Rotational osteotomies in either your femur (DFO) and/or your tibia (HTO) can be necessary to obtain a good outcome. All of us have variations in the way we are build, however some persons are build rather extreme. If either your femur or you tibia are rotated too much in either directions, this can cause kneecap problems.
Femoral (DFO) or tibia rotational osteotomies
Are your hip or thigh bone (femur) turned or rotated too much inwards or outwards? If you kneecaps are pointed towards each other you call this squinting patella. For some people this can lead to anterior knee pain (patellofemoral pain) and/or patella instabiity. By clinical examination this can be ruled out like seen below. However clinical examination is difficult. More precisely this torsional abnormalies can be measured by either CT or MRI of femoral neck + knee + ankle. If your rotation is abnormal and you have significantly problems you can be helped out by derotational osteotomies. Sometimes only the femur (Derotational Femoral Osteotomy = DFO) or only the tibia (High Tibia Osteotomy = HTO) needs to be rotated. Eventually both have to rotated simultaneously.
This girl was severely troubled by anterior knee pain for several years. Physiotherapy guided exercises for hip and knee did not work out. She also tried shoes inlay.
This is a typical example of a young women having had anterior knee pain for several years. Notice how much she can rotate in her hips. In one direction it´s too much, while in the other direction it´s too little. This is due to increases femoral anteversion.