scholarly journals Biomechanical Comparison of Different Volar Screw Placements for Horizontal Oblique Scaphoid Fractures

2020 ◽  
Vol 10 (23) ◽  
pp. 8592
Author(s):  
Ting-Sheng Lin ◽  
Ching-Hou Ma ◽  
Chin-Hsien Wu ◽  
Cheng-Yo Yen ◽  
I-Ming Jou ◽  
...  
Keyword(s):  
Clinical Investigation ◽  
Biomechanical Model ◽  
Screw Placement ◽  
Fixation Strength ◽  
Volar Approach ◽  
Scaphoid Fractures ◽  
Group I ◽  
Load To Failure ◽  
Fresh Frozen ◽  
Biomechanical Comparison

Recently, some surgeons reported that most scaphoid waist fractures were horizontal oblique and not transverse in orientation. Therefore, this cadaveric study aimed to biomechanically compare fixation strength between central and eccentric screw placements for the volar fixation of this most common scaphoid waist fracture. Eight matched pairs of fresh-frozen forearm cadaver specimens were prepared for testing and randomly assigned to two groups: group I specimens were fixed by screws in a central placement, and group II specimens were fixed by screws in an eccentric placement. Horizontal oblique osteotomy was performed along the scaphoid waist. Then, each specimen was placed under the increasing load of a pneumatically driven plunger. We recorded stiffness, load to failure, and failure mechanisms between the central and eccentric screw placement groups. Stiffness was higher in central screw placement (74.1 N/mm) than in eccentric screw placement (29.39 N/mm). The median loads to failure in groups I and II were 54.14 and 26.22 N, respectively. In this biomechanical model, we demonstrated that central screw placement is superior to eccentric placement in terms of fixation strength. However, further clinical investigation is warranted to evaluate whether the different screw placements for volar approach of horizontal oblique scaphoid fractures affect the clinical outcomes.

scholarly journals Proximal Adductor Avulsion: A Biomechanical Comparison of Suture Anchor Repair Techniques

2019 ◽  
Vol 7 (7_suppl5) ◽  
pp. 2325967119S0042
Author(s):  
Elan J. Golan ◽  
Nicholas Yohe ◽  
Ernest M. J. Schilders ◽  
Srino Bharam
Keyword(s):  
Suture Anchor ◽  
Musculotendinous Junction ◽  
Anchor Group ◽  
Pull Out ◽  
Acute Injuries ◽  
Load To Failure ◽  
Collection Data ◽  
Fresh Frozen ◽  
Biomechanical Comparison ◽  
Repair Techniques

Objectives: Acute avulsion of the proximal fibrocartilaginous origin of the adductor longus (AL) is an injury mostly occurring in individuals that perform cutting and rapid lateral movements such as in hockey, soccer, and rugby. Especially in competitive athletes, recent trends have advocated for surgical repair of these acute injuries. However, while multiple repair configurations have been proposed, the current literature lacks biomechanical data to guide surgical technique. Therefore, the purpose of this study was to determine load-to-failure values for two proximal adductor repair techniques and to compare their strength to that of a native, uninjured proximal adductor tendon. Methods: Seventeen cadaveric fresh frozen pelvic specimens were dissected to preserve the proximal adductor tendon and the fibrocartilage attachment to the pubis. The specimens were then divided into three groups: an intact AL tendon(baseline control), and ‘torn’ tendons repaired with either a 2-suture anchor or 4-suture anchor technique. Once repaired, specimens were cyclically loaded on a custom jig to simulate a maximal effort soccer-style kick. Testing endpoints included suture anchor pull-out, loss of clamp fixation, or catastrophic tendon failure. To control for individual differences, values were reported both in terms of gross force and as load-to-displacement ratios. Following collection, data from each of the three groups were recorded and analyzed via Kruskal-Wallis and multiple comparison tests. Results: The mean load to failure for the 4-anchor group was 83.74±19.28 N, which was significantly greater than for either the intact (25.43±3.46 N, p <0.05) or 2-anchor repair (20.58±1.33 N, p <0.001) conditions. All intact and 4-anchor repair specimens failed via disruption distal to the adductor’s musculotendinous junction, with no failure at the bone-anchor interface noted in either of these groups. In contrast, 80% of 2-anchor repairs failed at the bone to anchor interface. In this group, following initial pullout, failure of a secondary anchor occurred with 41.4% less force than for the index failure (p < 0.001). Conclusion: This study provides biomechanical data which identifies a 4-anchor repair as being much more resistant to surgical-site failure than a 2-anchor construct. Further, the 4-anchor group failed at the same anatomic location as the intact adductor group, suggesting that a 4-anchor construct results in a repair that acts similar to an uninjured control. Based on this finding, a 4-anchor repair construct should be preferentially used in proximal adductor repair whenever clinically feasible. [Figure: see text][Figure: see text]

