Massive irreparable rotator cuff tears are difficult to manage. Synthetic materials have been proposed as one solution to bridge tendon defects in these tears. This study aimed to analyze the biomechanical properties of synthetic patch-bone repairs using 2 different repair configurations.Methods:
An irreparable rotator cuff defect was created ex vivo in 12 ovine shoulders and then secured to a synthetic patch (2 mm Gore-Tex ePTFE, Gore, Flagstaff, AZ). The patch was then repaired to the humeral footprint with 2 suture anchors using either vertical mattress sutures (n=6) or the inverted mattress tension-band repair (n=6) technique. Footprint contact pressure was measured at 10-N, 20-N, and 30-N tension and −10, 0, and +10 degrees of abduction. Repair strength was determined using a pull-to-failure test.Results:
Tension-band repairs provided significantly higher footprint contact pressure than mattress repairs in 7 out of 9 tension/abduction combinations (P<0.05). Footprint contact was maximized with decreasing abduction angle and increasing tension. Tension-band repairs had higher pullout strength (220 N ±7) than mattress repairs (188 N ±10) (P<0.03).Discussion:
The tension-band repair technique of synthetic patch to bone provided better footprint contact and was stronger than mattress repairs of synthetic patch to bone. Interestingly, tendon-synthetic patch-bone repairs had higher contact pressure and pullout strength than similar tendon-bone repairs.