Sunday, March 23, 2014

Latest Unloader Knee Braces

I often tell people that the theory behind unloader knee braces for unicompartmental osteoarthritis has been around for many years. The problem was that the initial products designed to perform the task were below par and did not achieve the goal.
This put clinicians off referring their patients for bracing.
Around 7 or 8 years ago this changed as effective products entered the market and good results followed.
I have previously posted on a number of different products that had good results but as time has moved on what has changed?

Once clinical efficacy was achieved, a lot of the focus shifted to the experience of the user. Comfort, ease of application and weight were all targeted to increase compliance and widen the target market.

From the "original" unloaders, Ossur's Unloader One was one of the lightest as it was a single hinged device. This cut down on bulk and weight but its main limitations were that it only unloaded the joint in extension (making it unsuitable for those who had symptoms with a flexed knee such as climbing or descending stairs) and it offered no additional stability for those with ligamentous problems like ACL deficiency.

The Donjoy OA Adjuster addressed both of the above problems as it unloads throughout range and supports the ligaments of the knee (it is based on an ACL brace design) but it was significantly heavier than the Unloader One.

As Ossur and Donjoy (DJO Global) tend to be the innovators in knee brace development, I thought it was about time to see what had changed.

Ossur have not had a noted addition to their unloader range for the last few years but are probably due for an announcement.
Donjoy have added an update to the OA Adjuster range with the OA Adjuster 3. This is essentially the same unloading mechanism as the previous version but it is significantly lighter and has a slightly shorter calf cuff length. There are also improvements in the padding and liners while the durability and ligamentous support remain.

The biggest innovation from Donjoy is the OA Nano.

The design is based on the OA Adjuster, but magnesium is used in the frame to drastically reduce the weight.
A lighter frame makes application easier (as features such as the anti-migration strap are no longer required) and the malleable thigh and calf  ensure a customizable fit. Its main limitation is its effectiveness on sizes above XL. Larger people are advised to stick with the strength of the OA Adjuster 3.

As need develops, so does technology. The braces listed above are improvements of existing designs. I expect a new mechanism will be released in the next 18 months that will challenge the traditional designs.
Product advancement is always welcomed and we are sure to face interesting times ahead.

Saturday, July 23, 2011

Different Aspects of Arthritis Knee Pain

It has long been known that the perception of pain is multi-factorial. In the case of knee osteoarthritis it is more than the wear of the joint surface that leads to the experience of pain.

Red heads have been shown to be more sensitive to pain and there are differences in perception between men and women. Women are more sensitive to pain (but are just as good as men at tolerating it).

A recent Korean study looked at knee x-rays and the level of reported pain in over 650 people. Those diagnosed with depression experienced more pain than others with the same level of osteoarthritis.

It has been suggested that a comprehensive treatment should address both the depression and the osteoarthritis. The role of chronic pain in potentially contributing to the depression should also be investigated.

Living with pain is difficult and the more that is understood, the better the available treatments will be.
For more on the Korean study, click here.

Wednesday, June 29, 2011

More Stem Cell Research

There are many reasons to delay major surgical intervention until the benefits significantly outweight the risks. One of these is that the passage of time allows for the development of new treatments.

A simple point worth considering: There is likely to be more research into osteoarthritis treatment in the next 5 years than there was in the last 15.


Money, that's why.

Multinational companies spend their research and development funds on areas most likely to produce a return on their investment. Easy problems are solved first, then more difficult problems are addressed in order of their market size. The good news for sufferers of osteoarthritis is that the large baby boomer population is reaching retirement age. The number of people with knee osteoarthritis is rising exponentially and with it potential profits for the company that comes up with a minimally invasive treatment that is effective for the majority of patients.

Stem cell research is one area showing a lot of promise in the treatment of many diseases. On top of the first human arthritis stem cell research in the UK, another study is looking at the ability of stem cells to repair meniscal tears - a common sporting injury that often leads to early onset osteoarthritis. Both of these studies are of limited size and both involve the surgical implantation of cells but they represent important steps on the path to the goal treatment of a simple injection that has major benefits (for more on this study, click here.)

Every year you are able to delay a knee replacement gives researchers more time to develop new treatments. This is why I am a big advocate of (essentially risk-free) delaying tactics such as weight loss, quads exercises, and unloader knee braces.

Saturday, May 28, 2011

Lateral Heel Wedges

Medial compartment osteoarthritis often leads to a varus deformity commonly known as being knock-kneed. This alters the biomechanics of the leg and the angle causes an increase in the percentage of body weight taken through the worn half of the knee.

For this reason many treatments for unicompartmental knee osteoarthritis look at addressing this deformity.

These include:

Lateral Heel Wedges.

Lateral heel wedges are thought to work by raising the outside border of the heel that in turn unloads the medial compartment of the knee.

