CORE EM: Tibial Plateau Fractures

• Fracture of the articular portion of the proximal tibia

Mechanism

• 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

Epidemiology

• 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

Imaging

• X-ray
  • 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.
• MRI
  • 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

Tibial Plateau Fracture with Lipohemarthrosis (imageinterpretation.co.uk)

Schatzker Classification

• 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

Prognosis

• 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.

References

Baxter A. Emergency Imaging: A Practical Guide. Stuttgart, Germany: Thieme; 2016: 458-459.

Berkson EM, Virkus WW. High-energy tibial plateau fractures. J Am Acad Orthop Surg 2006; 14:20-31. PMID: 16394164

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, 5^th 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.

Zeltzer DW, Leopold SS. Classifications in Brief: Schatzker classification of tibial plateau fractures. Clin Orthop Relat Res 2013; 471:371-4. PMID: 22744206