Knee osteoarthritis – common cause of bow-leggedness

Q. I am 52 and have knee osteoarthritis. What causes this?

Would it make me more likely to develop bow-leggedness? Can I prevent this from happening?

A. The hallmark of bow-leggedness is having both knees appear to remain wide apart even when the feet are together while standing. This condition is commonly associated with knee osteoarthritis.

Osteoarthritis is a chronic condition due to degeneration of the cartilage.

The cartilage cushions the impact on walking and produces a natural lubricant to improve the gliding of joints. Loss of cartilage leads to inflammation and pain.

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The inner aspect of the knee tends to degenerate faster because weight distribution is not spread evenly on the joint. Normal human knees tend to bear more body weight on the inner aspect.

As the cartilage erodes and becomes thinner over time, the inner part of the knee will “sink” in and the thigh bone (femur) will rub on the shin bone (tibia).

Bowing of the knee puts more strain on the outer knee ligament, increasing the likelihood of knee sprains and perpetuating the discomfort.

Bowing of the knee puts more strain on the outer knee ligament, increasing the likelihood of knee sprains and perpetuating the discomfort. If left untreated, the loss of cartilage will lead to bone erosion, exacerbating the deformity.

If left untreated, the loss of cartilage will lead to bone erosion, exacerbating the deformity.

The causes of knee osteoarthritis are multi-factorial, a combination of environmental and genetics factors.

It progresses slowly over time with no clear predisposing factor inmost cases.

You can prevent it by:

  • Maintaining a healthy lifestyle coupled with low-impact exercises like swimming and brisk walking. Strength training increases muscle tone and support for the knee.
  • Avoiding stair climbing and daily activities including housework that require prolonged and frequent knee-bending or squatting for those with established knee osteoarthritis.
  • Maintaining joint and ligament flexibility with yoga which can help to reduce loading on the knees and hips.
  • Keeping excess weight off.
  • Eating a healthy balanced diet. Short-term supplements taken with glucosamine sulphate may reduce knee inflammation for those with knee pain but there is no evidence of any long-term benefit.
  • Maintaining healthy bone mass with daily supplements of vitamin D and calcium for post-menopausal women and men over the age of 75.

There are various treatments available for knee osteoarthritis. The management will have to be tailored according to the severity of the underlying condition and lifestyle demands.

Mild osteoarthritis with no bowing of the leg can be managed with physiotherapy to improve flexibility and muscle strength.

Application of cold or hot packs may ease knee discomfort. Soft bracing to improve support and restrict movement may help with the inflammation.

Your doctor may prescribe anti-inflammatory oral medication and ointment.

Most patients have good and bad days and learn to cope by adjusting their lifestyles.

Moderately severe osteoarthritis with evidence of mild loss of cartilage and minor bowing of the knee may be treated with special bracing to help unload the weight on the damaged part of the knee.

In selected cases, injection of the lubricant “hyaluronic acid” may give medium-term control of symptoms.

Severe bowing with apparent shortening of the knee will require knee replacement surgery to restore the alignment and leg length.

The results are generally instantaneous, with 80 to 90 per cent of patients having significant pain relief and returning to normal daily activity.

An assessment by an orthopaedic specialist is recommended if symptoms do not improve through conservative treatment

Dr Leslie Ng

Consultant orthopaedic surgeon at Island Orthopaedic Consultants, Mount Alvernia Hospital

A version of this article appeared in the print edition of The Straits Times on June 28, 2016, with the headline 'Knee osteoarthritis – common cause of bow-leggedness'. Print Edition | Subscribe