Single Load Cycle Research Articles

Improving greater trochanteric reattachment with a novel cable plate system

Cable-grip systems are commonly used for greater trochanteric reattachment because they have provided the best fixation performance to date, even though they have a rather high complication rate. A novel reattachment system is proposed with the aim of improving fixation stability. It consists of a Y-shaped fixation plate combined with locking screws and superelastic cables to reduce cable loosening and limit greater trochanter movement.The novel system is compared with a commercially available reattachment system in terms of greater trochanter movement and cable tensions under different greater trochanteric abductor application angles.A factorial design of experiments was used including four independent variables: plate system, cable type, abductor application angle, and femur model. The test procedure included 50 cycles of simultaneous application of an abductor force on the greater trochanter and a hip force on the femoral head.The novel plate reduces the movements of a greater trochanter fragment within a single loading cycle up to 26%. Permanent degradation of the fixation (accumulated movement based on 50-cycle testing) is reduced up to 46%. The use of superelastic cables reduces tension loosening up to 24%. However this last improvement did not result in a significant reduction of the grater trochanter movement.The novel plate and cables present advantages over the commercially available greater trochanter reattachment system. The plate reduces movements generated by the hip abductor. The superelastic cables reduce cable loosening during cycling. Both of these positive effects could decrease the risks related to grater trochanter non-union.

A Biomechanical Evaluation of a Hybrid Dynamic Compression Plate and a CastLess Arthrodesis Plate for Pancarpal Arthrodesis in Dogs

To determine mechanical differences between two plates with different requirements for supplementary casting after pancarpal arthrodesis (PCA): the Veterinary Instrumentation Hybrid Dynamic Compression Plate (HDCP), and the OrthoMed CastLess Arthrodesis Plate (CLP). In vitro mechanical analysis. HDCP(n = 10), CLP(10). Single-cycle load to failure using a materials-testing machine and cyclic loading between 38 and 380 N ± 5% to simulate estimated in vivo loads until failure or 10(6) cycles. Single-cycle to failure: bending stiffness was significantly higher for the HDCP(2269 ± 175 N/mm) than CLP(1754 ± 88 N/mm; P < .001). Bending structural stiffness was higher for the HDCP(3.8 ± 0.3 Nm(2) ) versus CLP(2.9 ± 0.2 Nm(2) ; P= .0022). A difference between the 2 plates for bending strength was not demonstrated; HDCP= 13.9 ± 1.4 Nm, CLP13.2 ± 0.5 Nm (P= .24). Cyclic Loading: no failures occurred with either plate type when plates were cycled to 10(6) cycles. There is no mechanical advantage in bending resistance afforded by the CLPover the HDCP. Fatigue failure of either plate during the convalescent period of an estimated 150,000-250,000 cycles is unlikely. Based on the bending performance, there is no evidence to support the use of the CLPover the HDCPfor castless PCA.

Tension band wire fixation for anterior cruciate ligament avulsion fracture: biomechanical comparison of four fixation techniques

The purpose of this study is to design a new fixation method to treat tibial eminence fractures and assess its stability compared with conventional fixation methods. Eighty fresh porcine knees were stripped of all soft tissue, leaving intact only the femur-anterior cruciate ligament (ACL)-tibia complex. A standardized type III fracture was simulated at the anterior cruciate ligament attachment region using an osteotome. Then, the 80 specimens were randomly divided into 4 groups consisting of 20 knees each. The bony fragments were, respectively, fixed with sutures, steel wire, screws, and the newly designed tension band wire. All specimens were subsequently tested on a Material Testing Machine at a load rate of 60 mm/min. The statistically significant difference between the methods in terms of ultimate failure load, yield load, and displacement of the fragment under single-cycle loading and cyclic loading were analysed. Steel wire encircling K-wire fixation showed significantly higher maximum loads, yield loads, and less displacement than all the other fixation methods tested. Specimens fixed with steel wire had the second highest maximal load followed by fixation with the cannulated screw. The lowest maximal load was observed in the group using PDS II suture. The ultimate strength of tension band wire fixation of tibial eminence fractures in these specimens was significantly greater than those of the other three fixation methods. Tension band wire fixation of eminence fractures appears to provide biomechanical advantages over the other three fixation methods; hence, it is a practical alternative to conventional fixation techniques.

