Squinting Patella – Rotational osteotomies

By LB-Admin

Squinting Patella - 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 and if she turn her feet in frontal direction she have squinting patella. 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.

On the picture left you can notice that she her knee caps point inwards. On the picture on the right you can notice that her left knee is not that extreme anymore. Her femur and tibia both were rotated 10 degrees. She previously suffered for chronic anterior knee pain. In a case like this you call it 'miserable malaligment' or better 'tetratorsional malalignment'. Since she was desperate, she had visited several doctors, orthopaedic surgeons as well as several physiotherapist. She was tolded that everything was normal. She had several times been told that she was a hypochondriac and she should consult a psychologist.

Picture at left is a CT scan 3D reconstruction. Try to notice the rotation of the left femur. It is rotated too much. The patient have had recurrent patella dislocation. She had previously undergone MPFL reconstruction, however this failed after a couple of years. She had a derotational femoral osteotomy and a revision MPFL reconstruction and responed positively. However she as most others had to have the plate removed when the osteotomy had healed securely. You can see the x-ray on the right, before the plate was removed.

The typical patients with this problem often have a long history, seeing many physiotherapist, doctors and orthopedic surgeons, and have been told nothing is wrong or have undergone failed surgery . Often when the surgery and recovery (often with plate removal as a second surgery) the patients ask me why their problem was not noticed before hand and regret the many years wasted. I naturally understand why they are upset.

This young women above had patellofemoral pain since she was 12 years old and was succesfully operated

This 30 year young man became pain free and active, however he was really sad for the years he felt he had missed

Importantly many patients are told that their tibial tubercle is located to much to the outer site (lateral) and therefore they are offered at medialization of the tibial tubercle. Nevertheless is the problem are commonly a result of an external rotation of the tibia and a rotational osteotomi gives better outcome. So if you is told you have and increased TT-TG distance be aware of this.