Tibial Plateau Fracture Case File

Tibial Plateau Fracture Case File

Eugene C. Toy, MD, Andrew J. Rosenbaum, MD, Timothy T. Roberts, MD, Joshua S. Dines, MD

CASE 8

A 43-year-old man was crossing the street when he was struck by a car moving at approximately 35 miles per hour. He was brought to the emergency department and is complaining of left knee pain. He did not lose consciousness. He has no other significant complaints. He has no significant past medical or surgical history. Findings on physical examination are notable for pain on palpation of his proximal left tibia with knee pain throughout passive range of motion. His skin is intact. His neurovascular examination is normal. His leg is circumferentially firm, but compressible. An anteroposterior (AP) radiograph is obtained and is shown in Figure 8–1 .

Figure 8–1. AP radiograph of the left knee.

► What is the most likely diagnosis?

► What additional injuries are you most concerned about?

ANSWER TO CASE 8:

Tibial Plateau Fracture                              

Summary: A 43-year-old man sustained a direct, high-energy injury to his left knee. Plain films of the left knee show a split depression of the medial condyle without lateral condylar involvement.

• Most likely diagnosis: Left tibia medial plateau split fracture, or a Schatzker IV injury
• Additional injuries: Meniscal tears, collateral and cruciate ligamentous injuries, peroneal nerve, popliteal artery injury (typically associated with medial plateau fractures), and compartment syndrome are soft-tissue injuries associated with tibial plateau fractures.

ANALYSIS

Objectives

1. Understand the anatomical and mechanistic principles behind the Schatzker classification of tibial plateau fractures.
2. Be familiar with basic treatment options for tibial plateau fractures.
3. Recognize potential complications arising from both the initial injuries and their treatments.

Considerations

This patient sustained a high-energy, direct impact injury to the region immediately below his right knee. In addition to his medial plateau fracture, he is at significant risk for several additional injuries, including collateral ligament complex, peroneal nerve injury, and popliteal artery injury. Medial meniscal tears may occur in up to 50% of plateau fractures, most commonly occurring with medial plateau injuries; likewise, lateral meniscal injuries are associated with lateral plateau fractures. Ligamentous integrity should be evaluated. A careful neurovascular evaluation is also essential. Although this patient has palpable pulses distal to his injury, a pulseless limb must be evaluated with Doppler probe and/or ankle-brachial index measurements (normal > 0.9). Should audible Doppler waveforms be absent or diminished compared with the uninvolved side, vascular surgery should be consulted and the patient will likely require arteriography to evaluate the integrity of the popliteal artery.

    Although this patient sustained no other obvious injuries, his mechanism warrants a complete and thorough physical exam, typically performed by a trauma team, with careful examination of all extremities and the axial skeleton performed by an orthopaedist. Although some tibial plateau fractures may be immobilized and sent away from the emergency department for outpatient follow-up, the high-energy nature of this injury necessitates admission to the hospital. As an inpatient, frequent leg compartment checks may easily be performed to ensure this patient does not develop a compartment syndrome. Intimal damage to the popliteal artery may take up to 48 hours to become symptomatic.

APPROACH TO:

Tibial Plateau Fracture                                             

DEFINITIONS

TIBIAL PLATEAU: Term describing the weightbearing area of the proximal tibia. It is composed of the concave medial plateau and smaller convex lateral plateau. These regions are separated by the intercondylar eminence.

SCHATZKER CLASSIFICATION: A widely used classification system for tibial plateau fractures that helps orthopaedic surgeons with assessing the initial injury, formulating a management plan, and predicting prognosis. The classification divides tibial plateau fractures into 6 types.

CLINICAL APPROACH

Anatomy and Mechanisms of Injury

The tibial plateau is the predominantly cancellous region of bone that articulates with the distal femur. It includes the relatively larger, stronger, and more concave medial plateau and the relatively weaker, smaller, and more convex lateral plateau. Medial plateau injuries, therefore, typically result from higher energy mechanisms, which are defined as falls from greater than 12 feet or sudden-impact mechanisms such as motor vehicle collisions or bumper versus pedestrian events. Lateral plateau injuries, conversely, may occur from low-energy falls from standing in elderly osteoporotic patients. The direction and magnitude of fracture force, in addition to the underlying quality of bone, determine the fracture pattern.

Classification

The Schatzker classification is commonly used to describe tibial plateau fractures. They are classified in the following way:

Type I     Lateral split

Type II     Lateral split depression

Type III     Lateral pure depression

Type IV     Medial plateau split and/or depression

Type V     Bicondylar

Type VI     Metaphyseal-diaphyseal disassociation

    Schatzker I through III fractures are generally considered low-energy injuries, whereas IV through VI injuries are high-energy injuries ( Figure 8–2 ). Young adults with strong bone typically exhibit split fractures and have increased propensity to suffer ligamentous damage; older patients with osteoporotic bone are more inclined to suffer depression and split-depression patterns in the absence of ligamentous damage. Medial injuries (type IV) are considered by some authors to represent transient knee dislocations that have spontaneously reduced; the incidence of neurovascular injury is thus higher with these events.

Tibial Plateau Fractures of Schatzker Classification

Figure 8–2. Schatzker classification of tibial plateau fractures. (A) Type I: lateral split, (B) type II: lateral split depression, (C) type III: lateral depression, (D) type IV: medial plateau, (E) type V: bicondylar, and (F) type VI: bicondylar with separation of metaphysis from diaphysis.

Radiographic Evaluation

In addition to the AP and lateral films mentioned previously, oblique views of the proximal tibia (40 degrees of internal and external rotation) should be obtained to better visualize the fracture. Computed tomography may be helpful in evaluating depressions and comminution for preoperative planning. Magnetic resonance imaging may be used to evaluate menisci and ligamentous damage.

