Biomechanical Testing of Epitenon Suture Strength in Achilles Tendon Repairs

2007 ◽  
Vol 28 (10) ◽  
pp. 1074-1077 ◽  
Author(s):  
Michelle E. Shepard ◽  
Derek P. Lindsey ◽  
Loretta B. Chou
Keyword(s):  
Achilles Tendon ◽  
Adhesion Formation ◽  
Testing Machine ◽  
Biomechanical Testing ◽  
Gap Formation ◽  
Load To Failure ◽  
Fresh Frozen ◽  
Tendon Ruptures ◽  
Active Mobilization ◽  
Eden Prairie

Background: Recent evidence that early, active mobilization protocols after Achilles tendon repairs increase recovery speed and strength make operative repair strength critical to positive outcomes after Achilles tendon ruptures. While previous research has focused on core (tendon proper) repair techniques, no previous literature has reported testing of core repairs augmented with epitenon sutures, which have been shown to increase the strength of repairs of flexor tendons of the hand. Methods: Five matched pairs of fresh frozen human Achilles tendons were tested with and without the addition of an epitenon suture to the core repair suture. All specimens were repaired using a No. 2 Ethibond Krakow locking loop core suture. The epitenon suture was added to one tendon randomly chosen from each pair, using a 40 nylon suture. All specimens were mounted on an MTS testing machine (MTS Systems Corp., Eden Prairie, MN) and loaded to failure, which was defined as a 1-cm gap formation. Results: The addition of epitenon sutures significantly increased the force necessary to produce a 2-mm gap as compared to core sutures alone by 74%, and it increased the average load to failure by 119%. Also, initial tendon stiffness was 173% greater in tendons reinforced with epitenon sutures. Conclusions: This study demonstrates that greater resistance to gap formation, approximation of tissue ends, and tensile strength were achieved by the addition of an epitenon suture. Clinical relevance may improve healing by decreased gap formation at the repair site and a lower risk of adhesion formation.

scholarly journals Biomechanical Head-to-Head Comparison of 2 Sutures and the Giftbox Versus Bunnell Techniques for Midsubstance Achilles Tendon Ruptures

2017 ◽  
Vol 5 (5) ◽  
pp. 232596711770747 ◽  
Author(s):  
Rufus O. Van Dyke ◽  
Sejul A. Chaudhary ◽  
Gregory Gould ◽  
Roman Trimba ◽  
Richard T. Laughlin
Keyword(s):  
Cyclic Loading ◽  
Achilles Tendon ◽  
Biomechanical Testing ◽  
Gap Formation ◽  
Postoperative Rehabilitation ◽  
Repair Technique ◽  
Significant Difference ◽  
Load To Failure ◽  
Tendon Ruptures ◽  
To Receive

Background: Acute midsubstance Achilles tendon ruptures are a common orthopaedic problem for which the optimal repair technique and suture type remain controversial. Head-to-head comparisons of current fixation constructs are needed to establish which stitch/suture combination is most biomechanically favorable. Hypothesis: Of the tested fixation constructs, Giftbox repairs with Fiberwire will exhibit superior stiffness and strength during biomechanical testing. Study Design: Controlled laboratory study. Methods: Two biomechanical trials were performed, isolating stitch technique and suture type, respectively. In trial 1, 12 transected fresh-frozen cadaveric Achilles tendon pairs were randomized to receive either the Giftbox-modified Krackow or the Bunnell stitch with No. 2 Fiberwire suture. Each repair underwent cyclic loading, oscillating between 10 and 100 N at 2 Hz for 1000 cycles, with repair gapping measured at 500 and 1000 cycles. Load-to-failure testing was then performed, and clinical and catastrophic failure values were recorded. In trial 2, 10 additional paired cadaveric Achilles tendons were randomized to receive a Giftbox repair with either No. 2 Fiberwire or No. 2 Ultrabraid. Testing and data collections protocols in trial 2 replicated those used in trial 1. Results: In trial 1, the Bunnell group had 2 failures during cyclic loading while the Giftbox had no failures. The mean tendon gapping after cyclic loading was significantly lower in the Giftbox repairs (0.13 vs 2.29 mm, P = .02). Giftbox repairs were significantly stiffer than Bunnell (47.5 vs 38.7 N/mm, P = .019) and showed more tendon elongation (5.9 ± 0.8 vs 4.5 ± 1.0 mm, P = .012) after 1000 cycles. Mean clinical load to failure was significantly higher for Giftbox repairs (373 vs 285 N, P = .02), while no significant difference in catastrophic load to failure was observed (mean, 379 vs 336 N; P = .61). In trial 2, there were no failures during cyclic loading. The Giftbox + Fiberwire repairs recorded higher clinical load-to-failure values compared with Giftbox + Ultrabraid (mean, 361 vs 239 N; P = .005). No other biomechanical differences were observed in trial 2. Conclusion: Simulated early rehabilitation biomechanical testing showed that Giftbox-modified Krackow Achilles repair technique with Fiberwire suture was stronger and more resistant to gap formation at the repair site than combinations that incorporated the Bunnell stitch or Ultrabraid suture. Clinical Relevance: A more in-depth understanding of the biomechanical properties of the Giftbox repair will help inform surgical decision making because stronger repairs are less likely to fail during accelerated postoperative rehabilitation.

