Suture anchor materials, eyelets, and designs: update 2008.
OBJECTIVE
Our purpose was to evaluate recently introduced sutures and suture anchors for single pull load to failure strength and failure mode.


METHODS
Suture anchors were tested in fresh porcine metaphyseal cortex and cancellous troughs using an established protocol. An Instron machine applied tensile loads parallel to the axis of insertion at a rate of 12.5 mm per second until failure and mean anchor failure strengths were calculated. The mode of failure was recorded (anchor pullout, suture eyelet cut out, or suture failure). Anchors tested included the Kinsa, Kinsa RC, BioRaptor 2.3 PK, TwinFix PK FT 5.5 and 6.5, BioCleat, Healix Peek, VersaLok, BioKnotless, BioKnotless BR, Corkscrew FT III, SwiveLock C, and PEEK SutureTak.


RESULTS
The mean cortical failure loads were as follows: Kinsa (219 N), Kinsa RC (222 N), BioRaptor 2.3 PK (172 N), TwinFix PK FT 5.5 (491 N) and 6.5 (503 N), BioCleat (218 N), Healix Peek (407 N), VersaLok (376 N), BioKnotless (249 N), BioKnotless BR (265 N), Corkscrew FT III (386 N), SwiveLock C (712 N), and PEEK SutureTak (168 N). Pullout was the predominant failure mode for the VersaLok, BioKnotless, BioKnotless BR, and BioRaptor 2.3PK anchors. Eyelet failure was the predominant failure mode for the Kinsa, Kinsa RC, BioCleat, Healix Peek, Corkscrew FT III, SwiveLock C, and PEEK SutureTak.


CONCLUSIONS
The newer anchors showed markedly increased load to failure strengths. Two or more high-strength sutures are commonly used as well as new anchor materials (PEEK and Biocryl Rapide), new eyelet designs, and the increased use of a "knotless" concept.


CONCLUSIONS
An anchor which fails principally by pull out at a low load to failure is at risk for creating an intra-articular loose body.
Barber
F Alan
FA
Plano Orthopedic and Sports Medicine Center, Plano, Texas 75093, USA.
Herbert
Morley A
MA
Beavis
R Cole
RC
Barrera Oro
Fernando
F
D000818:Animals; D004867:Equipment Design; D005269:Femur / Q000601:surgery; D066298:In Vitro Techniques; D008422:Materials Testing; D053441:Suture Anchors; D013536:Suture Techniques; D013537:Sutures; D013552:Swine; D013718:Tensile Strength; D016474:Weight-Bearing