scholarly journals Biomechanical Comparison of a Prepared Thick Fresh Frozen Irradiated Fascia Lata Allograft to the Native Superior Capsule (212)

2021 ◽  
Vol 9 (10_suppl5) ◽  
pp. 2325967121S0032
Author(s):  
Nicholas Debellis ◽  
John Manning ◽  
James Tibone ◽  
Michelle McGarry ◽  
Gregory Adamson ◽  
...  
Keyword(s):  
Ultimate Load ◽  
Fascia Lata ◽  
Cadaveric Specimen ◽  
Yield Load ◽  
Total Displacement ◽  
Pull Out ◽  
Significant Difference ◽  
Load To Failure ◽  
Fresh Frozen ◽  
Biomechanical Comparison

Objectives: Superior Capsule Reconstruction (SCR) has been described as treatment option for irreparable tears of the superior rotator cuff. Reported outcomes on the success of the surgery have been variable, with graft choice seeming to be one of the most important factors. Fascia Lata (FL) allograft has been proposed as a potential option as it provides adequate graft thickness while avoiding the morbidity of an autograft harvest. The purpose of this study was to compare the biomechanical characteristics of an SCR with FL allograft (FL-SCR) to a native superior capsule in a cadaveric specimen. Methods: Eight cadaver shoulder specimens were used. Each specimen was tested with a custom shoulder system twice. Initial testing was performed after the specimen was dissected of all soft tissue except for the native superior capsule. Subsequent testing was performed after FL-SCR was done. All allografts were fresh frozen and irradiated. Capsule and graft dimensions were recorded before testing. Biomechanical values recorded were cyclic and load to failure for both the native capsule and FL-SCR, and fixation displacement for the SCR-FL construct. A Paired T-test was performed to compare the biomechanical values of the native superior capsule to the FL-SCR. Results: The mean thickness of the NSC was 2.4 ± 0.6 mm and 7.4 ± 1.2mm for the FL graft. The native superior capsule had an average linear stiffness of 94.5 ± 20.4 N/mm, yield load of 386.9 ± 63.6 N, ultimate load of 444.9 ± 67.7 N and energy absorbed of 1418.4 ± 248.8 N-mm. The FL-SCR construct had an average linear stiffness of 28.0 ± 1.6 N/mm, yield load of 123.8 ± 54.3 N, ultimate load of 369.0 ± 43.4 N and energy absorbed of 5021.2 ± 755.1 N-mm. Comparing the two groups there was a statistically significant difference for stiffness (P = 0.013), yield load (P = 0.03) and energy absorbed (P = 0.003). There was no statistically significant difference between ultimate load. The total displacement of the FL-SCR fixation was 5.8 ± 0.6 mm after 1 cycle, 8.5 ± 0.7 mm after 30 cycles, 11.4 ± 1.8 mm at the yield load and 29.5 ± 1.8 mm at the ultimate load. For the failure mode, 8/8 NSC specimens failed at the mid-substance. The FL-SCR, 3/8 specimens failed at the suture tendon interface and 4/8 had medial anchor pull out. Conclusions: Performing SCR with FL allograft in a cadaver model creates a construct that is sufficiently strong enough to withstand normal physiologic loading of the shoulder, although it does not fully re-create the biomechanical characteristics of a native shoulder superior capsule.

