Letter Regarding “Effects of Tension Across the Tendon Repair Site on Tendon Gap and Ultimate Strength”

We report sonographic findings with clinical outcomes after zone 2 flexor digitorum profundus tendon repairs in ten fingers. The tendons underwent a six-strand M-Tang core repair, no circumferential suture, and partial or complete division of the pulleys. Over 12 months after surgery and using ultrasound, we found no gapping at the repair site during finger motion. When the pulleys were divided, there was sonographic evidence of tendon bowstringing, but the bowstringing was minimal. Clinically, we did not find any fingers that displayed tendon bowstringing or had functional loss. With ultrasound examination, the repaired tendons remained enlarged over 12 months. Two patients developed heterotopic ossifications at the repair site without tendon gliding, and these required tenolysis. We conclude that the tendon repair site does not gap when a strong core suture is used in the repair without adding peripheral sutures. There is no notable tendon bowstringing clinically, though the repaired tendons have sonographic evidence of minor bowstringing. Level of evidence: III

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

Journal of Hand Surgery (European Volume) ◽

10.1016/j.jhsb.2005.04.003 ◽

2005 ◽

Vol 30 (4) ◽

pp. 374-378 ◽

Cited By ~ 52

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.

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Defining the activation profile and fate trajectory of adult Scleraxis-lineage cells during tendon healing by combining lineage tracing and spatial transcriptomics

10.1101/2021.06.02.446663 ◽

2021 ◽

Author(s):

Jessica E Ackerman ◽

Katherine T Best ◽

Samantha N Muscat ◽

Chia-Lung Wu ◽

Alayna E Loiselle

Keyword(s):

Time Course ◽

Molecular Mechanisms ◽

Healing Process ◽

Tendon Repair ◽

Tendon Healing ◽

Cell Types ◽

Healing Time ◽

Lineage Tracing ◽

Repair Site ◽

Temporal And Spatial

The tendon healing process is regulated by the coordinated interaction of multiple cell types and molecular processes. However, these processes are not well-defined leading to a paucity of therapeutic approaches to enhance tendon healing. Scleraxis-lineage (ScxLin) cells are the major cellular component of adult tendon and make time-dependent contributions to the healing process. Prior work from our lab and others suggests heterogeneity within the broader ScxLin population over the course of tendon healing; therefore delineating the temporal and spatial contributions of these cells is critical to understanding and improving the healing process. In the present study we utilize lineage tracing of the adult ScxLin population to determine whether these cells undergo cellular activation and subsequent myofibroblast differentiation, which is associated with both proper healing and fibrotic progression in many tissues. We show that adult ScxLin cells undergo transient activation in the organized cellular bridge at the tendon repair site, contribute to the formation of an organized neo-tendon, and contribute to a persistent myofibroblast population in the native tendon stubs. The mechanisms dictating this highly specialized spatial response are unknown. We therefore utilized spatial transcriptomics to better define the spatio-molecular program of tendon healing. Integrated transcriptomic analyses across the healing time-course identifies five distinct molecular regions, including key interactions between the inflammatory bridging tissue and highly reactive tendon tissue at the repair site, with adult ScxLin cells being a central player in the transition from native tendon to reactive, remodeling tendon. Collectively, these data provide important insights into both the role of adult ScxLin cells during healing as well as the molecular mechanisms that underpin and coordinate the temporal and spatial healing phenotype, which can be leveraged to enhance the healing process.

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Asymmetric six-strand core sutures enhance tendon fatigue strength and the optimal asymmetry

Journal of Hand Surgery (European Volume) ◽

10.1177/1753193416631454 ◽

2016 ◽

Vol 41 (8) ◽

pp. 802-808 ◽

Cited By ~ 14

Author(s):

N. Kozono ◽

T. Okada ◽

N. Takeuchi ◽

M. Hanada ◽

T. Shimoto ◽

...

Keyword(s):

Fatigue Strength ◽

Cyclic Loading ◽

Tendon Repair ◽

Longitudinal Axis ◽

Suture Repair ◽

Repair Site ◽

Beneficial Effects ◽

The Core

Under cyclic loading, we recorded the fatigue strength of a six-strand tendon repair with different symmetry in the lengths of suture purchase in two stumps of 120 dental rolls and in 30 porcine tendons. First, the strengths of the repairs with 1, 2, 3, 4 and 5 mm asymmetry were screened using the dental rolls. The asymmetric core suture repairs were then made with a Kessler repair of equal suture purchase (10 mm) in two tendon stumps, and shifting two other Kessler repairs by 1, 3 or 5 mm, respectively, along the longitudinal axis of the tendon in relation to the first (symmetric) Kessler repair. The core repairs with 3 mm or more asymmetry in suture purchases in two tendon ends showed significantly greater fatigue strength and significantly smaller gaps compared with 1 mm asymmetry in core suture repair. Our results support that asymmetric placement of core sutures in two tendon ends favour resisting gapping at the repair site and 3 mm or more asymmetry is needed to produce such beneficial effects.

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Comparison of Tendon Lengthening With Traditional Versus Accelerated Rehabilitation After Achilles Tendon Repair: A Prospective Randomized Controlled Trial

The American Journal of Sports Medicine ◽

10.1177/0363546520909389 ◽

2020 ◽

Vol 48 (7) ◽

pp. 1720-1726 ◽

Cited By ~ 3

Author(s):

Kelechi R. Okoroha ◽

Najib Ussef ◽

Toufic R. Jildeh ◽

Lafi S. Khalil ◽

Laith Hasan ◽

...

