The biomechanical analysis of a tendon fixation device for flexor tendon repair.
OBJECTIVE
Stainless steel suture is high in tensile strength but is not widely used in flexor tendon repair because of difficulty with handling and knot tying. The purpose of this study was to examine the biomechanical characteristics of the single-strand multifilament stainless steel Teno Fix device (Ortheon Medical, Winter Park, FL) designed for zone II flexor digitorum profundus (FDP) tendon repair.


METHODS
Sixty cadaveric flexor tendons were transected and randomized to receive a Teno Fix or 4-stranded (3-0 or 4-0 braided polyester) suture repair; all repairs were tested with and without a 5-0 monofilament polypropylene circumferential epitendinous suture. By using a material testing system all tendons were tested to failure in tension using a linear model with a loading rate of 1 mm/s. Stiffness, force, and energy at both 2-mm gap and peak force were calculated from the resulting force-displacement curves.


RESULTS
The 2-mm gapping force was significantly greater for the Teno Fix and the 3-0 repairs than for the 4-0 repairs. The energy absorbed up to 2-mm gap was significantly greater for the Teno Fix, however, than for all suture repairs both with and without a circumferential suture. There was no statistically significant difference in peak force or energy absorbed at peak force between the Teno Fix and suture repairs; the average gap at peak force for all repairs was 5.2 mm. The addition of a circumferential suture increased the 2-mm gapping and peak forces of the Teno Fix repair to 54.5 N and 66.7 N, respectively.


CONCLUSIONS
Increased strength and energy absorbed at 2-mm gap and ease of installation makes the Teno Fix a promising repair method.
Su
Brian W
BW
Trauma Training Center, New York Orthopaedic Hospital, Columbia University Medical Center, New York, NY 10032, USA.
Protopsaltis
Themistocles S
TS
Koff
Matthew F
MF
Chang
Ketharin P
KP
Strauch
Robert J
RJ
Crow
Scott A
SA
Rosenwasser
Melvin P
MP
D001696:Biomechanical Phenomena; D002102:Cadaver; D005383:Finger Injuries / Q000601:surgery; D006801:Humans; D008422:Materials Testing; D013193:Stainless Steel; D013537:Sutures; D013708:Tendon Injuries / Q000601:surgery*; D013710:Tendons / Q000601:surgery
D013193:Stainless Steel