Leg alignment describes the relationship between the hip, knee and ankle and the way weight is transmitted through the leg when standing and walking.
There is natural variation in alignment between individuals, and a small degree of bow-legged or knock-kneed alignment does not necessarily cause symptoms or require treatment.
However, more significant changes in alignment can alter how load is distributed across the knee. This may place greater stress on one side of the joint and, in some patients, contribute to pain or the progression of osteoarthritis.
In varus alignment, the knees sit further apart when the ankles are closer together. This is commonly described as bow-legged alignment and can increase loading through the inner, or medial, side of the knee.
In valgus alignment, the knees sit closer together while the ankles remain further apart. This is commonly described as knock-kneed alignment and can increase loading through the outer, or lateral, side of the knee.
Treatment depends on the cause and degree of the alignment change, the condition of the knee and how much it is affecting the patient’s symptoms and activities.
For some patients, non-operative treatment may help manage symptoms. This can include physiotherapy, strengthening, activity modification, weight management where appropriate and pain-relieving treatment.
These approaches can improve symptoms and function but do not usually change established bony alignment in an adult.
Where significant malalignment is contributing to symptoms or uneven loading of the knee, surgical realignment may sometimes be considered.
An osteotomy is an operation used to change the alignment of the leg by carefully repositioning the bone.
In appropriately selected patients, the aim is to redistribute load away from an overloaded or arthritic part of the knee and towards a healthier part of the joint.
Osteotomy is a joint-preserving procedure and may be considered for some active patients where arthritis or overload predominantly affects one part of the knee.
Suitability depends on several factors and requires individual assessment.
A high tibial osteotomy changes alignment through the upper part of the shin bone (tibia). It is commonly considered when correction is required for certain patterns of varus, or bow-legged, alignment.
Learn more about high tibial osteotomy →A distal femoral osteotomy changes alignment through the lower part of the thigh bone (femur). It may be considered for certain patterns of valgus, or knock-kneed, alignment.
Learn more about distal femoral osteotomy →The site and nature of the deformity must be assessed individually.
There is natural variation in leg alignment. Alignment is assessed by looking at the relationship between the hip, knee and ankle and how load passes through the leg. A small degree of varus or valgus alignment does not necessarily cause symptoms or require treatment.
Visual appearance alone cannot determine whether alignment is contributing to knee symptoms. Clinical examination and, where appropriate, standing X-rays can provide a more accurate assessment.
Varus alignment is commonly described as bow-legged alignment, with greater loading often occurring through the inner side of the knee. Valgus alignment is commonly described as knock-kneed alignment, with greater loading often occurring through the outer side of the knee.
Significant malalignment can alter the distribution of load through the knee and may contribute to osteoarthritis in some patients. However, arthritis is influenced by multiple factors and not everyone with varus or valgus alignment develops arthritis.
Physiotherapy, strengthening and other non-operative treatments may improve symptoms and function, but they do not usually change established bony alignment in an adult. Whether structural correction is necessary depends on the individual patient.
Alignment correction surgery usually involves an osteotomy, in which the bone is carefully repositioned to alter how load passes through the knee. It is a joint-preserving option for selected patients rather than a treatment required for everyone with malalignment.
An osteotomy is an operation in which a bone is carefully cut and repositioned to change alignment. Around the knee, high tibial or distal femoral osteotomy may be used in selected patients to redistribute load across the joint.
