Ossur Cold Rush Cold Therapy Unit Review

Ossur Cold Rush Cold Therapy Unit Review

One of the first things you hear after knee surgery is R.I.C.E: rest, ice, compression and elevation. The R.I.C.E protocol is an excellent way to manage post-op swelling and hasten recovery.

Cold therapy (also known as cryotherapy) reduces inflammation and pain, by applying cooling, and in some cases compression, to the affected area. A cold therapy machine is the best way to achieve this, far superior to using ice packs, and one of these machines is a post-op must have. If you're considering purchasing one of these, first consult your physician or primary healthcare provider and seek appropriate advice and supervision prior to use.

In the world of cold therapy units, there are two types: motorized and non-motorized. The latter can be had for a fraction of the cost of motorized units, but a motorized unit has some advantages. 

Many non-motorized units are gravity fed, meaning that for the cold to get to your knee, a reservoir of ice cold water must be located higher than the level of your knee. As you may spend much of your post-op recovery time lying around, unless you have a table nearby that's higher than the level you will be lying, a non-motorized gravity fed unit won't be feasible. Motorized units have a pump, which eliminates the need to place the reservoir higher than your knee and allows for more placement options.

The other advantage of a motorized unit, and this applies to the Ossur Cold Rush, is that the amount of cold water flowing through the cooling pad can be varied. This allows you to adjust both the compression effect and cooling to a level that suits you. Personally, I found this indispensable.

One thing to note with this and all cold therapy units, is that there must always be a barrier between the cooling pad and your skin. These units get cold enough to seriously damage your skin if applied directly to it for any length of time. From my experience, a compression bandage was the ideal barrier, since it also provided additional compression to the knee. 


The Ossur Cold Rush is a powerful, compact, silent and competitively priced cold therapy unit. One thing that stood out is the flow rate - it's very strong for such a small and quiet unit. It provides excellent cooling and compression, even if your knee is elevated well above the reservoir. If you position the reservoir either the same level of your knee or just above, you can maximize the flow rate and the effects are more pronounced.

This little machine is simple to use and set up. Fill the reservoir with ice to the recommended level, fill with water to the recommended level, connect the knee pad and switch on - that's it! The water will stay cold for about 4-6 hours, so you won't have to change it every time you want to use it, provided it's within that time window.

One thing I found very useful was to use frozen bottles of water instead of ice cubes. These machines really chew through ice and if you use large blocks of ice, it will last longer. This machine will hold four frozen 500 ml bottles easy. Using frozen bottles of water also has the advantage of being very simple to change. Just take out the bottles and replace with fresh frozen ones. No need to lug to a sink and dump out water every time you want to replenish the reservoir. Also, no need to be constantly buying ice. Having eight bottles handy, four in use and four frozen, will ensure you're always ready to go and makes things a heck of a lot easier.

The knee pad for this unit deserves special mention. The Velcro straps that are used to secure the knee pad work well. I'd advise using an Ace wrap or other bandage to apply the pad to the knee though, it gives better compression than the Velcro straps. What I love about the knee pad is it fits your knee well whether it's straight or in flexion, allowing you to comfortably ice you knee in whatever position is comfortable for you. The knee pad is very robust and has not deteriorated or leaked once.

The one thing I'd watch out for with this machine is condensation. While the tube that runs between the reservoir and knee pad is insulated, it still gets pretty cold and generates a lot of condensation. So much so that if you're using this in bed, it might be wise to lay down a towel under it so that there isn't a damp spot under the tube when your finished. Other than that, this machine works like a charm and has done so without a hitch for months of every day use.

So in summary ...

What's good: compact, quiet, powerful, durable, competitively priced, knee pad fits well.

What's not: condensation around the flow tube can leave things a bit damp.

Final Verdict

Ossur is a well known brand in orthopedic appliances. The Cold Rush reflects the Ossur brand's attention to detail and quality. This compact, motorized, cold therapy unit is extremely easy to use and has a strong flow rate, which is adjustable - providing control over the amount of cooling and compression provided. These machines go through ice pretty quickly so do yourself a favor and use frozen bottles of water instead of ice. It will last longer and replenishing the reservoir between uses will be much easier.

If you'd like to purchase this unit, you can find it here. Still on the fence? Feel free to contact us or leave a comment for more information.


  • Nora

    I had knee replacement surgery on June 5, 2018. At that time the surgeon began cold therapy with an Ossur Cold Rush, B 232000310. I had been home 1 week (5 weeks after surgery) when it quit working. I called Ossur to ask for a replacement. I was told to call the one who ordered it to get a replacement. The nurse told me to just use ice. End of subject. Having a rather small refrigerator and two of us on ice packs has been a stretch. So the Ossur was a major letdown for us in the following weeks. I definitely would NOT buy one myself! NO customer support

  • Knee Surgery Recovery Admin

    Hi Angela, none that I know of. For bilateral cold therapy all I can recommend is doubling up on a good knee cold compression wrap. Hyperice makes an excellent one, as does Übertherm and Shock Doctor.

  • Angela

    Having bi lateral knee surgery – which coolers have bi lateral knee pads?

  • Knee Surgery Recovery Admin

    Hi Marnie, this hasn’t happened to me … sorry I can’t offer any advice on how to fix it. My Cold Rush unit has worked almost flawlessly thus far. The only problem I ever had was the hose got clogged once, but with a little cleaning it soon was good as new.

  • Marnie

    We have the cold rush system and have used it and loved it for the past 2 years. We set it up yesterday to use and the water was leaking out of the hose where it joins the unit. After wiggling the hoses in a bit tighter, the leakage stopped there and proceeded to pour out from the bottom of the unit – it appeared to be through the cracks of the screwed on plate.
    I am looking for any info or advice on this situation. Has it happened to you and what could possibly be done to fix it.
    Ossur told me it’s not under warranty and nothing they could suggest. Thanks

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