Knee replacement (or knee arthroplasty if you feel like being a smartypants) is a surgery that replaces the part of your knee that bears your weight. It is done to help alleviate pain or because of a physical disability. Some of the main reasons for a knee replacement could be severe rheumatoid arthritis, severe osteoarthritis or some sort of trauma to the knee.
I've known two people who have had knee replacements, my aunt and my previous boss, and it's because of them that I know so much about getting knees replaced. (Mainly my old boss's fault, she had a tendency to overshare about anything to anyone, willing listener or not.) My aunt is a mix of the trauma/osteoarthritis category as she completely shattered her knee because my cousin left his skateboard at the bottom of the stairs during the skateboard fad of the 1990s (and she's never let him forget it) and that combined with the wear and tear of age led to osteoarthritis. My boss was more basic; she had severe osteoarthritis that wasn't helped by being on her feet all day at the shop.
One of the first steps to knee replacement (besides asking your doctor if the procedure is right for you) is making a few adjustments to your lifestyle. A few simple things that can be done all on your own are things like getting some exercise (within reason of course, I mean you are considering knee replacement surgery for a reason), getting your body in shape (now's a good time to drop the cigarette habit, or at least cut back), and practicing your physical therapy moves (so you don't spend the first thirty minutes of your first therapy session going "I'm doing what again?"). My boss, for example, had to lose twenty pounds before her surgery because getting rid of the extra weight would make her recovery easier on her and it would mean less strain on her brand new knee.
It's also a good idea to make arrangements for help around the house after the surgery, especially if you live alone, because this is a major surgery and it's going to take a while for you to be back to full capacity. If you're thinking to yourself "Nah, I can handle it", may I remind you that you are replacing a part of your body?! This was a hard concept for my boss to wrap her brain around; she basically thought it was going to go: knee surgery on Friday, back to standing on her feet all day at the shop on Monday. Now I'm not saying you get to just lay around all day watching The Price is Right, it's actually very important that you do home therapy exercises and move around because no activity means you won't recover your flexibility and strength in the new knee. You will want to make sure you get rid of anything that may make it easier for you to trip, like throw rugs or in-the-way furniture. It's also a good idea to install a shower chair and some hand rails near your toilet, these things will make your life easier in the long run.
As for the actual surgical process, it goes something like this:
- You'll go to the hospital and they'll perform the basic pre-operation procedures you would expect, giving you a gown and an IV, getting you situated on the operating table, shaving the area around the knee if necessary, and possibly inserting a catheter. (I don't know if this last one happened to my aunt or my boss and, for obvious reasons, I'm happy I don't.)
- Next the anesthesiologist will put you under and monitor your vitals so from this point on you won't know what's going on. (Well you'll know what they are doing but you won't be aware of it.)
- The knee area will be disinfected with antiseptic and the doctor will make an incision. The incision will be a straight line from about an inch or two above the knee down to about an inch or two below the knee. (At least that's about how long my aunt and my boss's were.)
- The doctor will start by removing the damaged parts of the knee by basically trimming the end of the femur (thigh bone) and the tibia (shin bone) where the cartilage and bone have been worn down. The part of the patella (kneecap to those of us not medically inclined) that is in contact the femur and tibia is removed as well.
- Next, the prosthesis is put into place using a surgical cement. There are three parts to your new knee: a piece to replace the surface of your femur, a piece to replace the surface of your tibia and a piece to replace the back of the patella. These pieces can be made of metal, special plastic or ceramic.
- After your new hardware has been put into place, the incision will be closed using either stitches or staples. (The staple option was used for my aunt and boss, just in case you were burning with curiosity.)
- They may put a drain in to help get fluid out of the incision but other than that, after applying bandages, the actual surgery part is done and it's on to recovery.
Basically after you get out of the operating room, your physical therapy begins. Well, of course this is after your anesthesia wears off and they make sure your vitals are good to go. Your physical therapist will help you come up with your routine for actual therapy sessions and for your at home exercises. Also, they may have you use a continuous passive motion machine also know as a CPM or as my aunt lovingly described it, the torture machine. It's not actually a torture machine obviously, though it can't be very comfortable to use, it's a necessary evil. This machine moves your knee through its range over motion, which is essential because getting your knee moving after surgery is very important for healing properly. Now they may have you use a CPM almost immediately after surgery but it shouldn't hurt too badly because you'll be on pain medications.
Now the recovery work is going to begin. The recovery time for knee surgery is about 3 months, most of which you'll be doing outside of the hospital. My aunt's recovery took about that long and her physical therapy regime consisted of visits to a physical therapist and at home exercises. I had to take her to a few of her therapy sessions since she had her right knee replaced so she wasn't able to drive for about 8 weeks. From what I saw, her sessions were pretty simple. The therapist would help her through some exercises to work on the range of motion of her knee and to work on building up her strength again. One important thing you need to remember is that movement is good for you while you're recovering; walking is a good exercise but you still have to do the exercises prescribed by your doctor.
So that's it, that's knee replacement surgery in a nutshell. If you are more interested in the technical, medical language, here's a list of the websites I used to get my technical information. There's also a Youtube video link for an animation showing a knee replacement if you're a visual person like me. (And FYI, just typing knee replacement surgery in Youtube will give you videos of actual surgeries, not for those who are squeamish.)
Sources
http://en.wikipedia.org/wiki/Knee_replacement
http://www.hopkinsmedicine.org/healthlibrary/test_procedures/orthopaedic/knee_replacement_surgery_procedure_92,P07673/
http://orthoinfo.aaos.org/topic.cfm?topic=a00357
http://www.youtube.com/watch?v=y8-nN8NV_5E