RT Journal
A1 Ritter, Merrill A.
A1 Lutgring, Joseph D.
A1 Davis, Kenneth E.
A1 Berend, Michael E.
T1 The Effect of Postoperative Range of Motion on Functional Activities After Posterior Cruciate-Retaining Total Knee Arthroplasty
JF The Journal of Bone & Joint Surgery
JO The Journal of Bone & Joint Surgery
YR 2008
FD April 1
VO 90
IS 4
SP 777
OP 784
DO 10.2106/JBJS.F.01022
UL http://dx.doi.org/10.2106/JBJS.F.01022
AB Background: Range of motion is recognized as an important indicator of the success of a total knee replacement; however, an optimal range of motion has yet to be defined. This study was designed to determine the optimal range of motion for knee function after total knee arthroplasty with a posterior cruciate-retaining prosthesis.Methods: We retrospectively reviewed 5556 primary total knee arthroplasties performed with posterior cruciate-retaining prostheses between 1983 and 2003. The relationship between postoperative range of motion and pain, walking ability, stair-climbing ability, and knee function scores was examined at three to five years postoperatively. The relationship between a postoperative flexion contracture or hyperextension and knee function was also examined.Results: Patients with 128° to 132° of motion obtained the highest scores for pain, walking, and knee function and the highest Knee Society scores. The outcomes became substantially compromised with motion of <118°. Patients with 133° to 150° of motion had the highest scores for stair-climbing. A postoperative flexion contracture and hyperextension were associated with lower scores for pain, walking, stair-climbing, and knee function.Conclusions: The best functional results following total knee arthroplasty are achieved with 128° to 132° of motion. A postoperative flexion contracture and hyperextension of =10° are associated with a poorer outcome except that stair-climbing is improved with more motion.Level of Evidence: Prognostic Level II. See Instructions to Authors for a complete description of levels of evidence.