Intramedullary Tibial Nailing

The tibia is a long, tubular bone with a triangular cross section (Fig. 37-1).
It has a subcutaneous anteromedial border and is bounded by four tight
fascial compartments. The nutrient artery of the tibia arises from the
posterior tibial artery, entering the posterolateral cortex distal to
the origination of the soleus muscle, at the oblique line of the tibia.
If the nutrient artery is disrupted, there is reversal of flow through
the cortex, with the periosteal blood supply becoming more important.
The fibula is responsible for 6% to 17% of the weight-bearing load. The
common peroneal nerve courses around the neck of the fibula, where it
is vulnerable to a direct blow or traction injury.

There is no universally accepted classification scheme.
It may be best to describe the fracture in terms of (1) an open or
closed injury; (2) its anatomic location (i.e., proximal, middle, or
distal third); (3) the fragment number and position (e.g., comminution,
butterfly fragments); (4) fracture configuration (i.e., transverse,
spiral, or oblique); (5) angulation (e.g., varus or valgus, anterior or
posterior); (6) shortening; and (7) displacement and percentage of
cortical contact.

The Orthopaedic Trauma Association (OTA) classification of tibial fractures is useful for research purposes (Fig. 37-2):

Operative stabilization of the tibia is indicated in
patients with an open fracture; multiple injuries; an ipsilateral
fracture of the femur, ankle, or foot; vascular injury; compartment
syndrome; and unacceptable fracture position after closed reduction and
casting. An acceptable reduction includes less than 1.0 to 1.5 cm of
shortening and up to 5 degrees of angulation (e.g., varus or valgus,
anterior or posterior). Unstable fractures with high-grade soft tissue
injury, whether closed or open, require operative stabilization.

Indications for intramedullary nailing include fractures
located in the middle two thirds of the tibia. Indications for
intramedullary nailing may be extended proximally or distally, but they
are associated with an increased risk of fracture malreduction.
Contraindications to intramedullary nailing include immature patients
with open physes, patients with very small medullary canals, or a
history of tibial osteomyelitis.

Preoperative anteroposterior and lateral radiographs of
the fractured extremity, including the knee and ankle, are critical to
define the fracture and geometry of the tibial injury (Fig. 37-3).
The lateral radiograph should be carefully inspected and the size of
the intramedullary canal measured. An ossimeter can be used to measure
the tibia and to establish the length and diameter of the nail required.

The equipment necessary for intramedullary tibial nailing includes the following (Fig. 37-4):

Intramedullary tibial nailing can be performed with the
patient positioned supine on a radiolucent table or on a fracture
table. Supine positioning on a radiolucent table with a bolster under
the knee is the simplest technique and is my preferred method. The knee
is flexed over a radiolucent pad, which permits access to the proximal
tibia and visualization of the starting point (Fig. 37-5).
However, the disadvantage to this method of treatment is that it can be
difficult to obtain and maintain fracture length in addition to
controlling angulation and rotation.

A fracture table is more complex to set up but is more
effective in maintaining length and rotation. With the fracture table,
the knee is flexed 90 degrees over a post, which is placed proximal to
the popliteal fossa to prevent compression of the vessels or peroneal
nerve. Tape can be placed around the thigh to prevent external rotation
of the extremity.

Most tibial shaft fractures can be manually reduced using a combination of longitudinal traction and angular directed force (Fig. 37-6). Although rarely necessary, a femoral distractor

can be used with a pin placed proximally in the posterior tibia and
distally just above the ankle joint. In acute fractures, a unilateral
frame is usually adequate.

The incision extends from the tibial tubercle to the inferior aspect of the patella (Fig. 37-7). The medial aspect of the patella tendon is identified and the patella tendon reflected laterally (Fig. 37-8). A curved awl is used to open the medullary canal at the junction of the anterior tibia and knee joint (Fig. 37-9). It
is important to stay extraarticular, because backout of the nail may
impinge on the femoral condyle. It is equally important not to enter at
the tibia tubercle, because this leads to a more oblique
anteroposterior starting angle with a greater risk for penetration of
the posterior cortex with the nail. The exact starting point for
the awl is determined on the anteroposterior and lateral fluoroscopic
views. In midshaft and distal tibial fractures, the anteroposterior
starting point should be in line with the center of the tibial shaft.
On the lateral radiograph, the point of the awl should be just inferior
to the joint line. In proximal fractures, the
incision and starting point is just lateral to the patellar tendon;
this results in the nail abutting against the lateral tibial cortex,
which helps prevent translation and angulation.

