Background: There may be a perception in clinical practice that any deficit in the patellar tendon reflex arc could be attributed to a total knee arthroplasty (TKA). There is no evidence in the literature to support this conclusion. 
Methods: Sixty-six knees were examined to determine whether TKA affects the patellar tendon reflex.
Results: There was no difference observed between the knees with a history of TKA and those knees without a history of TKA.
Discussion: There is no plausible reason that TKA should affect the patellar tendon reflex. Despite this, in clinical practice TKA is often thought to be responsible for absent patellar tendon reflexes. This study supports the hypothesis that there is no effect of TKA on patellar tendon reflexes.