scholarly journals Pilot Biomechanical Evaluation of Spring Ligament Augmentation with the Internal Brace in a Cadaveric Flatfoot Model

2018 ◽  
Vol 3 (3) ◽  
pp. 2473011418S0014
Author(s):  
Michael Aynardi ◽  
Kaitlin Saloky ◽  
Paul Juliano ◽  
Gregory Lewis
Keyword(s):  
Cyclic Loading ◽  
Surgical Reconstruction ◽  
Suture Repair ◽  
Talonavicular Joint ◽  
Ligament Repair ◽  
Spring Ligament ◽  
Ligament Augmentation ◽  
Significant Difference ◽  
Internal Brace ◽  
Contact Pressures

Category: Hindfoot Introduction/Purpose: Surgical reconstruction for flexible acquired flatfoot deformity from posterior tibial tendon dysfunction has been described and often includes a medial displacing calcaneal osteotomy (MDCO), Flexor digitorum longus (FDL) transfer, and possible spring ligament repair. However, the spring ligament is often attenuated leaving surgeons with few options for robust repair. Meanwhile, the Internal Brace (Arthrex, Naples, Florida) has been reported in a patient series as an excellent adjunct for spring ligament augmentation for the treatment of flatfoot correction with good clinical results. However, there are no biomechanical studies, which evaluate its safety or efficacy. The aim of this study is to perform a biomechanical comparison of spring ligament repair with Internal Brace augmentation to controls undergoing reconstruction of a flatfoot model. Methods: 4 paired (8 total), below the knee, cadaveric specimens, age 45.3 years (range; 30-60), without pre-existing foot deformity were utilized. Flatfoot model was achieved as described in the literature. Surgical reconstruction included MDCO (7.5 mm calcaneal plate), a spring ligament repair reefing (2-0 fiber wire suture), and an FDL transfer through a navicular bone tunnel with interference fixation via a biotenodesis screw (Arthrex, Naples, Florida). The experimental group received spring ligament augmentation with an internal brace as described by the manufacturer’s specifications. After potting, specimens were loaded statically to measure contact pressures and flatfoot correction. Achilles was tensioned to 350 N and cyclic loading was performed in a stepwise fashion after preconditioning. Loading occurred at 1 Hertz for 100 cycles, increasing at 100 N intervals to 1800 N. Tekscan contact pressures, radiography, and digitized measurements were repeated. Spring ligament repair site was evaluated and failures were recorded. Results: There was a statistically significant difference under cyclic loading of the internal brace augmented repair compared to standard suture repair alone (p=0.001). There were no failures of the internal brace device. Control spring ligament repair failed via suture cutout. There was 1 catastrophic specimen failure through the tibio-talar joint in each group (1000 N control; 1800 N experimental). The average change in talometatarsal angle was not statistically significant between the control (4.31±2.82) and the internal brace (4.06±2.74) (p=0.66) after loading. There was no difference in the change of peak intra-articular contact pressure at the talonavicular joint between flatfoot model and surgical correction when comparing the internal brace reconstruction (1478.8±306.6 pKa) and controls (1816.5 ±436.7pKa) (p=0.79). Conclusion: The use of the Internal Brace device to augment spring ligament reefing repair appears biomechanically safe and effective under cyclic specimen loading in a pilot, cadaveric flatfoot reconstruction model. Furthermore, it does not appear to alter intra-articular talonavicular joint contact pressures.

Biomechanical Evaluation of Spring Ligament Augmentation With the FiberTape Device in a Cadaveric Flatfoot Model

2019 ◽  
Vol 40 (5) ◽  
pp. 596-602 ◽  
Author(s):  
Michael C. Aynardi ◽  
Kaitlin Saloky ◽  
Evan P. Roush ◽  
Paul Juliano ◽  
Gregory S. Lewis
Keyword(s):  
Cyclic Loading ◽  
Biomechanical Study ◽  
Control Group ◽  
Posterior Tibial Tendon ◽  
Posterior Tibial Tendon Dysfunction ◽  
Spring Ligament ◽  
Metatarsal Angle ◽  
Ligament Augmentation ◽  
Significant Difference ◽  
Contact Pressures

