Dr. Ebraheim’s educational animated video describes the condition know as Valgus knee deformity.
When the knee is not perfectly aligned from side to side, either a valgus or varus malalignment may occur.
Difference between varus and valgus deformity
Valgus alignment causes the load bearing axis of the leg to shift towards the outside. Valgus knee or “knock knee” is commonly caused by arthritis of the knee and the feet are not touching.
Varus alignment causes inward angulation and stress on the medial (inner) part of the knee. Varus deformity is called “bowleg” or outward bowing of the leg in relation to the thigh.
Severe valgus deformities place stress on the articular cartilage, bone, and ligaments of the knee joint which causes the progression of knee osteoarthritis.
Valgus knee deformities have intrinsic complications. if you correct the valgus knee deformity, the patella can sublux laterally. Often correction of the deformity can tether or stretch the peroneal nerve.
Treatment
•If valgus deformity is unicompartmental, treat with distal femoral osteotomy and correct the axis to neutral.
•If tricompartmental with moderate valgus, treatment by total knee replacement.
•You may need a lateral release.
•Be aware of the injury to the peroneal nerve.
•Postoperatively peroneal nerve palsy requires removal of all constrictive dressings and flex the knee.
•If tricompartmental with severe valgus treatment by osteotomy and total knee replacement.