The Effect of Suture Anchor Insertion Angle on Calcaneus Pullout Strength: Challenging the Deadman’s Angle

2016 ◽  
Vol 10 (5) ◽  
pp. 411-414 ◽  
Author(s):  
William M. Weiss ◽  
Ramon P. Saucedo ◽  
John D. Robinson ◽  
Chung-Chieh Jason Lo ◽  
Randal P. Morris ◽  
...  
Keyword(s):  
Suture Anchor ◽  
Tensile Load ◽  
Achilles Tendinopathy ◽  
Fixation Strength ◽  
Suture Anchors ◽  
Insertion Angle ◽  
Load To Failure ◽  
Biomechanical Comparison ◽  
Anchor Fixation

Background. Refractory cases of Achilles tendinopathy amenable to surgery may include reattachment of the tendon using suture anchors. However, there is paucity of information describing the optimal insertion angle to maximize the tendon footprint and anchor stability in the calcaneus. The purpose of this investigation is to compare the fixation strength of suture anchors inserted at 90° and 45° (the Deadman’s angle) relative to the primary compressive trabeculae of the calcaneus. Methods. A total of 12 matched pairs of adult cadaveric calcanei were excised and potted to approximate their alignment in vivo. Each pair was implanted with 5.5-mm bioabsorbable suture anchors placed either perpendicular (90°) or oblique (45°) to the primary compressive trabeculae. A tensile load was applied until failure of anchor fixation. Differences in failure load and stiffness between anchor fixation angles were determined by paired t-tests. Results. No significant differences were detected between perpendicular and oblique suture anchor insertion relative to primary compressive trabeculae in terms of load to failure or stiffness. Conclusion. This investigation suggests that the fixation strength of suture anchors inserted perpendicular to the primary compression trabeculae and at the Deadman’s angle are possibly comparable. Levels of Evidence: Biomechanical comparison study

scholarly journals Influence of peracetic acid-ethanol sterilisation on the biomechanical properties of human meniscus transplants

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Volker Eras ◽  
Josefine Graffunder ◽  
Norus Ahmed ◽  
Jan C. Brune
Keyword(s):  
Peracetic Acid ◽  
Biomechanical Properties ◽  
Bone Block ◽  
Test Device ◽  
Level Of Evidence ◽  
Load To Failure ◽  
Graft Extrusion ◽  
Fresh Frozen ◽  
Failure Loads ◽  
N Loading

Abstract Purpose Meniscus allograft transplantation (MAT) is a possible treatment for patients suffering with pain after meniscectomy. Here, peracetic acid (PAA) sterilised meniscus transplants were investigated on whether they would provide an adequate alternative to fresh-frozen transplants in their viscoelastic and mechanical properties. Methods In this analysis, 31 menisci donors (26 male and 5 female) were included. The average donor age was 49.87 years, ranging from 32 to 65 years. Menisci of matched pairs of knees underwent chemical sterilisation while counterparts were left fresh-frozen. Stiffness and load to failure were determined via suture retention. Further menisci were analysed while attached to the tibial bone block using a novel test device to mimic physiological load distribution. Meniscus relaxation, stiffness and failure loads were determined. Histology and biphasic properties of the menisci were examined and results were analysed using paired t-tests. Results A novel custom built test device allowed the application of physiological loads for suture retention testing and revealed no significant differences between PAA sterilised (14.85 ± 4.46 N/mm, 50.49 ± 17.01 N) and fresh-frozen (18.26 ± 4.46 N/mm, 59.49 ± 21.07 N) regarding stiffness and failure load, respectively. Furthermore, initial 200 N loading showed significantly higher strain in sterilised menisci (18.87 ± 1.56) compared to fresh frozen (13.81 ± 1.04). Load relaxation experiments demonstrated significantly lower relaxation for sterilised menisci (77.71 ± 1.62) compared to fresh-frozen (89.11 ± 1.00, p-value < 0.0001). Conclusion Peracetic acid sterilised human menisci performed equally to fresh-frozen counterparts in a suture retention test and in physiological failure testing providing an adequate alternative. However, meniscus relaxation, biphasic properties and strain were shown to be significantly different between the groups. A common problem of MAT is graft extrusion or shrinkage, therefore the parameters measured here should be considered and may influence meniscus extrusion after transplantation. Level of evidence n/a (experimental study)

scholarly journals Biomechanical stability of complex coronal plane fracture fixation of the capitellum

