title: Part II: Biomechanical assessment for a footprint-restoring transosseous-equivalent rotator cuff repair technique compared with a double-row repair technique.
abstract: We hypothesized that a transosseous-equivalent repair would demonstrate improved tensile strength and gap formation 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 two medial anchors was bridged over the tendon and fixed laterally with an interference screw. In 6 contralateral matched-pair specimens, a double-row repair was performed. For all repairs, a materials testing machine was used to load each repair cyclically from 10 N to 180 N for 30 cycles; each repair underwent tensile testing to measure failure loads at a deformation rate of 1 mm/sec. Gap formation between the tendon edge and insertion was measured with a video digitizing system. The mean ultimate load to failure was significantly greater for the transosseous-equivalent technique (443.0 +/- 87.8 N) compared with the double-row technique (299.2 +/- 52.5 N) (P = .043). Gap formation during cyclic loading was not significantly different between the transosseous-equivalent and double-row techniques, with mean values of 3.74 +/- 1.51 mm and 3.79 +/- 0.68 mm, respectively (P = .95). Stiffness for all cycles was not statistically different between the two constructs (P > .40). The transosseous-equivalent rotator cuff repair technique improves ultimate failure loads when compared with a double-row technique. Gap formation is similar for both techniques. A transosseous-equivalent repair helps restore footprint dimensions and provides a stronger repair than the double-row technique, which may help optimize healing biology.
authors.affiliation: Kerlan-Jobe Orthopaedic Clinic, Los Angeles, CA, USA. mcp16@columbia.edu
authors.forename: Maxwell C
authors.initials: MC
authors.lastname: Park
authors.forename: James E
authors.initials: JE
authors.lastname: Tibone
authors.forename: Neal S
authors.initials: NS
authors.lastname: ElAttrache
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Ahmad
authors.forename: Bong-Jae
authors.initials: BJ
authors.lastname: Jun
authors.forename: Thay Q
authors.initials: TQ
authors.lastname: Lee
mesh_terms: D000368:Aged; D001696:Biomechanical Phenomena; D002102:Cadaver; D006801:Humans; D008875:Middle Aged; D017006:Rotator Cuff / Q000601:surgery*; D013536:Suture Techniques; D013718:Tensile Strength