Preoperative factors:
(1) preoperative range of motion (ROM)
(2) obesity and deconditioning
(3) joint disease underlying the need for the joint replacement
(4) revision surgery and the reason for reoperation
Technical factors:
(1) malpositioning of the impant
(2) geometry of the implant design
(3) postoperative joint line
(4) soft-tissue conditioning
Postoperative factors:
(1) post-operative pain
(2) reflex sympathetic dystrophy
(3) post-operative infection with or without septic loosening
(4) aseptic loosening of the prosthesis
(5) arthrofibrosis (scarring in and around the joint following surgery)
(6) increased thickness of the patella following surgery
(7) heterotopic ossification
Additional factors that could be added:
(1) patient attitude
(2) quality of the rehabilitation
