Knee Replacement “Clicking”

Following , patients sometimes report hearing clicks or a clicking sound during certain activities or at a certain point or points during their gait cycle.  In most cases, this sound is believed to be benign and is not associated with pain or other adverse consequences.

So what causes this clicking?

To answer this question, it is helpful to understand a little bit about the nature of total knee replacement.  In knee replacement, the ends of the bones that make up the knee joint are “resurfaced” with metal and plastic components.  The surgeon uses specialized instrumentation and surgical technique to properly align the implants to the bones and the bones to one another.

This alignment is not straightforward because in the replaced knee joint, as in the normal knee, the bones are not “mechanically interconnected”; rather the joint is constrained by the remaining soft tissue (ligaments, muscles/tendons) and the conformity of the implant components.  During the knee replacement operation, the surgeon works to optimize range of motion and joint stability through proper alignment and sizing of the implant.

The resulting tension in the replaced joint can, therefore, vary slightly from patient to patient and can be different within the range of motion of a single patient.  That is, some patients may have “tighter” knees or “looser” knees or a single knee can be “tight” in flexion, but “loose” in extension and vice versa, but in general, some degree of laxity is desirable to allow for adequate motion.

Because there is almost always some laxity in a replaced knee, clicking can sometimes be heard as a result of contact between the metal and plastic components during activity.  Often it is heard during a transition from low or non-weight bearing to weight bearing.  For example, a patient may hear the click while walking as the leg comes out of swing phase and makes contact at heal strike.  For the most part, the clicking is usually not associated with any adverse conditions.

Comments

4 Responses to “Knee Replacement “Clicking””

  1. Matt Hopkinson on January 29th, 2009 8:27 pm

    In my extensive physiotherapy experience, quadriceps control also plays a role with this. If there is a decrease in optimum strength the movement becomes sloppy and uncontrolled causing the knee to jar. Good basic tone will also give the knee a tighter feel. Finally patients with both hip and knee replacements will initally be understandably focussed on their new joint. Instead of feeling the softer arthritis feel, a new harder feel is evident. As they get used to having a new joint and enjoying its capabilities (without the pain) they no longer notice the clicking.

  2. L Serpe on January 30th, 2009 2:44 am

    Matt,
    The idea that initial laxity and subsequent “clicking” would be mitigated or perhaps eliminated by post-op rehab and strengthening of surrounding musculature is plausible. Thanks for your input and perspective on this topic!

  3. robert johnson on August 12th, 2010 7:45 pm

    The above article sounds like the kind of information we hear BEFORE the operation. On the surface ,it makes sense and seems reasonable. But there are two problems with this information.

    1. There is clicking, and then there is CLUNKING. Ask someone on the Topix.com thread: “Popping and clunking sounds coming from new knee” what they think of this article, and I think alot of them will tell you this is what they were told, but that’s not the issue. Clunking is a much more serious variety of clicking, and apparently it is not all that uncommon.

    2. Because of this propaganda that clicking is to be expected, when you find yourself in the situation post-op where you are experiencing clunking instead of clicking, it is extremely difficult to break through to the Doctor and his assistants that your understand about the clicking expectations, but that’s not what you are experiencing. It is very hard to convince them that something is wrong, because they have this built in excuse of clicking as normal.

  4. admin on August 13th, 2010 1:05 am

    Hello Robert,

    Thank you for your comment. You are correct, there is a distinction between the typically “benign” clicking described above and more serious “clunking” which can sometimes occur (and unfortunately, what you seem to be experiencing). A clunking involving the patella (patellar clunk syndrome) is described in the following post:

    http://www.totalkneeweb.com/patellar-clunk-syndrome-complication-following-knee-replacement-surgery

    There are also related posts listed at the end as well.

    Hopefully you find this additional information useful.

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