Background: The structural importance of the spring ligament complex in arch stability has been described. Furthermore, the pathology of this complex is often noted in patients with posterior tibial tendon dysfunction. The purpose of this biomechanical study was to evaluate spring ligament repair alone versus augmentation with the FiberTape device in a cadaveric flatfoot model. Methods: Eight paired, below-the-knee, cadaveric specimens underwent flatfoot creation and reconstruction. The experimental group received augmentation with FiberTape (InternalBrace). After potting, specimens were loaded statically to measure talonavicular contact pressures and flatfoot correction. Cyclic loading was performed in a stepwise fashion. Loading was performed at 1 Hz and 100 cycles, at 100-N intervals from 500 to 1800 N, with the Achilles tendon also loaded to simulate weightbearing in the postoperative period. Results: Control specimen analysis demonstrated failures of 8 of 8 (100%) spring ligament suture repairs, occurring through suture cut-through (5 specimens), suture fatigue and elongation (2), or knot failure (1). One of 8 (12.5%) FiberTape-augmented repairs failed after cyclic loading. The difference in number of repair failures was statistically significant between the 2 groups ( P = .0014). Analysis revealed that at forces of 1600 N ( P = .03) and 1700 N ( P = .02) there were statistically significant differences between the FiberTape-augmented group and the control group, with a greater collapse in the lateral Meary talo–first metatarsal angle in the controls. There was no significant difference or abnormal increase in contact pressures of the talonavicular joint in both groups. Conclusion: FiberTape augmentation of the spring ligament appears biomechanically safe and effective under cyclic loading. Clinical relevance: Spring ligament augmentation with this device may be another biomechanically safe and reasonable treatment modality for surgeons during flatfoot reconstruction. It is possible that early protected weightbearing after these procedures may be performed.

Comparison of All-Inside Meniscal Repair Devices With Matched Inside-Out Suture Repair

2011 ◽  
Vol 39 (12) ◽  
pp. 2634-2639 ◽  
Author(s):  
Claudio Rosso ◽  
Konstantin Kovtun ◽  
William Dow ◽  
Brett McKenzie ◽  
Ara Nazarian ◽  
...  
Keyword(s):  
Cyclic Loading ◽  
Meniscal Repair ◽  
Suture Repair ◽  
Initial Displacement ◽  
Displacement Response ◽  
Significant Difference ◽  
Mode Of Failure ◽  
Load To Failure ◽  
Suture Failure ◽  
Inside Out

Background: All-inside meniscal repairs are performed with increasing frequency because of the availability of newly developed devices. A comparison of their biomechanical characteristics may aid physicians in selecting a method of meniscal repair. Hypothesis: All-inside meniscal repairs will be superior to their inside-out controls in response to cyclic loading and load-to-failure testing. Study Design: Controlled laboratory study. Methods: Sixty-six bucket-handle tears in matched porcine menisci were repaired using the Ultra FasT-Fix, Meniscal Cinch, Ultrabraid No. 0, and FiberWire 2-0 sutures. Initial displacement, cyclic loading (100, 300, and 500 cycles), and load-to-failure testing were performed. The displacement, response to cyclic loading, and mode of failure were recorded. The stiffness was calculated. Results: The Meniscal Cinch demonstrated a significantly higher initial displacement than the other methods tested ( P = .04). No significant difference was found among the methods in response to cyclic loading. The inside-out FiberWire repair demonstrated the highest load to failure (120.8 ± 23.5 N) and was significantly higher than both the Meniscal Cinch (64.8 ± 24.1 N, P < .001) and the Ultra FasT-Fix (88.3 ± 14.3 N, P = .002). It was not significantly higher than the inside-out Ultrabraid suture repair (98.8 ± 29.2 N). The inside-out FiberWire repair had the highest stiffness (28.7 ± 7.8 N/mm). It was significantly higher than the Meniscal Cinch (18.0 ± 8.8 N/mm, P = .01). The most common mode of failure in all methods was suture failure. Conclusion: An inside-out suture repair affords surgeons the best overall biomechanical characteristics of the devices tested (initial displacement, response to cyclic loading, and load to failure). For an all-inside repair, the Ultra FasT-Fix reproduces the characteristics of its matched inside-out suture repair more closely than the Meniscal Cinch. Clinical Relevance: Inside-out sutures and all-inside devices have similar responses to cyclic loading.

scholarly journals How Many Proximal Screws Are Needed for a Stable Proximal Humerus Fracture Fixation?