On-Site In-Suit Test Research of Horizontal Bearing Capacity on Inclined Steel Pipe Piles

The in-situ tests of horizontal bearing capacity on inclined steel pipe piles were conducted in the sea near Shanghai. Based on the field experiment with the lateral unidirectional and single cycle loading test method, this document presents the horizontal displacement and bearing capacity on the inclined steel pipe piles with negative and positive inclination angles. And the horizontal bearing capacity of the steel pipe pile with positive inclination angle is larger than the one with negative inclination angle. And the tests results can be provided for similar engineering reference.

Biomechanics of polyaryletherketone rod composites and titanium rods for posterior lumbosacral instrumentation

Object Interest is increasing in the development of polyaryletherketone (PAEK) implants for posterior lumbar fusion. Due to their inherent physical properties, including radiolucency and the ability to customize stiffness with carbon fiber reinforcement, they may be more advantageous than traditional instrumentation materials. Customization of these materials may allow for the development of a system that is stiff enough to promote fusion, yet flexible enough to avoid instrumentation failure. To understand the feasibility of using such materials in posterior lumbosacral instrumentation, biomechanical performances were compared in pure moment and combined loadings between two different PAEK composite rods and titanium rods. Methods Four human cadaver L3–S1 segments were subjected to pure moment and combined (compressionflexion and compression-extension) loadings as intact specimens, and after L-4 laminectomy with complete L4–5 facetectomy. Pedicle screw/rod fixation constructs were placed from L-4 to S-1, and retested with titanium, pure poly(aryl-ether-ether-ketone) (PEEK), and carbon fiber reinforced PEEK (CFRP) rods. Reflective markers were fixed to each spinal segment. The range of motion data for the L3–S1 column and L4–5 surgical level were obtained using a digital 6-camera system. Four prewired strain gauges were glued to each rod at the level of the L-4 screw and were placed 90° apart along the axial plane of the rod to record local strain data in the combined loading mode. Biomechanical data were analyzed using the ANOVA techniques. Results In pure moment, when compared with intact specimens, each rod material similarly restricted motion in each mode of bending, except axial rotation (p &lt; 0.05). When compared with postfacetectomy specimens, each rod material similarly restricted motion (p &lt; 0.05) in all bending modes. In combined loading, rod stiffness was similar for each material. Rod strain was the least in the titanium construct, intermediate in the CFRP construct, and maximal in the pure PEEK construct. Conclusions Pure PEEK and CFRP rods confer equal stiffness and resistance to motion in lumbosacral instrumentation when compared with titanium constructs in single-cycle loading. The carbon fiber reinforcement reduces strain when compared with pure PEEK in single-cycle loading. These biomechanical responses, combined with its radiolucency, suggest that the CFRP may have an advantage over both titanium and pure PEEK rods as a material for use in posterior lumbosacral instrumentation. Benchtop fatigue testing of the CFRP constructs is needed for further examination of their responses under multicycle loading.

Study on Stud Shear Connectors Subjected to Single Cyclic Loading

In order to study the behavior of connectors used in steel-concrete composite beam subjected to single cyclic loading, three groups of studs were tested with new specimen and new method, stud’s diameter is different among each group(Φ16,Φ19,Φ22). Stud’s fatigue behavior subjected to single cyclic loading various with the diameter.

Comparison of fracture energy testing by means of double cantilever beam-(DCB)-specimens and lap joint testing method for the characterization of adhesively bonded wood

In this study, lap shear strength as well as specific fracture energy of bonded specimens from spruce wood were determined in order to verify whether the calculation of adhesive fracture energy is a suitable tool for the mechanical characterization of different adhesive systems, especially in comparison to the commonly used lap joint test method according to the European standard method EN 302-1. Two different test methods were applied for measuring the fracture energy by using a double cantilever beam (DCB). For both methods the DCB is separated along the bond in mode I fracture. While both adhesive systems applied showed similar shear strength values, differences were much more pronounced regarding the specific fracture energy of the bonded joints. Especially the application of the fracture energy concept, i.e., the separation of the DCB in a single load cycle, provided results with higher informative value than the results of standard lap shear tests.

