title: Biomechanical advantages of triple-loaded suture anchors compared with double-row rotator cuff repairs.
abstract: OBJECTIVE
  To evaluate the strength and suture-tendon interface security of various suture anchors triply and doubly loaded with ultrahigh-molecular weight polyethylene-containing sutures and to evaluate the relative effectiveness of placing these anchors in a single-row or double-row arrangement by cyclic loading and then destructive testing.
  
  
  METHODS
  The infraspinatus muscle was reattached to the original humeral footprint by use of 1 of 5 different repair patterns in 40 bovine shoulders. Two single-row repairs and three double-row repairs were tested. High-strength sutures were used for all repairs. Five groups were studied: group 1, 2 triple-loaded screw suture anchors in a single row with simple stitches; group 2, 2 triple-loaded screw anchors in a single row with simple stitches over a fourth suture passed perpendicularly ("rip-stop" stitch); group 3, 2 medial and 2 lateral screw anchors with a single vertical mattress stitch passed from the medial anchors and 2 simple stitches passed from the lateral anchors; group 4, 2 medial double-loaded screw anchors tied in 2 mattress stitches and 2 push-in lateral anchors capturing the medial sutures in a "crisscross" spanning stitch; and group 5, 2 medial double-loaded screw anchors tied in 2 mattress stitches and 2 push-in lateral anchors creating a "suture-bridge" stitch. The specimens were cycled between 10 and 180 N at 1.0 Hz for 3,500 cycles or until failure. Endpoints were cyclic loading displacement (5 and 10 mm), total displacement, and ultimate failure load.
  
  
  RESULTS
  A single row of triply loaded anchors was more resistant to stretching to a 5- and 10-mm gap than the double-row repairs with or without the addition of a rip-stop suture (P < .05). The addition of a rip-stop stitch made the repair more resistant to gap formation than a double row repair (P < .05). The crisscross double row created by 2 medial double-loaded suture anchors and 2 lateral push-in anchors stretched more than any other group (P < .05).
  
  
  CONCLUSIONS
  Double-row repairs with either crossing sutures or 4 separate anchor points were more likely to fail (5- or 10-mm gap) than a single-row repair loaded with 3 simple sutures.
  
  
  CONCLUSIONS
  The triple-loaded anchors with ultrahigh-molecular weight polyethylene-containing sutures placed in a single row were more resistant to stretching than the double-row groups.
authors.affiliation: Plano Orthopedic Sports Medicine and Spine Center, Plano, Texas 75093, USA.
authors.forename: F Alan
authors.initials: FA
authors.lastname: Barber
authors.forename: Morley A
authors.initials: MA
authors.lastname: Herbert
authors.forename: F Alexander
authors.initials: FA
authors.lastname: Schroeder
authors.forename: Jorge
authors.initials: J
authors.lastname: Aziz-Jacobo
authors.forename: Matthew M
authors.initials: MM
authors.lastname: Mays
authors.forename: Jay H
authors.initials: JH
authors.lastname: Rapley
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001696:Biomechanical Phenomena; D002417:Cattle; D004868:Equipment Failure; D008422:Materials Testing; D020959:Polyethylene; D017006:Rotator Cuff / Q000601:surgery*; D013314:Stress, Mechanical; D053441:Suture Anchors; D013536:Suture Techniques
chemical_list: D020959:Polyethylene