Again, Peter pretty much has it all correct (for those who aren't informed about joint replacement).
However, I can walk without a limp with less than 0 extension, probably with 10-15 degrees since I did it for decades. In the last five years or so, I went bone on bone and bowlegged (vagus) from the knee joints losing all space medially (inside) and bowing outwards.
For me, I am much more concerned about getting to 120 degrees flexion COMFORTABLY on both knees for doing steps and and one leg squats (half squats are enough for me.)
My knees are VERY STRONG from protecting themselves for decades -- once he gets me decent space, tracking, and removes the severe osteophytes (bone spurs etc.) I expect things to improve RAPIDLY.
Right now, I am working out for both my legs to get them ready, and for my upper body to allow easier movement when my arms and shoulders have to get me up and down while the knees are recovering.
I am not moving a LOT of weight, about 90 lbs for both legs together on the leg extension and about 80 on the femoral biceps (hamstring) curl -- 2 rounds x 2 sets x 10 reps.
Probably going to start taking the weight up in the next week or so (and reducing the reps as needed) as long as the inflammation doesn't get bad. (High weight for lower reps produces STRENGTH as opposed to muscle building or stamina.)
If the knee joints complain, then the current weights and reps will need to suffice.
Similarly for dips and pull-ups to prepare the upper body.
If you want reports, then I would be delighted (I was banned* from BoneSmart.org so nowhere else useful to post my progress except for Facebook.)
* Basically, they banned me on phony charges of "giving medical advice" due to having an inate opposition by the forum admins to telling people how easy a joint replacement CAN be. (Really.)
It bugged the crap out of them.
BTW: For anyone having a joint replacement (especially a hip or knee, total or partial, single or bilateral) I still HIGHLY RECOMMEND BoneSmart.org (no matter what issue they may have with me). There is a LOT of good advice and support over there -- is the closest thing to THIS forum you will find for joint replacement and mostly a bunch of really nice and helpful people.
The admins aren't crazy or bad people, but they have invested so much effort in explaining HOW HARD IT CAN BE to people having trouble (e.g., like people who come here months or years without getting good therapy) that it's hard for them to accept and admit that the other end of the spectrum is possible too.
Always, I explained that MY results were exceptional (but possible) and not the norm. The members regularly expressed interest and enjoyment in my results and methods that worked for *ME*.
My real 'offense' was having a PERFECT HIP REPLACEMENT experience in which I actively enjoyed the ENTIRE experience.
This is literally true -- I had FUN throughout, and have the videos to prove it.
All the videos are short, less than a minute each.
Outpatient Total Hip Replacement (THR) home on same day as surgery -- video was made on my back deck the day of the surgery (I am still wearing the compression stockings and have the hospital tape on my right hand)
The following three videos were made on the evening of Day 1 Post-Op of the Total Hip Replacement when I did 20 minutes of my Combatives & Self-Defense class (one of my friends is running it during my recovery).
http://Outpatient Total Hip Replacement ...as surgery
I am the old, bald guy wearing the DARK SHIRT -- (still with hospital tape on my right hand and actually have the stockings under my long pants too.)
Any problems with movement are mostly the knees -- and not the brand new baby hip -- but the hip flexion was still bit low at this time and now is up around 110-120 degrees easily.
My weight is down a little since this video and I am working on reducing it further (as well as strength & ROM) over the next month (exactly from Sunday) getting ready for Oct 21st, 2014.
Bottom line: My primary goal is to have the BEST possible Bilateral Total Knee Replacement (BTKR) that *I* can have, based on the actual results of the surgery whatever that may be.