The Case: A 46-year-old otherwise healthy female presents to the emergency department with left knee pain after falling off a moped. Since then, she has been unable to bear weight and complains of persistent pain and swelling of the left knee and leg. Physical exam demonstrates ecchymosis and moderate swelling around her left knee with tenderness to palpation around the knee joint and proximal tibia.
Figure 1. XR L Knee - Displaced split fracture of the medial tibial plateau
Why does it matter?
The tibial plateau is the high load bearing surface of the knee joint. Vital structures such as the popliteal artery and peroneal nerve run nearby. Mechanism of injury is typically an axial loading injury combined with a bending force on the knee. In young patients this is typically a high-energy trauma whereas in elderly patients or those with osteoporotic disease it is usually after a low impact force, such as a ground level fall.
Regardless of mechanism, all patients will typically present with a refusal to bear weight on the injured leg. Knee effusions may be present, and range of motion and strength testing are frequently limited due to pain.
High-energy traumas more often result in fractures to the medial or bicondylar tibia and are more frequently associated with injury to adjacent ligamentous and/or neurovascular structures. For this reason, tibial plateau fractures from high velocity traumas are more likely to be unstable and are at very high risk of developing compartment syndrome. As such, management may require an observational period for serial neurovascular and compartment checks; and the ED provider should have a low threshold to involve their orthopedic colleagues.
Once all orthopedic emergencies have been ruled out, patients can be safely discharged from the hospital in a knee immobilizer and counseled on strict non-weight bearing precautions. All patients should be given urgent orthopedic clinic follow up as surgical repair may be needed for appropriate healing.
Written by:
Dr. Sofia Gambuto, MD
Emergency Medicine, PGY-3
Cook County Health
Reviewed by:
Dr. Scott Sherman, MD
Associate Program Director
Cook County Health
References:
Bond M. The Knee. In Sherman SC (8Ed). Simon’s Emergency Orthopedics. McGraw-Hill Education. New York, NY. 2019.
Prat-Fabregat S, Camacho-Carrasco P. Treatment strategy for tibial plateau fractures: an update. EFORT Open Rev. 2017;1(5):225-232. Published 2017 Mar 13. doi:10.1302/2058-5241.1.000031
Malik S, Herron T, Mabrouk A, et al. Tibial Plateau Fractures. [Updated 2021 Feb 16]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK470593/