2021 ◽  
Vol 12 ◽  
pp. 215145932199274
Author(s):  
Hyojune Kim ◽  
Myung Jin Shin ◽  
Erica Kholinne ◽  
Janghyeon Seo ◽  
Duckwoo Ahn ◽  
...  
Keyword(s):  
Cyclic Loading ◽  
Proximal Humerus Fracture ◽  
Locking Plate ◽  
Proximal Humerus ◽  
Humerus Fracture ◽  
Proximal Fragment ◽  
Maximum Displacement ◽  
Significant Difference ◽  
Load To Failure ◽  
Screw Group

Purpose: This biomechanical study investigates the optimal number of proximal screws for stable fixation of a 2-part proximal humerus fracture model with a locking plate. Methods: Twenty-four proximal humerus fracture models were included in the study. An unstable 2-part fracture was created and fixed by a locking plate. Cyclic loading and load-to-failure tests were used for the following 4 groups based on the number of screws used: 4-screw, 6-screw, 7-screw, and 9-screw groups. Interfragmentary gaps were measured following cyclic loading and compared. Consequently, the load to failure, maximum displacement, stiffness, and mode of failure at failure point were compared. Results: The interfragmentary gaps for the 4-screw, 6-screw, 7-screw, and 9-screw groups were significantly reduced by 0.24 ± 0.09 mm, 0.08 ± 0.06 mm, 0.05 ± 0.01 mm, and 0.03 ± 0.01 mm following 1000 cyclic loading, respectively. The loads to failure were significantly different between the groups with the 7-screw group showing the highest load to failure. The stiffness of the 7-screw group was superior compared with the 6-screw, 9-screw, and 4-screw groups. The maximum displacement before failure showed a significant difference between the comparative groups with the 4-screw group having the lowest value. The 7-screw group had the least structural failure rate (33.3%). Conclusion: At least 7 screws would be optimal for proximal fragment fixation of proximal humerus fractures with medial comminution to minimize secondary varus collapse or fixation failure. Level of Evidence: Basic science study.

scholarly journals Dynamic Characteristics of Deeply Buried Spherical Biogas Digesters in Viscoelastic Soils

2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Hongwei Hou ◽  
Shihu Gao ◽  
Qianqian Guo ◽  
Long Chen ◽  
Bing Wu ◽  
...  
Keyword(s):  
Cyclic Loading ◽  
Fractional Derivative ◽  
Elastic Medium ◽  
Shell Structure ◽  
Fractional Derivatives ◽  
Analytic Solution ◽  
Analytic Solutions ◽  
Dynamic Responses ◽  
Significant Difference ◽  
The Continuum

The harmonic vibration characteristics of a deeply buried spherical methane tank in viscoelastic soil subjected to cyclic loading in the frequency domain are investigated. The dynamic behavior of the soil is described based on the theory of fractional derivatives. By introducing potential functions, the closed-form expressions for the displacement and the stress of the viscoelastic soil surrounding the deeply buried spherical methane tank are obtained. Two die structures are considered: a homogeneous elastic medium and a shell structure. Based on the theory of elastic motion and the Flügge theory, analytic solutions for the dynamic responses of the spherical methane tank in a fractional-derivative viscoelastic soil are derived explicitly. Analytic solution expressions of the undetermined coefficients are determined by using the continuum boundary conditions. The system dynamic responses to the homogeneous elastic medium and the shell structure and the influences of the parameters of the fractional derivative, soil, and die on the dynamic characteristic of the system are compared and analyzed. The results indicate a significant difference between the dynamic responses of the die structures for the two models.

scholarly journals Transarticular external fixation versus deltoid ligament repair in treating SER IV ankle fractures: a comparative study

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Bohua Li ◽  
Shanxi Wang ◽  
Zhengdong Zhang ◽  
Hai Yang ◽  
Jun Li ◽  
...  
Keyword(s):  
External Fixation ◽  
Short Form ◽  
Ankle Fractures ◽  
Deltoid Ligament ◽  
Functional Evaluation ◽  
Ligament Repair ◽  
Fracture Union ◽  
Significant Difference ◽  
Group 2 ◽  
Group 1

