Verified By: Dr. Gautam Tawari (MBBS, MRCS, M.Sc, SEM, M.Ch(Orth), FRCS(Tr&Orth) Specialist Shoulder & Knee Surgeon, Sports , Arthroscopy, Elbow & Hand Surgeon) | Updated On June 14, 2021
What is Knee deformity?
The knee deformity occurs because of the difference in growth of both the sides of the knee joint, which means that if there is more growth in bones around the knee joint on the inner side, the leg will bend inward or outward causing bow legs or knock knees respectively. This can happen in case of traumatic injury, metabolic disorders like rickets, dysplasias, physical injuries. The children need to be reviewed periodically to make sure that the deformity does not recur.
What are bow legs?
Bow legs are also known as genu varum. It is a common condition occurring in infants and toddlers. In most of the cases, this condition corrects itself as a child grows.
A child with bow legs has a distinct space between his or her lower legs and knees. This may be a result of either one or both legs curving outward. Walking often exaggerates this appearance of bowlegs.
What causes bow legs?
Many babies are born with bow legs because their legs were folded tightly in their mother’s womb during pregnancy. Bow legs usually straighten once the babies with this condition start to walk and when their legs bear weight.
Bow legs are common among infants. However, some toddlers develop bow legs as a result of rickets, a disease associated with low levels of vitamin D that causes soft bones. This condition may require surgery when the child gets older to correct the bow legs.
Bow legs can occur because of Blount’s disease, in which the abnormal growth in the upper part of the shin bone (tibia) causes the legs to bend. Unlike bow legs, the bowing with Blount’s disease will be progressive and get worse over time. Blount’s disease can be treated with bracing or surgery.
What tests are used to diagnose bow legs?
A Bow leg is diagnosed through a physical examination. However, a doctor will need to obtain an X-ray to assess bone alignment; blood tests and additional visits over time are required to check how the legs develop.
How are bowed legs treated?
Treating bow legs depends on the cause. If it is caused by rickets, your child may simply need to take vitamin D or calcium supplements if the disease is still in its early stages. Sometimes, supplements are enough to strengthen the bones and improve the condition.
Other causes, including more advanced rickets, require surgery. But for mild cases that don’t cause much pain, physical therapy and weight training will help to strengthen the muscles surrounding your leg bones. However, they won’t straighten your bones.
The most common type of surgery used to treat bow legs without significant osteoarthritis, particularly in younger patients, is a high tibial osteotomy. This procedure realigns the tibia by cutting into the bone and reshaping it. This relieves the pressure on your knee. However, if you have bow legs, osteotomy surgery can also help to prevent, or at least delay, the need for total knee replacement surgery in future.
Following a high tibial osteotomy procedure, you will need to wait three to eight months before getting back to your usual level of activity. You will also need to wear a brace for at least a month or two.
Generally, bow legs do not require any special shoes or braces. The bowing should improve as the child grows from 15 to 18 months until about 3 years of age. If there is an alignment concern that continues past 7 or 8 years, parents should consult a pediatric orthopaedic provider to determine whether there is a need for treatment. Bow legs or one bowed leg beyond the age of 3 can indicate a leg length discrepancy. It can also be a sign of a more serious condition, such as rickets or Blount’s disease.
What is knock knees?
Knock knees is also known as Genu valgum. It is a knee misalignment that turns your knees inward. When children with knock-knees stand up with their knees together, there’s a gap of 3 inches or more between their ankles. This is because their knees are bent inward. Knock knee symptoms may include an unusual walking pattern, difficulty walking, and rare instances of pain.
Knock knees is very common in children and it usually corrects itself as they grow. Up to 75 percent of children between the ages 3 and 5 have knock-knees. Knock knees can also develop later in life from:
- an injury or infection in your knee
- severe lack of vitamin D and calcium
- arthritis in the knee
This condition cannot be prevented, but its effects can be minimized. Physical therapy and exercise are a successful alternative to surgery.
What are the symptoms of Knock knees?
Knock knees that persist beyond childhood may have other symptoms besides misaligned knees. They include:
- stiff joints
- knee pain
- walking with a limp
Stressed ligaments and muscles can also cause pain in your hips, ankles, or feet. If only one knee is out of line, then your stance may be unbalanced.
What causes knock knees?
The exact cause of knock knees is not clear but it seems to run in families and obesity makes knock knees more severe. Children in their first 3-4 years of growth will often develop a mild degree of knock knees that resolve spontaneously. However, some cases are a result of additional bone diseases or injuries. Knock-knees may also be caused by:
- injury or infection in your knee
- bone malformation from rickets, a disease caused by lack of vitamin D and calcium
- other bone diseases
- obesity, which puts extra pressure on your knees
- arthritis in your knee joints
How is it diagnosed?
During a physical examination, your doctor will observe how you stand and walk. They will also assess:
- Inequality in your leg length
- Your knee alignment angle
- Uneven wear on the soles of your shoes
In some cases, your doctor may ask for X-ray or MRI scan to look at your bone structure.
What are knock knees treatment options?
In many cases, parents can expect that a child’s knock knees will resolve by age 8 but for some a course of physical therapy and exercises can help realign their knees. It can also strengthen the surrounding muscles and avoid damage to other joints. If these efforts are not successful then surgery may be performed to realign your knees. However, treatment for knock knees depends on the cause and severity of your symptoms. For example, if rickets are causing your knock-knees, your doctor will prescribe vitamin D and calcium supplements to help your child restore levels.
- Exercise – For most people with knock knees, exercise can help realign and stabilize their knees. The physical therapist can evaluate your child’s gait and suggest exercises designed to strengthen your child’s leg, hip, and thigh muscles. Specific stretches will also be useful in relieving symptoms.
- Orthotics – If your child’s legs are of unequal length as a result of knock knee, a heel insert into the shoe on the shorter side can equalize your leg length and help regularize your gait. It may also relieve leg pain. For children whose knock knee does not resolve by age 8, a brace or a splint may help guide bone growth.
- Surgery – When knock knee is severe, or when exercise is not enough to relieve pain and stabilize your knee, your doctor may recommend surgery.
For children, a small metal plate inserted in their knee can help direct future bone growth. This minor procedure is called guided growth surgery. The plate is removed when the bone growth is corrected.