Increases in suture purchase of same magnitude lead to a higher gap resistance force for barbed sutures used in flexor tendon repair.

OBJECTIVE: There is still no optimal suture material or configuration for flexor tendon repair. Barbed sutures provide an alternative for flexor tendon repair with unidirectional clefts that effectively resist sliding. Increasing the suture purchase results in an expected increase in the tensile force. This study investigated the relationship between suture purchase length and repair strength in flexor tendon. This addresses the question of whether it is possible to achieve sufficient tensile strength compared to a 2-strand polypropylene suture by simply increasing the barbed suture course inside the tendon. METHODS: The study involved 24 sheep flexor digitorum tendons, which were divided into 4 subgroups, each comprising 6 tendons. Group P1 utilized polypropylene sutures 1 cm from the incision, while group P2 used it 2 cm away. Group B1 utilized a barbed suture positioned 1 cm from the incision, while group B2 employed a barbed suture 2 cm from the incision. The outcome measures included testing for 2-mm Gap Resistance (2mm-GR) and maximum tensile strength (MTS) using an Instron® 3345K7023 tensile testing device (Norwood, MA, USA). RESULTS: A 2 cm suture purchase length increased by the mean 2mm-GR by 6.9 N for polypropylene and 12.6 N for barbed sutures. Group B2 showed the highest 2mm-GR (20.7 N). Groups P2 and B2 had significantly higher 2mm-GR than groups P1 and B1 (P < .05). The MTS did not differ significantly between the groups (P = .743). Suture breakage occurred in 92% of cases, with knot failure observed in 8%. CONCLUSION: Extending the purchase length of the barbed suture within the tendon significantly enhances the MTS and 2mm-GR. With further refinement, barbed sutures have the potential to become a favorable option for tendon repair, possibly facilitating early and effec tive postoperative rehabilitation.   Cite this article as: Cırdı YU, Günay AE, Ekici M, Şekerci ÖT, Ozturk Rİ, Gürsoy S. Increases in suture purchase of same magnitude lead to a higher gap resistance force for barbed sutures used in flexor tendon repair. Acta Orthop Traumatol Turc., 2025;59(6):434-438.