Review Question - QID 211309

The patient is presenting with a posterior tibial plateau shear fracture that is axially and length unstable with significant soft tissue swelling. The application of an external fixator with delayed open reduction and internal fixation would be the most appropriate next step.

Tibial plateau fractures are typically high energy injuries that disrupt the articular surface of the proximal tibia. Posteromedial tibial plateau shear fractures are rare injuries that typically occur as a result of a fall on a flexed knee and lead to length instability. Medial tibial plateau fractures are often associated with a knee dislocation and are at high risk for a vascular injury. Often, this may not be apparent as there is a spontaneous reduction from soft tissue recoil following the initial injury displacement. The initial evaluation should include assessment of peripheral pulses and neurologic status (high incidence of vascular injury associated with peroneal nerve palsy), followed by ankle-brachial indices (ABI). Advanced vascular studies should be performed in the presence of ABIs <0.9. Damage control with external fixation may be required in the presence of soft tissue swelling. In posteromedial tibial plateau shear fractures, there is both axial and length instability that would ideally be addressed as soon as possible with external fixation or open reduction internal fixation if soft tissues are permitting.

Bhattacharyya et al. performed a retrospective study of 13 patients with posterior shearing tibial plateau fractures that were treated with open reduction and internal fixation via a posterior approach through an extensile S-shaped incision. They reported 2 complications consisting of one wound dehiscence and one flexion contracture, 88.9% of patients reporting satisfaction with surgical outcomes at 20 months, and a 76% rate of good-excellent radiographic reduction. The authors concluded a direct posterior approach for the posterior shear tibial plateau fractures provides efficient reduction and fixation.

He et al. performed a retrospective study of eight patients with posterior bicondylar tibial plateau fractures that were treated with open reduction and internal fixation via a direct posterior approach through an inverted L-shaped incision. The authors reported all patients had a satisfactory reduction with the exception of one case, no complications, a 100% union rate, and no significant loss of knee range of motion. They concluded the posterior approach to the knee via an inverted L-shaped incision provides full exposure to the posterior tibial plateau without the necessity of osteotomies, tenotomy, or muscle division.

Carlson performed a retrospective case series of eight patients with posterior bicondylar tibial plateau fractures that underwent open reduction and internal fixation with dual posteromedial and posterolateral incisions. The author reported a 100% union rate, range of motion between 2° and 121° at a mean 13 months follow-up, and 3/5 patients returned to manual labor jobs. The author concluded that the dual-incision approach for the treatment of posterior bicondylar tibial plateau fractures results in good to excellent knee function.

Halvorson et al. reviewed the diagnosis and management of lower extremity trauma with associated vascular injuries.

Figures A and B are the AP and lateral radiographs of the left knee with a posterior tibial plateau shear fracture. The authors recommend performing an ABI if there is an abnormal physical examination and proceeding with CT angiography if less than 0.90. They further could not recommend, based on lack of high-quality evidence, whether a vascular repair should be performed before or after orthopedic stabilization of the injury, rather a coordinated effort between the vascular and orthopedic services.

Incorrect answers:
Answer 1: Application of a knee immobilizer with outpatient surgical scheduling would be inappropriate for this patient given the instability associated with this fracture pattern.
Answer 2: The patient does have significant soft-tissue swelling, but does not have a diagnosis of compartment syndrome based on the physical exam findings. A 4-compartment fasciotomy would not be indicated at this time.
Answer 3: An open reduction internal fixation through an anteromedial approach would not sufficiently reduce the fracture in this patient. Also, the patient should be temporized with an external fixator given the significant soft-tissue swelling.
Answer 4:An open reduction internal fixation through a posteromedial approach may be an ideal definitive treatment for this injury, initial management should consist of temporizing external fixation to permit soft tissue stabilization.