Introduction: Limited surgical technology in treating injuries of the anterior cruciate ligament (ACL) in the past led to the development of a huge number of functional braces. Today, with the advance of the surgical techniques and a more aggressive rehabilitation approach in the postoperative course the use of functional braces after the ACL reconstruction is seriously questioned. The aim of this study was to review the basic functions of functional braces. Mechanical, and biomechanical functions of functional braces have been described, the psychological aspect of wearing them, their impact on thigh circumference, functional performance, muscle activity and postural control and propriocepation have also been addressed. Functional braces definitely increase the knee stability under low clinical loads. However, biomechanical investigations show that functional knee braces do not restore the normal knee stability under high forces related to certain activities. Furthermore, functional braces do not significantly influence proprioceptive abilities, nor functional performance, but have a negative impact on thigh atrophy, and inhibit joint muscle stabilizing activity.
Conclusion: Given the generally high surgical success rates, there has been no scientific evidence so far to support the routine use of a functional knee brace following a successful anterior cruciate ligament reconstruction in the controlled rehabilitative postoperative course.