Outcomes of Posterior Malleolar Fixation in Ankle Fractures in a Major Trauma Centre

SLR - September 2021 - Garrett M. Biela

Reference: Jeyaseelan L, Bua N, Parker L, Sohrabi C, Trockels A, Vris A, Heidari N, Malagelada F. Outcomes of Posterior Malleolar Fixation in Ankle Fractures in a Major Trauma Centre Injury. 2021 Apr;52(4):1023-1027. doi: 10.1016/j.injury.2020.12.006. PMID: 33376016.

Scientific Literature Review

Level of Evidence: III

Reviewed By: Garrett M. Biela, DPM
Residency Program: University of Florida Health – Jacksonville, FL

Podiatric Relevance: Posterior malleolus fractures are a unique injury sustained in complex ankle fractures and are commonly managed by Podiatric foot and ankle surgeons. The peer-reviewed literature is conflicting on the necessity to fixate these fracture patterns. While many specialists advocate for correction based on size of fragments and intra-articular involvement, others recommend allowing secondary bone healing without fixation due to risk of post-operative complications.

Methods: The retrospective case control study reviewed trimalleolar ankle fractures with a variation of severity and fixation methods of the posterior malleolus that is compared to an unfixed group. There were 320 ankle fractures with inclusion criteria of >18 years old, complete medical records with pre and post-operative imaging. The subjects were split evenly with 160 in the unfixed group (Group 1) and 160 in the fixed group (Group 2) that was subsequently divided into based on additional syndesmotic fixation being performed (Group 3). The Manchester-Oxford Foot Questionnaire (MOXFQ) was used as the primary measure, which a higher value indicated a poorer outcome that is previously validated as a useful tool to assess surgical outcomes.

Results: The fixed and unfixed groups were well-matched in basic patient co-morbidities with an average follow up of 33.5 months. Posterior malleolar fractures were classified based on the Mason classification system. The study noted that all Type 3 posterior malleolar fractures were fixated, while a higher proportion of 2B were fixated, whereas 2A were less likely to be fixated. Type 1 fractures were all managed conservatively. The mean MOXFQ scores were statistically improved in the fixed group compared to the unfixed group. Of note, 114 subjects of the unfixed group underwent syndesmotic fixation versus 31 subjects of the fixed group. The unfixed group had a statistically significant reduction in post-operative complications, mainly due to hardware irritation.

Conclusions: The authors reached the conclusion that posterior malleolar fixation more accurately restored syndesmotic stability compared to syndesmotic screw fixation alone based on the theory that the PITFL has an inherent role in the structural integrity of the syndesmosis. However, the reoperation rate was higher with posterior malleolar correction and the need to further analyze fixation methods. Further studies are necessary to further explore these findings in larger retrospective and randomized control studies with longer follow up. Furthermore, these findings suggest improved MOXFQ scores with fixation of these fracture types but do come at the risk of reoperation and higher complication rates. It is adamant for experienced foot and ankle traumatologists to continue to evaluate fracture patterns and patient selection to determine if posterior malleolar fixation is necessary for improved outcomes.