A biomechanical comparison of the FasT-Fix meniscal repair suture system and the RapidLoc device in cadaver meniscus.
OBJECTIVE
This biomechanical study compared the fixation characteristics of horizontally or vertically implanted FasT-Fix devices (Smith & Nephew, Endoscopy Division, Andover, MA) consisting of two 5-mm PLLA suture T-bar anchors with a pretied self-sliding knot (No. 0 nonabsorbable, USP, braided polyester suture material) and the RapidLoc device (Mitek Surgical Products, Westwood, MA) consisting of a PLLA T-bar anchor or "backstop," a connecting suture (No. 2 nonbiodegradable Ethibond; Ethicon, Somerville, NJ), and a PLLA grommet, for repairing posterior third lesions in human menisci.


METHODS
Controlled laboratory biomechanical study.


METHODS
After repair of a vertical longitudinal meniscus lesion with either vertically or horizontally implanted FasT-Fix devices or RapidLoc devices, 3 groups of 6 specimens underwent cyclic loading (5 mm/minute, cycling between 5 and 50 N at 1 Hz for 500 cycles) before load to failure testing on a servo hydraulic device. One-way analysis of variance and Tukey HSD post hoc tests were used to evaluate group differences (P < .05).


RESULTS
The vertical FasT-Fix device group (3.2 +/- 0.49 mm) had less displacement after cyclic testing than either the horizontal FasT-Fix (4.4 +/- 0.73 mm, P = .003) or the RapidLoc (4.6 +/- 0.22 mm, P = .002) device groups. The vertical FasT-Fix device group had greater stiffness during cyclic testing (14.4 +/- 2.1 N/mm) than the horizontal FasT-Fix (10.4 +/- 1.6 N/mm, P = .0001) or the RapidLoc (9.7 +/- 0.44 N/mm, P = .0001) device groups. During load to failure testing, the vertical FasT-Fix group (125.3 +/- 39 N) had 28% greater strength than the horizontal FasT-Fix device group (89.7 +/- 14 N, P = .02) and 30% greater strength than the RapidLoc device group (87.1 +/- 13 N, P = .028), whereas displacement and stiffness did not show statistically significant group differences.


CONCLUSIONS
The vertical FasT-Fix group had superior biomechanical characteristics for meniscal fixation during cyclic and load to failure testing compared with horizontal FasT-Fix or RapidLoc devices.


CONCLUSIONS
Although the RapidLoc devices provided fixation characteristics comparable to horizontally implanted FasT-Fix devices, vertically implanted FasT-Fix devices may provide superior all-inside fixation.
Division of Sports Medicine, Department of Orthopaedic Surgery, University of Louisville, Louisville, Kentucky 40202, USA.
Yavuz
Y
Kocabey
Haw Chong
HC
Chang
Jeff C
JC
Brand
Akbar
A
Nawab
John
J
Nyland
David N M
DN
Caborn
D020341:Absorbable Implants; D000368:Aged; D001696:Biomechanical Phenomena; D005260:Female; D050724:Fractures, Cartilage / Q000601:surgery*; D006801:Humans; D020007:Implants, Experimental; D016268:Internal Fixators; D008297:Male; D008592:Menisci, Tibial / Q000601:surgery*; D008875:Middle Aged; D011091:Polyesters; D011093:Polyethylene Terephthalates; D013314:Stress, Mechanical; D013536:Suture Techniques / Q000295:instrumentation*; D013537:Sutures; D016474:Weight-Bearing
C014534:Ethibond; D011091:Polyesters; D011093:Polyethylene Terephthalates; C033616:poly(lactide)