A bulb-tip guide wire is inserted down the canal (Fig. 37-10). It
is helpful to place a small bend in the guide wire 2 cm from the tip.
This often facilitates passing of the wire across the fracture site.
A T-handle, which is used to control the bulb-tip guide, is placed in
the midportion of the guide wire. The bulb tip is initially aimed
posteriorly to enter the tibia and then immediately turned anteriorly
and passed down to the fracture site, avoiding penetration of the
posterior cortex proximally or exiting through the fracture site
posteriorly. The guide wire is advanced to the fracture site (Fig. 37-11), the fracture is reduced, and the guide wire is

advanced under image intensification into the distal fragment (Fig. 37-12). It is impacted into the subchondral bone above the ankle (Fig. 37-13)
to stabilize the bulb tip and to aid in determining length. A second
bulb tip of identical length is placed at the joint line, and a long ruler is used to determine nail length (Fig. 37-14).
Another method to determine the nail length is to measure the tibia
externally with a long ruler with hatch marks and confirm it with the
image intensifier.

Reaming is a critical part of the surgical technique and must be done well to avoid complications (Fig. 37-15). Reaming
must be done with sharp cutting reamers that dissipate heat and
pressure. To prevent soft tissue damage around the incision, a skin
protector should be used. A tourniquet should be avoided because of the increased risk for thermal heat necrosis. The surgeon starts with a small-diameter reamer and increases by 0.5-mm increments until cortical contact is reached. The fracture must be reduced as the reamer passes.
The operator must take care to prevent loss of the guide wire position
during each reamer introduction and removal. If the canal diameter
permits, it is mechanically beneficial to place a nail that is 10 mm in
diameter or larger. If necessary, an 8- or 9-mm nail may be used.
However, with smaller nails, the patient’s postoperative management may
need to be modified.

Before nail insertion, a plastic exchange tube is passed over the bulb tip and across the fracture site (Fig. 37-16).
The bulb tip is removed, a straight tip guide wire is inserted, and the
plastic tube is removed. The nail is introduced down the tibial canal
over this guide wire (Fig. 37-17). It is important to push posteriorly on the proximal end of the nail to minimize penetration of the posterior cortex. As the nail approaches the fracture, the fracture must be aligned in two planes. The
nail should be inserted in slight external rotation. If the nail is
allowed to rotate internally, interlocking occurs on the posteromedial
cortex proximally and distally, which is much more difficult than if
carried out on the flat surface of the tibia. To make targeting an
easier process, the nail should be externally rotated approximately 10
degrees in relation to the long axis of the tibia.

As the nail crosses the fracture site, it is important
to avoid fracture distraction. In stable fracture patterns, traction
can be released when the nail tip is 1 cm past the fracture. This
allows fracture impaction and avoids distraction. Distal
counterpressure can also be used as the nail crosses the fracture to
prevent fracture distraction. As the nail is driven down the tibia, it
is important to reassess the accuracy of its length. The tibia should
be inspected proximally and distally. If the nail is too short or too
long, it should be removed and replaced with another nail.

After the nail is fully seated (Fig. 37-18),
proximal and distal interlocking screws are inserted. Targeting devices
that attach to the intramedullary nail are very successful in placing
the proximal tibial locking screws (Fig. 37-19). Only one

proximal screw is necessary for fractures in the midshaft and below.
For proximal fractures, two screws are necessary in the proximal end of
the nail. For stable transverse or short oblique tibial fractures, the
use of a dynamic slot at the proximal end of the nail is beneficial to
allow impaction of the fracture. If there is any sign of comminution or
a spiral component to the fracture, the nail should be statically
locked.

A freehand technique is employed for distal locking screw insertion (Fig. 37-20).
Proximal and distal locking screws are inserted from medial to lateral
in the subcutaneous border of the tibia. The freehand technique
requires targeting of the skin incision. The image intensifier is lined
up with the nail and tilted and rotated until a perfectly round hole is
visualized. It is helpful to move the C-arm head away from the tibia to increase the working space and aid in magnification of the hole.
The sharp point of the trocar-tipped pin is placed on the skin until it
is centered in the hole. A 1-cm stab wound is made directly over the
hole on the medial aspect of the tibia. The sharp, pointed pin is again
placed on the bone until it is centered in the hole. It is brought into
the longitudinal axis and checked with fluoroscopy to ensure that it is
centered in all planes. The pin is then passed into the tibia.
Fluoroscopy is used to verify that the pin has corrected targeted the
nail and the pin drilled through the far cortex. The length for the
locking is determined using a second pin of the same length or a depth
gauge, or it is estimated using the image intensifier. The screw is
then inserted. The screw should be 5 mm too long, because this makes removal of a broken screw easier.
A lateral radiograph should be checked again to be absolutely certain
the screw is in the nail and has not moved anteriorly or posteriorly.

The wounds are then irrigated and closed. Before wound
closure, it is important to again verify the adequacy of the fracture
reduction, including rotational alignment. If necessary, the patient is
checked for increased compartment pressure. Final radiographs are taken
with the patient under anesthesia.

The patient is placed in a well-padded posterior splint with the ankle neutral or in slight dorsiflexion to prevent an equinus

deformity. The patient remains in a splint until the swelling
decreases. In a reliable patient with a stable fracture pattern and a
dynamic locking screw, toe-touch weight bearing is desirable, with
progressive weight bearing over the first 4 weeks. For an unstable
injury pattern or an unreliable patient, avoidance of weight bearing is
recommended for the first 6 to 8 weeks.