Anterior Knee Pain in Adolescents

The purpose of this study was to determine historical and physical factors associated with anterior knee pain in a cross section of athletic and nonathletic adolescents. We studied 142 high-school students, each of whom answered a questionnaire addressing athletic involvement and a history of knee pain. All subjects underwent a complete knee examination, and measurements of quadriceps girth, Q angle, lower extremity flexibility, and limb length. Forty-five percent of the subjects had a diagnosis of anterior knee pain including patellofemoral pain, patellar tendinitis, or tibial tuberosity pain. Significant correlations were found between anterior knee pain and several historical variables: current pain, pain with exercise, pain with stair climbing, the theater sign, and pain with routine activity. Painful quadriceps “setting” was significantly related to the diagnosis of anterior knee pain. Multiple regression analysis showed that a history of current pain and painful quadriceps setting accounted for 34% of the variance of the diagnosis of anterior knee pain. No other measurement variable, including Q angle, was related to the current diagnosis. We conclude that traditional historical variables associated with anterior knee pain contributed to its diagnosis in a cross section of adolescents. Anterior knee pain could not be predicted from structural measurements of lower extremities.