Tibial Shaft Intramedullary Nail
The most commonly employed device for surgical fixation of tibia shaft fracture are intramedullary nails. However, tibial intramedullary nails may also be used for the following: corrective osteotomy for pseudoarthrosis (fibrous tissue that grows between bone ends), impending pathologic fractures/tumor resection, and non-unions or malunions of the tibial shaft.
These nails are essentially metal rods that are inserted from the top of the tibia and span nearly the full length of the bone. An incision to access the starting point of the nail may be made at the top of the tibia and below the patella (knee cap), or an incision will be made just above the knee and the nail inserted under the patella – this access point is now often used as it can help the surgeon properly insert the nail without causing malalignment of the tibia.
Once the appropriate starting point has been obtained, a small guide wire is passed down the full length of the tibia. In order to do so, the surgeon must first reduce the fractured portions of the tibia into appropriate alignment. Once the guide wire is in place, the canal may be hollowed out with drill bits, which ensures a snug fit of the nail. Once the nail is inserted, screws are then placed through the nail at both the proximal and distal portions of the tibia through small (~1-2cm) incisions in order to lock it in place.
Tibial Shaft Open Reduction Internal Fixation
The goals of successful surgical management of tibia shaft fractures are to restore limb length, alignment and rotation. This is most often achieved with the use of an intramedullary nail, however a metal plate with screws as well as an external fixator may also be used. External fixators involve inserting pins into the bone above and below the fracture.
These pins are then connected by rods that are outside the skin. These rods can then be adjusted with the intent of aligning and stabilizing the fracture. This method of fixation is often used in the trauma setting as a temporizing measure, as the soft tissue (e.g. muscle, fat, skin) surrounding the bone may be badly bruised and swollen, which can prevent closure of surgical incisions.
The use of an external fixator allows the surgeon to stabilize the fracture until the swelling goes down and then the definitive surgery can take place. However, the external fixator may be left in place until the fracture heals. This is often avoided if possible, as when compared to intramedullary nails, there is a higher incidence of malalignment, increased time to fracture union and increased time to weight-bearing. External fixators also come with the risk of pin tract infections.
Plate and screws can be used if the fractured portion of the tibia is too proximal or too distal to adequately secure the bone with an intramedullary nail. Although there is greater radiation exposure during the surgery, longer surgical duration and greater difficulty removing the hardware in the event that a secondary procedure needs to be performed, it has been shown to have equivalent time to union and lower postoperative pain when compared to intramedullary nailing.
Tibial Shaft Fractures
Tibial shaft fractures are the most common long bone fractures and account for 4% of all fractures seen in the Medicare population. Fractures that occur in older patients are usually the result of a low energy torsional injury (e.g. fall/trip) and cause a spiral fracture pattern.
In younger patients, tibia shaft fractures are typically caused by high energy direct trauma mechanism (e.g. pedestrian vs. automobile) and cause comminuted fracture patterns (three or more pieces). These injuries are most often treated with surgery, as it is critical to patient outcomes that the tibia heals in appropriate alignment.
In cases where the fractured tibia is not displaced (i.e. is in near perfect alignment), the option for non-surgical management exists in the form of a cast and complete non-weightbearing for 4-6 weeks. However, there is a significant risk of malunion (i.e. the bone heals in a crooked or rotated deformity) as well as non-union (i.e. the bone does not heal at all). Both of which necessitate surgical intervention. For this reason, in the adult population, tibia shaft fractures are most often treated surgically.
The Stryker T2 Alpha Tibia Nailing System ™ was first introduced in 2018, and in the time since it has become one of the most common intramedullary nail systems used today. This nail comes in a variety of sizes to accommodate a patient’s unique dimensions. Once the nail is inserted, it is kept in place by the use of locking screws. Older generation nails traditionally only had one or two screw holes in the same plane both above and below the fracture site.
The T2 Alpha offers the surgeon the added benefit of multiple proximal locking screw options (how the nail is “locked” in place above the fracture) as well as a distal locking pattern (below the fracture) for increased angular stability. Furthermore, after an intramedullary nail is placed past the fracture, the fracture ends can become separated. This nail allows for 7mm of active internal compression at the fracture site to ensure contact between bone ends, helping to prevent non-union (refer to pictures below for how this is accomplished).