TREATMENT

Low-energy, nondisplaced, or minimally displaced fractures may be treated nonoperatively. Patients typically receive a hinged knee brace for 8 to 12 weeks and may gradually progress to partial then full weightbearing. Nonambulating patients, patients with severely osteoporotic bone, or those not medically fit for surgery may receive similar management. Indications for surgical fixation generally include Schatzker IV through VI fractures as well as I through III fractures exhibiting articular stepoff greater than 3 mm, condylar widening greater than 5 mm, or instability with varus or valgus stress. Typical procedures include open-reduction internal fixation, or, for cases in which a satisfactory closed reduction is achieved, percutaneous screw fixation. Depressions of the articular surface often require bone grafting to fill the voids. Depressions may be filled with autogenous bone graft, allogenic bone graft, or bone substitutes, the strongest of which is calcium phosphate cement.

    Often, patients with tibial plateau injuries have sustained additional severe and life-threatening injuries that make them unfit for lengthy surgical procedures. These patients may benefit from temporary but fast external fixation that preserves the length and anatomical alignment of the tibia and allows for definitive fixation at a later date. Temporary external fixation is indicated similarly in patients whose severe soft-tissue swelling prohibits immediate surgical fixation.

Outcomes and Complications

Degenerative joint disease or posttraumatic arthritis of the knee is a common complication, often occurring 5 or more years after the initial injury. The incidence of arthritis is increased with significant cartilaginous or ligamentous injury and malalignment of the knee’s mechanical axis or articular incongruity after repair. Additionally, Schatzker VI fractures, with their characteristic separation of metaphysis from diaphysis, may exhibit nonunion or malunion at this junction.

COMPREHENSION QUESTIONS

8.1 A 24-year-old construction worker falls 8 feet and presents to the emergency department with complaints of left wrist and knee pain. He reports landing on his left leg first, with his knee buckling inward. Given this patient’s age and mechanism, which of the following best describes his risk for injury?

A. Increased chance of lateral plateau injury, increased chance of pure depression fracture, and increased chance of ligamentous and/or meniscal damage

B. Increased chance of medial plateau injury, increased chance of pure depression fracture, and increased chance of ligamentous damage

C. Increased chance of lateral plateau injury, increased chance of split fracture, and increased chance of ligamentous damage

D. Increased chance of medial plateau injury, increased chance of split fracture, and increased chance of ligamentous damage

E. Increased chance of lateral plateau injury, increased chance of split fracture, and decreased chance of ligamentous damage

8.2 A 55-year-old taxation lawyer with no significant past medical history is involved in a head-on motor vehicle collision at approximately 45 miles an hour and suffers the injury shown in Figure 8–3 . He has palpable pulses distally and is neurovascularly intact. Aside from abrasions and a concussion, he has no other significant injuries. He exhibits only mild swelling at the knee. Which of the following is the best treatment for his injury?

Figure 8–3. AP radiograph of the left knee.

A. Brace immobilization with early weightbearing

B. External fixation for 8 to 12 weeks, early weightbearing with fixator, active range-of-motion knee exercises

C. Closed reduction and casting, nonweightbearing for 8 to 12 weeks

D. Open reduction, internal fixation with screws and/or plates, nonweightbearing for 8 to 12 weeks

E. Functional bracing with gradual weightbearing and active range-of-motion knee exercises

8.3 A 44-year-old woman is involved in a high-speed motor accident and suffers a right-sided tibial plateau fracture. She is neurovascularly intact, and her compartments are soft. She has no other significant injuries, except for a minor concussion and several broken ribs. Which of the following, if present, is an indication for operative fixation?

A. Articular step-off 5 mm

B. Lateral meniscal tear on follow-up MRI

C. ACL tear on follow-up MRI

D. Condylar widening < 3 mm

E. Ipsilateral ankle fracture

ANSWERS

8.1 C. Given this young patient’s relatively strong bone, he is most likely to sustain a split fracture with ligamentous injury, as compared with elderly people with softer bone, who typically sustain depression-type injuries without ligamentous damage. Furthermore, given the axial/valgus (knee inward) force as described in his fall, he is most likely to exhibit a lateral split type injury.

8.2 D. This is a bicondylar split fracture, or a Schatzker V. Schatzker IV, V, and VI fractures are typically treated with open-reduction internal fixation in the absence of significant swelling or other contraindications.

8.3 A. Indications for operative fixation for tibial plateau fractures include highenergy plateau injuries (Schatzker IV through VI) or any plateau fracture with articular step-off greater than 3 mm, condylar widening greater than 5 mm, or instability with varus or valgus stresses. Concomitant ACL, meniscal, or even ankle fractures are not necessarily indications for fixation if the reduction is adequate and the fracture is immobilized.

    CLINICAL PEARLS    

► High-energy tibial plateau injuries (Schatzker IV, V, VI) are frequently associated with significant comorbidities, including compartment syndrome and neurovascular injury in the affected extremity. Advanced trauma life support protocol in such situations must be followed. ► Upwards of 50% of plateau fractures are associated with meniscal tears; ACL injuries are found in approximately 30% of injuries.

REFERENCES

Buchholz RW, Court-Brown CM, Heckman JD, Tornetta P, eds. Tibial plateau fractures. In: Rockwood and Green’s Fractures in Adults . 7th ed. 2 vol. Philadelphia, PA: Lippincott Williams & Wilkins; 2010:1790-1831. 

Egol KE, Koval KJ, Zukerman JD, eds. Tibial plateau fractures. In: Handbook of Fractures. 4th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2010.

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