Intercollicular sulcus of medial malleolus

The intercollicular groove is the shallow depression that lies between the anterior and posterior colliculi on the medial surface of the medial malleolus.

Anatomy

• It separates the larger anterior colliculus from the smaller posterior colliculus.

• The groove provides a surface for the attachment of the deep portion of the deltoid ligament, mainly the anterior and posterior tibiotalar fibers.

• It is located just above the talar articulation and forms part of the tibial contribution to the ankle mortise.

Function and Attachments

• The superficial part of the deltoid ligament attaches to the colliculi themselves, while the deep fibers (tibiotalar components) attach within the intercollicular groove.

• These fibers stabilize the talus against medial displacement and help control rotation and tilt of the talus during gait.

Clinical relevance

• The intercollicular groove is important in radiological and surgical anatomy of the ankle:

  • In fractures of the medial malleolus, involvement of the groove indicates potential injury to the deep deltoid ligament.

  • MRI evaluation of deltoid ligament injuries often focuses on this region, as the deep tibiotalar fibers anchor here.

  • The precise location helps distinguish whether the superficial or deep parts of the deltoid ligament are compromised, which has implications for ankle stability and surgical repair.