The Effect of Locking Loops on the Strength of Tendon Repair

A multiple X-raying method has been developed which allows examination of how the particular features of suturing techniques collapse or pull out of the tendon during tensile testing. This technique was used to examine the locking loop tendon sutures, such as the modified Kessler, Verdan and Ketchum techniques. Locking loops did not contribute towards the strength when small diameter sutures (5/0) of various materials were applied to the tendon, collapsing at 12 Newtons. Larger diameter sutures (4/0) slightly reduced the risk of failure of locking loops, but they still collapsed at 15 Newtons or less, so suture techniques which depend on locking loops will often lead to gap formation at low loads and hence poor results.

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The Mechanical Properties of Locking and Grasping Suture Loop Configurations in Four-Strand Core Suture Techniques

Journal of Hand Surgery (European Volume) ◽

10.1054/jhsb.2000.0441 ◽

2000 ◽

Vol 25 (6) ◽

pp. 548-551 ◽

Cited By ~ 33

Author(s):

A. WADA ◽

H. KUBOTA ◽

H. HATANAKA ◽

S. HOTOKEZAKA ◽

H. MIURA ◽

...

Keyword(s):

Mechanical Properties ◽

Tensile Testing ◽

Testing Machine ◽

Tendon Repair ◽

Suture Techniques ◽

Flexor Digitorum Profundus ◽

Tensile Testing Machine ◽

Pull Out ◽

Mode Of Failure ◽

Flexor Digitorum

We have compared the effect of locking and grasping suture loop configurations in four-strand core suture techniques for tendon repair. Forty canine flexor digitorum profundus tendons were repaired with one of four suture techniques (the grasping cruciate, the double-modified grasping Kessler, the locking cruciate and the double-modified locking Kessler) and tested to failure in a tensile testing machine. The mode of failure in all the locking suture specimens was breakage of the sutures in the locking loops or at suture knots. The sutures did not pull out of the tendon, as was seen in the grasping suture specimens. The greatest tensile strength was found with the double-modified locking Kessler technique which incorporated eight rectangular locking loop configurations.

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Dorsal-Enhanced Sutures Improve Tension Resistance of Tendon Repair

Journal of Hand Surgery (European Volume) ◽

10.1054/jhsb.2001.0687 ◽

2002 ◽

Vol 27 (2) ◽

pp. 161-164 ◽

Cited By ~ 23

Author(s):

Y. CAO ◽

R. G. XIE ◽

J. B. TANG

Keyword(s):

Ultimate Strength ◽

Tensile Testing ◽

Testing Machine ◽

Tendon Repair ◽

The Other ◽

Dorsal Part ◽

Gap Formation ◽

Tensile Testing Machine ◽

Finger Flexion ◽

Main Components

Thirty-six fresh pig flexor tendons were repaired using either the modified Kessler method or the Tang method. Nine tendons from each group were tested in an Instron tensile testing machine with the tendons passing 90° around a pulley. The other nine tendons from each group were pulled linearly by the testing machine. The 2mm gap formation force of the tendons repaired with the modified Kessler and Tang methods and pulled at 90° were 64%±5% and 79%±9% respectively of those forces recorded during linear testing. The ultimate strengths of tendons repaired by the modified Kessler and Tang methods and pulled at 90° were 76%±6% and 81%±8% respectively of the forces measured during linear testing. The percentage gap formation and ultimate strength of the Tang method was significantly higher than that of the modified Kessler suture when the tendons were pulled around a pulley. This demonstrates that the Tang suture, with its main components in the dorsal part of the repaired tendon, has greater tension resistance capacity than conventional tendon sutures which are placed in the middle of the tendon. This study suggests that dorsally-enhanced multiple tendon sutures are better placed to sustain the tension generated during active finger flexion.

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The Transosseous Internal Four Strand Technique: A New All-Inside Technique for Zone 1 Flexor Tendon Repairs

Hand ◽

10.1177/15589447211060430 ◽

2021 ◽

pp. 155894472110604

Author(s):

Patrick S. Harenberg ◽

Jörg G. Grünert ◽

Samuel M. Christen

Keyword(s):

Flexor Tendon ◽

Tendon Repair ◽

Suture Technique ◽

Suture Techniques ◽

Suture Repair ◽

Active Motion ◽

Pull Out ◽

Group 2 ◽

Pull Out Suture ◽

Group 1

Background: Multiple techniques for the repair of flexor tendon injuries in zone 1 have been proposed over time. While pull-out suture techniques and bone anchor seem to be stronger than internal suture techniques, they are associated with a higher complication rate. We therefore developed an alternative internal suture repair with similar biomechanical stability to those of pull-out sutures and bone anchors. Methods: Twenty porcine distal phalanges and deep flexor tendons were randomized to 2 groups of 10 each. The tendons were transsected at the level of the distal interphalangeal joint. In group 1, repairs were performed with a well-established intraosseous suture repair and in group 2 with our new multistrand technique. The repairs were biomechanically tested with linear distraction until failure. Results: We recorded a significantly higher 2-mm gap force (2GF)—and thus higher stability—of the repairs in group 1 in comparison to group 2. With a 2GF of more than 50 N, our suture technique allows for a modern early active motion rehabilitation protocol. Breakage of the suture construct occurred at random places in the repair in both groups. No pull-outs were noted. Conclusions: This study presents a strong transosseous multistrand repair technique for flexor tendon repair in zone 1 that is simple and fast to perform and should have enough strength to withstand early active motion rehabilitation.

