Arthroscopic coronal plane syndesmotic instability has been over-diagnosed

Area of Science:

• Orthopedic Surgery
• Sports Medicine
• Anatomy

Background:

• Ankle arthroscopy is a common diagnostic tool for syndesmotic instability, particularly in subtle cases.
• Current intraoperative diagnostic criteria for syndesmotic instability lack systematic review.
• Accurate intraoperative assessment is crucial to avoid overtreatment of high ankle sprains.

Purpose of the Study:

• To systematically review literature on tibiofibular displacement thresholds correlating with syndesmotic instability.
• To assess the methodological quality of research evaluating syndesmotic instability during ankle arthroscopy.
• To establish evidence-based intraoperative measurements for syndesmotic integrity.

Main Methods:

• Systematic literature searches were conducted across major databases (EMBASE, PubMed, CINAHL, Web of Science, Google Scholar).
• Studies involving arthroscopic evaluation of fibular displacement in syndesmotic ligament injury were included.
• Data extraction and quality assessment were performed independently by two reviewers using AQUA and MINORS tools.

Main Results:

• Eleven studies (8 cadaveric, 3 clinical) were reviewed, reporting displacement in coronal, sagittal, and rotational planes.
• Weighted mean displacement values for coronal instability were 2.9 mm anteriorly and 3.4 mm posteriorly.
• Sagittal plane data suggested thresholds of 2.2 mm posterior translation and 2.6 mm anterior translation.

Conclusions:

• The commonly used 2.0 mm threshold for distal tibiofibular diastasis may result in overtreatment.
• Recommended threshold values for syndesmotic instability are 2.9 mm (anterior) and 3.4 mm (posterior).
• Surgeons should consider using 3 mm probes instead of 2 mm probes for intraoperative assessment.