Fig 1. Flowchart of the 451 patients included in the study (and reasons for exclusion)^a.

^a All the primary UKAs performed between 2015 and 2017 and all the primary TKAs performed in 2016 within Region Skåne, the southernmost county council of Sweden, were screened for eligibility. To the author´s knowledge, neither any gliding in indication nor altering of the surgical technique occurred during this timeframe. ^b In accordance with the 2D radiograph-based consensus criteria for medial UKA [21], the degeneration on the medial side should present bone-on-bone, have indirect signs of functionally intact ACL, and show full thickness cartilage in the lateral compartment, otherwise be excluded. (Additionally, in the absence of medial/lateral stress x-rays, more than 15 degrees of varus deformity, translation in the coronal plane, and/or lateralization of the patella in the skyline projection also led to exclusion from further analyses in this study.). ^c 70 LINK® Sled prosthesis; 28 Triathlon® PKR, Stryker. ^d 318 Triathlon®, Stryker; 34 P.F.C.® Sigma®, DePuy Synthes; 1 Vanguard® XP, Zimmer-Biomet.