Syndesmosis Injury From Diagnosis to Repair

Physical Examination, Diagnosis, and Arthroscopic-Assisted Reduction

Jeffrey Wake, DO; Kevin D. Martin, DO, FAAOS


J Am Acad Orthop Surg. 2020;28(13):517-527. 

In This Article


Main complications in all techniques include malreduction and overcompression. With the emergence of SBF, concerns exist regarding impinging on medial neurovascular structures. Malreduction has been shown to be the most clinically significant complication of syndesmosis treatment demonstrating significantly worse outcomes.[55] Causes of malreduction include improper positioning of the clamp tines and incisura morphology. When using reduction forceps for syndesmosis reduction, the position of the tines are important. The lateral clamp tine should be placed on the fibular ridge and the medial clamp tine should be on the anterior third of the tibial line in the lateral view.[24,26] Cherney et al looked at the morphology of incisura and found that specific malreduction patterns are associated with particular morphology. They discovered that shallow incisura correlated with anterior fibular malreduction and was less likely to be rotated, whereas deep syndesmoses predisposed to posterior sagittal plane and rotational malalignment.[54] Malreduction is mitigated by using proper clamp placement[26,56] while also avoiding over compression. Haynes et al[57] have defined overcompression as fibular medialization greater than 1.0 mm when compared with noninjured extremity. In their study, those that were overcompressed had a mean clamp force of 163 N, and they found that those with mean clamp force of 130 N had adequate compression of the syndesmosis. They describe that the appropriate amount of force would be equal to that needed to indent a 12oz beverage can. We also verify the reduction with fluoroscopy and direct arthroscopic visualization as described by Lui et al and Miller et al[58,59] (Figure 8). Regarding at-risk structures in SBF, it has been identified that the saphenous nerve and vein are in close proximity, leading to entrapment of these structures. Cadaveric studies of SBF have shown that nerve entrapment occurs 10% to 20% of the time and saphenous vein entrapment occurs 10% to 37% of the time, regardless of how proximal the SBF was placed, leading these authors to suggest medial incisions to ensure entrapment is avoided.[60–62] We have also transitioned to newer SBF techniques which help flip the button, potentially reducing the saphenous nerve complications that have been described. A newer knotless device is also available which has demonstrated good clinical results with the possibility of reducing entrapment and skin irritation seen in previous devices.[35]

Figure 8.

Photograph showing the Mercedes sign visualized on arthroscopic reduction of the distal tibiofibular joint. A, Talus; B, Fibula; and C, Tibia.