Current fit of medial and lateral unicompartmental knee arthroplasty.

Whether failure in unicompartmental knee arthroplasty (UKA) is related to implant design remains unclear. We hypothesize that current available UKAs fit within 2 mm. Forty-eight CTs of cadaveric knees were compared to current available UKA brands. Overall no-fit compared to at least one component within 2 mm is high (91.7%) and worse for males (100%) compared to females (833%). Good fit was observed for the medial but not for the lateral tibia plateau. Seven males (29.2%) had larger dimensions of more than 2 mm. For the widest UKA brand, 12 (57%) males and 2 females (8. 3%) had lateral femoral condyles 3 mm larger. Current UKA's in our sample population fit less on the lateral tibia and on femoral condyles.