V54.81 is for aftercare following a joint replacement. If it has been a year & they are out of the healing phase & are just coming in for a check I use V67.09 & the code for whichever joint was replaced (ie. V43.65, V43.64, etc.) V54.82 is for explantation, meaning they had it removed (explanted). Read the description of the code more closely.
Coding Clinic Fourth Quarter 2011 gave some guidance on the use of these codes, which I think will provide some direction as to how to proceed:
"Aftercare:
Code V54.82, Aftercare following explanation of joint prosthesis, has been created to allow the reporting of patient encounters for aftercare following the removal of joint prosthesis. The aftercare includes encounters for joint replacement insertion surgery where it was necessary to stage the procedure or for joint prosthesis insertion following a prior explanation of the prosthesis. There may be a medical need to remove an existing joint prosthesis (e.g., due to infection or other problem), but it may not be possible to replace the prosthesis at the same encounter, thereby requiring a return encounter to insert a new prosthesis. This code may be used with the appropriate code from subcategory V88.2, Acquired absence of joint, to specifically identify the joint."