Acute Ankle Diastasis Injuries Treated with Dynamic, Static Fixation or Anatomic Repair
Authors: Liu Jiayong , Senthilkumar Shiva , Cho Thomas , Sanford Chris G. 
Published: May 2024

Background:
Acute ankle diastasis injuries are complex and debilitating. These injuries occur when the syndesmotic complex becomes compromised. Treatments of acute syndesmotic injuries include static fixation with screws, dynamic fixation with an elastic device, or anatomic repair of the damaged ligament. However, there is disagreement over which method is most effective. The primary purpose of this study was to compare the 3 treatment methods for acute syndesmotic injuries.

Methods:
A systematic literature search was conducted on Embase and PubMed. Studies that compared at least 2 groups with relevant American Orthopaedic Foot & Ankle Society (AOFAS), Visual Analog Scale (VAS), reoperation rate, and complication (implant failure, implant irritation, and infection) data were analyzed. Statistical analysis for this study was performed using Review Manager 5.4, with a standard p-value of ≤0.05 for statistical significance.

Results:
Twenty-one studies including a total of 1,059 patients (452 dynamic, 529 static, and 78 anatomic) were included for analysis. Dynamic fixation had significantly higher mean AOFAS scores at 3 months postoperation by 5.12 points (95% confidence interval [CI], 0.29-9.96, p = 0.04) as well as at 1 year postoperation by 4.64 points (95% CI, 1.74-7.55, p = 0.002) than static fixation. Anatomic repair had significantly higher AOFAS scores at 6 months postoperation by 3.20 points (95% CI, 1.06-5.34, p = 0.003) and 1 year postoperation by 1.86 points (95% CI, 0.59-3.14, p = 0.004) than static fixation. Dynamic fixation had significantly higher AOFAS scores at 6 months postoperation by 2.81 points (95% CI, 0.76-4.86, p = 0.007), 12 months postoperation by 3.17 points (95% CI, 0.76-5.58, p = 0.01), and at 2 years postoperation by 5.56 points (95% CI, 3.80-7.32, p < 0.001) than anatomic repair. Dynamic fixation also had a lower VAS score average (favorable), only significant at 12 months postoperation, than static fixation by 0.7 points (95% CI −0.99 to −0.40, p < 0.001). Anatomic repair did not have significant difference in VAS scores compared with static fixation. Anatomic repair had significantly lower VAS scores at 12 months postoperation by 0.32 points (95% CI −0.59 to −0.05, p = 0.02) than dynamic fixation. Dynamic fixation had significantly less implant failures (odds ratio [OR], 0.13, 95% CI, 0.05-0.32, p < 0.001) than static fixation. Anatomic repair was not significantly different from static fixation in the complication metrics. Dynamic fixation and anatomic repair were not significantly different in the complication metrics either. Dynamic fixation had a significantly lower reoperation rate than static fixation (OR, 0.23, 95% CI, 0.09-0.54, p < 0.001). Anatomic repair did not have a significantly different reoperation rate compared with static fixation. However, dynamic fixation had a significantly lower reoperation rate than anatomic repair (OR, 4.65, 95% CI, 1.10-19.76, p = 0.04).

Conclusion:
Dynamic fixation seems to demonstrate superior early clinical outcomes. However, these advantages become negligible in the long term when compared with alternative options. Dynamic fixation is associated with a lower risk for complications, specifically seen with the decrease in implant failures. This method also presents a significantly lower reoperation rate compared with the other treatment approaches. Apart from showing improved early clinical outcomes in comparison with static fixation, anatomic repair did not have significant distinctions in other metrics, including complications or reoperation rate.

Level of Evidence:

Level III. See Instructions for Authors for a complete description of levels of evidence.