Written by Caroline Meyer
Knock-knees and bowlegs are not uncommon in toddlers and for most it is part of their normal development and growth. Most children will outgrow this condition. For a few, surgery or bracing may be required especially if they suffer from Blount’s disease or Rickets in early childhood. If a child does not outgrow bowed legs or if one side is bowed while the other straightens, an x-ray may be required to determine the cause. Knock knees that occur after elementary school phase can be a sign of osteomalacia (a bone disease) or Rickets. There are also rare occasions where knock knees and bowed legs are as a result of benign tumours.
WHAT ARE KNOCK KNEES AND BOWED LEGS?
Looking from the front, when a child stands with their feet together and toes pointed forward, if their knees do not touch, they are said to have bowed legs. Bowed legs are also referred to as “genu varum” in medical terms. “Genu valgum” is given to knock knees by the medical profession. This is characterised by the knees touching but the ankles still being apart when the child stands with feet pointed forward and legs together. This is very common in little ones and for most, will not require any form of treatment.
As children grow, they may start with knock knees or bowed legs, which does not affect them when it comes to physical activity. They should still be able to run, walk and crawl with ease. Some children may appear a little clumsier when they start walking as their toes may be pointed inwards, causing them to trip more than normal. The bowed legs and knock knees can appear quite severe in some children, but even these youngsters will eventually outgrow the condition for the most part.
From infancy to around 18 months, the legs are generally bowed, which makes them walk with their feet wider apart than normal. By 2.5 years of age, they have usually straightened out. From the age of 3 to 4, the legs can often grow in a more knock-kneed position. By 10 years old, the legs should be straightened into their adult alignment.
For the most part, children that have knock knees or bowed legs just need to be monitored. Parents can get advice from their doctor if there are any concerns. Growth phase knock knees and bowed legs are not affected by vitamins, bracing, special shoes or physical therapy. If the doctor has concerns about your child, they may refer you for an evaluation by a paediatric orthopaedic surgeon. Referrals are usually only done if one side of the body is affected more than the other, if there is a family history of problems or if the misalignment is very severe. X-rays will be performed to rule out conditions such as Blount’s disease and Rickets as well as other potential diagnosis.
You may be asked questions concerning nutrition, general development and for familial medical history of skeletal dysplasia (aka dwarfism) or Rickets. The doctor will check knees, hips and legs to compare alignment as well as the motion. This is done while the child lies on their backs and on their stomachs to check torsional alignment. The doctor may also ask the child to run and walk to see their alignment while in motion. For most small children, this examination is often enough to determine whether or not the growth phase is the reason for the bowed legs or knock knees or if something more serious is going on. If they suspect a problem, an x-ray will be first on the agenda, followed by a blood test if Rickets is suspected.
Rickets disease is caused by a lack of calcium vitamin D or phosphates. The bones may become softer and weaker leading to knock knees or bowed legs. With Rickets, there may be a requirement for surgery or for bracing to correct the condition depending on how severe the condition may be. When treated with medication, often the misalignment will correct itself over time. Genetic diseases which cause low vitamin D levels can also lead to Rickets in children.
Blount’s disease is an issue in the growth plate of the upper part of the tibia (shinbone) which may cause the bone to grow abnormally. This disease can also be seen in some overweight teenagers. Poor nutrition causing a lack of Vitamin D, phosphorous and calcium can also cause bowed legs in older children as well as toddlers. Treatment may include medication, nutritional supplements and observation, bracing and even surgery in severe cases. Toddlers are usually treated with bracing and surgery is usually only performed after the age of 4 if the bracing does not correct the problem.
Older children will generally require surgery. The surgeries may differ depending on the level of bowing. This can involve cutting and re-alignment of the bone or preventing the growth on the one side of the growth plate, allowing the other side to grow and eventually match up, straightening the leg. A less often performed surgery involves the removal of part of the growth plate on the abnormal side.
While most toddlers outgrow knock knees and bowed legs, some do not. With corrective treatment, this can often be resolved fairly early on leading to normal alignment at a later stage. Older children that are not treated may have limitations to their physical activity, may experience significant pain and even experience substantial deformity of alignment. Speak to your doctor if you have any concerns so that potential problems can be treated early on or simply to lay your fears to rest in this regard.