Post-traumatic osteonecrosis of the lateral tibial plafond

We report a series of patients who presented with post-traumatic osteonecrosis of the lateral tibial plafond. Nine patients were identified with evidence of osteonecrosis limited to the lateral tibial plafond. All of them were seriously impaired with a mean valgus collapse of the ankle joint of 15.3°. Seven patients had a Weber C open medial fracture-dislocation, and two had a closed Weber C fracture-dislocation. This series confirms that post-traumatic osteonerosis of the lateral tibial plafond is associated with Weber C fracture-dislocation. It evolves into a valgus deformity of the ankle due to collapse of the lateral tibial plafond. The prognosis is poor and required further reconstructive surgery in all cases.