CT-based morphologic study of 57 consecutive posterior malleolar ankle fractures. Proposes a three-type classification based on fracture line location at the tibial plafond. Answers whether plain radiographs can reliably size and characterize these fragments — they cannot.
Posterior malleolar fragments were historically sized on lateral radiographs, and the fixation threshold of >25-30% of the plafond was applied based on that single-plane estimate — a method now shown to be unreliable.
When you see a posterior malleolar fragment on ankle films, get a CT before taking the patient to the OR. CT tells you the true fragment size, whether a medial-extension component exists, and whether the injury is actually a two-part fracture.
If the fragment exceeds 25% of the plafond, plan for a medial approach: in this series, 78% of those large fragments extended to the medial malleolus, where a posterolateral incision gives you poor access.
For Type II fractures with two fragments, the authors' approach is to fix the medial fragment first. This converts the injury to an effectively Type I pattern. Then assess whether the lateral fragment still requires fixation.
CT-based morphologic study of 57 consecutive posterior malleolar ankle fractures. Proposes a three-type classification based on fracture line location at the tibial plafond. Answers whether plain radiographs can reliably size and characterize these fragments — they cannot.
Posterior malleolar fragments were historically sized on lateral radiographs, and the fixation threshold of >25-30% of the plafond was applied based on that single-plane estimate — a method now shown to be unreliable.
When you see a posterior malleolar fragment on ankle films, get a CT before taking the patient to the OR. CT tells you the true fragment size, whether a medial-extension component exists, and whether the injury is actually a two-part fracture.
If the fragment exceeds 25% of the plafond, plan for a medial approach: in this series, 78% of those large fragments extended to the medial malleolus, where a posterolateral incision gives you poor access.
For Type II fractures with two fragments, the authors' approach is to fix the medial fragment first. This converts the injury to an effectively Type I pattern. Then assess whether the lateral fragment still requires fixation.