Table 5.

Comparison of data in previous and the present study

Study characteristic	Epinette et al. [14]	Sierra et al. [16]	Present study
Number of cases	418	175	471
Mean age at revision (years)	63.9	66	67.7
The average time from UKA to revision (months)	6.21	6.0	6.1
Most common cause for failure	Aseptic loosening	Aseptic loosening	Other compartment arthritis