- Fracture of the articular portion of the proximal tibia
- Axial load combined with varus (inward angulating) or valgus (outward angulating) force on weight bearing knee.
- Lateral plateau fractures more common than medial (involved in 85-90% cases) (Schwartz, 2008). The medial plateau is stronger as it bears the majority of the load transferred across the knee.
- Medial plateau fractures generally result from a high-energy mechanism
- Pedestrian struck against fixed knee, classically described as “bumper fracture” or “fender fracture” of lateral plateau
- Low-energy mechanisms (e.g. simple fall, stepping awkwardly off bus) more common in elderly female patients with underlying osteopenic bone typically result in depressed fractures (Cole, 2009)
- High-energy mechanism (falls, sports-related injuries or motor vehicle accidents (MVAs)) are more common in younger patients
- Frequently missed fracture due to subtle radiographic findings
Presentation + Initial Evaluation
- Refusal to bear weight on the affected extremity
- Presence of a knee effusion
- Evaluate for compartment syndrome particularly in those with a high-energy mechanism injury (high-speed MVC, fall from height etc)
- Evaluate for neurovascular injury (popliteal artery, peroneal nerve) which may be seen if there was concomitant knee dislocation spontaneously reduced
- Views: AP, lateral and oblique views
- Fractures can be subtle as slope of tibial plateau makes accurate assessment of depression difficult on AP view
- Increased trabecular density may represent compression fracture (see image B)
- Joint widening is not reliable sign in standard AP because it requires a weight bearing view which should not be attempted if this injury is suspected
- Knee effusions and lipohemarthrosis (fat-fluid level), although non-specific, may indicate underlying bony injury. The latter is seen best on cross-table lateral view when the beam is tangential to the fat-blood interface.
- CT Scan
- May be necessary for fracture diagnosis in the ED, especially if clinical suspicion persists despite negative x-rays.
- Frequently required for further characterization of fracture pattern and evaluation of involvement of articular surface, as well as preoperative planning.
- Typically not necessary in ED management
- May be scheduled as part of follow up evaluation for meniscal and ligamentous injury or for identification of occult fractures
- Type I: lateral plateau, split fracture
- Results from axial load with valgus stress
- Cancellous bone of lateral plateau prevents depression in young healthy patients
- Type II: lateral plateau, split-depression fracture (most common)
- Same mechanism of injury as Type I but with underlying osteopenic bone unable to resist depression
- Type III: lateral plateau, isolated depression fracture (rare)
- Compression fracture of lateral plateau, usually laterally or centrally located
- Rare and see only in older individuals or those with severe osteopenia
- Type IV: medial plateau fracture
- Results from axial or varus stress, split or split-depression fracture
- Medial plateau stronger than lateral, represents higher energy injury than Types I, II, III
- Type V: bicondylar fracture
- Medial and lateral plateau fractures with or without compression
- Results from pure axial force on extended knee, high-energy injury
- Type VI: plateau fracture with separation of metaphysis from diaphysis
- Results from combination of high-energy forces
- Complex bicondylar fracture with separation of condylar components from diaphysis
- Depression and impaction of fragments
Emergency Department Management
- Evaluate for other associated injuries especially in high-energy fracture patterns (Type IV, V, VI). These include other axial load fracture sites such as femoral neck, calcaneus, spine, and pilon fractures
- Medial Plateau Fractures (Type IV)
- High rate of vascular injury from concomitant knee dislocations
- Consider checking ankle-brachial index (ABI) in these patients (Egol, 2015)
- Low-energy fractures
- Do not usually require a period of observation for compartment syndrome
- Well-padded knee immobilizer/Bulky Jones dressing
- Strict non-weight bearing with orthopedic follow up
- High-energy fractures
- Often have multi-system trauma
- Increased likelihood for compartment syndrome
- Consider observation in all patients looking for development of compartment syndrome
- Open fractures and those with associated compartment syndrome or vascular compromise must be evaluated by orthopedics emergently for surgery
- Most elderly patients are managed non-surgically if fractures are only minimally displaced
- Operative management will ultimately depend on age of patient and practice patterns but most Type II and almost all medial/bicondylar injuries will be operative
Take Home Points
- Tibial plateau fractures can have subtle radiographic findings. Maintain a high clinical suspicion for obtaining additional imaging or CT for patients unable to bear weight in the ED following injury.
- Evaluate patients with high-energy mechanisms of injury for compartment syndrome and consider observation for serial examinations
- Discharge patients in knee immobilizer and strict non-weight bearing. This prevents further injury to articular cartilage and many patients will have concomitant ligamentous and meniscal injuries.
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Cole P et al. Tibial plateau fractures. In: Browner B, Levine A, Jupiter J, Trafton P, Krettek C, eds. Skeletal Trauma: Basic Science Management and Reconstruction. Philadelphia: Saunders Elsevier, 2009: 2201-2287.
Egol KA et al. Handbook of Fractures, 5th ed. Philadelphia: Wolters Kluwer, 2015: 445-453.
Schatzker J et al. The tibial plateau fracture. The Toronto experience 1968–1975. Clin Orthop Relat Res 1979; 138:94-104. PMID: 445923
Schwartz DT. Emergency Radiology: Case Studies. New York: McGraw-Hill, 2008: 307-316.
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