2021 ◽  
Author(s):  
Paul Borbas ◽  
Rafael Loucas ◽  
Marios Loucas ◽  
Maximilian Vetter ◽  
Simon Hofstede ◽  
...  
Keyword(s):  
Fracture Fixation ◽  
Ultimate Load ◽  
Locking Plate ◽  
Distal Humerus ◽  
Coronal Plane ◽  
Fixation Strength ◽  
Biomechanical Stability ◽  
Significant Difference ◽  
Load To Failure ◽  
Headless Compression Screws

Abstract Introduction Coronal plane fractures of the distal humerus are relatively rare and can be challenging to treat due to their complexity and intra-articular nature. There is no gold standard for surgical management of these complex fractures. The purpose of this study was to compare the biomechanical stability and strength of two different internal fixation techniques for complex coronal plane fractures of the capitellum with posterior comminution. Materials and methods Fourteen fresh frozen, age- and gender-matched cadaveric elbows were 3D-navigated osteotomized simulating a Dubberley type IIB fracture. Specimens were randomized into one of two treatment groups and stabilized with an anterior antiglide plate with additional anteroposterior cannulated headless compression screws (group antiGP + HCS) or a posterolateral distal humerus locking plate with lateral extension (group PLP). Cyclic testing was performed with 75 N over 2000 cycles and ultimately until construct failure. Data were analyzed for displacement, construct stiffness, and ultimate load to failure. Results There was no significant difference in displacement during 2000 cycles (p = 0.291), stiffness (310 vs. 347 N/mm; p = 0.612) or ultimate load to failure (649 ± 351 vs. 887 ± 187 N; p = 0.140) between the two groups. Conclusions Posterolateral distal humerus locking plate achieves equal biomechanical fixation strength as an anterior antiglide plate with additional anteroposterior cannulated headless compression screws for fracture fixation of complex coronal plane fractures of the capitellum. These results support the use of a posterolateral distal humerus locking plate considering the clinical advantages of less invasive surgery and extraarticular metalware. Level of evidence Biomechanical study.

Biomechanical Comparison of Four Methods of Fixation of a Polymeric Cranial Cruciate Ligament in the Canine Femur and Tibia

2019 ◽  
Vol 32 (02) ◽  
pp. 112-116
Author(s):  
Brian Bufkin ◽  
Alan Litsky ◽  
Matthew Barnhart
Keyword(s):  
Cruciate Ligament ◽  
Biomechanical Properties ◽  
Interference Screw ◽  
Fixation Strength ◽  
Artificial Ligament ◽  
Cranial Cruciate Ligament ◽  
Group 4 ◽  
Group 3 ◽  
Group 2 ◽  
Biomechanical Comparison

Objective The aim of this study was to compare the biomechanical properties of four different methods of artificial cranial cruciate ligament fixation in canine cadaveric tibias and femurs. Methods Femurs and tibias from skeletally mature large breed canine cadavers were assigned into four fixation groups: group 1, 4.5-mm interference screw (IS); group 2, 4.5-mm IS and 4.0-mm screw and spiked washer (SW); group 3, 5.0-mm IS; group 4, 5.0-mm IS + SW. Results The mean ultimate load was significantly greater for femur fixations than for tibias, when a SW was added, and for 5.0-mm IS compared with 4.5-mm sizes. There was also a significant interaction between SW and IS size. A SW significantly increased stiffness, a 5.0-mm IS in femurs provided more stiffness than 4.5-mm IS and was greater than 5.0-mm IS in tibias. In tibias, a 4.5-mm IS was stiffer than a 5.0-mm IS and a 4.5 IS + SW had greater stiffness than a 5.0-mm IS + SW. Groups 1 to 3 and tibias in group 4 failed by artificial ligament pullout. Nine femurs in group 4 failed by fracture, 5 by artificial ligament pullout, and 1 by artificial ligament tearing. Clinical Significance A 5.0-mm IS + SW provided superior artificial ligament fixation strength in femurs and tibias compared with a 4.5-mm IS without SW. Overall, artificial ligament fixation with 5.0-mm IS in femurs had the mechanical characteristics that most closely matched those reported in normal canine cranial cruciate ligaments.

