Part I: Footprint contact characteristics for a transosseous-equivalent rotator cuff repair technique compared with a double-row repair technique.

Rotator cuff repair via transosseous tunnels can improve footprint contact area and pressure when compared with suture anchor techniques. A double-row technique has been used clinically to improve footprint coverage by a repaired tendon. We hypothesized that a transosseous-equivalent rotator cuff repair via tendon suture bridges would demonstrate improved pressurized contact between the tendon and tuberosity when compared with a double-row technique. In 6 fresh-frozen human shoulders, a transosseous-equivalent rotator cuff repair was performed: a suture limb from each of 2 medial anchors was bridged over the tendon and fixed laterally with an interference screw (4 suture bridges). In 6 of the contralateral specimens, two types of repair were performed randomly in each specimen: (1) a double-row repair and (2) a transosseous-equivalent repair with a single screw (2 suture bridges). For all repairs, pressure-sensitive film was placed at the tendon-footprint interface, and software was used to obtain measurements. The mean pressurized contact area between the tendon and insertion was significantly greater for the 4-suture bridge technique (124.2 +/- 16.3 mm2, 77.6% footprint) compared with both the double-row (63.3 +/- 28.5 mm2, 39.6% footprint) and 2-suture bridge (99.7 +/- 22.0 mm2, 62.3% footprint) techniques (P < .05). The mean interface pressure exerted over the footprint by the tendon was greater for the 4-suture bridge technique (0.27 +/- 0.04 MPa) than for the double-row technique (0.19 +/- 0.01 MPa) (P = .002). The transosseous-equivalent rotator cuff repair technique can improve pressurized contact area and mean pressure between the tendon and footprint when compared with a double-row technique. A transosseous-equivalent technique, using suture bridges, may help optimize the healing biology at a repaired rotator cuff insertion.