Predicting the effect of tray malalignment on risk for bone damage and implant subsidence after total knee arthroplasty

Tibial tray malalignment has been associated with increased subsidence and failure. We constructed a finite element model of knee arthroplasty to determine the biomechanical factors involved in increasing the risk of subsidence with malalignment. Four fresh-frozen human knees were implanted with a tibial tray and subjected to forces representative of walking for up to 100,000 cycles. Cyclic displacement was measured between the tray and proximal tibia. The vertical load was shifted medially to generate a load distribution ratio of 55:45 (medial/lateral) to represent neutral alignment or 75:25 to represent varus alignment. Subjected specific geometry and material properties were obtained from qCT scans of tibia to construct a finite element model. The tray was subjected to a single load cycle representing experimental conditions. Tray displacement computed by the model matched that measured experimentally. Forces representing varus tray alignment generated greater strains in the proximal tibia and a greater volume of bone was subjected to strains higher than the fatigue threshold. Local compressive strains directly correlated with experimental subsidence and failure. Our results indicate that failure after tray malalignment is likely due to fatigue damage to the proximal tibia rather than shear across the implant-bone interface or failure of the cement mantle.

Residual stress relaxation in shot peened high strength low alloy steel and its implications for hydrogen assisted cracking

The relaxation of compressive residual stress in shot peened and laser peened 300M high strength low alloy steel in response to applied loads has been investigated and for the shot peened specimens the implication for resistance to hydrogen assisted cracking assessed. The near surface residual stress was measured predominantly by X-ray diffraction (first 10 μm) but supplemented by measurements using high resolution, fine increment hole drilling to yield depth profiling. Relaxation of residual stress was most significant under compressive loading (single load cycle) with a loss of ∼70% of the peak residual stress when the applied stress was at the compressive 0·2% proof stress. Constant load tests in 3·5%NaCl were conducted on cadmium or SermeTel coated specimens at open circuit and with uncoated specimens at an applied potential corresponding to the minimum value of the protection potential associated with these coatings. For all peened specimens, stress relaxation was induced by a prior applied stress, usually close to the compressive 0·2% proof stress. Most tests were conducted with notched specimens with a target notch depth about 50–60 m m, close to the peak residual stress on shot peened specimens. Despite the comparative severity of the tests, with applied tensile stresses up to 95% of the tensile 0·2% proof stress and the maximum expected residual stress relaxation, none of the shot peened specimens failed. This is reassuring from an engineering perspective. However, notched specimens did fail below the tensile 0·2% proof stress under slow strain rate conditions and the performance under corrosion fatigue conditions remains to be established.

Post-Operative Assessment of an Implant Fixation in Anterior Cruciate Ligament Reconstructive Surgery

The objective of this paper is to numerically simulate the behaviour of an anterior cruciate ligament (ACL) reconstructed knee using interference screw fixation under a single cycle loading or a cyclic loading test and to compare the numerical results with experimental tests using porcine samples of knee joint. A hyper-elastic material model was used to model the tendon graft and evaluate its elongation during continuous and cyclic tensile loading. The rigidity of the interference screw fixation was also examined using the finite element based numerical model. The finite element model uses the benefit of an anatomical 3D geometry of the tibial bone and tendon graft which was created from a CT scan of a patient.

Assessment of stable tearing on fatigue fracture surfaces

Fatigue fracture surfaces in a range of structural metals sometimes exhibit bands, visible as dull crescent-shaped regions which contrast to the “bright” background fatigue surface. Such bands are believed to be created within a single load cycle under either constant-amplitude or variable-amplitude load conditions. Microscopically, crack advance by tearing has similarity to the final unstable fracture of the component, with the difference that the tearing is stable: it arrests after a certain distance of crack front advance, which is then followed by further fatigue crack growth. Multiple stable tearing bands, separated by regions created by fatigue crack growth, may be visible on a single fracture surface, to the extent that they may even make up the majority of the fracture surface area. Post-failure analysis of fracture surfaces often relies on quantitative fractography to relate various crack-front progression markings to specific loads in the load history, in order to estimate the crack growth history in the component. Matching this data to predicted crack growth, however, is complicated by the fact that stable tearing is not included in fatigue predictive models, and so the presence of significant tearing can greatly complicate the derivation of a crack growth history which can be matched to a crack growth model. The post-failure analysis of fracture surfaces is particularly difficult in cases where the load history record is poor, and that process has been observed to be much more difficult when significant tearing is present. Several empirical models and concepts have been proposed to assist with post-failure analysis of tearing, but as yet we do not have a good understanding of the parameters which influence both the onset and the arrest of the tearing, and the factors which control crack shape change as tearing progresses. As a result, the interpretation of tearing on service fracture surfaces remains difficult. This paper reviews the existing empirical models for tearing analysis, and describes a series of tests which produced tearing in an aircraft aluminium alloy, with the aim of developing a better understanding of these fracture surface features. The analysis of the tearing shapes indicates that one of the empirical models may have broad value as an engineering analysis tool, since it correlates reasonably well with tearing characteristics in these tests. The study reveals that the stress intensity factor is one of the key controlling parameters in tearing onset and arrest, although simple methods for estimation of relevant stress intensity values are problematic because of the key role of crack front curvature. The main conclusions relate to the notable differences between tearing under constant-amplitude and variable-amplitude loading. The constant-amplitude conditions confer some resistance to stable tearing, and this is believed to result from the high loading prior to tear onset; several mechanisms could be involved. This research is part of a program which is developing improved analytical and prognostic models for stable tearing.

