A cyclic testing comparison of FasT-Fix and RapidLoc devices in human cadaveric meniscus.
BACKGROUND
Cyclic testing may provide a more valid depiction of how arthroscopic meniscal repairs will withstand the forces of activities of daily living (ADLs) and therapeutic exercises early post-surgery than single cycle load to failure testing. This study compared the meniscal fixation provided by vertically or horizontally placed FasT-Fix devices to horizontally placed RapidLoc devices under submaximal cyclic test conditions.


METHODS
Eighteen human cadaveric menisci were divided into three groups of six specimens. A scalpel was used to create a 2 cm lesion at 3 mm from the outer edge of the posterior third of each specimen. Merselene tape loops were placed around each side of the lesion and the tears were repaired using two vertical FasT-Fix, two horizontal FasT-Fix, or two RapidLoc devices. Cyclic testing (5-50 N at 1 Hz for 500 cycles) was performed on a servo hydraulic device. One-way ANOVA and Scheffe post-hoc tests were used to evaluate group differences (P < 0.05).


RESULTS
The vertical FasT-Fix group had less displacement over the initial ten loading cycles compared to the RapidLoc group (P = 0.004), but did not differ from the horizontal FasT-Fix group (P = 0.07). At 50, 100, 200, 300, 400, and 500 cycles, the vertical FasT-Fix group had less displacement than the horizontal FasT-Fix or RapidLoc groups (P < or = 0.004). At each interval the vertical FasT-Fix group had greater relative stiffness than the other groups (P < or = 0.009).


CONCLUSIONS
The vertical FasT-Fix group had comparatively less displacement (primarily repair site gapping) and greater relative stiffness.
Nyland
J
J
Division of Sports Medicine, Department of Orthopaedic Surgery, University of Louisville, 210 East Gray St., Suite 1003, Louisville, KY, USA. john.nyland@louisville.edu
Chang
H
H
Kocabey
Y
Y
Nawab
A
A
Brand
J
J
Caborn
D N M
DN
D000368:Aged; D001182:Arthroscopy; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D008422:Materials Testing; D008592:Menisci, Tibial / Q000502:physiology / Q000601:surgery*; D053441:Suture Anchors; D013718:Tensile Strength