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Medial Malleolar Fractures

   


- 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;
    - associated 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;

- Non Operative Treatment:
       - Conservative treatment of isolated fractures of the medial malleolus.
       - Nonoperative treatment of the medial malleolus in bimalleolar and trimalleolar ankle fractures: a randomized controlled trial.

- Surgical Treatment:   
    - screw fixationvertical malleolar frx
    - screw fixationhorizontal-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;
    - short screw theory:
           - better fixation with shorter 30 mm partially threaded cancellous screws which engage the physeal scrar;
           - ref: Screw fixation of medial malleolar fracture. A cadaveric biomechanical study challenging the current AO philosophy   
    - bicortical fixation screws:
           - Lag screw fixation of medial malleolar fractures: a biomechanical, radiographic, and clinical comparison of unicortical partially threaded lag screws and bicortical fully threaded lag screws.
           - Comparison of pullout strength between 3.5-mm fully threaded, bicortical screws and 4.0-mm partially threaded, cancellous screws in the fixation of medial malleolar fractures.
           - Medial malleolar fractures: a biomechanical study of fixation techniques.
           - Bicortical fixation of medial malleolar fractures: a review of 23 cases at risk for complicated bone healing.
      - tension band technique:
           - Ostrum and Litsky, tension band wiring has better mechanical properties than 2 cancellous screws (4 times stiffer than two screws);
           - bone fragment is held in reduced position w/ tenaculum clamp;
           - two 0.45 K wires are driven thru 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);
           - K wires are cut and turned medially and then tapped into the bone; 
           - references:
                  - Technical Tip: Fixation of Medial Malleolar Fractures Using a Suture Anchor
                  - Tension band fixation of medial malleolus fractures.  
                  - Modified tension band wiring of medial malleolar ankle fractures
                  - Comparison of tension band wire and cancellous bone screw fixation for medial malleolar fractures

                                   

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Hardware in the medial malleolus: is it intra-articular?

Safe Zone for the Placement of Medial Malleolar Screws

Medial Malleolar Fractures: A Biomechanical Study of Fixation Techniques

Stress fracture of the medial malleolus.