Tibiofemoral contact mechanics after serial medial meniscectomies in the human cadaveric knee.
BACKGROUND
There is no consensus regarding the extent of meniscectomy leading to deleterious effects on tibiofemoral contact mechanics.


OBJECTIVE
The meniscus aids in optimizing tibiofemoral contact mechanics, increasing contact area, and decreasing contact stress.


METHODS
Controlled laboratory study.


METHODS
Twelve fresh-frozen human cadaveric knees each underwent 15 separate testing conditions-5 serial 20-mm posterior medial meniscectomy conditions (intact, 50% radial width, 75% radial width, segmental, and total meniscectomy) at 3 flexion angles (0 degrees , 30 degrees , and 60 degrees )-under an 1800-N axial load. Tekscan sensors were used to measure total force and medial force, contact area, mean contact stress, and peak contact stress.


RESULTS
All posterior medial meniscectomy conditions resulted in significantly decreased contact areas and increased mean and peak contact stresses compared with the intact state (P < .05). The changes in contact mechanics after segmental and total posterior medial meniscectomies were not statistically different (P > .05). Incremental changes in contact area and mean contact stress increased as more peripheral portions of the medial meniscus were removed, whereas peak contact stresses exhibited similar incremental changes throughout all meniscectomy conditions.


CONCLUSIONS
The meniscus is a crucial load-bearing structure, optimizing contact area and minimizing contact stress. Loss of hoop tension (ie, segmental meniscectomy) is equivalent to total meniscectomy in load-bearing terms. The peripheral portion of the medial meniscus provides a greater contribution to increasing contact areas and decreasing mean contact stresses than does the central portion, whereas peak contact stresses increase proportionally to the amount of meniscus removed.


CONCLUSIONS
Because the degree of meniscectomy leading to clinically significant outcomes is unknown, a prudent strategy is to preserve the greatest amount of meniscus possible.
Lee
Stephen J
SJ
The Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.
Aadalen
Kirk J
KJ
Malaviya
Prasanna
P
Lorenz
Eric P
EP
Hayden
Jennifer K
JK
Farr
Jack
J
Kang
Richard W
RW
Cole
Brian J
BJ
D000328:Adult; D000704:Analysis of Variance; D002102:Cadaver; D005260:Female; D005269:Femur / Q000502:physiology / Q000503:physiopathology*; D006801:Humans; D008297:Male; D019563:Mechanics; D008592:Menisci, Tibial / Q000473:pathology / Q000502:physiology / Q000503:physiopathology* / Q000601:surgery*; D008875:Middle Aged; D019637:Orthopedic Procedures; D016059:Range of Motion, Articular; D012107:Research Design; D013314:Stress, Mechanical; D013977:Tibia / Q000502:physiology / Q000503:physiopathology*; D016474:Weight-Bearing