Total knee arthroplasty with limitations of flexion.

UNLABELLED: Does total knee arthroplasty (TKA) increase mobility in stiff knees, where flexion is restricted due to degenerative changes associated with osteoarthritis, inflammatory disease, hemophilia, or post-traumatic sequelae also affecting soft tissue? The results of one hundred twenty eight TKA from five specialized centers were retrospectively reviewed. Only knees with pre-operative flexion less than 90 degrees were included. Forty six of these also had severe flexion contracture (>20 degrees). As a result of the arthroplasty, the flexion increased by 23+/-17 degrees in group 1 (stiff flexion only, 82 cases), and by 17+/-15 degrees in group 2 (combined stiffness), in which the total range of motion (ROM) increased by 39+/-21 degrees. Improvements in mobility were greater in the cases with severe pre-operative stiffness. One-year functional results did not correlate with final flexion. Flexion at last follow-up did not depend on pre-operative flexion; however, in group 2, final postoperative ROM did correlate with pre-operative ROM. Complications concerned mainly those cases with severe stiffness, in which extensive quadriceps release was performed (two cases of skin necrosis, one infection and one rupture of the patellar tendon), or the patients of group 2 (one skin necrosis, two femoral fractures, one infection and one sciatic nerve palsy). Hemophilia was a factor of poor prognosis. Overall, TKA provided significant flexion gain. It often required tibial tuberosity osteotomy, to improve exposure and prevent injury to the extensor mechanism. Extensive quadriceps release should be reserved to post-traumatic cases with intact skin and no recent infection.

TYPE OF STUDY: level 4 retrospective.