Spatially resolved magnetometry using cold atoms in dark optical tweezers

We use Faraday spectroscopy of atoms confined to crossed hollow beam tweezers to map magnetic fields over 3 millimeters with 200 micron resolution in a single trap loading cycle. The hollow beams are formed using spatial light modulation, and the trap location is scanned using acousto-optic deflectors. We demonstrate the technique by mapping a linear quadrupole magnetic field with 10 nT sensitivity.

Relaxation of Shot-Peened Residual Stresses Under Creep Loading

Shot peening is a commonly used surface treatment process that imparts compressive residual stresses into the surface of metal components. Compressive residual stresses retard initiation and growth of fatigue cracks. During the component loading history, the shot-peened residual stresses may change due to thermal exposure, creep, and cyclic loading. This paper describes a methodical approach for characterizing and modeling residual stress relaxation under elevated temperature loading, near and above the monotonic yield strength of nickel-base superalloy IN100. The model incorporates the dominant creep deformation mechanism, coupling between the creep and plasticity models, and effects of prior plastic strain. The initial room temperature residual stress and plastic strain profiles provide the initial conditions for relaxation predictions using the coupled creep-plasticity model. Model predictions correlate well with experimental results on shot-peened dogbone specimens subject to single cycle and creep loading conditions at elevated temperature. The predictions accurately capture both the shape and magnitude of the retained residual stress profile.

Olecranon fracture fixation with a new implant: Biomechanical and clinical considerations

This study aims to describe the first clinical results in the treatment of dislocated olecranon fractures with 2.2-mm, fine-threaded wires with a washer. Furthermore, in the second part of the article, the stability of these new implants has been compared to standard tension band wiring in a sawbone model. Patients The radiological and clinical outcomes in 24 patients (mean age: 53.6 years) with 24 isolated Mayo type I and II fractures of the olecranon were evaluated in a prospective study after open reduction and internal fixation (ORIF) with a new fixation device (FFS; Orthofix™). The quality of reduction with the implementation of 24 FFS constructions was compared with 24 tension band-wiring procedures performed by six different surgeons in a standard sawbone Mayo type IIa fracture model. Stability was tested in all constructs using a single cycle load to failure protocol (group I), cyclic loading for 300 cycles between 10 and 500 N (group II) and incremental sinusoidal loading from 10 to 200 N with an incremental increase of 10 N per cycle (group III) in a laboratory study. Results The Morrey elbow score was excellent in 23 patients and good in one patient, with mean DASH score of 1.6. No implant migration, secondary dislocation or nonunion was observed. In the sawbone model, the quality of reduction was the same with the FFS implants compared to the tension band wiring in the sawbone model. Here, bending moments in all three groups showed no significant difference, whereas displacement at failure was significantly greater in the tension band-wiring group at a single cycle load ( p = 0.017). Conclusion Clinical results were comparable to tension band wiring and stability of the implants in the sawbone model was the same; thus, we conclude that the FFS technique can serve as an alternative treatment option for isolated olecranon fractures.