Biomechanical Comparison of Fibrin Sealants for Mesh Fixation

2018 ◽  
Vol 84 (5) ◽  
pp. 633-636
Author(s):  
Charles P. Shahan ◽  
Nathaniel F. Stoikes ◽  
Esra Roan ◽  
Patrick Reese ◽  
David L. Webb ◽  
...  
Keyword(s):  
Mesh Fixation ◽  
Early Recurrence ◽  
Fixation Strength ◽  
Spray Application ◽  
Lap Shear ◽  
Application Techniques ◽  
Tissue Interface ◽  
Application Methods ◽  
Biomechanical Comparison ◽  
Early Fixation

Adhesive use for fixation in hernia repair allows for complete and immediate mesh surface area adherence. Little is known about the fixation strengths of the products and application methods available. The purpose of this study was to compare the immediate and early strength of fixation of Tisseel™ and Evicel™ using hand and spray application techniques. Sixteen Mongrel swine underwent implantation of large-pore, mid-weight polypropylene mesh fixated with either Tisseel™ or Evicel™, applied by hand or with a spray apparatus. Time points studied were zero and four days. All samples underwent lap shear testing to quantify the strength of the mesh–tissue interface as an indicator of mesh fixation strength. Thirty Day 4 and 16 Day 0 samples were tested. Manually applied Tisseel™ mean fixation strength was 2.05 N/cm at Day 0 and 6.02 N/cm at Day 4. Sprayed Tisseel™ had mean fixation strength of 1.22 N/cm at Day 0 and 7.21 N/cm at Day 4. Manually applied Evicel™ showed mean fixation strength of 0.92 N/cm at Day 0 and 6.73 N/cm at Day 4. Mean fixation strength of sprayed Evicel™ was 0.72 N/cm at Day 0 and 6.70 N/cm at Day 4. Analysis of variance showed no difference between groups at Day 0 or Day 4. Immediate strength of mesh fixation could have significant implications for early recurrence and mesh contraction. This study demonstrates that no difference exists in immediate or early fixation strength between these two brands of sealants or their method of application.

Recovery Profile, Costs, and Patient Satisfaction with Propofol and Sevoflurane for Fast-track Office-based Anesthesia 

1999 ◽  
Vol 91 (1) ◽  
pp. 253-261 ◽  
Author(s):  
Jun Tang ◽  
Lei Chen ◽  
Paul F. White ◽  
Mehernoor F. Watcha ◽  
Ronald H. Wender ◽  
...  
Keyword(s):  
Patient Satisfaction ◽  
Clinical Investigation ◽  
Postoperative Nausea And Vomiting ◽  
Ambulatory Setting ◽  
Anesthetic Technique ◽  
Clinical Effects ◽  
General Anesthetic ◽  
Early Recovery ◽  
Group I ◽  
Recovery Profile

Background Office-based surgery is becoming increasingly popular because of its cost-saving potential Both propofol and sevoflurane are commonly used in the ambulatory setting because of their favorable recovery profiles. This clinical investigation was designed to compare the clinical effects, recovery characteristics, and cost-effectiveness of propofol and sevoflurane when used alone or in combination for office-based anesthesia. Methods One hundred four outpatients undergoing superficial surgical procedures at an office-based surgical center were randomly assigned to one of three general anesthetic groups. In groups I and II, propofol 2 mg/kg was administered for induction followed by propofol 75-150 microg x kg(-1) x min(-1) (group I) or sevoflurane 1-2% (group II) with N2O 67% in oxygen for maintenance of anesthesia In group m, anesthesia was induced and maintained with sevoflurane in combination with N2O 67% in oxygen. Local anesthetics were injected at the incision site before skin incision and during the surgical procedure. The recovery profiles, costs of drugs, and resources used, as well as patient satisfaction, were compared among the three treatment groups. Results Although early recovery variables (e.g., eye opening, response to commands, and sitting up) were similar in all three groups, the times to standing up and to be "home ready" were significantly prolonged when sevoflurane-N2O was used for both induction and maintenance of anesthesia. The time to tolerating fluids, recovery room stay, and discharge times were significantly decreased when propofol was used for both induction and maintenance of anesthesia. Similarly, the incidence of postoperative nausea and vomiting and the need for rescue antiemetics were also significantly reduced after propofol anesthesia. Finally, the total costs and patient satisfaction were more favorable when propofol was used for induction and maintenance of office-based anesthesia Conclusion Compared with sevoflurane-N2O, use of propofol-N2O for office-based anesthesia was associated with an improved recovery profile, greater patient satisfaction, and lower costs. There were significantly more patients who were dissatisfied with the sevoflurane anesthetic technique.

