Distal tibial fracture managed with fixator assisted Synthes Expert tibial nail with supra-patella nail approach and blocking screw

Imaging in plaster shows a fracture at extending into the metaphysis. The patient was admitted overnight for elevation and observation for compartment syndrome and planned for the next days theatre list. A pre-operative CT was arranged to assess the fracture in more detail.

The pre-operative CT scan revealed an undisplayed posterior malleolar fracture.
This was not apparent on the plain films. Intra-articular involvement is present in 20-40% of these injuries. The surgical plan needs to consider how to address this component of the injury. In this case there is sufficient bone stock in the distal segment to place 3 locking bolts in the nail (37mm from the physeal scar for the Synthes expert tibia nail). I therefore planned to stabilise the posterior malleolar fragment with an anterior to posterior position screw and then nail the main fracture.

My preferred approach for tibial nailing is supra-patella.
This allows nailing with the leg in an extended position (rather than deep flexion for infra-patella techniques) which makes fracture reduction easier.
To hold the limb during the nailing I mount it in a ‘half frame’ fixator. This is made up from Ilizarov components, using femoral arches (1), threaded rods and sockets (2) and slotted fixation bolts. Owing to the vagaries of our local sterilisation service the frame has to be built from scratch each time it is used.

Firstly 2 long rods are made.
These are constructed from 2 threaded rods joined each end of a threaded socket and locked in place with nuts. The whole rod will need to be long enough to span the distance from the the patients knee to their heel.

The long rods are then connected to two femoral arches.
The rods are connected at either end of the arch to connect the 2 femoral arches together.

Further rods are then added, spaced along the arch.

The rods in the middle of the arch are connected to a carbon ring section.
Finally slotted connecting bolts are placed at the end of each arch (ie 2 per arch).

Note that at one end (1.) the nuts on the rods have been left untightened, this will allow traction to be applied via the frame by sliding the arch along the rods once the leg has been mounted in the frame.

Long Ilizaorv wires (1.8mm, smooth) are used to mount the frame.
The first wire is placed in the proximal tibia under image control. This should be just beneath the joint line and about half way from the front to the back of the tibia to avoid impeding insertion of the tibial nail.
If the wire entry point is too far posterior and distal the common peroneal nerve is at risk. It is important that the wire is inserted parallel to the floor with proximal tibia rotation corrected (ie patella pointing vertically), this not only keeps the wire in a safe corridor but also ensures that tibial rotation will be corrected once the leg is mounted in the frame.

The second wire is placed in the calcaneum.This is placed from medial to lateral to avoid injury to the neurovascular bundle on the medial side of the foot.
The landmark for safe insertion is identified by imaging a line from the tip of there medial malleolus to a the angle of the heel, inserting the wire 2/3 of the distance along this line (starting from the malleolus) allows good purchase in the bone and avoids injury to the posterior tibial neurovascular bundle.
Again this wire is inserted parallel to the floor with the foot rotation corrected.

The wires are then mounted into the slotted fixation bolts (1.).

Wires are then tensioned with the Italian tensioner.The wire is passed into the hole in the tensioner and the arms of the tensioner positioned on the ring (1.). The tensioner is then held (in left hand as shown, 2.) and tightened by the turning the mechanism at the base clockwise (right hand as shown, 3.). The tensioner then grasps the wire and pulls it tight, the amount of tension applied to the wire can be gauged from the numerical scale (Newtons, 4.)

Proximally they are tensioned to 130N, distally to 110N (due to softer bone).Once the desired tension has been applied to the wire the nut on the slotted bolt is tightened and the tensioner undone and removed.
After the leg in mounted on the frame with both wires tensioned the arch holding the foot is pulled distally along the threaded rod to restore limb length and the nuts on the threaded rods tightened.

The leg is now mounted in the half frame.Limb length has been restored. By paying close attention to the orientation of the wires and the limb position during insertion we have restored rotation to a neutral position- it is important to check the rotation of the uninjured limb prior to surgery to ensure no anatomical variance in rotation. I check the rotation of the uninjured limb prior to prepping and draping, many surgeons opt to prep and drape both limbs to allow intra-operative comparison. If rotation has not been restored, then the foot can be repositioned in the distal arch to the corrected position. With length and rotation restored only angulation and translation remain uncorrected, in nearly all cases it is possible to restore these intra-operatively with closed techniques as demonstrated below.

The approach to the nail entry point is based on an incision a thumbs breadth above the superior pole of the patella.The incision is 2-3 cm long, in line with the long axis of the tibia and the centre of the patella (marked).
Dissection proceeds down to the quadriceps tendon. A sharp incision is made in the tendon in line with the skin incision and directed distally- thus the supra-patella pouch is entered.