Fatigue testing of two porcelain–zirconia all-ceramic crown systems

Objective To evaluate the mouth-motion step-stress fatigue behavior of two porcelain–zirconia all-ceramic crown systems. Methods The average dimensions of a mandibular first molar crown were imported into CAD software; a tooth preparation was modeled by reducing proximal walls by 1.5 mm and occlusal surface by 2.0 mm. The CAD-based tooth preparation was made by rapid prototyping and used as a master die to fabricate all-ceramic crowns with 1.0 mm porcelain veneered on 0.5 mm Y-TZP cores (LAVA veneer + LAVA frame, 3M/ESPE, and Vita veneer + CERCON frame, Dentsply). Crowns were cemented on aged (60 days in water) composite (Z100, 3M/ESPE) reproductions of the die. Three crowns from the LAVA group were subjected to single cycle load to failure for stress profile design; remainder subjected to step-stress mouth-motion fatigue (three step-stress profiles). All mechanical testing was performed by sliding a WC indenter of 6.25 mm diameter 0.7 mm lingually down the mesio-distal cusp. Master Weibull curves and reliability for missions of 50,000 cycles at 200 N load were calculated (Alta Pro 7, Reliasoft). Results Single load to failure showed fractures through the zirconia core. Reliability for a 200 N × 50K cycle mission was not significantly different between systems. In fatigue, failure occurred by formation of large chips within the veneer originating from the contact area without core exposure. Conclusions LAVA and CERCON ceramic systems present similar fatigue behavior; fatigue loading of both systems reproduces clinically observed failure modes.

Orthogonal Pin Construct Versus Parallel Uniplanar Pin Constructs for Pelvic External Fixation: A Biomechanical Assessment of Stiffness and Strength

The purpose of this study is to compare the structural stiffness of an orthogonal pelvic external fixator pin construct with 2 different parallel external fixator pin constructs in a simulated bone model. An orthogonal pelvic external fixator pin construct would be significantly more stiff than a parallel pin construct when loaded in-plane under similar conditions. Thirty synthetic pelvic bone models were configured with orthogonal pins (group 1), parallel iliac crest pins (group 2), or parallel supra-acetabular pins (group 3). Specimens were loaded either in-plane (flexion/extension moment) or out-of-plane (internal/external rotation moment) to assess construct stiffness. Orthopaedic industry mechanical testing laboratory (Stryker Orthopedics, Mahwah, NJ). Single load cycle to failure with load application modified to assess stiffness both in-plane and out-of-plane with the pin constructs. Pelvic external fixation pin construct stiffness. Stiffness for in-plane loading was 150.2 +/- 51.2 N/mm for the orthogonal pin construct, 105.0 +/- 46.9 N/mm for the iliac crest pin construct, and 104.7 +/- 20.7 N/mm for the supra-acetabular pin construct. Pairwise comparisons demonstrated that the difference was significant (P < 0.05) between groups 1 and 2 and groups 1 and 3 but not between groups 2 and 3. Stiffness for out-of-plane loading was 49.6 +/- 3.4 N/mm for the orthogonal pin construct, 53.9 +/- 3.5 N/mm for the iliac crest pin construct, and 100.6 +/- 4.3 N/mm for the supra-acetabular pin construct, with significant differences (P < 0.05) between groups 1 and 3 and groups 2 and 3 but not between groups 1 and 2. An orthogonal pelvic external fixator pin construct produced a significantly stiffer construct for in-plane loading (flexion/extension moment) compared with either parallel pin construct; however, a parallel supra-acetabular pin construct was stiffer for out-of-plane loading.

Effects of geometry on fracture initiation and propagation in all‐ceramic crowns

The complex and patient-unique geometry of posterior all-ceramic dental crowns represents a particularly interesting set of challenges to understanding stress concentration and fracture evolution in response to loading. A series of numerical and physical experiments, with both single cycle and fatigue loading, show that geometry profoundly influences the stress concentration and fracture initiation and propagation. In stylized crowns with uniform axial wall height, stresses concentrate beneath the indenter. As the height of the axial wall increases, loads to cause failure increase linearly. In crowns with variation in axial wall height around the periphery, stresses concentrate both beneath the indenter and at the margin of the core ceramic. The magnitude of the stress concentration at the margin is directly related to the amount of variation in axial wall height around the periphery of the crown. Anatomically correct veneered zirconia core crowns subjected to single-cycle loads, fracture in areas of greatest stress concentration identified by finite element models. Fractures and stress concentrations that occur in response to single-cycle loading are important indicators of initiation sites for fatigue failure. (c) 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009.