scholarly journals A Biomechanical Comparison of a Limited Open and Standard Open Technique for Achilles Tendon Rupture Repair

2017 ◽  
Vol 2 (3) ◽  
pp. 2473011417S0001
Author(s):  
Robert Dekker ◽  
Charles Qin ◽  
Cort Lawton ◽  
Muturi Muriuki ◽  
Robert Havey ◽  
...  
Keyword(s):  
Soft Tissue ◽  
Achilles Tendon ◽  
Open Repair ◽  
Achilles Tendon Rupture ◽  
Testing Machine ◽  
Tendon Repair ◽  
Lower Limbs ◽  
Gap Formation ◽  
Load To Failure ◽  
Biomechanical Comparison

Category: Basic Sciences/Biologics, Sports Introduction/Purpose: The drive to reduce soft tissue complications after Achilles tendon repair has led to increased interest in less invasive techniques. The PARS Achilles Jig System is one option that has gained popularity as an alternative to open repair. For many surgeons, standard open repair consists of a Krackow locking-loop technique. We compared the load to failure of a limited open and open Krackow technique for repair of Achilles tendon ruptures. Methods: Nine pairs of human cadaver lower limbs were randomized to undergo either a Krackow locking loop repair with epitendinous weave or a PARS Achilles Jig System Repair. Specimen were loaded to failure on a servo-hydraulic material testing machine. From load- displacement curves, initial linear stiffness, load to failure, and work to failure were calculated. Results: The average load to failure for Krackow repair (353.8 ± 88.8 N) and PARS repair (313.3 ± 99.9 N) was not statistically different (p = .38). The average work to failure for open repair (6.4 ± 2.3 J) and PARS repair (6.3 ± 3.5 J) was also not statistically different (p = .904). Mean initial linear stiffness of the Krackow repair (17.8 ± 5.4 N/mm) was significantly greater than the PARS repair (11.8 ± 2.5 N/mm) (p = .011). The predominant location of failure for Krackow repair was at the suture itself. In contrast, the PARS repair predominantly failed at the suture-tendon interface. Conclusion: The results suggest no difference between the Krackow and PARS repairs in terms of ultimate strength or work to failure. The Krackow repair demonstrated a higher initial linear stiffness than the PARS, which may imply a greater ability to withstand gap formation. With less devitalization to surrounding soft tissue and equal repair strength, the PARS system should be considered a favourable option for repair of ruptured Achilles tendons.

