Knock Knees: Types, Causes & Treatments

What are Knock Knees?

Knock knee, also called Genu Valgum, is a condition where a person has a large gap between their feet when standing with their knees together. Normally, many children have knock knees, which becomes obvious around age 4. It's just a regular part of their development, and their legs will normally straighten by age 7. However, knock knees can very occasionally be a sign of an underlying condition that needs treatment, especially if the condition develops in older children or adults, or doesn't improve with age.

Types of Knock Knees

Genu valgum can appear in two main categories: Physiologic and Pathologic.

Physiologic Knock Knees

Physiologic knock knees are a natural part of a child's development. It's common for children aged 3 to 5 to exhibit genu valgum, with studies indicating that up to 75% of them may experience this condition. Fortunately, for most youngsters, knee deformity resolves on its own as they grow. As they reach their 8th year, their legs typically straighten out.

Pathologic Knock Knees

Pathologic knees valgus, on the other hand, is severe, persists beyond age 8, or develops during adulthood. Such cases are often associated with underlying medical conditions, such as obesity, vitamin D deficiency, calcium deficiency, arthritis, knee joint infection and trauma.

Knock Knees Symptoms

Knock knee syndrome, characterised by the inward angling of the knees when standing with feet together, may not always exhibit noticeable symptoms. Let’s take a closer look at some common symptoms of knock knees to help you easily identify the condition and seek professional help:

• Visible Inward Angling: An apparent misalignment of the knees when standing with the feet together.
• Knee Pain: Knee pain is often experienced on the inner side of the knee joint.
• Walking and Running Difficulties: In severe cases, individuals may struggle with carrying out basic activities.
• Gait Abnormalities: Some people may develop a waddling or awkward walking pattern.
• Joint Pain: Joint pain is not limited to the knees, as knock knees can also cause discomfort in the hips and ankles due to altered alignment.
• Limited Range of Motion: Knock knees can restrict the natural movement of the knees.
• Discomfort During Physical Activities: Engaging in sports or physical activities can become uncomfortable or painful.

When to Get Medical Advice?

Knee valgus in children isn't usually a cause for concern and should improve as your child gets older. However, visit an orthopaedic doctor, if you have the following issues.

• The gap between the ankles is greater than 8 cm while standing with the knees together.
• There's a big difference between the angle of the lower legs when standing compared with the upper legs.
• If you feel that the knock knee problem is worsening, you need to immediately visit a reputable orthopaedic hospital in Delhi or near you.
• A child under the age of 2 or over the age of 7 has knock knees.
• Only one leg is affected.
• There are other symptoms, such as knee pain or difficulty walking.
• You have any other concerns about the way your child stands or walks.
• You develop knock knees in adulthood.

Knock Knees Causes

Knock Knees (Genu valgum) can stem from a multitude of underlying factors. Understanding the diverse genu valgum causes is crucial for proper diagnosis and effective treatment. Below, we explore the range of factors that can contribute to knock knees:

• Physiological Variation: A certain degree of knock knees is considered normal in young children. It arises from the natural alignment of bones and often self-corrects as they grow.
• Rickets: Knock knees can result from weakening of the bones as a result of deficiency in vitamin D, calcium, or phosphate. Rickets, more prevalent in children, is typically linked to inadequate nutrition or poor nutrient absorption.
• Osteoarthritis: This degenerative joint disease can impact the knees, potentially leading to the development of knock knees, especially among older adults.
• Blount's Disease: A growth disorder affecting the tibia (shin bone) that can cause significant leg bowing, leading to knock knees. It is commonly diagnosed in childhood.
• Osteochondroma: Benign bone tumours can interfere with normal bone growth, resulting in deformities such as knock knees.
• Trauma or Injury: Fractures or injuries to the lower leg or knee joint can disrupt bone alignment, resulting in knock knees.
• Congenital Factors: Structural abnormalities in the legs present from birth can contribute to the development of knock knees.
• Obesity: Excess body weight adds stress to the knee joints, increasing the risk of developing knock knees.
• Connective Tissue Disorders: Conditions like Ehlers-Danlos syndrome or Marfan syndrome, which affect connective tissues, can lead to joint laxity, potentially resulting in knock knees.
• Infection or Tumour: In rare instances, infections, or tumours in the bones or joints of the lower limbs can impact growth and alignment, ultimately leading to knock knees.

How are Knock Knees Diagnosed?

Diagnosing knock knees typically involves a comprehensive assessment encompassing medical history, physical examination, and sometimes, specialised imaging studies. Here's a breakdown of how the diagnosis is typically conducted:

Medical History and Symptom Assessment

The initial step in the diagnosis is a thorough discussion of the patient's medical history. This includes inquiries into any family history of musculoskeletal conditions and a detailed account of the onset and progression of symptoms.

Healthcare providers will delve into specific symptoms such as knee pain, instability, walking difficulties, or any limitations in daily activities.

Physical Examination

A crucial aspect of the diagnosis is a physical examination to assess the alignment of the lower limbs. During this phase, patients may be asked to stand with their feet together, ensuring that their knees touch. This allows the examiner to observe the position of the knees accurately.

