Into-Tunnel Repair Versus Onto-Surface Repair for Rotator Cuff Tears in a Rabbit Model.

Background:Clinically, onto-surface repair is commonly used for rotator cuff tears. The retear rate after rotator cuff repair (RCR) is relatively high, with failure occurring mostly at the tendon-bone connection site. For anterior cruciate ligament (ACL) reconstruction, into-tunnel reconstruction is commonly employed. The retear rate after ACL reconstruction is relatively low, with retears seldom occurring at the tendon-bone interface. No study on into-tunnel RCR has been conducted.Hypothesis:Into-tunnel RCR could promote fibrocartilage regeneration at the tendon-bone interface and has biomechanical advantage over onto-surface repair in a rabbit rotator cuff tear model.Study Design:Controlled laboratory study.Methods:Thirty-six New Zealand White rabbits were used in this study. The supraspinatus tendons were cut from the footprint to create a rotator cuff tear on both shoulders. On one side, the supraspinatus was cut longitudinally into 2 halves, sutured, and pulled into 2 tunnels through the greater tube...