Keyword(s):

Randomized Controlled Trial ◽

Achilles Tendon ◽

Controlled Trial ◽

Tendon Repair ◽

Repair Site ◽

Randomized Controlled ◽

Achilles Tendon Repair ◽

Tendon Lengthening ◽

Accelerated Rehabilitation ◽

Tendon Ruptures

Background: Early weightbearing protocols after Achilles tendon repair promote mobilization, yet little is known about their effect on tendon lengthening. Purpose: To evaluate tendon lengthening after Achilles tendon repair with accelerated rehabilitation. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: Patients undergoing primary repair for acute Achilles tendon ruptures consented to have tantalum beads placed within the tendon. Patients were randomized into either a traditional (weightbearing at 6 weeks) or accelerated (graduated weightbearing at 2 weeks) rehabilitation group. The primary outcome of the study was postoperative tendon elongation as measured by radiostereometric beads. Secondary outcomes included Achilles Tendon Total Rupture Score (ATRS) and Patient-Reported Outcomes Measurement Information System Pain Interference Short Form (PROMIS PI-SF) score. Results: All 18 patients included in the final analysis were found to have significant tendon lengthening after surgery, with a mean lengthening of 15.9 mm. No significant differences were found in overall lengthening between the traditional and accelerated rehabilitation groups (15.3 ± 4.5 vs 16.4 ± 4.7 mm, respectively; P = .33) at final follow-up. The repair site in each group was found to lengthen more than the intratendinous site (traditional group, 13.2 vs 2.1 mm; accelerated group, 16.8 vs −0.4 mm); however, no difference in lengthening was seen between groups ( P = .82 and P = .31, respectively). The greatest amount of lengthening occurred between 2 and 6 weeks, and the least amount of lengthening occurred between 6 and 12 weeks, with no difference between the traditional and accelerated groups at these time points ( P = .84 and P = .38, respectively). No differences were noted in ankle range of motion (dorsiflexion, P = .16; plantarflexion, P = .08) or outcome scores (ATRS, P = .56; PROMIS PI-SF, P = .54). Conclusion: This study’s findings demonstrate that all patients undergoing operative repair of Achilles tendon ruptures had lengthening after surgery. No difference was found in tendon lengthening (repair site or intratendinous) at any time point between patients undergoing traditional versus accelerated rehabilitation postoperatively. The greatest amount of lengthening was found to occur between 2 and 6 weeks postoperatively, and tendon lengthening decreased significantly after 6 weeks. Registration: NCT04050748 (ClinicalTrials.gov identifier).

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

Journal of Hand Surgery (European Volume) ◽

10.1054/jhsb.2000.0547 ◽

2001 ◽

Vol 26 (4) ◽

pp. 301-306 ◽

Cited By ~ 74

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.

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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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Surgical adhesive BioGlue™ does not benefit tendon repair strength: an ex vivo study

Journal of Hand Surgery (European Volume) ◽

10.1177/1753193414566566 ◽

2015 ◽

Vol 40 (7) ◽

pp. 700-704 ◽

Cited By ~ 5

Author(s):

M. C. Jordan ◽

V. Schmitt ◽

S. Dannigkeit ◽

K. Schmidt ◽

R. H. Meffert ◽

...

Keyword(s):

Tensile Strength ◽

Ex Vivo ◽

Tendon Repair ◽

Suture Repair ◽

Load Testing ◽

Flexor Tendon Repair ◽

Level Of Evidence ◽

Repair Site ◽

Surgical Adhesive ◽

Ex Vivo Study

Surgical adhesives are useful supplements in surgery, but their benefit in tendon repair is uncertain. The purpose of this study was to evaluate the effect of BioGlue™ on strength of flexor tendon repair. A total of 60 porcine flexor tendons were divided into three groups. In group one, a conventional core and peripheral suture repair was used. In group two, a core suture and BioGlue™ were used. In group three, a conventional core and peripheral suture repair and BioGlue™ were used. We performed static and cyclic axial load testing and measured diameter of the repair site. We found that BioGlue™ did not improve the tensile strength when added to a core and peripheral suture and that there was an increase in bulk at the repair site. We conclude that BioGlue™ application cannot replace a peripheral suture as tensile strength significantly decreases without a peripheral suture, and it does not benefit a tendon already repaired with a core and peripheral suture. Level of evidence: n/a

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Evaluation of Simple and Looped Suture and New Material for Flexor Tendon Repair

Journal of Hand Surgery (European Volume) ◽

10.1177/1753193408097319 ◽

2009 ◽

Vol 34 (3) ◽

pp. 329-332 ◽

Cited By ~ 22

Author(s):

C. J. BROCKARDT ◽

L. G. SULLIVAN ◽

B. E. WATKINS ◽

M. D. WONGWORAWAT

Keyword(s):

Flexor Tendon ◽

Tendon Repair ◽

Flexor Tendon Repair ◽

Repair Site ◽

New Material ◽

Pass Through

Flexor tendon repair strength is proportional to the number of suture strands crossing the repair site but it is not clear if each strand needs to result from a separate pass through the tendon. We examined whether one throw of looped suture across a repair site equals two separate throws of suture and whether fewer passes with stronger material such as Fiberwire is equivalent to more passes with a comparatively weaker material such as Supramid. When evaluating the repairs for force required to generate a 2 mm gap and for gap formed at the instant prior to failure, looped suture cannot substitute for two separate passes of suture (Supramid Kessler looped vs. separate passes, 14 N vs. 35 N and 8.8 mm vs. 4.1 mm, respectively; Fiberwire Kessler looped vs. separate passes, 25 N vs. 43 N and 7.6 mm vs. 4.6 mm, respectively; all p<0.05). Two-stranded Fiberwire Kessler repair equalled four-stranded cruciate repair with Supramid for all tested parameters (force at 2 mm gap: 17 N vs. 22 N, respectively; force at failure: 42 N vs. 46 N; and gap formed prior to instant of failure: 6.9 mm vs. 5.6 mm; all p>0.05).

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