I saw this gentleman, David, in 2015. He was a fit and active architect of 55, but had a bilateral varus deformity (bow legs) that was becoming progressive.
You can see on the left side of these long-leg films the extent of the bowing, which was more marked on his right side. Long-leg weight-bearing films like this are used for calculating the site and extent of the osteotomy for optimum correction , and you can see this marked on his right knee.
The problem reached a point where the deformity was progressing rapidly, and he became very upset with his immobility as well as the cosmetic appearance of his bent legs.
He underwent the relevant High Tibial Osteotomy (HTO) surgery and says it has given his life back. He can now walk normally and did so within a few weeks and is keen to get the other knee done.