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The biomechanical assessment of gap formation after flexor tendon repair using partial interlocking cross-stitch peripheral sutures

Journal of Hand Surgery (European Volume) ◽

10.1177/1753193411406632 ◽

2011 ◽

Vol 36 (7) ◽

pp. 584-589 ◽

Cited By ~ 10

Author(s):

N. Takeuchi ◽

H. Mitsuyasu ◽

K. Kikuchi ◽

T. Shimoto ◽

H. Higaki ◽

...

Keyword(s):

Fatigue Strength ◽

Cyclic Load ◽

Flexor Tendon ◽

Tendon Repair ◽

Suture Techniques ◽

Load Testing ◽

Gap Formation ◽

Flexor Tendon Repair ◽

Biomechanical Assessment ◽

Dental Roll

The gap formation of five core plus peripheral suture techniques for flexor tendon repair was evaluated by cyclic load testing. Fifty pairs of dental roll tendon models were sutured using six-strand Pennington modified Kessler core suture with 4-0 Polypropylene. One-half or three-fourths circumferential interlocking cross-stitch, or three complete circumferential peripheral suture techniques were performed using 6-0 Polypropylene. An initial cyclic load of 10 N for 500 cycles was applied and increased by 5 N for an additional 500 cycles at each new load until rupture. The complete circumferential interlocking cross-stitch had the greatest fatigue strength. The partial circumferential cross-stitches resulted in significantly larger gap formations at both the repaired and unrepaired sides than the complete circumferential sutures, and were also associated with early rupture. The full circumference of the cut tendon must be sutured using an interlocking cross-stitch peripheral suture to improve strength and avoid gap formation.

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BIOMECHANICAL PROPERTIES OF EXTENSOR TENDON REPAIR USING THE SIX-STRAND SINGLE-LOOP SUTURE TECHNIQUE: A COMPARATIVE ANALYSIS WITH THREE OTHER TECHNIQUES IN CADAVERIC MODELS

Journal of Mechanics in Medicine and Biology ◽

10.1142/s0219519411004113 ◽

2011 ◽

Vol 11 (04) ◽

pp. 845-855 ◽

Cited By ~ 3

Author(s):

BENG HAI LIM ◽

LAI HOCK OOI ◽

SIAW MENG CHOU ◽

KHENG LIM GOH

Keyword(s):

Tendon Repair ◽

Extensor Tendon ◽

Biomechanical Properties ◽

Suture Technique ◽

Maximum Force ◽

Gap Formation ◽

Single Loop ◽

Extensor Tendons ◽

Pull Out ◽

Gap Opening

A six-strand single-loop technique has been implemented for repairing extensor tendons. This paper describes an investigation to compare the biomechanical properties of extensor tendons repaired using this technique with three other commonly used techniques, namely the Kessler-Tajima (two-stand) technique, the Tsuge (two-strand) technique, and the modified (four-strand and double-loop) Tsuge technique. Epitendinous stitches were implemented on all techniques. From human cadaveric hands, extensor tendons were harvested, transected, and repaired using these techniques. Tensile test was performed on the repaired tendons to determine the force at the first gap opening, 1-mm and 2-mm gap distances and at the maximum load. We have observed that at the first gap opening, the forces generated in the tendons repaired using the six-strand, Kessler-Tajima, and modified Tsuge techniques are significantly larger than the Tsuge technique. Thereafter, the force generated at gap distances of 1 mm, 2 mm, and the maximum force depend on the number of strands and the epitendinous stitches. In this case, the maximum force (31.80 N ± 4.73 N) from the six-strand technique is significantly higher than that from the Kessler-Tajima technique. In particular, all samples from the six-strand technique failed by suture pull-out. In contrast, suture pull-out is less common for the other techniques; these samples also exhibited suture rupture. This study is important because it reveals that cadaveric tendons repaired using the Kessler-Tajima, modified Tsuge, and six-strand techniques can accommodate higher initial forces (compared to the Tsuge technique) and, thus, are more effective for resisting gap formation. Among these techniques, it is shown that the six-strand configuration is reliable because the strands, rather than breaking, results in pull-out at sufficiently high loads. Thus, the six-strand approach for anchoring the ruptured tissue results in the transfer of large forces to the suture. It is suggested that the six-strand technique may be a viable technique since it requires only a single-loop suture and this may simplify the repair procedure and tendon handling without increasing the bulk of the repaired tendon appreciably.

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