Strength of side-to-side and step-cut repairs in tendon transfers: biomechanical testing of porcine flexor tendons

2020 ◽  
Vol 45 (10) ◽  
pp. 1061-1065
Author(s):  
Eivind Strandenes ◽  
Peter Ellison ◽  
Anders O. Mølster ◽  
Nils R. Gjerdet ◽  
Irene O. Moldestad ◽  
...  
Keyword(s):  
Tensile Properties ◽  
Testing Machine ◽  
Biomechanical Testing ◽  
Maximum Load ◽  
Side Group ◽  
Tendon Transfers ◽  
Flexor Tendons ◽  
Active Mobilization ◽  
The Difference

The aim of the study was to compare side-to-side with step-cut repairs to determine how much of the width it is possible to remove and still keep the repair strong enough to start active mobilization. Porcine flexor tendons were used to create side-to-side, one-third step-cut and half step-cut repairs. There were 15 repairs in each group. The tensile properties of the constructs were measured in a biomechanical testing machine. All repairs failed by the sutures splitting the tendon longitudinally. The maximum load and stiffness were highest in the side-to-side group. Our findings suggest that the half step-cut repair can withstand the forces exerted during active unrestricted movement of the digits in tendons of this size. The advantage of the step-cut repair is reduced bulkiness and less friction, which might compensate for the difference in strength.

scholarly journals A Biomechanical Comparison of Limited Open Versus Krackow Repair for Achilles Tendon Rupture

2017 ◽  
Vol 2 (4) ◽  
pp. 247301141771543 ◽  
Author(s):  
Robert G. Dekker ◽  
Charles Qin ◽  
Cort Lawton ◽  
Muturi G. Muriuki ◽  
Robert M. Havey ◽  
...  
Keyword(s):  
Soft Tissue ◽  
Achilles Tendon ◽  
Tendon Rupture ◽  
Achilles Tendon Rupture ◽  
Tendon Repair ◽  
Lower Limbs ◽  
Gap Formation ◽  
Postoperative Rehabilitation ◽  
Significant Difference ◽  
Load To Failure

Background: Soft tissue complications after Achilles tendon repair has led to increased interest in less invasive techniques. Various limited open techniques have gained popularity as an alternative to open operative repair. The purpose of this study was to biomechanically compare an open Krackow and limited open repair for Achilles tendon rupture. We hypothesized that there would be no statistical difference in load to failure, work to failure, and initial linear stiffness. Methods: A simulated Achilles tendon rupture was created 4 cm proximal to its insertion in 18 fresh-frozen cadaveric below-knee lower limbs. Specimens were randomized to open or limited open PARS Achilles Jig System repair. Repairs were loaded to failure at a rate of 25.4 mm/s to reflect loading during normal ankle range of motion. Load to failure, work to failure, and initial linear stiffness were compared between the 2 repair types. Results: The average load to failure (353.8 ± 88.8 N vs 313.3 ± 99.9 N; P = .38) and work to failure (6.4 ± 2.3 J vs 6.3 ± 3.5 J; P = .904) were not statistically different for Krackow and PARS repair, respectively. Mean initial linear stiffness of the Krackow repair (17.8 ± 5.4 N/mm) was significantly greater than PARS repair (11.8 ± 2.5 N/mm) ( P = .011). Conclusion: No significant difference in repair strength was seen, but higher initial linear stiffness for Krackow repair suggests superior resistance to gap formation, which may occur during postoperative rehabilitation. With equal repair strength, but less soft tissue devitalization, the PARS may be a favorable option for patients with risk factors for soft tissue complications.

Biomechanical Evaluation of a Four-Strand Modification of the Tang Method of Tendon Repair

2005 ◽  
Vol 30 (4) ◽  
pp. 374-378 ◽  
Author(s):  
Y. CAO ◽  
J. B. TANG
Keyword(s):  
Ultimate Strength ◽  
Testing Machine ◽  
Tendon Repair ◽  
Gap Formation ◽  
Single Cycle ◽  
Tensile Testing Machine ◽  
Load To Failure ◽  
Biomechanical Evaluation ◽  
Finger Motion ◽  
Initial Force

We report a four-strand modification of the Tang technique of tendon repair that uses fewer sutures and fewer knots on the tendon surface. This repair consists of four longitudinal and two horizontal strands that form a “U” configuration within the tendon made with a single looped suture. Thirty-four fresh pig flexor tendons were divided into 3 groups and repaired with the four-strand modified Tang method, a double-looped four-strand method or a double Kessler repair (four-strand). The tendons were subjected to a single cycle of load-to-failure test in a tensile testing machine. The initial force, 2-mm gap formation force and ultimate strength of the four-strand modified Tang repair were statistically identical to those of the double looped suture and were superior to those of the double Kessler repair. Ultimate strength was 43.4 ± 4.3 N for the four-strand modified Tang method, 45.2 ± 4.0 N for the double-looped method and 39.1 ± 4.0 N for the double Kessler repair. The four-strand modification of the Tang method appears to have strength sufficient for protected active finger motion. Given our preliminary clinical experience with this method, we recommend this new and simplified technique for clinical flexor tendon repairs.

