Don't patients have two knees?
Harrison
Barry A
BA
Destephano
Christopher C
CC
De Ruyter
Martin L
ML
D019645:Arthroplasty, Replacement, Knee / Q000706:statistics & numerical data*; D016208:Databases, Factual; D006801:Humans; D011183:Postoperative Complications / Q000453:epidemiology*; D012107:Research Design; D018401:Sample Size