50-year-old male patient, stock boy in a supermarket chain. He reports progressive inability to bend over for years and lately difficulty in getting up from seats and daily pain. He can no longer walk well.

He reports progressive deformity of his legs, which are becoming more and more separated.

He is fitted with a knee prosthesis, correcting his valgus deformity, which also allows him to correct the compensatory valgus of the other knee and return to work without complications. He was informed that the other knee might require surgery in the future, but for the time being he said he did not need it due to the improvement of the discomfort in both knees when the main deformity was corrected.