Biomechanical Evaluation of Polylactide Absorbable Screws Used for Syndesmosis Injury Repair

1997 ◽  
Vol 18 (10) ◽  
pp. 622-627 ◽  
Author(s):  
David B. Thordarson ◽  
Thomas P. Hedman ◽  
Dominic Gross ◽  
George Magre
Keyword(s):  
Computed Tomography ◽  
Fatigue Testing ◽  
Clinical Situation ◽  
Stainless Steel Screw ◽  
Syndesmosis Injury ◽  
Computed Tomography Scans ◽  
Load To Failure ◽  
Fresh Frozen ◽  
Biomechanical Evaluation ◽  
And Control

Simulated syndesmosis injuries were created in 12 fresh-frozen, below-knee cadaver specimens. Six specimens were repaired with a 4.5 mm stainless steel screw, and six were repaired with a 4.5 mm polylactide screw. Three specimens of each group were tested in load to failure by axially loading with 1400 N and externally rotating to 90°. Three specimens in each group underwent fatigue testing by axially loading with 700 N and applying 2.5 N-m of torque for 57,700 cycles. Radiographs and computed tomography scans were evaluated. None of the screws broke or failed. Similar load to failure was noted in polylactide and control groups. Fatigue testing revealed no significant change in stiffness. No significant screw damage was evident on radiographic or computed tomography evaluation. The data suggest that a polylactide screw has sufficient fatigue and failure strength to allow for healing of this injury in a clinical situation.

scholarly journals Comparing Biomechanical Properties, Repair Times, and Value of Common Core Flexor Tendon Repairs

Hand ◽  
2017 ◽  
Vol 13 (3) ◽  
pp. 313-318 ◽  
Author(s):  
Aakash Chauhan ◽  
Patrick Schimoler ◽  
Mark C. Miller ◽  
Alexander Kharlamov ◽  
Gregory A. Merrell ◽  
...  
Keyword(s):  
Flexor Tendon ◽  
Maximum Load ◽  
Biomechanical Properties ◽  
Barbed Suture ◽  
Load To Failure ◽  
Fresh Frozen ◽  
Post Hoc ◽  
Biomechanical Strength ◽  
Determining Factor

Background: The aim of the study was to compare biomechanical strength, repair times, and repair values for zone II core flexor tendon repairs. Methods: A total of 75 fresh-frozen human cadaveric flexor tendons were harvested from the index through small finger and randomized into one of 5 repair groups: 4-stranded cross-stitch cruciate (4-0 polyester and 4-0 braided suture), 4-stranded double Pennington (2-0 knotless barbed suture), 4-stranded Pennington (4-0 double-stranded braided suture), and 6-stranded modified Lim-Tsai (4-0 looped braided suture). Repairs were measured in situ and their repair times were measured. Tendons were linearly loaded to failure and multiple biomechanical values were measured. The repair value was calculated based on operating room costs, repair times, and suture costs. Analysis of variance (ANOVA) and Tukey post hoc statistical analysis were used to compare repair data. Results: The braided cruciate was the strongest repair ( P > .05) but the slowest ( P > .05), and the 4-stranded Pennington using double-stranded suture was the fastest ( P > .05) to perform. The total repair value was the highest for braided cruciate ( P > .05) compared with all other repairs. Barbed suture did not outperform any repairs in any categories. Conclusions: The braided cruciate was the strongest of the tested flexor tendon repairs. The 2-mm gapping and maximum load to failure for this repair approached similar historical strength of other 6- and 8-stranded repairs. In this study, suture cost was negligible in the overall repair cost and should be not a determining factor in choosing a repair.

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