I use my little finger to sweep the pouch and clear any plica or synovial folds and clear a path behind the patella to facilitate trocar insertion.

The entry trocar is now assembled.This consists of a metal inner sleeve covered by a silicon outer sleeve (1.) and the trocar itself- made of soft plastic (2.), these are mounted on a handle (3.) to help insertion and allow the protection sleeve to be controlled intra-operatively.

The trocar is gently inserted into the supra-patella pouch.It is then guided into the trochlea groove of the femur, behind the patella. I often use a lateral X-ray to help guide the trocar.
Occasionally the patella-femoral joint is very tight and insertion of the trocar is not possible, in these cases the incision can be extended around the supra-lateral border of the patella to perform a mini-lateral release. By following the trochlea the anatomy tends to guide the trocar towards the entry point on the proximal tibia.

Once the trocar has been inserted it is replaced with a metal, cannulated, trocar to allow insertion of the initial guide wire.This trocar has 2 parallel holes (1.) to allow adjustment of the guide wire position if needed.

A 3.2mm enty wire is inserted via the trocar into the proximal tibia under image control.

On the AP image the wire should be in the centre of the metaphysis and parallel with the long axis of the tibia.Here the wire is too medial and adjustment is needed.

The first wire is left in situ.By rotating the trocar the second, parallel, hole in the trocar can be positioned to allow correct placement of a second guide wire (1.).

The wire is now correctly aligned on the AP image.

On the lateral image the entry point is at the junction of the anterior slope of the tibia and the plateau.It is important that the wire is not directed posteriorly as this risks inadvertent penetration of the posterior cortex of the tibia.
The correct entry point is key to a successful nailing and it is worth spending time at the start of the operation getting this right to avoid problems later in the procedure.

The trocar is now removed from the protection sleeve and the entry point is opened with the 12.5mm cannulated drill inserted over the guide wire.

I use the lateral X-ray to ensure I am not too close to the posterior cortex during this step.

Once the proximal tibia has been opened the reaming wire and reduction arm are inserted.This consists of a ball tipped reaming wire, together with a reduction arm (1.) and bevelled end (2.) and T-handle (3.).
The reduction arm consists of a flexible wire that can be passed over the guide wire and a bevelled end with angled tip which helps to manoeuvre the guidewire across the fracture and alter its position to the desired location.

The reaming wire and reduction arm are inserted into the proximal tibia via the protection sleeve.Gentle rotation allows the wire to be advanced along the tibia to the level of the fracture.

The reduction arm and wire have now been advanced to the level of the fracture.The fracture remains translated and in varus. Before proceeding further the posterior malleolar fracture needs to be stabilised. The intended screw position is first identified using image intensifier (1.)

A small incision is made and dissection down to bone carried out with a small clip.A 2.5mm drill is passed across the fracture taking care that the screw position will not impede placement of the tibial nail. The fracture is undisplaced and I have used a 3.5mm cortical screw to hold it in position and prevent displacement as the nail is inserted.

Next we can address the fracture displacement.It is important that the reaming wire is correctly placed within the distal segment before reaming starts as once a channel has been reamed the nail will follow that path and it is difficult to reposition.

To achieve reduction and correctly position the reaming wire we will use a blocking technique.This can be achieved with a screw however I prefer to use a 2.5mm k-wire (DHS guide wire) as this is easier to reposition if fine-tuning is needed.
The blocking screw or wire is placed in the concave side of the deformity, here within the metaphysis. The position is marked with image guidance and then the wire passed to engage both cortices.

The bevelled reduction arm is now gently passed beyond the blocking wire.As the reduction arm engages the blocking wire, and passes beyond it, the distal segment is pushed to the side that the wire is positioned on (medially in this case).

The distal segment is being pushed medially and the fracture is being reduced.If the blocking wire position is not allowing an adequate reduction the reduction arm can be retracted and the wire position moved to improve the reduction, for instance if the fracture is over-reducing the blocking wire is repositioned to reduce the correction and the reduction arm then re-advanced.

Once a satisfactory reduction can be seen the reaming guide wire is advanced and can is now positioned with in the centre of the distal segment (1.).

