Dual Plating of Distal Femoral Fractures

Abstract

Background: Dual plating of the distal femur is indicated for the treatment of complex intra-articular fractures, supracondylar femoral fractures, low periprosthetic fractures, and nonunions. The aim of this procedure is anatomical alignment of the articular surface, restoration of the articular block, and prevention of varus collapse.

Description: Following preoperative planning, the patient is positioned supine with the knee flexed at 30°. The lateral incision is made first, with a mid-lateral incision that is in line with the femoral shaft. If intra-articular work is needed this incision can be extended by curving anteriorly over the lateral femoral condyle. Next, the iliotibial band is transected in line with its fibers. The vastus lateralis fascia is incised and elevated off the septum, working distal to proximal. Care should be taken to maintain hemostasis when encountering femoral artery perforating vessels. Once there is adequate exposure, several reduction aids can be utilized, including a bump under the knee, Schanz pins, Kirschner wires, and reduction clamps. A lateral precontoured plate is placed submuscularly, and the most proximal holes are filled percutaneously. The medial incision begins distally at the adductor tubercle and is a straight incision made proximally in line with the femoral shaft. The underlying fascia is transected in line with the skin incision, and the vastus medialis is elevated. Care should be taken to avoid the descending geniculate artery, as well as its articular branch and the muscular branch to the vastus medialis. A lateral tibial plateau plate is contoured and placed.

Alternatives: Nonoperative treatment of distal femoral fractures is rare, but relative indications for nonoperative treatment include frailty of the patient, lack of ambulatory status, a non-reconstructible fracture, or a stable fracture. These patients are placed in a long-leg cast followed by a hinged knee brace¹. There are several other surgical fixation options, including lateral plating, retrograde intramedullary nailing, distal femoral replacement, and augmentation of a retrograde nail with a plate.

Rationale: Dual plating has several benefits, depending on the clinical scenario. Biomechanical studies have found that dual plating results in increased stiffness and construct strength^2,3. Additional construct stability can be offered through the use of locking plates, particularly in osteoporotic bone. Taken together, this increased stability and construct strength can allow for earlier weight-bearing, which is particularly important for fractures in the geriatric population. Furthermore, the increased stiffness and construct strength make this procedure a favorable treatment option for nonunion, and it has been shown to result in lower rates of postoperative nonunion compared with lateral plating alone^4-7. Adjunctive use of a medial plate also has been suggested to prevent varus collapse, particularly with metaphyseal comminution and poor bone quality^2,3,8. Finally, in the periprosthetic fracture population, dual plating also removes the concern of incompatibility with a retrograde nail.

Expected outcomes: The outcomes of dual plating are promising, given the severity of the injury. When comparing operative to nonoperative treatment outcomes, nonoperatively managed patients had worse functional outcomes and higher rates of complications related to immobility¹. Dual plating of supracondylar fractures and intra-articular distal femoral fractures yields nonunion rates ranging from 0% to 12.5%, lower than the 18% to 20% reported with lateral locking plates^4-7,9-12. This reduction in nonunions has been shown to lead to fewer revisions when compared with single-plating techniques⁷. In prior studies, 95% of nonunions treated with the dual-plating technique achieved union postoperatively¹¹. One concern when utilizing the medial approach is critical damage to medial vascularity; however, this result has not been reported in the literature, and there is a safe operating window¹³. Despite the benefits of dual plating, there are relatively high rates of infection following dual plating (0% to 16.7%) compared with lateral plating alone (3.6% to 8.5%)^5,14-17. However, many of these studies are small case series, highlighting that a surgeon's comfort and skill with these procedures is paramount to patient outcomes.

Important tips: Meticulous placement and contouring of lateral and medial plates are required to prevent malreduction of the articular block that creates a "golf-club deformity."^18,19During the medial approach, be aware of descending geniculate artery-particularly its muscular branch, which is ∼5 cm from the adductor tubercle/medial epicondyle, and its root, which enters the compartment at the adductor hiatus at ∼16 cm¹³.