Deltoid ligament repair versus trans-syndesmotic fixation for bimalleolar equivalent ankle fractures

SLR - December 2022 - Justin K. Metli, DPM 

Title: Deltoid ligament repair versus trans-syndesmotic fixation for bimalleolar equivalent ankle fractures

Reference: Whitlock KG, LaRose M, Barber H, Fletcher A, Cunningham D, Menken L, Yoon RS, Gage MJ. Deltoid ligament repair versus trans-syndesmotic fixation for bimalleolar equivalent ankle fractures. Injury. 2022 Jun;53(6):2292-2296.

Level of Evidence: Level IV

Reviewed by: Justin K. Metli, DPM 
Residency Program: Regions Hospital/HealthPartners Institute, Saint Paul, MN

Podiatric Relevance: Ankle fractures are a devastating injury commonly seen in Podiatric medicine and can have profound implications on a patient’s ability to ambulate. Distal fibula fractures are one of the most common ankle fracture patterns encountered and when these are of the bimalleolar equivalent they can lead to syndesmosis instability. When there is instability of the syndesmosis, the ankle is unstable and can lead to decreased tibiotalar contact area. When it comes to the surgical correction of syndesmosis instability there is no unanimity on the optimal method of stabilization. In fact, the role of deltoid ligament repair in the treatment of bimalleolar equivalent ankle fractures is one that has been very controversial. This study retrospectively analyzed patients who had ORIF of isolated unstable distal fibula fractures with the goal of comparing functional outcome scores and reoperation rates. 

Methods: A level IV retrospective review was performed to identify patients who underwent ORIF of the distal fibula along with one of the following: trans-syndesmotic fixation, deltoid ligament repair, or a combination of the two. The functional status of each patient was assessed utilizing the American Academy of Orthopedic Surgeons Lower Limb Outcomes Assessment – Foot and Ankle Module (AAOS-FAM). Secondary outcomes that were measured included rates of reoperation and complications between the three stabilization procedures. 

Results: A total of 108 patients were included with 66 (61%) undergoing trans-syndesmotic fixation, 16 (15%) deltoid ligament repair, and 26 (24%) were treated with a combination of the two between 2005 and 2019. Mean follow-up was 4.6 (range 3-5) years postoperatively. The AAOS-FAM mean scores between the three groups were not statistically significant. The study found a higher reoperation rate for trans-syndesmotic fixation compared to the deltoid ligament repair. However, there was no statistical significance between deltoid ligament repair and combined fixation or between trans-syndesmotic and combined fixation. There were three major complications, two of them being with trans-syndesmotic fixation (one suture button and one screw fixation) and one with the combined fixation. 

Conclusions: The authors conclude, acute deltoid ligament repair should be considered when surgically planning for unstable distal fibula fractures. This study demonstrates the crucial role that the deltoid ligament plays when it comes to ankle stabilization. It yielded similar functional scores and significantly less reoperation rates when compared to trans-syndesmotic fixation. Overall, this article sheds light onto why one should repair the deltoid ligament when it comes to unstable distal fibula fractures. However, this study has its limitations specifically the fact that there were multiple different surgeons who performed the procedures but also the retrospective design and lack of clinical outcomes evaluated. Further higher-level studies are needed to evaluate clinical outcomes associated with each procedure and with one or two surgeons performing the procedures to decrease heterogeneity when it comes to post-operative and surgical techniques.