SLR - June 2019 - Sara Mateen

Syndesmosis and Syndesmotic Equivalent Injuries in Tibial Plafond Fractures

Reference: Haller JM, Githens M, Rothberg D, Higgins T, Barei D, Nork S. Syndesmosis and Syndesmotic Equivalent Injuries in Tibial Plafond Fractures. J Orthop Trauma. 2019 March; 33(3), e74–78.

Scientific Literature Review

Reviewed By: Sara Mateen, DPM
Residency Program: Temple University Hospital, Philadelphia, PA

Podiatric Relevance: Rotational ankle fractures are commonly seen in podiatric practice with the majority of severe rotational injuries, including syndesmotic instability. In axial loading ankle fractures, such as tibial plafond fractures, it is also important to rule out syndesmotic injury, as it is commonly missed. These types of ankle fractures tend to be associated with syndesmotic instability, which can lead to posttraumatic arthritis. This study reviews 735 tibial plafond fractures, identifying the incidence and fracture patterns associated with syndesmotic injury in tibial plafond fractures as well as the incidence of posttraumatic arthritis.

Methods: A level IV retrospective comparative study was performed for all patients who had tibial plafond fractures, which were categorized into two groups, acutely diagnosed syndesmotic injury and missed syndesmotic injury. The acutely diagnosed injury was based on positive intraoperative manual stress examination compared to the missed syndesmotic injury based on postoperative radiographs or CT scan. The fracture characteristics, such as Chaput and/or Volkmann size, logsplitter injury and fibular avulsion fracture, were also analyzed. Patients needed a minimum of six months follow-up, and joint degeneration was based on the anteroposterior and lateral ankle radiographs using the Marsh et. al arthrosis scale.

Results: Of the 735 patients identified with tibial plafond fractures, 108/735 (15 percent) were classified with syndesmotic injury. Based on patients with syndesmotic injury, the male gender and open fractures were statistically significant. Fourteen of 735 (2 percent) patients had missed syndesmotic injury. There were significantly more tibial plafond injuries with syndesmotic compromise associated with valgus alignment (53 percent) compared to injuries without syndesmotic injury in valgus alignment (34 percent). Ninety-four of 108 (87 percent) syndesmotic injuries were diagnosed acutely and treated with syndesmotic screws or direct repair with suture. Volkmann fragment size < 10 mm and distal fibular avulsion fracture were significantly more common in missed syndesmotic injuries than in acutely diagnosed syndesmotic injuries. Ninety of 108 fractures (83 percent) had more than 12 months of follow-up and were included in analysis. Most of the patients [13/14 (93 percent)] with missed syndesmotic injury developed moderate or severe posttraumatic arthritis and 34/76 (45 percent) tibial plafond fractures with acute syndesmotic injury developed arthrosis, which was statistically significant. When controlling for malreduction, patients who had syndesmotic repair with <10 mm Chaput, Volkmann or fibular avulsion fractures were less likely to develop arthrosis.

Conclusions: Fifteen percent of tibial plafond fractures were associated with syndesmotic or syndesmotic equivalent injury. The patients with missed syndesmotic injury had a higher rate of developing posttraumatic arthritis and those patients with associated fracture characteristics benefited from syndesmotic reduction. A few limitations to the study include length of follow-up to properly assess posttraumatic arthritis and functional outcome scores. This study demonstrates the importance of testing the syndesmosis for adequate surgical planning with proper treatment of the syndesmosis through reduction and fixation. 

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