Flexor tendon pulley V–Y Plasty: an Alternative to Pulley Venting or Resection

2006 ◽  
Vol 31 (2) ◽  
pp. 133-137 ◽  
Author(s):  
E. DONA ◽  
W. R. WALSH
Keyword(s):  
Flexor Tendon ◽  
Testing Machine ◽  
Tendon Repair ◽  
Partial Resection ◽  
Attractive Alternative ◽  
Custom Made ◽  
Load To Failure ◽  
A2 Pulley ◽  
Active Mobilization

Zone 2 flexor tendon repairs can require “venting” or partial resection of the A2 and/or A4 pulleys. We propose and biomechanically assess a technique used by the authors in which the A2 and A4 pulleys are divided and repaired using a V–Y plasty. Two groups of cadaveric fingers were used, one group for assessing the A2 pulley and the second for assessing the A4 pulley. Prepared fingers were mounted onto custom-made jigs, tested using a servohydraulic testing machine and assessed for load to failure. The loads obtained were 75N (SD = 26N) and 234N (SD = 73N) for the A4 and A2 pulleys, respectively. These loads are well in excess of those one would anticipate during a postoperative active mobilization protocol. Tendon pulley V–Y plasty creates a mechanically sound pulley and maintains sufficient cover of the underlying tendon. This technique provides access to perform a tendon repair and/or permits free tendon gliding post-repair, thus providing an attractive alternative to simply “venting”, or resecting, an otherwise troublesome pulley.

Comparison of Postoperative Early Active Mobilization and Immobilization in Vivo Utilising a Four-Strand Flexor Tendon Repair

2001 ◽  
Vol 26 (4) ◽  
pp. 301-306 ◽  
Author(s):  
A. WADA ◽  
H. KUBOTA ◽  
K. MIYANISHI ◽  
H. HATANAKA ◽  
H. MIURA ◽  
...  
Keyword(s):  
Ultimate Strength ◽  
Flexor Tendon ◽  
Testing Machine ◽  
Tendon Repair ◽  
Flexor Digitorum Profundus ◽  
Gap Formation ◽  
Flexor Tendon Repair ◽  
Tensile Testing Machine ◽  
Active Mobilization

We evaluated a technique of four-strand double-modified locking Kessler flexor tendon repair in healing tendons. Seventy-two canine flexor digitorum profundus tendons in Zone 2 were repaired and evaluated following either active mobilization or immobilization at 0, 7, 14, 28 and 42 days after surgery. Fifty-six tendons were examined for gap and ultimate strength using a tensile testing machine and 16 were evaluated with standard hematoxylin and eosin, and Masson’s trichrome staining. All tendons healed without rupture or gap formation of more than 1 mm, thus demonstrating that this repair technique has enough tensile strength to withstand early active mobilization. The gap and ultimate strength of actively mobilized tendons did not decrease significantly during the first 7 days, and were significantly greater than those of immobilized tendons throughout the 42-day study period. Actively mobilized tendons healed without the extrinsic adhesions and large tendon calluses that were found in immobilized tendons.

