Originally Posted by
clubman
My total knee replacement went poorly and hurts at 95 degrees. I just moved to 127 mm cranks on my town tourer and its working well enough. They're short but you can compensate with a wider range cluster.
I'm looking at revision surgery in the winter. We're going to shave my patella down, as it appears to be a couple of mms thicker than normal and could be the source of restriction. Fingers crossed.
Based on your numbers and going with 120° as what is required for no issues (not positive about this number but, using it as what is needed to accommodate what has become the industry standard of 175 mm cranks), I'm guessing that ~115° might be what's needed to feel comfortable on 165 mm cranks... Just playing with numbers as there is no information that I have been able to find on this issue. I have read about an implant that was designed specifically to accommodate a greater ROM but the results seemed to be inconclusive. Dr's seem pretty happy with achieving at least 90° for their patients and this amount certainly increases the quality of life for any in need of a new knee but that amount is limiting when it comes to cycling. Seems like shooting for at least 145 mm cranks should be a reasonable objective --e.g., by the math above, getting to ~105°.