Ortho Oracle - orthopaedic operative atlas
Home » Bones » Tibia and Fibula » Weber B: Lateral Malleolus Frx

Weber B: Lateral Malleolus Frx

   

- See:
      - Antiglide Plate
      - Lateral Malleolus
      - Radiographic Studies
      - Stability of Weber B Fractures
      - Supination Eversion Injury
      - Surgical Treatment

- Discussion:
     - Type B: fibula frx at level of syndesmosis-transsyndesmosis;
     - most common type of frx of fibula is caused by external rotation, resulting in oblique frx at level of sydesmosis (Weber B) which is equivalent to a supination eversion injury;
     - anterior syndesmotic lig are partially or completely torn in about 50% of type B injuries, while posterior syndesmosis ligaments usually remain attached to the posterior aspect of distal fibular fragment;
     - frx of fibula by external rotation or abduction injury, is preceded by rupture of anterior tibiofibular ligament;
           - occasionally anterior tibial tubercle is avulsed, producing fragment of Tilaux, or avulsion is from fibular attachment, producing fragment of Wagstaff;
           - when lateral malleolus is displaced, posterior tibiofibular ligament either ruptures or avulses posterior tibial tubercle from back of fibular notch;
     - Frx Subtypes:
              B1  Isolated
              B2  w/ medial lesion (malleolus or ligament)
              B3  w/ a medial lesion and fracture of posterolateral tibia

- Radiographic Studies
     - comminuted fractures of the fibula are often high energy injures resulting from direct lateral trauma or vertical loading;
     - comminution alters landmarks & complicates rotation and length assessment;
     - there may be an assoc impaction frx of lateral tibial plafond, metaphysis of the tibia (Pilon frx), & medial malleolus;
     - ref:
            Comparison of two conservative methods of treating an isolated fracture of the lateral malleolus.

- Non Operative Treatment:
     - isolated Weber B fractures (no medial injury) can be treated w/ a cast if there is up to 3 mm of fibular displacement;
           - it has been observed that x-rays tend to over-estimate displacement (as compared to CT scans) and because the apparent displacement may be mostly due to internal rotation of the proximal fibula as compared to pathologic external rotation of the external fibula;

- Indications for Surgery:
     - unstable Weber B fracture:
     - presence of medial tenderness, > 5 mm of medial clear space is seen on static or stress radiograph, indicates injury of the deltoid ligament;
           - treat as bimalleolar frxs, w/ ORIF of lateral malleolus;
     - routine exploration of medial side of the ankle is not necessary unless there is evidence that portion of the deltoid ligament has entered the joint and is blocking reduction of the talus;

- Surgical Treatment

- Case Examples

 

-----


   comparison mortise views in neutral dorsiflexion;


   postop films.


Comparison of two conservative methods of treating an isolated fracture of the lateral malleolus.

Fractures of the Ankle and the Distal Part of the Tibia.

Instability of the distal tibiofibular syndesmosis after bimalleolar and trimalleolar ankle fractures.

The Dorsal Antiglide Plate in the Treatment of Danis-Weber Type-B Fractures of the Distal Fibula.

Rush rods versus plate osteosyntheses for unstable ankle fractures in the elderly.