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

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

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

scholarly journals The Loop ’n’ Tack Knot: Biomechanical Analysis of a Novel Suture Technique for Proximal Biceps Tenodesis

2020 ◽  
Vol 8 (9) ◽  
pp. 232596712095231
Author(s):  
Jonathan Acosta ◽  
John M. Rinaldi ◽  
J. Jared Guth ◽  
Sam Akhavan
Keyword(s):  
Biomechanical Testing ◽  
High Strength ◽  
Poor Quality ◽  
Suture Technique ◽  
Biomechanical Analysis ◽  
Suture Techniques ◽  
Longitudinal Splitting ◽  
Mode Of Failure ◽  
Load To Failure ◽  
Fresh Frozen

Background: Secure tendon grasping is critical to the success of any tenodesis procedure. Several techniques currently used for tendon grasping can result in longitudinal splitting of the tendon, causing construct failure and failure of the tenodesis. Purpose: To compare the Loop ’n’ Tack knot as a tendon-grasping technique with other common suture techniques. We investigated the biomechanical strength and mode of failure. Study Design: Controlled laboratory study. Methods: Eleven matched pairs of proximal biceps were harvested from fresh-frozen cadaveric shoulders. One tendon from each pair was stitched using 1 of 4 different techniques. The suture techniques evaluated included the Loop ’n’ Tack with 2 different types of high-strength nonabsorbable suture, a double half-racking stitch, and a Krakow stitch. Samples were cyclically loaded between 5 and 20 N for 100 cycles, followed by a pull to failure at 33 mm/s. Results: The Loop ’n’ Tack techniques were equivalent to the double half-racking and Krakow techniques for load to ultimate failure ( P = .817 and P = .984, respectively). The double half-racking technique was the stiffest construct, which was significantly greater than the second-stiffest group, the Loop ’n’ Tack method with both FiberLink suture ( P = .012) and SutureTape ( P = .002), which had greater stiffness than the Krakow group ( P < .001). The most common failure mode for the Loop ’n’ Tack stitch was suture breakage compared with the Krakow and double half-racking methods, where the most common mode of failure was suture pullout from the tendon ( P < .001). Conclusion: Biomechanical testing found that the Loop 'n’ Tack techniques had similar ultimate load to failure values when compared with the double half-racking and Krakow methods. Mode-of-failure analysis showed that the Loop 'n’ Tack construct typically failed by suture breakage, whereas the other techniques failed by suture pullout. Clinical Relevance: The Loop 'n’ Tack technique allows for secure grasping of tissue without the need for externalization of the tendon. This technique may be beneficial in compromised or poor-quality tissue without reducing overall pullout strength when compared with a standard half-racking or Krakow stitch.

scholarly journals Comparison of the double loop knot stitch and Kessler stitch for Achilles tendon repair: A biomechanical cadaver study

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0243306
Author(s):  
Stephan Frosch ◽  
Gottfried Buchhorn ◽  
Thelonius Hawellek ◽  
Tim Alexander Walde ◽  
Wolfgang Lehmann ◽  
...  
Keyword(s):  
Cyclic Loading ◽  
Achilles Tendon ◽  
Ultimate Load ◽  
Testing Machine ◽  
Tendon Repair ◽  
Early Mobilization ◽  
Cadaver Study ◽  
Double Loop ◽  
Load Testing ◽  
Gap Formation

Tendon elongation after Achilles tendon (AT) repair is associated with the clinical outcome. Reliable suture techniques are essential to reduce gap formations and to allow early mobilization. Cyclic loading conditions represent the repetitive loading in rehabilitation. The aim of this study was to compare the Kessler stitch and double loop knot stitch (DLKS) in a cyclic loading program focussing on gap formation. Sixteen human cadaveric ATs were transected and sutured using either the Kessler stitch or DLKS (eight matched pairs). The suture-tendon configurations were subjected to cyclic loading and additional ultimate load to failure testing using the Zwick 1446 universal testing machine. Each AT survived cyclic loading, with a mean gap formation less than 5 mm after 1000 cycles. The mechanical properties of the Kessler stitch and DLKS were not significantly different after cyclic loading with a mean displacement of 4.57 mm (± 1.16) for the Kessler stitch and 4.85 mm (± 1.14) for the DLKS (P = .76). There were no significant differences in the ultimate load testing (P = .85). Both bioprotective techniques prevent excessive gaping in cyclic testing when tendon loading is moderate. Our data and those from literature of gap formation in cyclic and ultimate loading allow the conclusion, that early aggressive AT loading after repair (e.g. full weightbearing) overstrain simple as well as complex suture configurations. Initial intraoperative tightening of the knots (preloading) before locking is important to decrease postoperative elongation.

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