A recent study in Melbourne, Australia looked at the effect of patients wearing these wedges for a period of 12 months.

They found that those wearing the lateral wedges (5 degree inclination) had no difference in pain scores to those in the control group who had zero degree insoles.

The authors also looked to see if there was any difference in the progression of arthritis but again found no difference in cartilage loss or the presence of bone marrow lesions.

The conclusion: Lateral Heel Wedges provide no symptomatic or structural benefits when worn for a period of 12 months.

This is in agreement with the Knee Osteoarthritis Guidelines published by the American Academy of Orthopedic Surgeons in 2008 (see AAOS Knee Arthritis Guidelines) who included heel wedges in the list of treatments that have been shown to be ineffective.

For more information on the Australian study, click here.

Sunday, March 13, 2011

Chondroitin - New Research

Chondroitin has long been found combined with Glucosamine in supplements claiming to help those suffering from osteoarthritis. The majority of the studies done have been either on Glucosamine alone or on Glucosamine plus Chondroitin.

A new paper published in The Annals of the Rheumatic Diseases has looked at Chondroitin in isolation and the effect it has on the progression of osteoarthritis.

What makes this study different is the outcome measures used to examine the effect of Chondroitin. Previous studies have used subjective measures (such as reported pain and ability to sleep) with objective functional measurements (such as timed walking tests, ability to climb stairs).

As the object of this paper was not to see if the supplement decreased pain or improved activity but if it changed the disease process, MRI scans were used to "keep score".

The scan measured changes in cartilage volume, lesions in the subchondral bone (an important predictor of severity) and synovitis as well as noting any reported changes in symptoms.
The study was randomized, double blinded and placebo controlled and the total number of patients was 69.

The treatment dose was 800mg of Chondroitin once a day.

The results showed that the treatment group:
  • Had less cartilage loss at both 6 and 12 months
  • Had less subchondral bone marrow lesions at 12 months
  • Had no difference in reported symptoms
This is an important study as it demonstrates that Chondroitin alters the progression of osteoarthritis, offering some form of protection to the structures that make up the joint. Although there was no significant difference in symptoms such as pain over the 12 months observed, it would be hoped that a better preserved joint will result in better outcomes over the medium to long term. Obviously, there is more work to be done investigating the effects of Chondroitin, especially over a longer period of time so it can be determined if the changes decrease the symptoms.


It can be difficult to find Chondroitin supplements on their own. I was unable to find any 800mg (or 400mg) Chondroitin but was able to find 600mg here. I am personally going to give this a go for at least 12 months. I am particularly impressed by the changes in the bone marrow lesions and although I do not currently have any myself, I consider anything that may prevent them of high importance.

It is much easier to find Chondroitin combined with Glucosamine, I was able to find this product (3 caps = 1500mg Glucosamine / 750mg Chondroitin) with one years supply only costing $50.

This works out significantly cheaper than getting Chondroitin on its own (as there is much more competition in this market). Having said that, I am a follower of the evidence and will stick with the Chondroitin until a study comes along to show the benefits of the combination are better than the single supplement. The evidence to date on Glucosamine has been borderline and although it is a safe supplement I am unaware of a study such as the one mentioned above that shows a strong positive effect from its use.

This study produced some exciting results and it should inspire a lot of follow up research. It is enough for me to go from taking nothing more than fish oil to giving Chondroitin a one year trial.

To read more on the Chondroitin article, click here.

Wednesday, January 26, 2011

Prehabilitation - Exercise in the lead up to surgery

It is never too late to start exercising.

I spend a lot of time educating people about the benefits of exercise. Increased strength and function, decreased pain and the potential slowing of the disease process are all good reasons to do a knee exercise program.

Physical therapists have long noted that those with good quadriceps muscles on average recover quicker following knee replacement surgery. Those who have decided to go ahead with a joint replacement should not cease normal activities or feel they have nothing to gain from the lead up to their surgery.

A recent study in the Journal of Strength and Conditioning Research looked at the effects of 'Prehabilitation' - an exercise program done in the period before surgery.
Although the exercises were only done for between 4 and 8 weeks prior to surgery, the exercise group outperformed the control group in both leg strength and ability to perform functional tasks.

It really is never too late to start and anyone on a waiting list for surgery or who feels that the time for them to consider it is close should be looking to exercise.

Exercise has consistently shown to offer benefits from diagnosis through to post-operative rehabilitation.
It does take will power and persistence but offers good results. Despite this, thousands of people ignore exercise and spend a fortune on unproven remedies.

Sometimes you need to do the work to get ahead. If you have been unable to get started with an exercise program due to pain in your knee, seek the help of a physical therapist and see what you can achieve.

For more on the 'Prehabilitation' article, click here.