Knees With Needs
The oft-underappreciated meniscus finally gets its due.
Shock absorbers, pressure dispersers, friction reducers and all-around knee nourishers, the menisci — two specialized, C-shaped pads of joint tissue — are important players in locomotion maintenance. Few understand this better than Trent Guess, MU’s HealthSouth associate professor of physical therapy, a scientist who also serves on the School of Medicine’s orthopedic surgery faculty. With two colleagues, Guess has recently published findings showing that even small menisci changes can spell big trouble.
“The menisci are sensitive, and a fine line exists between the menisci doing what they’re supposed to do and the menisci not functioning properly,” says Guess. “As the meniscal attachments to the tibia—the calf bone—become more lax, it doesn’t take much for the menisci to lose all their function. This function declines as individuals age and could be one contributing factor to osteoarthritis.”
In their laboratory, Guess and his team sought to better understand this risk by using sophisticated sensors and computational modeling to assess the structural stress exerted on knees during common activities. They discovered the stress was substantial, bolstering their view that a healthy meniscus is an indispensable buffer against osteoarthritis.
“Getting up and out of a chair, an individual can put four times her body weight just across one knee,” says Guess. “Can you imagine a basketball player jumping up and down, the force that he would put across his knees? It is a huge amount of force… The menisci act as a cushion, distributing [these] forces over a larger area while also nourishing and lubricating the knee.”
The findings, published earlier this year in the Journal of Biomechanics, suggest physicians and physical therapists may want to reconsider how they treat injuries, Guess says.