The Journal of hand surgery
June 30, 2026 · via Europe PMC
Comparison of One- and Two-knot Techniques in Eight-Strand Flexor Tendon Repair Using Looped Sutures: A Biomechanical Study in a Porcine Model.
Takami H, Ota H, Niwa S, Cho H, Tamemoto T, Uchibori K.
AI summary — for doctors, generated from the abstract only
In a biomechanical study using a porcine tendon model, a one-knot configuration for eight-strand flexor tendon repair provided significantly better resistance to gap formation than a two-knot configuration, while both achieved similarly high ultimate failure strength.
What was studied
A controlled biomechanical study using 16 porcine Achilles tendons randomized to one-knot (n=8) or two-knot (n=8) configurations of an eight-strand flexor tendon repair technique (modified Adelaide repair using looped sutures), measuring tensile force required to produce 1-, 2-, and 3-mm gap formation and ultimate failure load.
Key findings
- The one-knot group required significantly higher tensile force to produce 1mm (12.4 vs. 6.8 N, p=.011), 2mm (20.4 vs. 10.3 N, p=.004), and 3mm (28.0 vs. 17.0 N, p=.011) gap formation compared with the two-knot group.
- Mean ultimate failure load was similar between groups (100.1 N for one-knot vs. 91.1 N for two-knot, p=.175, not statistically significant).
- Knot failure was the predominant failure mode in the one-knot group (7 of 8 specimens), while suture breakage was predominant in the two-knot group (7 of 8 specimens).
- Both techniques achieved high overall ultimate failure strength despite the difference in gap resistance.
Clinical relevance
The findings suggest that using a one-knot configuration for looped suture-based eight-strand flexor tendon repairs may offer better mechanical stability against gapping during early rehabilitation, which the authors note could potentially reduce adhesion formation risk, though this is based on cadaveric/animal tissue testing rather than clinical outcomes.
Who should care
Limitations
This was a biomechanical study using porcine (not human) tendon tissue and a small sample size (8 per group), which cannot directly establish clinical outcomes, healing rates, or complication differences in actual patients undergoing this repair technique.
Using a single knot rather than two knots in a common flexor tendon repair technique provided better resistance to gapping in this lab study, suggesting it may offer a mechanical advantage during the critical early healing period after tendon surgery.
This is an AI-generated summary of the published abstract, not a clinical recommendation. It may not reflect the full text or subsequent updates — verify against the original source before acting on it.
Abstract
Purpose
This study aimed to compare the biomechanical properties of one-knot and two-knot configurations in eight-strand flexor tendon repair using looped sutures. The influence of knot-tying strategy on gap resistance and ultimate failure strength was evaluated using a standardized porcine Achilles tendon model.
Methods
Sixteen fresh porcine Achilles tendons were transected and randomly assigned to one-knot or two-knot repair groups (n = 8 per group). Repairs were performed using an eight-strand core suture technique with a single 4-0 looped suture-based on a modified Adelaide repair. Biomechanical testing was conducted using a digital force gauge to measure the tensile force required to produce 1-, 2-, and 3-mm gap formations and ultimate failure load. Failure modes were visually assessed and categorized into three categories: suture breakage, knot failure, or suture pull-out.
Results
The one-knot group demonstrated significantly higher tensile forces required for 1-mm (12.4 ± 4.5 N vs 6.8 ± 2.8 N, P = .011), 2-mm (20.4 ± 7.5 N vs 10.3 ± 3.8 N, P = .004), and 3-mm (28.0 ± 9.2 N vs 17.0 ± 5.4 N, P = .011) gap formation compared to the two-knot group. Mean ultimate failure load was 100.1 ± 11.5 N in the one-knot group and 91.1 ± 13.7 N in the two-knot group, with no significant difference between them (P = .175). Knot failure was predominant in the one-knot group (7 of 8), whereas suture breakage was the primary failure mode in the two-knot group (7 of 8).
Conclusions
The one-knot configuration provided superior gap resistance compared to the two-knot configuration in looped suture-based eight-strand flexor tendon repair. Both techniques achieved high ultimate failure strength.
Clinical relevance
In flexor tendon repairs using looped sutures, the one-knot configuration may offer improved mechanical stability during the early rehabilitation phase, potentially reducing the risk of gapping and adhesion formation.
DOI
10.1016/j.jhsa.2026.05.015
PMID
42376723
Research metadata (titles, abstracts, authors, publication dates) is sourced from Europe PMC, which aggregates content from PubMed/MEDLINE, PubMed Central, and other providers under the U.S. National Library of Medicine (NLM/NCBI). NLM does not claim copyright on abstracts; the original journal publishers or authors may hold rights to the full articles. AI-generated summaries are derived only from the abstract, never the full text, and are always labeled as AI-generated.
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