The Importance of the Deep Deltoid Ligament Repair in Treating Supination-External Rotation Stage IV Ankle Fracture: A Comparative Retrospective Cohort Study

SLR - March 2021 - Nikita Grama

Reference: Chen H, Yang D, Li Z, Niu J, Wang P, Li Q, He X, Wu G. The Importance of the Deep Deltoid Ligament Repair in Treating Supination-External Rotation Stage IV Ankle Fracture: A Comparative Retrospective Cohort Study. Biomed Res Int. 2020 Nov 29;2020:2043015. doi: 10.1155/2020/2043015. PMID: 33313312; PMCID: PMC7719498

Level of Evidence: Level III

Scientific Literature Review 

Reviewed By: Nikita Grama, DPM 
Residency Program: Mercy Hospital and Medical Center – Chicago IL

Podiatric Relevance: Supination-external rotation injuries are a severe and frequent type of ankle fracture managed by foot and ankle surgeons. Appropriate surgical management of traumatic injuries such as these are vital to improve patient prognosis and increase successful outcomes. It is important to be able to identify which patients will benefit from the repair of the deep deltoid ligament given the ongoing controversy regarding the topic. Recent literature suggests that the repair of the deltoid ligament leads to reduced medial clear space and enhanced outcomes in the repair of the distal tibiofibular ligament. The goal of treatment in repairing these fractures is to allow for early mobilization, participation in rehabilitation, and fewer post-operative complications. The authors of this study aimed to compare the radiographic and functional outcomes of patients with SER injuries treated surgically with and without deep deltoid repair. They hypothesized enhanced functional outcomes in patients with the repair.

Methods: A comparative retrospective cohort study was performed on 63 patients ≧16 years old with stage IV SER injuries between March 2015 and March 2018.  31 patients were assigned to the deep deltoid ligament repair (DDLR) group and 32 patients assigned to the non-deep deltoid ligament repair (NDDLR) group. The deltoid ligament was repaired using two 3.5 millimeters suture anchors. Radiographic parameters that were examined included the talocrural angle (TA), fibular length (FL), medial clear space (MCS), tibiomedial malleolar angle (TMMA), and tibiofibular clear space (TCFS). Outcomes were evaluated using the visual analog scale (VAS) for pain, AOFAS ankle-hindfoot scores for functionality, and range of motion of bilateral ankles (RMBA). 

Results: All patients completed follow up ranging from 12-22 months. The DDLR group had reduced VAS score 3 days postoperatively at 1.18 compared to 1.36 in the NDDLR group. The DDLR group showed markedly increased flexion, extension, and total arc range of motion compared to the NDDLR group. No statistically significant difference was noted in the average fracture healing time of the DDLR vs. NDDLR group (9.12 + 1.27 weeks vs. 9.23 + 2.05 weeks). Similarly, there was no significant difference noted in the radiographic indices including MCS, TMMA, FL, TA, TCFS, and AOFAS scores between the two groups at the three, six and 12-month follow up. 

Conclusions: The current study  demonstrates less pain and better range of motion in the DDLR group when compared to the NDDLR group for stage IV SER ankle fractures. Although, the radiographic indices and AOFAS ankle-hindfoot scale scores were similar in both groups, the three-day postoperative pain score was significantly reduced in patients in the DDLR group. The same group also exhibited a shorter postoperative stay. The increase in flexion, extension, and full arc range of motion may indicate that the deep deltoid ligament repair is a potentially better alternative for the treatment of stage IV SER injuries.