Knock Knees 

Knock knees is a condition where the knees touch while the ankles remain apart. This problem can affect people of all ages. This common alignment issue often raises concerns about its impact on mobility and overall health. Understanding knock knees is crucial for those seeking treatment options or managing associated symptoms effectively. Let's delve into the causes, symptoms, and potential complications of knock knees. It explores various diagnostic methods and outlines available knock knees treatments, from conservative approaches to surgical interventions. 

What is Knock Knees? 

Knock knees, also known as genu valgum, is a condition where the knees bend inward & touch or "knock" against one another. It happens even when a person is standing with their ankles apart. This alignment issue is part of the coronal plane deformities of the lower extremity. The condition is typically bilateral, affecting both legs, but it may only affect one knee in some cases. 

Knock knees are characterised by a valgus angle (Q Angle) of 10° or more. This deformity results from anatomical variations, including bone tissue remodelling and soft tissue contraction or elongation. The lateral side of the knee may experience contraction of structures such as the lateral collateral ligament, popliteus tendon, and iliotibial band, while the medial side may have attenuated soft tissues. 

Intermalleolar distance is often used to assess the degree of knock knees. This is the distance between the medial malleoli when the patient is standing while touching medial femoral condyles. An intermalleolar distance greater than 8 cm is considered pathologic.

It's important to note that temporarily knocked knees are part of most children's standard developmental growth stage. Children typically develop physiologic genu valgum around age 2, becoming most prominent between ages 3 and 4. After that, it usually decreases to a stable, slightly valgus position by age 7. In the adolescent age group, minimal, if any, change in this alignment is expected. 

However, knock knees that persist beyond six years of age, are severe, or affect one leg significantly more than the other may indicate a more serious condition requiring further evaluation by an orthopaedic specialist. 

Risk Factors and Causes of Knock Knees 

In children, knock knees typically develop as they begin to walk. This inward tilt of the knees helps them maintain balance and compensate for feet that may roll inward or turn outward. However, knock knees that persist beyond the age of six or seven may indicate an underlying issue. 

Several medical conditions can be a reason for knock knees, including: 

• Metabolic bone disorders, such as rickets, which results from a vitamin D deficiency 
• Genetic disorders, including skeletal dysplasias and lysosomal storage diseases like Morquio syndrome, may also be responsible. 
• Physical trauma or injury to the growth area of the shinbone (tibia) or thighbone (femur) 
• Bone infections (osteomyelitis) and fractures that heal with a deformity (malunion) 
• Excess weight puts abnormal pressure on the knees. 
• Other risk factors like arthritis, particularly in the knee, which can alter joint alignment 
• Calcium deficiency 
• Rarely, benign bone tumours or congenital (inborn) conditions 

Symptoms of Knock Knees 

The most noticeable symptom of knock knees is the inward angulation of the knees when a person stands with their legs straight, and toes pointed forward. This results in a gap between the ankles while the knees touch. This alignment issue often leads to an unusual walking pattern and outward rotation of the feet. 

Knock knees can cause various discomforts and complications, including: 

• Pain typically affects the knees, hips, feet, or ankles 
• Stiff or sore joints, reduced range of motion in the hips, and difficulty walking or running 
• Knee instability, as the abnormal knee alignment, puts excessive force on one or both knees, which can lead to further bone deformity and progressive degeneration of the knee joint. 
• Patellofemoral instability in adult patients who have had knock knees for many years causes an overload of the lateral compartment of the knee while stretching the medial collateral ligament. 
• Some individuals or their parents may experience emotional trauma, as they are unhappy with the aesthetic appearance of knock knees. 

Complications 

Knock knees can lead to various complications if left untreated, particularly in cases that persist beyond childhood or are caused by underlying conditions. 

