Knock Knees, also known as Genu Valgum, is an orthopedic condition that causes the knees to bend inwards and touch each other. The condition is common during a child’s developmental stage, till the age of 2 or 3 years and gets self-corrected with age. However, in rare cases when knees begin to knock after the age of 6 years, it can be an indicator of an underlying bone disorder.
What Are Knock Knees and Bowlegs?
The leg is supported by three long bones. The upper leg is composed of the femur, the largest and strongest bone in the body, and the lower leg is composed of the tibia and fibula. Knock knees is the inverse of bowlegs and both of the conditions are normal parts of development. Both conditions are the manifestation of growth of the tibia and fibula causing angulation of the legs. Knock knees touch when standing straight and the ankles apart, while bowlegs would have the ankles touching while standing straight with a gap between the knees. Infants are born with bowlegs, transition into knock knees and then straighten up right before puberty. There is ethnic and gender variation in the timeline that these changes occur as well as the amount of angulation that occurs. Females tend to have larger angulation of knock knees for example.
Do Knock Knees or Bowlegs Need Treatment?
Knock knees and bowlegs are both normal conditions during development. However, there are times when development does not go as planned as well as potential pathogenic causes of both conditions. If angulation is extreme where walking becomes too painful, or causes a limp, causes recurrent patella dislocation or is non-symmetrical then it would be time to seek medical advice. Also, if knock knees or bowlegs have not cleared up by puberty then seeking medical advice would also be appropriate to rule out pathogenic conditions such as metabolic bone disorders.
Causes of Knock Knees
- Osteomyelitis, a bone infection
- Rickets
- Scurvy
- Infection or injury to the shinbone
- Obesity
- Overpronation
- Irregular bone growth
- Genetic skeletal abnormalities
Symptoms of Knock Knees
- More than 10 cm of gap between both ankles
- Changes in gait patterns
- Excessive inward angle of knees
- Pain at the anterior part of the knee, in severe cases
Diagnosing Knock Knees
Diagnosing Knock Knees involves a thorough physical examination and a review of the patient’s medical history. The orthopedic doctor may observe the positions of the patient’s lower legs, ankles and knees. He may measure the distance between the inner parts of the ankle joints to assess the severity of the condition. The doctor may also evaluate certain other factors including:
- Height, weight and body mass index (BMI)
- Walking pattern
- Skeletal alignment of the lower leg
- Range of motion of the lower leg
Conservative Treatment for Knock Knees and Bowlegs
Depending on the cause or amount of angulation in the patient with knock knees or bowlegs the treatment will vary. Obesity can enhance the complications and progression, so losing weight may be recommended to start with. There are also exercises that can be suggested to help relieve the symptoms as well. In cases that are severe or pathogenic bracing may be used to help guide the bones as they grow into correct alignment. Bracing is very effective having very low levels of failure that would need to progress to surgical intervention.
If the condition does not subside after the age of 7 or 8 years, the orthopedic doctor may recommend the following treatment:
- Braces: Wearing a brace during nighttime may help to straighten and restore the normal alignment of the knees. Depending upon the severity of the condition, the doctor may recommend a customized knee brace for effective results.
- Exercise: Performing certain exercises, as prescribed by the physical therapist, may help to strengthen the knee muscles so that they are better able to bear the weight of the body.
Surgical Treatment of Knock Knees and Bowlegs
Surgical treatment can be considered for knock knees and bowlegs when conservative measures fail. If surgery is indicated an osteotomy, or bone removal, would be the surgical intervention of choice. Depending on the needs of the patient the osteotomy would be a closed wedge osteotomy, or an open wedge osteotomy. In this procedure an orthopedic surgeon would remove a small piece of the tibia to correct to the proper angle for the leg. This procedure is a last resort and rarely needed, but when it is used patients have good surgical outcomes with a recovery process that lasts about six months and includes physical therapy.
In severe cases, the patient may be recommended to undergo any of the following surgical treatments:
- Osteotomy: This involves manipulating the knee bones to bring the joint back to their normal position. The procedure also helps in even distribution of weight through the knee.
- Guided Growth Surgery: This surgery slows down the growth of knee bone. Guided growth surgery is usually recommended for children who are in their developmental stage.
Bowleg
Bowleg or varus deformity occurs when the alignment of the knee appears to bend outward. Bowleg originates during infancy past the age of 3. Bowleg is difficult to diagnose since pain is a rare symptom and most parents are not aware of the deformity. Parents begin to notice once the infant is past the age of 6 when their knee alignment is not straight at an anatomical position. Bowing of the knee causes an uneven load compression. This can lead to a multitude of issues later in life such as arthritis (which eventually will be needing a total knee replacement), excess stress on the medial meniscus and articular cartilage, and more than likely obtaining iliotibial band pain.
Parents may prevent their child to develop bowleg deformity by paying attention to the following:
- The child’s knee is facing outward when walking
- The child’s thighbone to shinbone is out of normal range
- The child’s foot is angled outward
Symptoms of Bowleg Deformity
Bowleg deformity’s most common symptom is when a person’s knee does not touch when their feet and ankles are diagonal together.
People may experience other symptoms such as:
- Knee instability
- Knee or hip pain
- Difficulty walking or running
- Unable to perform deep flexion in the hips
Diagnosing Bowleg
To diagnose bowleg deformity, the orthopedist begins by asking the patient’s full history. The orthopedist will then begin a physical examination following a request for an X-ray or EOS scan. The orthopedist will review the scans to determine where the deformity originates, determine the severity and the mechanical axis. The scans will help the orthopedist see if there is another disorder related to the child’s bowlegs.
How Do Physicians Treat Bowleg?
Physicians have a couple of ways to treat the deformity. If a child is diagnosed with bowleg deformity and it is a mild case, the pediatric orthopedist may observe the child over time and make sure their alignment eventually straightens out. A corrective brace may also be recommended if only the diagnosis is correct and caught early. A leg brace will decrease the compression load of the medial side of the leg to straighten out the bowlegged deformity. The child must wear the leg brace all day and night until shown improvements.
If bracing does not work, surgery will be the next course of action. The surgical approach for bowleg deformity is a minimally invasive treatment called an osteotomy. Osteotomy procedure is recommended for patients that are 16 years of age and older since by this time the patient is done maturing. The osteotomy procedure usually takes an hour if there are no complications. The orthopedist has two options in which device he may use to correct the deformity. The orthopedist may use an internal fixator, which applies using a plate or rod to straighten out the knee, this approach is most common when there is a moderate deformity. If the deformity is more severe, the orthopedist uses an external fixator, which applies to inject pins into the bone to bulge out of the body and attaching it to an external stabilizing structure to straighten the alignment.
Recovery and Healing
Patients spend no more than one evening in the hospital after the surgical procedure. The orthopedist recommends the patient to walk and place weight on the leg almost immediately once the procedure is done. Most patients feel little to no pain when walking after the procedure and rarely in need of any assistance. The physician recommends that the patient stays active and follows through with physical therapy treatment. If so, depending on the scans, in two months or so, the patient will be fully healed, and the frames may be taken away. Patients may experience little scarring from the operation but if they maintain a healthy physical lifestyle, the patient will enjoy a pain-free life.
The surgeons at OrthoTexas specialize in the treatment of Knock Knees and other medical conditions.