A twenty-three-year-old woman was seen at the Maricopa County Medical Center after she had jumped off a gate and landed on the left foot with the knee flexed. She had pain and swelling in the left knee and was unable to bear weight on that side. Physical examination revealed a large effusion in the left knee with soft-tissue swelling. The compartments of the leg were soft, and the neurovascular status was intact. Radiographs revealed a fracture that involved the posterior aspect of both the medial and the lateral tibial plateau (Figs. 1 and 2). Computerized axial tomographic scans showed fracture lines in the coronal plane involving more than one-third of the medial plateau and two-thirds of the lateral plateau (Fig. 3). Coronal computerized tomographic reconstructions showed approximately one centimeter of depression of the lateral plateau with less displacement medially (Figs. 4 and 5).
Open reduction and internal fixation was chosen because of the split-depressed fracture pattern involving the lateral plateau and the displaced fracture of the posterior part of the medial plateau. On the basis of the radiographic findings, it was thought that direct visualization, reduction, and internal fixation was necessary. Operative stabilization was performed on the day after the injury.
Operative Approach
After the administration of a general anesthetic, the patient was placed in the prone position with chest-rolls under the torso and appropriate padding of osseous prominences. Cefazolin (one gram) was administered intravenously before the tourniquet was inflated. The tourniquet was used during the exposure of each plateau and was deflated during fixation of each fracture.
Medial plateau: With the knee in 0 to 5 degrees of flexion, a gentle s-shaped curvilinear incision, ten centimeters long, was made posteromedially over the anterior border of the semimembranosus insertion on the tibia (Fig. 6). The anterior border of the semimembranosus was exposed, and the most anterior of its five insertions on the tibia was transected and retracted posterolaterally. The underlying popliteal fascia and popliteus muscle were identified and carefully elevated in an extraperiosteal fashion from proximal to distal and from medial to lateral, exposing the site of the fracture. The joint was opened posteriorly by lifting the medial meniscus from its site of insertion on the tibia (Fig. 7). Retention sutures were placed in the meniscus to allow for visualization and reduction of the fracture. After the fracture had been reduced, provisional fixation was accomplished with use of a Kirschner wire. Definitive fixation then was performed with the insertion of a lag screw and the application of a four-hole, one-third tubular small-fragment buttress plate (Synthes, Paoli, Pennsylvania). The medial meniscus was reattached to its site of insertion with use of 0 Vicryl suture (Ethicon, Somerville, New Jersey).
Lateral plateau: With the knee maintained in 0 to 5 degrees of flexion, a gentle s-shaped curvilinear incision, ten centimeters long, was made over the posterior border of the biceps femoris (Fig. 6). The common peroneal nerve was identified and mobilized to allow gentle lateral retraction. The lateral head of the gastrocnemius was retracted medially to expose the underlying soleus. The soleus was elevated from the proximal tibiofibular joint distally and medially, exposing the comminuted and depressed lateral tibial plateau (Fig. 8). The lateral meniscus, which was avulsed from its peripheral soft-tissue attachments, was retracted to allow for visualization of the joint. With the knee held in full extension, the depressed articular surface was elevated and the metaphyseal defect was filled with croutons of cancellous allograft bone. The posterior cortex was reduced, and a small-fragment T plate (Synthes) was applied in a buttress fashion; subchondral screws and Kirschner wires were used to provide additional support to the elevated plateau. The attachments of the lateral meniscus had been avulsed at the time of the injury, and direct repair of the meniscus was not possible. The lateral meniscus was thus held in a reduced position with use of 0 Vicryl suture (Ethicon) that was tied around the heads of the most proximal screws in the plate.
Postoperative Care
Postoperatively, a continuous-passive-motion machine was used for six hours per day for two weeks. The patient was managed with non-weight-bearing on the left limb for eight weeks and then walked with toe-touch weight-bearing for two weeks before beginning to walk with full weight-bearing. At the six-month follow-up examination, the range of active and passive motion of the knee was 3 to 122 degrees of flexion. The knee was stable to varus-valgus and anterior-posterior stress. The only symptom was pain after prolonged periods of standing or walking. Radiographs that were made after the fracture had healed demonstrated maintenance of the reduction of the joint surfaces of both the medial plateau and the lateral plateau (Figs. 9 and 10).
De Boeck and Opdecam as well as Georgiadis separately reported on series of patients in whom a fracture of the posterior aspect of the medial tibial plateau was treated with use of a posteromedial operative approach. De Boeck and Opdecam recommended partial division of the medial head of the gastrocnemius as part of the exposure. The findings described in the present report, as well as those in other reports3,4, demonstrate that visualization of the posterior aspect of the medial plateau is possible without this extra dissection.
Waldrop et al. reported on a series of patients who had a fracture of the posterior aspect of the lateral tibial plateau. Those authors used either an open lateral approach or a percutaneous approach with arthroscopic assistance. The patients who did not have operative restoration of the anatomy of the lateral plateau had difficulty with activities that required stability of the knee in flexion.
As noted by Schatzker, fractures of the posterior aspect of the tibial plateau are difficult, if not impossible, to reduce and stabilize adequately through an anterior exposure. Direct exposure of the fracture was used for the patient described here because of the large portion of the joint surface that was involved in the fracture, the split-depressed fracture pattern involving the lateral plateau, and the need for a buttress plate to support both the medial plateau and the lateral plateau. Separate incisions were used to avoid an s-shaped incision across the popliteal fossa, which would have necessitated the elevation of a large skin flap and may have caused injury to the sural nerve. The two-incision approach also allowed adequate distal exposure for reduction and plate fixation of the fracture involving the posterior aspect of both the medial plateau and the lateral plateau.