Weber Fractures
Written by: Jessie Chen, DO; Edited by: Timothy Khowong, MD, MSEd
Introduction:
Weber Fractures are lateral malleolar fractures or distal fibular fractures. The incidence of ankle fractures is 187 in 100,000 patients. The Danis-Weber Classification was developed to characterize stability of the ankle joint based on the location of the fracture, specifically the involvement of the tibiofibular syndesmosis. 10% of all ankle fractures have associated syndesmotic injury, with higher incidence in more proximal fibular fractures.
Ankle Anatomy:
The ankle consists of three bones: tibia, fibula and talus. The area between the tibia and the talus is known as the tibial plafond. The tibial plafond along with the distal fibula (also lateral malleolus) and distal tibia (also medial malleolus) form the ankle mortise.
Multiple ligaments support the ankle joint. Three ligamentous complexes stabilize the ankle joint:
Deltoid: Superficial and Deep
Lateral Ligament Complex: anterior talofibular ligament (ATFL), posterior talofibular ligament (PTFL), calcaneofibular (CFL)
Syndesmosis: anterior inferior talofibular ligament (AITFL), posterior inferior talofibular ligament (PITFL) - strongest component, interosseous ligament, interosseous membrane, inferior transverse ligament
Patient Presentation and Physical Exam:
Ankle injuries are common and usually occur from a twisting injury. Symptoms consistent with a fracture usually consist of severe pain at the ankle and inability to bear weight on the affected ankle. Physical exam should evaluate for deformity, point tenderness, compartments, and neurovascular status. Fibula fractures will usually have significant lateral malleolar swelling and tenderness.
Imaging:
For all patients with suspected Weber fractures, a standard ankle x-ray should be obtained, in addition to a stress view. The stress view may reveal an occult syndesmotic or deltoid ligament injury and is obtained by having the patient sitting or laying supine with their leg internally rotated 15-20° while having another person hold the ankle into supination and external rotation.
Weber Classification (Danis-Weber System) and Treatment
Patient Management and Splinting:
Immobilization should focus on stabilizing the ankle joint, preventing flexion/extension, eversion/inversion, and dorsiflexion/plantarflexion. The splint of choice is the posterior short leg splint, and additional AO splint may be added for extra stability. As per usual, evaluate neurovascular status before and after placing the splint. Patients should be given crutches, as the ankle should be non-weight bearing and should be instructed to follow-up with an orthopedist in a week.
References:
Benjamin C. Taylor, MD, Ohio Health Orthopedic Trauma and Reconstructive Surgery. (n.d.). Ankle fractures - trauma - orthobullets. https://www.orthobullets.com/trauma/1047/ankle-fractures
Murphy, A. (2020). Ankle (stress view). Radiopaedia.org. https://doi.org/10.53347/rid-78052
UpToDate. (n.d.-b). UpToDate. https://www.uptodate.com/contents/fibula-fractures