The use of functional knee braces in the control of pathologic anterior knee laxity

Four designs of knee braces, Don-Joy 4 Point, RKS, Lenox Hill, and CTi, were evaluated in 42 patients with a unilateral knee brace. Brace migration was the predominant complaint, as noted in patient questionnaires. All braces tested reduced giving-way episodes (34 of 42 patients reported no giving way during brace usage). All four brands of braces reduced the grade of pivot shift (mean reduction = 0.8 grade). Instrumented laxity testing with the KT-1000 arthrometer was performed with an 89-N passive anterior displacement, high load passive anterior displacement, and a quadriceps contraction active displacement. Brace use decreased the measured pathologic anterior displacement on all tests. During functional testing with one-legged hop and 40-yard shuttle run, the mean values were not significantly changed by brace usage.