Pillar 3: Reduce the Load
Unloading the osteoarthritic knee through mechanical means . . .
As we saw in Pillar 1, bracing can be very effective for some patients with Knee Osteoarthritis through the provision of compression and stability. A third way braces can help is by ‘unloading’ the affected compartment. Appropriately, specialized brace that do this are called “Unloading”, or sometimes “Offloading” brace.
Multiple manufacturers make these braces, but they all work on the same principle - they shift the weight within the knee to decrease the load on the most affected parts. Although somewhat overdramatized in terms of knee angle, the video to the right from Breg Braces gives a good sense of how unloader bracing works.
What are the pros and cons of unloader braces?
When they work as they are designed and used with appropriate clients, unloader braces can provide an excellent relief of knee osteoarthritis pain. At times we have seen patients go from having great difficulty walking, to walking comfortably without any aids. As you can imagine, this significant improves their quality of life and ability to exercise.
However, as these braces need to provide a significant mechanical leverage, their construction requires more rigidity and some sort of offloading mechanism. This creates some trade-offs that need to be weighed against their benefit. Specifically, unloader braces:
tend to be more bulky than compression / light stability braces
require some learning to be able to put them on properly
can be quite costly
at times need to be custom made
Some of the most common unloaders that we have used in clinic with success are the Ossur Unloader One / X / Custom, the DJO Defiance, the Breg Fusion OA. All of these have their place, primarily in treatment of moderate to severe where there is pain preventing function.
Some recent developments . . .
in recent years, many different version of unloading braces have bee made to reduce the bulk and make knee OA unloading available to more knee OA patients, including those with mild to moderate knee OA. By unloading the affected compartments of these clients earlier in their OA journey, the hope is that they can remain more active, keep their strength, and delay or prevent progression of their arthritis.
One of the most successful new versions we have seen in the last few years is the Bauerfeind Genutrain OA. This brace uses an easy slip-on design instead of strapping. Unloading is provided through a single dial mechanism. Additionally, using a compression sock and upright stay rather than a rigid frame allows for non-custom fitting. This combination makes for a more patient-friendly unlaoder, that can be trialed in-clinic fairly easily to see if it is effective for a client.
What about Knee OA that is in more than one compartment?
Unloader braces are targeted at clients who have most of their joint space loss in one of the medial or lateral knee compartments (to review these concepts, re-visit the “Get Informed - Understanding Location” lesson). The opposite tibiofemoral comparmtent must be relatively healthy (or at least minimally arthritis compared to the most affected side) so that weight can be safely transferred to it. If both compartments are affected with significaint amounts of arthritis, unloaders have not been an option. Similarly, unloaders have not been appropriate for clients with primary arthritis under their kneecap (patellofemoral OA).
In the last several years, however, a company called SpringLoaded technologies has developed the “Levitation” brace that uses springs in both sides of the frame to derease the load on all three compartments of the knee. Initial research on this brace has been positive. It shows potential for those who have arthritis in both sides of their knee, significant patellofemoral arthritis, or those who can not undergo knee replacement surgery. You can
Is a knee unloader brace right for me?
Whether a knee unloader is appropriate for you, and what type would work best, depends on a number of factors. These include the location and severity of your arthritis, your leg shape, your ability to take the brace on and off, your resources, and more. The decision is best made together with a healthcare professional who can weight this factors with you. At FusionPhysio, we have had 25 years of making these decisions with clients and fitting the bracing decision into the context of their overall Knee OA management plan. Contact info@fusionphysiochilliwack.com to make an appointment for an unloader bracing assessment.