Abstract
BACKGROUND: The suture-tendon interface turned out to be the weak point of a repaired rotator cuff. A double rip-stop (DRS) technique was developed to enhance the strength of the suture-tendon interface. The first aim of this study was to compare the suture-tendon interface strength between mesh suture and the No. 2 FiberWire (FW), which is commonly used in the clinic. The second aim was to compare the biomechanical properties of rotator cuff repair between mesh suture and No. 2 FiberWire using a typical suture-bridge (SB) and DRS techniques. METHODS: Eighteen porcine subscapularis tendon (SST) was randomly assigned to the Mesh-tendon group and FiberWire-tendon group. A single suture loop was passed through the SST with a Mesh suture or FiberWire. Thirty-two infraspinatus tendons (ISTs) were randomly assigned to four groups: SB-Mesh group: SB technique with Mesh suture, SB-FW group: SB technique with FiberWire, DRS-Mesh group: DRS technique with Mesh suture, and DRS-FW group: DRS technique with FiberWire. All repaired specimens were underwent failure testing. Failure modes, load to create a 3-mm gap, failure load, and stiffness were compared. RESULTS: There were no significant differences between the Mesh-tendon group and FiberWire-tendon group regarding the failure load, stiffness, and ultimate stress. When the same technique was used, the rotator cuff repaired with a mesh suture had the similar load to create a 3-mm gap, failure load, and stiffness compared with FiberWire. When the same suture was used, the DRS technique had a significantly higher load to create a 3-mm gap formation and failure load compared with the SB technique. CONCLUSIONS: The repair failure strength and stiffness using the mesh suture were similar to the FiberWire suture regardless of the repair techniques. However, the repair strength in the DRS technique was significantly stronger than the SB technique when the same suture material was used.