A New Anterolateral Approach for Type C Fractures of the Distal Femur

To provide an anatomic basis for treating type C distal femoral fractures by a new anterolateral approach. Twenty surgical procedures were performed in 10 adult cadaveric specimens using a new anterolateral approach followed by dissection of all lower limbs. The main anterolateral muscles and ligaments were observed. Vessels and nerves related to the new anterolateral approach were also evaluated. Full exposure of the distal femur was achieved. The iliotibial band was protected, and damage to the quadriceps femoris was reduced. The distance between the common peroneal nerve and the new incision line at the level of the lateral epicondyle of the femur was ($\bar{\chi }$ ± s) 8.19 ± 0.79 cm (range, 7.48–9.57 cm). This new anterolateral approach to the distal femur is safe. Although it induces slight soft tissue damage, its exposure is excellent. Knee rehabilitation can be performed in the early postoperative period.Key words: Distal femur fracture, New anterolateral approach, AnatomyThe number of high-energy traumas causing distal femoral fractures is increasing.^1,2 The estimated frequency is 3% of femoral fractures.³ Müller⁴ classified these fractures according to their location and pattern. Their classification broadly divides distal femoral fractures into type A (extra-articular), type B (condylar or partial articular), and type C (bicondylar or complete articular). Types A and B permit less-invasive repair procedures, such as less-invasive stabilization systems and intramedullary nailing,⁵ but type C refers to comminuted fractures of both the lateral and medial femoral condyles in association with severe soft tissue injuries. This type of fracture requires anatomic reduction of the articular surface, internal fixation, and early functional rehabilitation to improve outcomes and reduce the incidence of posttraumatic complications.^6–8Although indirect reduction maneuvers are available for type C fractures of the distal femur, direct exposure with visualization of the articular surface and fracture fragments is recommended to ensure anatomic reduction.^8,9 Adequate exposure can reduce the operation time and address fractures anatomically, reducing the rates of malunion, nonunion, and infection.^9,10 Many approaches to the distal femur have been described. Lateral and anterolateral approaches are commonly used, but full exposure is difficult, and soft tissue injury may occur, potentially leading to malunion, nonunion, knee dysfunction, and other problems.¹¹ To minimize soft tissue injury, widely expose the joint, operate easily, and implement early postoperative functional exercise, we designed a new anterolateral approach termed the “S-shaped approach.” We performed a cadaveric anatomic study to confirm the technical feasibility of this approach.