The correct answer is:

TRUE:

This external tibial torsion is probably a major cause of the mechanical force which has caused this knee valgus. This severity of knee valgus is seldomly seen in diplegic CP and when it is present is usually related to this type of asymmetry with asymetric hip rotation and causing pelvic asymmetry (crab walking). If a proximal tibial osteotomy is planned it should include shortening of the tibia to protect the perineal nerve.