- Discussion:
- medial malleolar frx result from direct impact of talus or from tension as talus rotates or moves laterally following fibula;
- in children medial malleolus frx may represent
supination inversion frx;
-
injury patterns:
- deep
deltoid ligament may be torn, leaving malleolus intact;
- anterior colliculus may be avulsed by superficial deltoid, leaving deep
deltoid ligament either intact or ruptured;
- frx above level of the ligamentous attachment leaves deltoid ligament attached to the distal malleolar fragment;
-
associatted injuries: (w/ "isolated" medial malleolar fractures)
-
maisonneuve fracture;
-
talus neck fracture;
-
cuboid fracture;
-
deltoid ligament injuries arising from ankle frx:
- Radiographic Studies
- usually distal frag of medial malleolus is displaced anteriorly & distally;
- eval for osteochondral;
- r/o frx of talar neck;
- Surgical Technique:
-
vertical malleolar frx
-
horizontal-oblique frx:
-
comminution:
- if medial malleolus is fractured in coronal plane or is comminuted, screw purchase may be difficult;
- small,
one third tubular plate can be contoured to run along anterior, distal, & posterior edges of malleolus;
- individual fragments can also be reduced & fixed with a single K wire;
- series of figure of 8 wires can then be placed around these K wires to secure the fragments;
- impaction of articlar surface should be elevated during reduction;
- bone grafting may be needed;
-
avulsion fractures:
- avulsion frx of medial malleolus may be treated closed if isloated, minimally displaced, & involve distal portion of malleolus;
- reduced after exposing both the anterior and medial aspects of frx by sharply turning back the periosteum and attached fascia;
-
tension band technique:
- as pointed out by Ostrum and Litsky, tension band wiring has better mechanical properties than
2 cancellous screws (four times stiffer than two screws);
- bone fragment is held in reduced position w/ tenaculum clamp;
- two 0.45 K wires are driven thru the deltoid ligament and tip of medial malleolus and across frx site,
but not into proximal tibial cortex;
- tension band figure of 8 wire (20 gauge) can be anchored proximally thru an anterior to posterior drill
hole in metaphysis (or by wrapping wire around head of the screw placed oblique in metaphysis);
- 20 gauge wire is then passed around the K wires and tightened in a figure of 8 fashion (double twist
technique is more reliable);
- the K wires are cut and turned medially and then tapped into the bone;
The relationship between oblique fractures of the medial malleolus and concomitant fractures of the anterolateral aspect of the tibial plafond.
Vertical Shear Fractures of the Medial Malleolus: a biomechanical study of five internal fixation techniques.
Roolan BC, Koval KJ, Kummer FJ, Sanders R, Zuckerman JD.
Foot Ankle 15: 483-489, 1994.
Tension band fixation of medial malleolus fractures. RF Ostrum and AS Litsky J. Orthop. Trauma. Vol 6, No 4. p 464-468. 1992;
Hardware in the medial malleolus: is it intra-articular?
Safe Zone for the Placement of Medial Malleolar Screws.
