BOW LEGS & KNOCK KNEES

Do you know that children up to a few years old have some degree of bow-leggedness?  They do and its due to the time they spent in the cramped space in the womb.  Usually, babies have a bigger space between their knees and the soles of their feet face each other.  When they start to walk, they may appear to be bowlegged.  However, it gradually straightens after they can walk steadier and the legs begin to bear their weight.

However, if the bowleggedness remains after the child has grown up, then it becomes a deformity.  There are a variety of reasons for such deformity which includes Blount's disease, improper nutrition, sickness such as rickets caused by vitamin D deficiency, physical trauma etc.   Eventually, this will lead to difficulty in walking and early onset of arthritis.  One of the long term effects of Osteoarthritis (OA) in adults is bowlegs (vargus) or knock knees (valgus). 

 

When the surface of our joint is damaged due to the deterioration of cartilage, there is imbalance in the joint.  To describe it in another way (a very good analogy given by a medical professional), it is like a camping tent.   A tent is held by poles (bones) and guy ropes (muscles and ligaments) and pegs in the ground (their attachment on the bones).

If the surface upon which they depend on stability becomes out of balance, then the whole structure will lean over. This is exactly what happens to our knee joints.  The imbalance will cause deformities depending on which side the joint leans over.  If it is on the lateral side, it is called bow legs and on the medial side, it is called knock knees. And this state of collapse causes the muscles and ligaments to become slack and tight. Eventually, the muscles and ligaments become inflamed, sore, tight and painful.

My friend who had a bilateral TKR a few years ago used to have normal legs until she had OA.  Eventually, her OA worsened until her legs became seriously bowlegged leaving her with a great deal of pain and difficulty in walking.  As a last resort, she gathered her courage to go through a bilateral TKR.  In such a situation, both knees would have to be done at the same time otherwise, the operated leg would be longer than the other making things more difficult.  After TKR, both her legs were straightened and she is pain free from the knees and enjoying a better quality of life.  However, because of the delay in surgery, the damage has greatly affected her range of motion.

When I consulted with my Orthopaedic Surgeon (OS) about TKR, I was told that I have knock knees.  I thought my legs looked very straight but apparently, it is not normal.  He explained that normal legs have a certain degree of curvature from the knees downwards.   When I went back to look at my x-ray, I observed that the cartilage loss was in the medial side so it explains the knock knees.  And so my OS corrected the alignment of my legs during TKR.  Actually, I felt strange with the new alignment as both my feet could not touch each other when I stand now maybe its due to my fat knees.  I still feel strange looking at my legs in the mirror but my OS said that they are normal now, so I had to believe him.  Guess it takes some time to get used to it.

It is important to know that if we wait too long to seek treatment for OA especially if it has already resulted in bowed legs or knock knees, we will be left with a lot of damage caused by OA and there may be insufficient quality of bones to hold the implants.  So again, the earlier we seek treatment, the better.

Here are some pictures obtained from the Internet showing the x-ray and pictures of an elderly woman with bow legs due to severe arthritis before and after bilateral TKR.   What an amazing transformation!  Her courage is really admirable considering that she did this in her 70s or early 80s.  I hope this is a good inspiration to the rest of us.

X-ray of a bowed leg before & after surgery

 

 



Bowed legs before surgery

 

 

 

 



Legs after surgery