Abstract Background The topic that whether the injured deltoid ligament should be repaired when associated with ankle joint fractures is still discussed. The objective of this study was to compare the clinical effect of open reduction and internal fixation (ORIF) with deltoid ligament repair (DLR) or transarticular external fixation (TEF) in treating supination-external rotation type IV (SER IV) ankle fractures. Methods Between January 2012 and December 2015, 43 patients were diagnosed as SER IV ankle fractures, 20 underwent ORIF and transarticular external fixation (TEF) without DLR (group 1), 23 were treated with ORIF and DLR (group 2). The pre- and post-operative radiographic examination were performed, the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, the visual analog scale (VAS), the Medical Outcomes Short Form 36-item questionnaire score (SF-36), and the ankle range of motion (ROM) were used for functional evaluation. Results In both groups, the three scores improved significantly after surgery, but there was no significant difference between the two groups. At 6 weeks after surgery, patients in group 2 had better ankle ROM than group 1 (29.35 ± 2.033 vs. 40.35 ± 3.550, P <  0.001), but there was no difference at 12 months postoperatively. No cases of bone nonunion or post-traumatic arthritic changes were seen during the follow-up. Patients in group 1 required a shorter time to achieve fracture union than patients in group 2. Conclusions ORIF with TIF is an optional strategy to manage SER IV ankle fractures as it achieves comparable functional results to ORIF with DLR. It also allows patients to start relatively earlier weight-bearing and may promote fracture union.

scholarly journals Biomechanical Evaluation of Proximal Hamstring Repair: All-Suture Anchor Versus Titanium Suture Anchor

2020 ◽  
Vol 8 (1) ◽  
pp. 232596711989292 ◽  
Author(s):  
Alexander Otto ◽  
Alyssa M. DiCosmo ◽  
Joshua B. Baldino ◽  
Julian Mehl ◽  
Elifho Obopilwe ◽  
...  
Keyword(s):  
Cyclic Loading ◽  
Suture Anchor ◽  
Testing Machine ◽  
Optical Tracking ◽  
Rank Test ◽  
Suture Anchors ◽  
Posterior Aspect ◽  
Significant Difference ◽  
Load To Failure ◽  
Proximal Hamstring

Background: Proximal hamstring avulsions are severe tendon injuries and are commonly sports-related. Open and endoscopic techniques as well as different anchor configurations have already been described for proximal hamstring repair. Novel all-suture anchors have been developed to provide decreased bone loss during placement and reduced occupied bone volume when compared with titanium suture anchors. Hypothesis: Complete proximal hamstring avulsions repaired with all-suture anchors will demonstrate equal load to failure and comparable displacement under cyclic loading when compared with titanium suture anchors. Study Design: Controlled laboratory study. Methods: Complete proximal hamstring avulsions were created in 18 paired cadaveric specimens (mean ± SD age, 63.0 ± 10.4 years). Either all-suture anchors or titanium suture anchors were used for repair. Cyclic loading from 10 to 125 N at 1 Hz was performed for 1500 cycles with a material testing machine. Displacement was assessed along anterior and posterior aspects of the tendon repair with optical tracking. Specimens were loaded to failure at a rate of 120 mm/min. Displacement, load to failure, and repair construct stiffness were compared between matched pairs with the Wilcoxon signed-rank test. Correlations were determined by Spearman rho analysis. Results: The all-suture anchors showed significantly higher load-to-failure values when compared with the titanium anchor repairs (799.64 ± 257.1 vs 573.27 ± 89.9 N; P = .008). There was no significant difference in displacement between all-suture anchors and titanium suture anchors at the anterior aspect (6.60 ± 2.2 vs 5.49 ± 1.1 mm; P = .26) or posterior aspect (5.87 ± 2.08 vs 5.23 ± 1.37 mm; P = .678) of the repaired hamstring tendons. Conclusion: All-suture anchors demonstrated similar displacement and superior load to failure when compared with titanium suture anchors. Clinical Relevance: The results of this study suggest that all-suture anchors are an equivalent alternative to titanium suture anchors for proximal hamstring avulsion repair.

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