The healthcare provider will measure the degree of the angle between the knees, which serves as a key indicator of the severity of genu valgum. Additionally, they may evaluate the patient's gait (walking pattern) and look for signs of joint laxity or muscle weakness.

Imaging Studies

In certain cases, healthcare professionals may order imaging studies to obtain a more precise evaluation of bone alignment. Common imaging modalities used include X-rays and MRI scans.

X-rays provide clear images of the knee joint, thereby aiding in the measurement of the angle between the femur (thigh-bone) and tibia (shin-bone) and helping to determine the severity of knock knees.

MRI scans, on the other hand, are utilised when there is suspicion of underlying structural issues or joint damage, allowing for the assessment of soft tissues, cartilage, and ligaments.

Laboratory Tests (if applicable)

If there is a suspicion of an underlying medical condition contributing to knock knees, such as rickets, healthcare providers may perform blood tests to measure vitamin D, calcium, or phosphate levels.

Specialized Assessments (if needed)

In some instances, particularly when there are concerns about a specific underlying condition, further assessments by specialists such as paediatric orthopedists, rheumatologists, or geneticists may be recommended.

What are the Treatment Options for Knock Knees?

It's essential to understand that the treatment for knock knees can vary depending on factors such as age and the severity of the condition. Whatever the case, it remains highly recommended getting knock knee treatment from one of the best orthopaedic doctors in Delhi and other locations.

Knock Knees Treatment for Children

In most cases, knock knees don't need to be treated because the problem tends to correct itself as a child grows. The child doesn't need to avoid physical activity, wear supportive leg braces or shoes, or do any special exercises. Mild knock knees that persist into adulthood don't need to be treated unless they're causing issues, such as knee pain.

If knock knees are caused by an underlying condition, treatment for this may be necessary. For example, rickets can be treated with vitamin D and calcium supplements.

• Observation: Knock knees in children are often a part of normal growth and development, and may resolve naturally as they grow. Healthcare providers will typically begin by observing the child's condition to determine if any intervention is necessary.
• Physical Therapy: Physical therapy plays a crucial role in helping children with knock knees. Skilled therapists can provide exercises that target muscle strength around the knees while improving alignment. Additionally, they can teach proper walking and standing techniques to aid in correction.
• Orthotic Devices: Sometimes, custom-made shoe inserts or orthotic devices may be recommended for children. These devices support the feet and assist in improving alignment, particularly when walking or standing.
• Bracing: A brace or knee orthosis may be prescribed for more severe cases that do not respond to other treatments. Braces are designed to gradually guide the bones' growth and correct alignment issues over time.
• Guided Growth Surgery: In instances where knock knees persist and the child still has open growth plates, guided growth surgery might be considered. This surgical procedure involves the insertion of plates or screws to influence bone growth towards a more normal alignment.
• Knock Knee Surgery: Surgery for knock knees is rarely necessary, although it may be recommended if the condition is severe or persistent.

There are two main types of operations that may be carried out:

1. In children whose growth is not complete, small metal plates are placed on the inside of the knees, which helps correct their growth over a period of around 12 months; the plates are removed once the treatment is complete.
2. When the growth is complete an osteotomy is performed, where the bone is cut at the level of deformity, realigned into the correct position; plates and screws are used to fix the bones in their new position.

A patient can usually return to all normal activities after having an osteotomy in a few months.

Knock Knees Treatment for Adults

There are several available treatment options for genu valgum in adults.

• Physical Therapy: The therapy can benefit adults with knock knees, as it helps improve muscle strength and joint stability. Therapists can provide exercises and techniques aimed at alleviating pain and enhancing alignment.
• Orthotic Devices: Custom orthotic insoles or shoe inserts can offer support to the feet and aid in correcting alignment for adults dealing with knock knees.
• Weight Management: In cases where obesity contributes to the condition, healthcare professionals may recommend weight loss and lifestyle modifications to reduce stress on the knee joints.
• Pain Management: To manage knee pain and inflammation, over-the-counter pain relievers, such as nonsteroidal anti-inflammatory drugs (NSAIDs), can be considered.
• Knock knee surgery: In severe instances of genu valgum in adults, surgical intervention may be considered when other treatments prove ineffective and the condition significantly affects daily life or causes substantial pain. Surgical options may include osteotomy (bone realignment) or joint replacement for advanced cases of osteoarthritis.
• Addressing Underlying Conditions: When knock knees stem from an underlying medical condition, such as osteoarthritis or rheumatoid arthritis, it is crucial to focus on the appropriate treatment for the condition.

Read more - Key-Hole Surgery For Correction Of Knock Knee

Case Reports

We came across a 21yrs old female presented to us with genu valgum deformity involving both legs. Deformity was progressive, which was causing difficulty in walking. On examination, there were 15­o valgus in both knees. Figure 1 shows the whole lower leg x-ray showing genu valgum.

Corrective Femoral Osteotomy is done where the thigh bone is cut and a wedge shape piece of bone is removed and cut-ends are fixed with plate and screws as shown in Figure 2.

Postoperatively, the range of motion started on the day of surgery and weight-bearing at 6wks. Patient resumed her pre-surgery activities after 3 months and was able to participate in sports after 5 months of surgery, which she was not able to because of knock knees. Patient reports that the surgery has improved her quality of life, confidence, and ability to outperform her own expectations.