The incidence and results of manipulation after primary total knee arthroplasty

This study investigates a cohort of patients who required a manipulation after total knee arthroplasty (TKA) to determine whether there was an association between pre-TKA and post-manipulation range of motion (ROM). Thirty-seven of 800 TKAs were manipulated (4.6% incidence); complete data were available for 36 knees. The pre-TKA stiff group (< 110° total arc of motion; n = 16), on average, had 27° less arc of motion before TKA than the non-stiff group (n = 20; p < 0.001). Mean arc of motion in the stiff group was 68° before manipulation and 109° after manipulation (p < 0.001). Mean arc of motion in the non-stiff group was 80° before manipulation and 118° after manipulation (p < 0.001). Patients with pre-TKA stiffness improved from a total arc of motion of 94 to 109 (p < 0.001) while patients without pre-TKA stiffness changed from 121 to 118 (p = 0.169). In both groups, the success of TKA can still be high despite early motion loss and subsequent manipulation.