Varus alignment causes the load-bearing axis to shift to the inside, causing more stress and force on the medial (inner) compartment of the knee. If your doctor has said you have varus alignment of the knees (bow-legs), keep in mind that studies show that weight plays a critical factor.
With varus alignment, you are at risk for knee osteoarthritis regardless of your weight -- but if you are overweight or obese your risk is substantially higher than average. Varus alignment increases the risk of knee osteoarthritis 5-fold in obese patients.
Increasing degrees of varus alignment are also associated with progression of knee osteoarthritis as well as the development of knee osteoarthritis -- especially in overweight and obese patients.
Valgus Deformity of the Knee or Knock-Kneed Legs:
Valgus alignment shifts the load-bearing axis to the outside -- causing increased stress across the lateral (outer) compartment of the knee. Valgus alignment (knock-kneed) is not considered quite as destructive as varus alignment.
The Bottom Line Regarding Knee Malalignment:
If you are either bow-legged or knock-kneed, you are at higher risk for osteoarthritis, meaning you may develop knee pain and function problems later in life. It's important to keep your weight within a normal range, as obesity can make knee problems worse.
Consult an orthopedic surgeon if you suspect malalignment. Have it evaluated by your doctor and get advice on what you can or should do now to protect your joints. In some cases, joint replacement surgery can correct valgus or varus deformities.