It's been a year since I had a (successful) knee replacement. Is it too soon to do lipo around the knees (& calves, and thighs)?

Hello dear!!
Thanks for the question and provided information as well. 
You should be ok, but please talk to your primary doctor to see if you are clear for plastic surgery and then I suggest you to book a consultation with a board certified plastic surgeon to discuss the best options for your goals.
Hope this is helpful. Good luck :)

Liposuction of the knees can safely be performed after a knee replacement as long as all the swelling from the surgery has subsided.   Usually, a year would be sufficient in most cases as long as there has been no complications with the healing of the replacement.  Best of luck.

liposuction around the knees after surgery can be done right away but I have people wait 3-6 months then proceed.
You need a formal evaluation by an expert in body shaping and contouring to determine what is best.  Traditional liposuction awake and smart liposuction are old methods and do very poorly for tightening skin or significant skin tightening or contouring.  Small problem areas can be improved slightly by these methods.  The best in body contouring not only removes fat with energy devices like VASER ultrasound but also internally heat the skin with radio-frequency devices such as J PLASMA/RENUVION, InMode BodyTite, ThermiRF to heat the under surface of the skin and tighten it at the same time as fat removal. These combinations are called 4D HIDEF VASER contouring and can only be done by a well . trained body contouring specialist. At the same time fat should be harvested, PRP and stem cells added and injected into muscles or indentations/cellulite to get body shaping and contouring.  This is known as a Brazilian butt lift when you inject the fat to the buttock for contouring and lifting, but fat can also be used in areas such as the chest/breast, arms/shoulders, calves and face.  Cellulite should also be treated with cellfina, sculptra, subcision and/or fillers such as bellafill, renuva synthetic fat, or sculptra.  If skin is very loose before surgery then it will need to be removed such as lower abdominal skin (tummy tuck/abdominoplasty), breast skin (breast lift), arm skin (brachioplasty).  Overall you need a full assessment, but simple liposuction alone will not tighten skin and needs a combination of various methods -- fat removal, skin tightening, defining, fat grafting, skin removal -- to get the best in body contouring and body sculpting.  Dr. Emer.