The Hip book
Home » Bones » Tibia and Fibula » Ankle Varus Deformity

Ankle Varus Deformity

- Discussion:
    - varus deformity of the ankle may follow distal tibial fracture or distal tibial epiphyseal frx;
          - deformities due to distal tibial epiphyeal injuries are often progressive;
          - deformities due to tibial plafond injuries are usually static (from malreduction at the time of the original procedure);
    - left untreated, the varus deformity may lead to DJD of the ankle;
    - normally the average TAS angle (tibial shaft to tibial joint angle on an AP radiograph) measures 88 deg (in a sample Japanese population);
    - the avgerage TLS angle (tibial shaft to tibial joint line angle on the lateral view) measures 81 deg (in Japanese population);
    - indications for surgery:
          - when the TAS angle is less than 80 deg, and the patient is symptomatic despite non operative treatment;

- Technique: (from Takakura, et al (1998)).
    - involves a one stage opening wedge valgus osteotomy;
         - since the affected leg is most often short, an opening wedge rather than a closing wedge osteotomy is indicated;
    - fibular osteotomy:
         - performed through a small lateral incision;
    - tibial osteotomy site:
         - use a longitudinal medial incision;
         - make the osteotomy parallel to the joint line, but leave a small posterolateral portion of the distal tibia intact (for stability);
         - in adults attempt to place the osteotomy site at the level of the initial fracture;
                - if this is not possible then make the osteotomy cut 5 cm above the distal end of the medial malleolus;
         - in children, consider making the osteotomy cut about 2-3 cm proximal to the physis;
         - make the opening wedge correction, and then use calipers to determine the necessary width of the bone graft;
         - K wires can be used to stabilize the graft;
    - controversies:
         - physeal bone-bridge resection
         - ipsilateral and contralateral growth plate arrest;
               - in situations in which bone bridge resection is not advisable, growth plate excision is indicated;
               - be sure to arrest the fibular growth plate as well (which contributes to varus deformity);
    - complications: some patients will note a decrease in ROM

Results of opening wedge osteotomy for the treatment of a post traumatic varus deformity of the ankle.

Low tibial osteotomy for osteoarthritis of the ankle.  Results of a new operation in 18 patients.