The CFL is the middle of the three lateral ankle ligaments, unique in that it crosses both the ankle and subtalar joints and stabilises both when taut in dorsiflexion. It is torn in approximately 50 to 75 percent of lateral ankle sprains alongside the ATFL. The talar tilt stress test stresses the CFL by applying an inversion force with the ankle in the neutral position.
| Origin | Inferior tip of the lateral malleolus |
|---|---|
| Insertion | Lateral calcaneal surface posterior to the peroneal tubercle |
| Actions | Stabilises both the ankle and subtalar joints against inversion stress; taut in ankle dorsiflexion |
|---|
CFL integrity is critical for subtalar stability — isolated ATFL tears rarely produce subtalar instability, but combined ATFL and CFL tears can. The CFL is included in the Brostrom-Gould anatomical repair alongside the ATFL. Its extra-articular position makes it accessible to direct palpation between the lateral malleolus tip and the calcaneus.
Lateral ankle complex injury producing both ankle and subtalar instability from inversion force in a dorsiflexed position, requiring more extensive rehabilitation than isolated ATFL injury.
