Why is a Tourniquet Used in Knee Joint Replacement Surgeries

Boyd W. Haynes III, MD

Everyone knows that a tourniquet reduces or completely restricts blood flow.  We all learned that watching TV westerns, like Gunsmoke. Expendable guest stars regularly got bitten by the token diamondback rattler while crossing through Death Valley. They quickly tied on a tourniquet to slow the venom’s progress through the bloodstream to the heart, as the closest doctor could only be found a hard day’s ride away. If you wanted to know if Festus survived his snakebite to chew tobacco another day, you’d have to tune in next week.

What you might not know is that tourniquets are often used in surgery today, especially in orthopaedics.  In this article, I’ll discuss the pros and cons of tourniquet use in knee replacement surgery and why some surgeons choose to use them, and some don’t.

I have my own opinion and personal preference for my patients, based on over 30 years in Orthopaedic practice and thousands of knee replacements I’ve performed. I’m also going to reference a very large study published in December 2020 that studied patients who had knee replacements in the US, Europe, Asia, Australia and Canada.  If you are interested, you can look at the findings here: https://www.cochrane.org/CD012874/MUSKEL_what-are-benefits-and-risks-using-tourniquet-knee-replacement-surgery

Pros

1. No/less blood loss to the patient while the knee replacement is underway – After exsanguinating the leg (to drain of blood by raising it above the heart), a tourniquet is inflated on the thigh of the leg above the knee which is to be replaced. This completely stops blood flow to the leg below the tourniquet.
2. No/less blood in the surgical field while the knee replacement is underway – After exsanguinating the leg, the surgeon has a clear field of vision when operating.  Obviously, this is helpful to the surgeon in many ways.

Cons

1. More post-operative thigh pain in some patients
2. More post-operative bruising and swelling in some patients
3. Complications rates are higher – 5% with vs. 2.9% without tourniquet

It’s a Wash

1. Knee function one year after surgery is about the same with/without use of a tourniquet
2. Patient satisfaction six months post-operatively was about the same regardless of use or no use of a tourniquet.
3. Patients who rated their quality of life one year after TKA also reported about the same levels of satisfaction.

Each Orthopaedic surgeon will have his or her own reasons for using a tourniquet or not.  Discussing the potential use of a tourniquet is an important question to ask your surgeon, before having your procedure, to ensure you are fully informed about the risks and benefits.