A cyclic testing comparison of FasT-Fix and RapidLoc devices in human cadaveric meniscus

Cyclic testing may provide a more valid depiction of how arthroscopic meniscal repairs will withstand the forces of activities of daily living (ADLs) and therapeutic exercises early post-surgery than single cycle load to failure testing. This study compared the meniscal fixation provided by vertically or horizontally placed FasT-Fix devices to horizontally placed RapidLoc devices under submaximal cyclic test conditions. Eighteen human cadaveric menisci were divided into three groups of six specimens. A scalpel was used to create a 2 cm lesion at 3 mm from the outer edge of the posterior third of each specimen. Merselene tape loops were placed around each side of the lesion and the tears were repaired using two vertical FasT-Fix, two horizontal FasT-Fix, or two RapidLoc devices. Cyclic testing (5-50 N at 1 Hz for 500 cycles) was performed on a servo hydraulic device. One-way ANOVA and Scheffe post-hoc tests were used to evaluate group differences (P < 0.05). The vertical FasT-Fix group had less displacement over the initial ten loading cycles compared to the RapidLoc group (P = 0.004), but did not differ from the horizontal FasT-Fix group (P = 0.07). At 50, 100, 200, 300, 400, and 500 cycles, the vertical FasT-Fix group had less displacement than the horizontal FasT-Fix or RapidLoc groups (P < or = 0.004). At each interval the vertical FasT-Fix group had greater relative stiffness than the other groups (P < or = 0.009). The vertical FasT-Fix group had comparatively less displacement (primarily repair site gapping) and greater relative stiffness.

Comparison of Initial Fixation Properties of Sutured and Nonsutured Soft Tissue Anterior Cruciate Ligament Grafts With Femoral Cross-Pin Fixation

To determine whether or not suturing a soft tissue graft in a whipstitch fashion is an essential procedure in order to ensure sufficient initial fixation strength of the cross-pin fixation technique in anterior cruciate ligament reconstruction. Porcine digital extensor tendons were used as 4-stranded soft tissue grafts. Specimens were fixated within 52 porcine femoral bone tunnels using a cross-pin fixation technique (RigidFix; Ethicon, Norderstedt, Germany). In group I (n = 28), the looped-over part of the grafts was sutured using a whipstitch technique; in group II (n = 28) the grafts were not sutured. Initial fixation properties were determined using either a single cycle load to failure protocol or a dynamic loading protocol, submitting the graft to 1,000 cycles of flexion-extension loading between 0 degrees and 90 degrees , followed by ultimate loading to failure. The graft-pin interaction and the graft-tunnel interface was histomorphologically visualized in unloaded and dynamically loaded grafts. After dynamic loading, the residual displacement in sutured grafts was lower when compared to nonsutured grafts. The ultimate failure loads were significantly lower in nonsutured grafts when compared to sutured grafts after dynamic loading. The histomorphologic analysis demonstrated intratunnel displacement of nonsutured grafts after dynamic loading, while sutured grafts remained in situ. In cases where the cross-pins had not threaded the tendon loops, sutured grafts provided higher fixation strength and less graft displacement. The results of the present study suggest that suturing the looped-over portion of a quadruple tendon graft provides superior biomechanical graft fixation properties when compared to nonsutured grafts when using the femoral cross-pin fixation technique. Suturing the hamstring tendon graft in a whipstitch fashion is recommended for the femoral cross-pin fixation of an anterior cruciate ligament graft.

Biomechanical Characteristics of an Implant Used to Secure Semitendinosus–Gracilis Tendon Grafts in a Canine Model of Extra‐Articular Anterior Cruciate Ligament Reconstruction

To compare initial femoral fixation properties of a new implant, Graftgrab (GG), with 2 established methods of extra-articular femoral graft fixation, spiked washers (SW) and bone staples (ST). Experimental in vitro cohort study. Canine semitendinosus-gracilis tendon grafts were passed through bone tunnels and fixed to the lateral surface of femoral condyles with spiked washers, bone staples, or new implant prototypes. The fixations were tested to failure with a single-cycle load at a rate of 50 mm/min. Failure and yield strength, stiffness, energy, and elongation were determined from load-displacement curves and failure modes were recorded. The graft failed midsubstance in 4 SW, 4 ST, and 1 GG fixations. In 3 SW, 3 ST, and 1 GG specimens, the graft slipped from the fixation. The graft ruptured at the clip (3) and the intra-articular (2) surface of the bone tunnel in the remaining GG specimens. There were no significant differences between fixation groups in femoral tunnel length, femoral width, or the mechanical properties evaluated. The initial in vitro mechanical properties of the new fixation implant are comparable with those of spiked washers and bone staples. The initial mechanical performance of the new implant tested in this study was similar to those of comparable, established implants. The new implant is novel and may be useful for human anterior and veterinary cranial cruciate ligament graft reconstruction fixation.