Two knee replacements at once: the good and the bad.

So would you like one knee, or two?

It is called bilateral knee replacement. Two knees. At the same time. Usually, it is performed by one surgeon; at times it is done simultaneously by two surgeons. And it is a massive trend in knee replacement nowadays. We discuss the merits of doing two knee replacements at once below. And we have included the stories of a few recent bilateral knee patients to help you decide if you want one lump... or two.

Doctors are split on their opinions of this surgery.

Some orthopedic surgeons simply will not perform two knee replacements at once, preferring at least a three-month separation between surgeries. Many suggest that age, physical health, and mindset play a role in the final outcome. And that recovery is more demanding for two knees vs. one. There is also evidence that younger patients have a harder time recovering in the short-term, only to do well over the long-term. Other surgeons agree to perform double replacements knowing that it can be better for the patient to just get it done at once so they can get back to their lives more quickly.

The Consequences of this Trend

The problem is that with this seemingly irreversible trend toward “doubles”, patient results have suffered. Lisa Alarcon, Director of Physical Therapy at Michigan VNA notes that “if your knees are bad enough so that one knee cannot really support all of your weight then go ahead and do them both.” She also suggests that for rehabilitation, bilateral surgery has it advantages in that “you cannot cheat” when you are doing your rehab exercises because both knees are in recovery. Patients with two knee replacements at once can do very well in rehab because of this balanced recovery. Of course, there is double the danger of succumbing to scar tissue before you can get to a good range of motion. Lisa discusses the dangers of scar tissue here.

Trends in Bilateral Replacements

I recently took a look at a study on bilateral knee replacement surgery published by Hospital for Special Surgery, where much of the pioneering behind knee replacement was done. I was surprised at what I found. The number of bilateral total knee replacements performed between 1999 and 2008 increased by 75%. In 1999 bilateral procedures accounted for 3.7% of all knee replacement operations. By 2008 they accounted for 6% of operations. The average age for bilateral surgeries during that same time frame decreased by 2.5 years.

Not All Good News

However the rate of comorbidities (the presence of one or more additional disorders) increased measurably during this time frame. More complications and difficulties were seen for those with two knee replacements. Here is an article that discusses the fact that there can be twice the complications for bilateral patient vs. single knee patients: HSS Article

Obesity as a Factor

Clouding matters further was the fact that obesity increased by 131% during this time frame. It is all related as the number one cause for knee replacement surgery is obesity. Dr. Stavros Memtsoudis, the highly respected orthopedic surgeon who oversaw the study, said patients “should critically look at themselves and talk to their physicians about how their health status plays into the...