Arthritis Treatment: Assistive Devices for Osteoarthritis of the Knee

Osteoarthritis (OA) is the most common form of arthritis and is characterized by progressive deterioration of joint cartilage. Cartilage is the gristle that caps the ends of long bones and provides shock absorption and gliding properties. OA is also characterized by decreased regeneration of cartilage.

While it typically occurs after the age of 40, it is becoming clear that OA can actually begin much sooner, sometimes as early as the teen-age years.

OA incidence does increase with advancing age. While joint damage from osteoarthritis progresses relatively slowly, the inexorable progression leads to joint stiffness and pain, gradual deformity, joint instability and eventual loss of function.

The standard approach to OA involving the knee is fairly straightforward. Analgesic and non-steroidal anti-inflammatory drugs (NSAIDS), thermal modalities (ice), physical therapy, exercises, and injections of glucocorticoids and viscosupplements (lubricants), are pro forma. These measures are, at best, palliative.
Eventually, most patients go on to have joint replacement surgery.

[Recently, the use of mesenchymal stem cells for treatment of OA of the knee has been found to be effective in many cases, extending the time or even reducing the need for replacement.]

Studies looking at gait have shown that patients with OA of the knee shift their weight to the medial (inside) compartment of their knee while walking.

In addition, the pain, deformity, and instability of knee OA leads to gradual quadriceps weakness and atrophy. All of these play a role in the altered gait characterized by patients with OA of the knee.

In addition to quadriceps strengthening exercises, measures that unload the medial compartment of the knee may be effective in improving exercise tolerance, reducing pain, and improving function.
There are two types of devices that can accomplish this.

The first is an unloading type of brace. These braces, made of lightweight polymer materials, are designed to "open up" the closed medial compartment. When this is accomplished, there is a marked improvement in gait, as well as reduction in pain.

Another very effective device that's overlooked and sometimes even resisted by patients is a cane.

"The use of a cane with the purpose of reducing the biomechanical load on the joints of the lower limb is part of the treatment for patients with knee osteoarthritis. This strategy is expected to increase both independence and tolerance to exercise, allowing a more efficient gait, with a reduction in joint stress." (Jones A, Silva PG, Silva AC, et al. Impact of Cane Use on Pain, Function, General Health and Energy Expenditure During Gait in Patients With Knee Osteoarthritis. Ann Rheum Dis. 2012;71(2):172-179)

A cane should always be used in the hand opposite to the affected knee. Studies have shown this reduces the load on the medial compartment of the knee and also normalizes gait mechanics.

At our center, following stem cell procedures, we almost always temporarily have patients use an unloader type brace after the procedure and advise the use of crutches early on and a cane after that in most cases.