Enhanced anatomical accuracy in arthroscopic all-inside lateral ligament repair using ultrasound-guided anchor placement.

Background: With significant advancements in arthroscopic surgical techniques, the frequency of arthroscopic lateral ankle ligament repair procedures has increased. However, anchor positioning accuracy remains uncertain, with studies suggesting a higher probability of the anchor being fixed in non-anatomical positions, such as insertion proximal to the fibular obscure tubercle (FOT). Using ultrasound guidance, anchors can be positioned more anatomically. This study aimed to analyze anchor position in arthroscopic all-inside lateral ligament repair using ultrasound.

Methods: Thirty-three patients with chronic ankle instability were prospectively enrolled and underwent ultrasound-guided, arthroscopic all-inside lateral ankle ligament repair, termed Arthroscopic Ultrasound-Assisted All-Inside Repair of the Lateral Ankle Ligament (AURA). Postoperative computed tomography (CT) scans were taken to analyze anchor positions, with the FOT as the reference point. Subsequently, the anchor positions were classified as anatomic, sub-anatomic, and nonanatomic based on the relationship between the fibular anterior tubercle and the FOT.

Results: The mean distance between anchor position and the fibular obscure tubercle (FOT) was 2.08 mm (range, 0-12 mm). Based on postoperative CT analysis, anchor placements were classified relative to the FOT: 28 of 33 cases (84.8 %) were within 25 % of the fibular length distal to the FOT (anatomic zone), 4 cases (12.2 %) were positioned between 25-50 % (sub-anatomic zone), and 1 case (3.0 %) was beyond 50 % (non-anatomic zone).

Conclusion: The ultrasound-assisted technique demonstrated high anatomical accuracy in anchor placement, as confirmed by postoperative 3D-CT evaluation.

Level of evidence: IV, case study.