What did the study look at?
According to the authors, there is still no ideal suture material or technique for repairing the tendons that bend the fingers (flexor tendons). Barbed sutures carry one-way notches that resist sliding inside the tendon, and they need no knot. A longer course of the suture inside the tendon (suture purchase) is expected to increase the strength of the repair.
This study examined the link between the length of suture inside the tendon and repair strength. The question was whether simply lengthening the course of a barbed suture could achieve strength comparable to a conventional two-strand polypropylene repair.
How was it done?
This was a biomechanical study on animal tissue, not on patients (level of evidence given by the journal: Level V). Twenty-four deep flexor tendons were taken from the forelimbs of sheep slaughtered for food.
- Each tendon was cut across and repaired with a two-strand modified Kessler technique by a single hand surgeon.
- Using a computer-generated random sequence, the tendons were allocated to four groups of six: polypropylene suture 1 cm (P1) or 2 cm (P2) from the cut, and barbed suture 1 cm (B1) or 2 cm (B2) from the cut.
- The repaired tendons were pulled in a tensile testing machine. The force that opened a 2 mm gap at the repair (2 mm gap resistance) and the peak force at which the tendon ends fully separated (maximum tensile strength) were recorded.
What did it find?
- Increasing the suture purchase to 2 cm raised the mean 2 mm gap resistance by 6.9 N with polypropylene and by 12.6 N with barbed suture, an increase of 57% and 156.7% respectively.
- The highest 2 mm gap resistance was in group B2 (mean 20.7 N). Groups P2 (19.0 N) and B2 were significantly higher than groups P1 (12.1 N) and B1 (8.1 N).
- Maximum tensile strength did not differ significantly between the groups (P = .743).
- Failure occurred by suture breakage in 92% of specimens (22/24) and by knot failure in 8% (2/24); every barbed-suture repair failed by the suture breaking at the repair site.
In their discussion the authors also describe possible drawbacks of barbed sutures: the external barbs may increase friction with the tendon sheath and the work needed to bend the finger, they have been linked to a greater inflammatory response, and they are difficult to remove in revision surgery. In the authors' view, current evidence does not yet support their routine use in every case.
The authors' conclusion
The authors conclude that increasing suture purchase length raises 2 mm gap resistance more for barbed sutures than for polypropylene sutures. Used with an extended purchase, barbed sutures could offer practical benefits such as avoiding knots and reducing the bulk of traditional multi-strand repairs. With further refinement, they write, barbed sutures could become a favourable option for tendon repair.
Limitations
- As a biomechanical study it lacks clinical validation; its effectiveness needs to be confirmed in clinical trials.
- No cyclic (repeated) loading was performed; such testing is needed to assess durability and long-term performance.
- The findings suggest that a 1 cm purchase may be inadequate, so the benefits of barbed sutures depend on specific techniques and conditions.
Reference
Cırdı YU, Günay AE, Ekici M, Şekerci ÖT, Ozturk Rİ, Gürsoy S. (2025). Increases in suture purchase of same magnitude lead to a higher gap resistance force for barbed sutures used in flexor tendon repair. Acta Orthopaedica et Traumatologica Turcica, 59(6): 434-438. Licence: CC BY-NC 4.0.
DOI: 10.5152/j.aott.2025.25287
Free full text: PubMed Central (PMC12831060)
This article summarises a published scientific paper for general information; it does not replace an examination or a personal medical assessment. Please consult your doctor about your symptoms.
