SLR - November 2011 - Sara Karamloo

Evaluation of the syndesmotic-only fixation for Weber-C ankle fractures with syndesmotic injury

Reference:  Mohammed R., Syed S., Metikala S., Ali SA.  (2011).   Evaluation of the syndesmotic-only fixation for Weber-C ankle fractures with syndesmotic injury. Indian Journal of Orthopaedics, 45, 454-458.

 Scientific Literature Review

Reviewed by:  Sara Karamloo, DPM
Residency Program:  Yale New Haven / VA CT

Podiatric Relevance: 
Consensus for the treatment of ankle fractures with associated syndesmotic injury has yet to be reached within the podiatric arena.  This new technique described here provides the foot and ankle   surgeon with yet another possible avenue to treat patients who present with such injuries.  By following two simple rules: 1) restoration of  fibular length and 2) anatomical reduction of the syndesmosis, plating  of fibular fractures can be replaced with the use of a single tri-cortical screw across the syndesmosis, thereby decreasing complications associated with more internal fixation.

A retrospective observational study was conducted on twelve patients who sustained supra-syndesmotic fibular fractures with associated syndesmotic inury (Weber-C) between April 2007 and September 2008.  Exclusion criteria included those with other associated injuries, delayed presentation or diagnosis, open fractures, less than 6 months of follow up, as well as incomplete clinical notes or lack of x-rays.  At initial presentation all patients were placed in a plaster cast, given pain medication and told to elevate the appropriate extremity.  After adequate resolution of soft tissue swelling, the patients were taken to the operating room and syndesmotic rupture was confirmed via external rotation stress test or a hook test using fluoroscopy.  If a medial malleolar fracture was present, this was reduced and fixated prior to insertion of the syndesmotic screw.  If the two simple rules were met, a mini-open  reduction and clamp stabilization of the syndesmosis was performed,  followed by insertion of a single tri-cortical 3.5 mm cortical screw approximately 2 cm above the tibio-talar joint line.  Post-operatively, patients were non-weight bearing in a below the knee cast for 2 weeks at which point the wounds were inspected and the sutures removed. 

Next, compliant patients were kept non-weight bearing in a removable  cast, to allow for gentle movement of the ankle for an additional 4  weeks while non-compliant patients continued in a below the knee cast. Radiographs were taken at 6 weeks to evaluate the ankle mortise and fracture healing.  Patients were allowed to be partial weight bearing in the removable cast or walking cast for an additional two weeks before removal of the syndesmotic screw at an average of 8 weeks.  At the patients last follow-up, x-rays were repeated and a self administered  patient questionnaire based on the objective ankle scoring system was  distributed to the patients thereby dividing them into excellent, good, fair and poor.

Of the twelve patients, the average age was 35 years with the majority being male.  The most common mechanism of injury was accidental twisting falls followed by sports related injuries.  Nine of the fractures involved the middle third of the fibula while three  were classified as a Maisonneuve fracture.  Six of the fractures required medial malleolar screw fixation.  The average follow up was 13 months (range 7-21 months) and the functional outcome scores using the OMAS was 75 which corresponded to good, there were only two fair  outcomes and no poor outcomes.   The ankle mortise was reduced in all cases except for one in which the syndesmotic screw was removed prior to complete healing thereby resulting in a late diastasis.  This patient had to undergo revisional surgery with the use of bone grafting and internal fixation for the fibular non-union.  Finally, none of the syndesmotic screws broke prior to removal.

Prior studies have shown that anatomic reduction of the syndesmosis is the most important predictor of good functional outcomes in ankle fractures with syndesmotic injury. This study shows that the use of a single syndesmotic screw provides good functional outcomes in Weber C fracture reductions, as long as the fibular length can be restored and anatomic reduction of the syndesmosis can be obtained. The use of a single syndesmotic screw appears to be a viable fixation technique, potentially reducing post-op morbidity commonly associated with plating Weber C fibula fractures.

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