Intramedullary Nail for a Distal Tibia Fracture

Abstract

Summary: 

Extraarticular fractures of the distal tibia have historically been treated with open reduction and fixation with plates and screws. This technique requires a more extensive dissection and comes with a higher risk of wound complications than intramedullary nail fixation. This article and the accompanying video demonstrate the use of closed reduction and suprapatellar nail fixation appropriate for the treatment of most extraarticular distal tibial fractures. A variety of treatment decisions are discussed, including the nail insertion method, fixation of associated fibular fractures, and postoperative immobilization.

Appropriate fixation of extraarticular distal tibia fractures may be achieved with plates and screws or intramedullary nails. The use of a nail requires adequate distal bone stock to permit insertion of interlocking screws distal to the fracture. If simple fracture lines extend into the joint surface, a nail may still be used after stabilizing these with percutaneous screws. Advantages of nails include shorter operative times, improved postoperative function, and as much as a 2.5-fold reduction in wound complications.¹ The use of intramedullary nails for distal tibia fractures has been associated with a 12%–23% incidence of malunion,¹ but use of the suprapatellar insertion technique reduces this rate to 3.8%, most likely by permitting maintenance of the reduction without altering the position of the leg during reaming and nail insertion. Obtaining accurate fluoroscopic imaging throughout the procedure is also facilitated by the semiextended leg position. Despite previous concerns, this technique has not been associated with either cartilage injury or increased postoperative knee pain.^2–4 The use of distal interlocking screws is imperative because no stability is afforded distally by the isthmic fit. Biomechanical studies have demonstrated that neither the number of distal interlocking screws (2 vs. 3) nor their direction of insertion affects the stiffness of the final construct.^5–7 Maximizing the working length of the screws does increase stiffness,⁸ and because manufacturers vary the placement of anterior-to-posterior, medial-to-lateral, and oblique screw holes, the orientation that maximizes working length may vary with the nail system.

The effect of fibular fixation on malunion rates remains controversial, but it does increase construct stiffness and may increase the rate of delayed and nonunion.^9–11 Our preference is to avoid fibular fixation unless the fracture or ankle mortise remains unstable intraoperatively after nail fixation. A fluoroscopic external rotation stress performed after nail placement determines the need for fixation of the fibula. In addition, we consider fibular fixation before nail insertion when tibial reduction is challenging due to significant comminution or shortening.

The patient in this case is a 41-year-old woman who slipped on the stairs and had immediate pain and deformity of her left leg. Radiographs demonstrate an extraarticular distal tibia fracture, and a computed tomography scan was obtained to rule out extension into the posterior malleolus before proceeding with surgery. The patient is placed supine on a radiolucent table. After prepping and draping, the knee is placed in 20–30 degrees of flexion such that anteroposterior and lateral radiographs of the knee and tibia can be obtained without moving the leg. A foam ramp can be used based on surgeon preference.

A longitudinal incision is made 2–3 cm proximal to the patella, and the quadriceps tendon is split in line with its fibers. The entry cannula is inserted under the patella and docked in line with the medullary canal at the medial aspect of the lateral intercondylar eminence and just anterior to the articular surface. Care should be taken to ensure a proper starting point on perfect anteroposterior and lateral fluoroscopic images. The starting pin is advanced into the medullary canal, and the opening reamer is inserted over the pin. Care should be taken to avoid reaming the anterior tibial cortex. The pin is replaced with the guidewire, which is advanced to the fracture site. Before passing the guidewire into the distal segment, the fracture is manually held in a reduced position. If necessary, reduction can be performed with percutaneously placed pointed reduction clamps or, failing that, through a small incision. Once reduced, the tip of the guidewire is directed into the distal fragment and aiming towards a center–center position of the talar body. Cannulated reamers are advanced over the guidewire, and the nail is inserted before guidewire removal. Proximal interlock screws are placed using the targeting guide, and distal interlock screws are placed under fluoroscopic guidance. We advise accurate placement of interlocking screws before removing any clamps holding the reduction.

Ankle mortise and syndesmotic stability should then be evaluated with a stress radiograph. To protect the repair, our preferred postoperative protocol is toe-touch weight-bearing in a short-leg splint for 2 weeks then in a controlled ankle motion boot for 4 more weeks with physical therapy aiding in active range of motion and strengthening.

Distal tibial fractures that are either extraarticular or have simple, nondisplaced intraarticular fracture lines can be treated successfully with an intramedullary nail inserted through a suprapatellar approach. This technique facilitates maintenance of reduction during the procedure by minimizing movement of the limb during nail insertion. If performed carefully, accurate reduction is possible, and the wound complications associated with open reduction and plate fixation can be avoided.