Originally, total knee arthroplasty (TKA), or replacements, were for older people who had often begun to slow down or limit physical activities. However, the population of patients undergoing TKA is getting younger and more active – and more ethnically and culturally diverse, requiring the ability to flex the replacement in ways previously not needed.
The authors of this study wanted to identify articles in the literature that reviewed the postoperative range of motion of TKA. Among the articles one reviewed TKAs for stiffness and flexion (bending) contracture before the surgery. The findings of that study were that the more limited the flexion and the stiffer the joint before surgery, the more reduced the flexion would be after surgery.
Another study, looking at physiotherapy after surgery, determined that postoperative physiotherapy was particularly important, especially now that hospital stays after surgery are shorter than they have been in the past. The study also notes that the effective use of pain medications to encourage mobilization and flexion plays a role, as does patient motivation. It was also found that the patient’s state of mind after surgery can also have a significant effect.
Some studies looked at technical errors during surgery, while other examined motion of the implants. Finally, some studies reviewed the actual type of TKA design, how it is attached to the bones and how it operates.
The authors discuss the findings of the different studies in relation to the need of the receiving population, some of whom require the knee to be very flexible due to the need to squat or bend, for example. The researchers say, however, that merely the choice of the prosthesis will not ensure that the patient will regain suitable flexion of the knee because of the many variables that come into play, as evidenced by the studies that were reviewed.