From the Guidelines
For PCL laxity, I recommend a functional knee brace, as it provides additional support and control for mild to moderate PCL instability, according to the evidence provided by 1 and 1. When selecting a knee brace for PCL laxity, it's essential to consider the type of brace that offers the most benefits for this specific condition.
- Functional knee braces are indicated for additional support after ACL surgery, support for mild to moderate PCL or MCL instability, and control of knee hyperextension, as reported by 1.
- These braces can provide augmented knee proprioception, which is beneficial for patients with PCL laxity, as mentioned in 1.
- However, it's crucial to note that functional knee braces may have limitations, such as increased energy expenditure and decreased agility, as well as a potential false sense of confidence during athletics, as stated in 1 and 1. The ideal functional knee brace for PCL laxity should have a rigid frame, hinges that control range of motion, and straps positioned to counteract the posterior sag of the tibia.
- Proper fitting and regular reassessment are essential for optimal effectiveness, and the brace should be worn during physical activities that stress the knee, particularly those involving cutting, pivoting, or impact.
- Complementary to bracing, focusing on quadriceps strengthening exercises is also important, as these muscles act as dynamic stabilizers for the PCL, as implied by the need for muscular rehabilitation for graft protection following ACL reconstruction in 1.
From the Research
Knee Brace Selection for PCL Laxity
When selecting a knee brace for PCL laxity, several factors should be considered, including the type of brace, its functionality, and how it applies forces to the knee.
- The study 2 compared two knee braces designed for treatment of PCL injuries, a dynamic force (DF) PCL brace and a static force (SF) PCL brace, and found that the DF brace applied forces to the posterior proximal tibia that dynamically increased with increased flexion angle.
- This suggests that a dynamic force knee brace may be more effective in counteracting posterior translation of the tibia and improving posterior knee laxity following PCL injury.
Key Considerations
When choosing a knee brace for PCL laxity, consider the following:
- The ability of the brace to apply dynamic forces that increase with flexion angle, as this may help to more effectively counteract posterior translation of the tibia.
- The brace's functionality during various activities, such as squatting and stair descent, as these activities may put additional stress on the PCL.
- The potential for long-term improvement in posterior knee laxity, as clinical studies are necessary to determine the effectiveness of different knee braces in achieving this outcome.
Current Research and Limitations
Current research on knee braces for PCL laxity is limited, and more studies are needed to fully understand the effectiveness of different types of braces.
- The study 2 provides some insight into the forces applied by different knee braces, but further research is needed to determine the long-term outcomes of using these braces.
- Other studies, such as 3, 4, 5, and 6, provide information on PCL anatomy, biomechanics, and treatment options, but do not specifically address the selection of knee braces for PCL laxity.