gms | German Medical Science

Introduction: With recent commercialization of barbed suture materials and reports of the use of these materials for tendon repairs, we felt the need to design a specific repair method to draw the best utility from this material. In previous ex-vivo studies we could show superior bio-mechanical performances of our new knotless barbed suture tendon repair in comparison to conventional knotted tendon repairs. The aim of this present study was to investigate if this superior repair stability applies to an in-vivo scenario in a healing tendon.

Material and methods: A pilot study with ten male Meleagris Gallopavo (turkeys) showed that turkey deep flexor tendons not only show similar biomechanical properties to common animal models like pig or sheep deep flexor tendons, but also reflect similar in vivo healing as in chicken or rabbit experiments, but providing bigger tendons. Therfore 20 male Meleagris Gallopavo (turkeys) were used. The middle toe of the right leg was operated, while the left served as the contra lateral control. Two groups were operated:

1.

Repair of ten turkey feet (right middle toe deep flexor tendon) at zone 2 with a 4-strand knotted cross locked cruciate repair (Adelaid repair) with 4/0 Ethibond and running circumferential repair with 6/0 Prolene.

2.

Repair of ten turkey feet (right middle toe deep flexor tendon) at zone 2 with 4-strand knotless barbed suture repair (3D-repair) with a resorbable 4/0 V-Loc 180 suture device and running circumferential repair with 6/0 Prolene.

Endpoints were:

• Range of motion (ROM)
• Adhesion formation
• Core repair time
• Biomechanical stability
• Bulk

Results: In-vivo surgery on the turkey deep flexor apparatus is practicable and procedures are comparable to clinical scenarios in humans. Animals tolerate casting and show similar functional recovery of operated digits to human post-op recoveries.

Histology shows similar healing phases compared to human tendon repairs. Bio-mechanically, the barbed suture repairs could not reach the same stability as the conventional knotted repairs. More tendon repair failures were noted in the barbed suture group compared to the conventional knotted repair group. Also, bio-mechanical testing after 6 weeks showed more stable repairs in the conventional repair group compared to the barbed suture group.

Conclusion: This is the first in-vivo investigation of a knotless barbed suture repair. Our aim was to prove if a barbed suture repair can achieve similar results in an in-vivo setting as the conventional gold standard in 4-strand tendon repairs. This could not be proven. No non-resorbable, permanent barbed suture is currently commercially available in suitable small sizes. Resorbtion of the barbs on the suture surface of the currently available resorbable barbed sutures causes inferior repair stability and increased repair failures compared to conventional repairs in an in-vivo setting. Care should be taken if resorbable barbed suture devices are used for tendon repairs.