- equivalent to Weber type A fracture;
- transverse avulsion type fracture of the fibula (short oblique or transverse) below the level of joint or tear of the lateral collateral
ligaments and vertical fracture of the medial malleolus;
- mechanism:
- supination of foot is combination of inward rotation at ankle, adduction of the hindfoot, and inversion of the forefoot;
- as foot supinates the lateral structures tighten;
- continued supination & adduction force may rupture portions of lateral collateral ligaments or may avulse distal fibula,
resulting in transverse frx below the level of intact syndesmotic ligaments;
- subsequently, adduction forces talus against the medial side of the joint, resulting in vertical frx of medial malleolus;
- associated injuries:
- osteochondral frx of talus or injury to its articular surface;
- marginal impaction fractures:
- in the report by McConnell and Tornetta, the authors searched through 800 ankle fractures seen at the authors' institution,
and identified 44 (5 percent) of which were of the supination-adduction pattern;
- 19 of these injuries had displaced vertical medial malleolus fractures, of which eight (42%) showed marginal
impaction of the tibial plafond;
- all 8 patients underwent ORIF with elevation of impacted articular component and had good to excellent functional
outcome with no arthritis on radiograph at the time of the most recent follow-up;
- Radiographs: 
- Non Operative Treatment:
- frequently does well w/ closed reduction;
- Operative Treatment:
- may be fixed w/ 2 malleolar screws & single fibular screw;
- fibula:
- K wires, 1.6 mm & figure of 8 tension band wires;
- for larger frag use one third tubular plate;
- operative treatment of vertical malleolar frx;
- medial surface is inspected for articular crush of tibial surface or talar dome;
- if frx is w/o comminution, then consider screw fixation (usually w/ two screws);
- 4.0 mm cancellous bone screws, or 4.5 mm cannulated screws as lag screws for medial malleolus;
- w/ severe displacement and/or comminution of the verticle medial malleolar fragment, consider need for a medial butress
plate, esp if there is a varus deformity of talus
Supination-adduction injuries of the ankle in children--radiographical classification and treatment.