- Discussion:
- 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 et al, 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.
Marginal Plafond Impaction in Association With Supination-Adduction Ankle Fractures: A Report of Eight Cases
Timothy McConnell; Paul Tornetta III.
JTO 2001;15:447-449