• Premature Degeneration of the Knee Joint: The abnormal alignment places excessive force on the outer side of the knee, causing pain and damage over time. 
• Patellofemoral Instability: This instability may increase the risk of meniscal tears and patellar dislocation. 
• Off-centric Knee Caps: The misalignment can cause the kneecaps to be off-centre, increasing pressure and pain in the front of the knee. 
• Arthritis: The abnormal stress distribution in the knee joint can lead to early onset osteoarthritis, particularly in adults who have had the condition for many years. As the joint wears out further, the deformity may progress, creating a cycle of worsening symptoms. 
• Hip and Back Pain: They often result from abnormal hip rotation associated with the condition. 
• Ankle Pain and Potential Foot Problems: They occur due to increased stress in the ankle area 

Diagnosis 

• Physical Examination: A doctor may perform a comprehensive physical examination. The examination includes: 
  • The assessment of the growth trajectory of the legs in children 
  • Evaluation of the knee alignment when standing 
  • Observing the patient's walking pattern 
  • Checking for any differences in leg length 
  • Measuring the distance between the ankle bones (Normally, the gap should be less than 8 cm when standing with the knees together) 
  • Looking for uneven wear patterns on the soles of the patient's shoe 
• Imaging Tests: These include X-rays or MRIS and are particularly useful for patients older than 7 years or when the legs are not symmetrical in size and shape. 
• Gait and Rotational Profile Analysis: These assessments help identify the underlying cause of the angular deformity. 

Treatments for Knock Knees 

The cure for knock knees varies based on the severity and underlying cause of the condition. 

• Monitoring: Close observation is often sufficient for most children, especially those between 2 and 5 years old, as up to 99% of cases resolve naturally by age 7. 
• Conservative Management: This is the first line of treatment. This includes: 
  • Weight control to reduce stress on the knees 
  • Orthotics, such as heel inserts, can benefit individuals with leg length discrepancies. 
  • Vitamin D and calcium supplementation can be effective in treating rickets-related knock knees. 
• Surgical Interventions:  
  • Guided Growth Surgery: It is a common approach for children approaching puberty. This minor procedure involves inserting small metal plates on the inner side of the growth plates located in the knees, allowing the outer side to catch up and straighten the legs. 
  • Osteotomy Surgery: It may be recommended for adults or those with more severe deformities. This procedure includes cutting & realigning the bone above or below the knee to straighten the legs. 

When to See a Doctor 

Parents should consult a doctor if: 

• Their child's knock knees persist beyond the age of 5 
• The condition appears in children under 2 years old 
• The gap between the ankles is more than 8 cm when standing with the knees together 

Adults should consult a doctor if: 

• They develop knock knees later in life 
• The condition is accompanied by pain, swelling, stiffness, or warmth in one or both knees 
• Only one leg is affected 
• There's a noticeable difference in leg length 
• The problem is getting worse over time 
• If it's causing difficulty walking or limping 

Conclusion 

Knock knees can significantly impact a person's quality of life, affecting mobility and potentially leading to long-term joint issues. Understanding the causes, symptoms, and available treatments is crucial to manage this condition effectively. From conservative approaches like weight management and orthotics to surgical interventions in severe cases, various options exist to address knock knees and improve overall leg alignment. 

FAQs 

1. Are knock knees normal? 

Knock knees are often a normal part of a child's development. Many children experience this condition between the ages of 2 and 5 years. It's a common growth pattern where the knees angle inward when standing with the feet together. 

2. How do I fix knock knees naturally? 

Natural correction often occurs without medical intervention for mild cases of knock knees, especially in children. However, some exercises may help improve alignment. These include cycling, sumo squats, and leg raises. Maintaining a healthy weight is also crucial, as excess weight can put undue strain on the knees. 

3. Does walking reduce knock knees? 

While walking may not directly reduce knock knees, regular workouts can help strengthen the muscles around the knees and improve overall leg alignment. Activities that require running (playing football or basketball) can be beneficial. 

4. At what age do knock knees go away? 

In most cases, knock knees that develop as part of normal growth resolve by age 7 or 8. By this time, the legs usually straighten out naturally. However, some children may continue to have a mild degree of knock knees until they're 12 to 14 years old. 

5. How many days will it take to correct knock knees? 

The time it takes to correct knock knees varies and depends on the potential cause and severity of the condition. For children experiencing knock knees as part of normal development, the condition typically resolves on its own over several years. In cases where treatment is necessary, such as bracing or guided growth surgery, the correction process can take months to years. 

Dr. Shubham Chandrakant Padmawar

MBBS, MS
Ganga CARE Hospital Limited, Nagpur

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