Knock knees, known medically as genu valgum, is a common condition where the knees angle inward and touch each other when a person stands with their feet apart. This creates an alignment issue in the lower limbs, often giving the legs a noticeable “knock-kneed” appearance. For most individuals, particularly children, non-surgical approaches are highly effective for correction. The treatment strategy relies heavily on the patient’s age and the specific cause of the alignment issue, focusing on strengthening and support rather than invasive procedures.
Understanding Genu Valgum
Genu valgum is characterized by the inward angling of the thigh bone (femur) and shin bone (tibia), causing the knees to meet while the ankles remain separated. Alignment is typically measured by the distance between the inner ankles (intermalleolar distance) or by the tibiofemoral angle. A distance greater than 8 centimeters after early childhood is considered outside the normal range.
The condition presents in two primary forms: developmental and pathological. Developmental (physiological) genu valgum is a common, self-correcting part of growth, peaking around ages three to four and typically resolving spontaneously by age seven or eight. Pathological genu valgum is caused by underlying medical issues like rickets (vitamin D deficiency), skeletal dysplasias, or previous trauma, and is less likely to resolve without intervention. Non-surgical management is the primary approach for the developmental type and for mild to moderate cases in adults.
Active Non-Surgical Interventions
Physical therapy (PT) is the most active non-surgical intervention for genu valgum, especially when muscle imbalances contribute to misalignment. A specialized PT program focuses on strengthening the muscles responsible for stabilizing the knee joint and improving overall posture. This targeted strengthening helps pull the leg into a more neutral alignment.
Exercises frequently target the hip abductors, such as the gluteus medius, which are crucial for maintaining pelvic and femoral stability. Examples include side-lying leg raises and clam exercises, sometimes performed with a resistance band. The inner thigh muscles (adductors) and the quadriceps are also addressed to ensure balanced strength around the knee. Stretching protocols for tight muscle groups, like the hamstrings, are incorporated to improve flexibility and reduce inward pulling forces. Consistency with these exercises is necessary, as muscle strength and control provide lasting support to the joint.
Orthotics, Bracing, and Supportive Tools
Passive and supportive methods complement active physical therapy by managing mechanical forces and guiding growth. Custom-made foot orthotics, or shoe inserts, address excessive foot pronation—a common issue where the arch collapses inward, influencing knee alignment. By correcting the mechanics of the foot strike, orthotics create a more stable base for the entire leg.
For younger children whose bones are still developing, specialized bracing, such as a Knee-Ankle-Foot Orthosis (KAFO), may be prescribed to guide the bone’s growth. These braces are designed to apply a corrective force to the limb, most effectively used during the years of rapid growth. Lifestyle factors like weight management play a significant role, as excess body weight increases the load and stress on the knee joints, which can exacerbate the valgus deformity. Maintaining a healthy weight reduces mechanical strain and supports the long-term effectiveness of non-surgical treatment.
When Surgical Intervention Is Considered
Non-surgical treatment is the first line of defense, but it has limitations, particularly once skeletal growth is complete. Surgery is generally reserved for severe angular deformities or cases that fail to improve with conservative management by late childhood or adolescence. A common threshold for considering surgical correction is a tibiofemoral angle greater than 15 degrees or an intermalleolar distance exceeding 8 centimeters in an older child.
For children who still have growth plates open, a procedure called guided growth, or hemiepiphysiodesis, is often performed. This involves temporarily slowing the growth on the inner side of the knee with a small plate, allowing the outer side to continue growing and gradually straighten the limb. For skeletally mature patients, where growth plates have closed, a more extensive surgery called an osteotomy is needed. This procedure involves cutting and reshaping the bone to correct the alignment, and is reserved for cases causing significant pain, gait issues, or risk of early degenerative joint disease.