Recurvatum deformity

This is a rare case of reverse deformity. Here the knee goes out and behind while walking, making walking without support extremely difficult.

When you see this lady walking, you can appreciate how her knee buckles behind and outside. She can walk with difficulty with walking stick.

 
Her knee position. The knee goes behind, a deformity called "Recurvatum"
 
The knee also goes outside, a deformity called "Valgus"
 
See her walk after surgery. Now she is able to walk without support and the knee is stable