Fixation of tendon grafts for collateral ligament reconstructions: a cadaveric biomechanical study.
OBJECTIVE
To compare the biomechanical properties of 4 methods of fixation of tendon grafts to bone as used for ligament reconstructions.


METHODS
Thirty-two metacarpals were harvested from fresh-frozen cadavers and stripped of soft tissue. Flexor tendons were harvested from the same cadavers and cut into 2-mm-wide strips. Each tendon was fixed to a metacarpal head at the site of origin of a collateral ligament. Four different methods of fixation were tested. In group 1 the tendon was fixed to the bone with a 4.0-mm Arthrex bio-tenodesis interference screw (Arthrex, Inc., Naples, FL). In group 2 the tendon was passed through a bone tunnel and fixed with a 3.2-mm mini-Acutrak screw (Acumed, LLC, Hillsboro, OR) that was inserted in interference mode. In group 3 the tendon was passed through a bone tunnel and fixed with sutures tied over a polyethylene button. In group 4 the tendon was fixed with a mini-Mitek bone suture anchor (Mitek Worldwide, Norwood, MA). All specimens were clamped into a linear loading machine and loaded until failure. Statistical analysis was performed by 1-way analysis of variance testing.


RESULTS
The differences in maximal tensile strength and stiffness were statistically significant when comparing any 2 groups. The Arthrex biotenodesis interference screw was the strongest and stiffest fixation method, followed by the Acutrak screw inserted in interference mode. Next was the suture tied over a button method. The mini-Mitek bone suture anchor was the weakest.


CONCLUSIONS
Interference screw fixation of tendons to bone has statistically significant higher pullout strength and stiffness than 2 other commonly used fixation methods. The use of interference screws for fixation of tendon grafts to bone for hand ligament reconstructions is a promising new surgical technique.
Lee
Steve K
SK
Department of Orthopaedic Surgery, Hospital for Joint Diseases, New York University School of Medicine, New York, NY 10029, USA. drpinal@ono.com
Kubiak
Erik N
EN
Liporace
Frank A
FA
Parisi
Debra M
DM
Iesaka
Kazuho
K
Posner
Martin A
MA
D001696:Biomechanical Phenomena; D002102:Cadaver; D017885:Collateral Ligaments / Q000293:injuries / Q000601:surgery*; D006801:Humans; D050279:Metacarpal Bones / Q000601:surgery; D019637:Orthopedic Procedures / Q000379:methods*; D013710:Tendons / Q000637:transplantation*; D014184:Transplantation, Homologous