmar locking compression T plate (the experimental group) ( n = 8) or a dorsally applied Pi plate (the control group) ( n = 8). The constructs were tested on an Instron materials testing machine. Deformation was monitored during 500 loading cycles to 200 N. The mean permanent deformation and stiffness favoured the palmar locking compression T plate over the dorsal Pi plate ( P = 0.036). However, the absolute difference was only 0.5 mm. Such a small difference is unlikely to be clinically detectable and, therefore, we conclude that there is no clinically significant difference between the two types of fixation.

Sign in / Sign up

Export Citation Format

Share Document