The fracture reduction and guide wire position are checked on the lateral image.In this distal tibial fracture we are aiming to restore the coronal and sagittal alignment and limb length with the nail having already restored rotation with the frame. The nail has a larger diameter than the reduction so some further reduction will be achieved as the nail is seated. As a general rule if the reduction is not anatomical with the first pass to the nail I will attempt to improve this by resiting the blocking wire or using additional wires. Clearly an anatomical reduction is not always achievable with closed methods and I would hesitate to open a tibial fracture to improve the X-ray appearance. In general final fracture union with less than 5 degrees coronal and 10 degrees of sagittal malalignment is unlikely to give long term problems with the knee or ankle although deformities closer to the joint may be less well tolerated.

Reaming of the tibia is now performed using the Synream system.The majority of tibial nailings are performed using a reamed technique, this allows a larger diameter (with increased bending and rotational stiffness) nail to be used and also potentially introduces local bone graft at the site of the fracture.
Despite concerns that reaming damages the endosteal blood supply, the SPRINT study showed a lower rate of complications closed tibial fractures managed with a reamed tibial nail compared to unreamed nailing.

Study to Prospectively Evaluate Reamed Intramedullary Nails in Patients with Tibial Fractures (SPRINT) Investigators*. Randomized Trial of Reamed and Unreamed Intramedullary Nailing of Tibial Shaft Fractures
J Bone Joint Surg Am. 2008 Dec 1; 90(12): 2567–2578.
doi: 10.2106/JBJS.G.01694
PMCID: PMC2663330
PMID: 19047701

The reamer head (1.) is loaded onto the flexible reaming shaft (2.).These are then threaded onto the reaming guide wire. The initial reamer head has an 8.5mm diameter and has a front-cutting edge. The guide wire has a ball tip at the distal end to prevent reamer heads becoming dislodged within the bone- the wire does not however require later exchange before nail insertion as with earlier generations of reamed nails.

Once the reaming shaft and head have been loaded onto the guidewire the power tool can be applied.This ensures that control of the guidewire is maintained at all times.

The reamer is passed under image control.The reamer head should be advanced to the distal tibia. It is then removed in a reverse of the above process- once the reamer head has been retracted into the proximal metaphysis the power unit it detached and control of the guide wire maintained while the reamer shaft is removed by hand. This ensures that the position of the guide-wire is not lost.
It is generally considered good practice to always have the reamer rotating in a ‘forward’ direction although historical concerns of unravelling the reamer shaft if used in reverse are no longer valid.
Reaming is then repeated in 0.5 or 1mm increments until the desired diameter is achieved. I generally choose a nail diameter that corresponds to the point at which ‘chatter’ is felt in the tibial isthmus and then ream a further 1-1.5mm.

The nail length is selected using a metal ruler.Distally the ruler is positioned over the phsyeal scar (as shown on imaging) before the length is measured on X-ray over the proximal tibia.

The nail (1.) is now mounted onto the insetion handle (2.).A bolt is passed into the insertion handle and tightened onto the nail with the screwdriver (3.). This is easier with 2 people, the nail is left in the plastic packaging to minimise handling prior to insertion.

Next the jig for proximal locking bolts is attached to the insertion handle.

We now test the alignment of the jig and the locking bolt holes in the nail.This prevents disappointment later in the procedure. A trocar (1.) is then passed through the jig to check that the jig and nail are correctly aligned (ie trocar aligns with the corresponding locking bolt hole in the nail).

Before the nail is implanted the metal protection sleeve is removed leaving just the silicone protection sleeve the behind the patella.The nail is then passed over the guide wire.

The connector (1.) is screwed into the insertion handle and tightened with an 11mm spanner.The nail can now be advanced with gentle hammer blows. If the nail is not advancing with gentle force the nail position should be checked with X-ray.
It may be caught on a cortex and need gentle repositioning, occasionally it may be necessary to go back a step and ream a further 0.5-1mm to allow the nail to pass.
Excessive force should always be avoided as this risks propagating the fracture.

As the nail advances into the distal segment it begins to engages the blocking wire.
The fracture is lying in varus with lateral translation as the blocking wire is not being engaged and the reaming guide wire is loose with the reamed tract in the canal.

The nail engages with the blocking wire which is pushed medially by the nail and the fracture reduction is completed.
The nail is advanced to the physeal scar. The position distally is checked on AP and lateral views before the proximal position is also checked to ensure the nail in not prominent at the knee which would cause impingement pain.
Although there is invariably a low fibula fracture associated with these injuries this rarely results in ankle instability and therefore usually do not require fixation.

Distal locking is now performed using a freehand technique.
The image intensifier is placed in a lateral position to give as near perfect round hole images of the medial-lateral locking bolt holes in the distal nail.
An incision is made over the holes.
The saphenous vein and nerve are at risk with these incisions and blunt dissection down to bone should be carefully performed with a clip. The drill bit (4.2mm) is then positioned over the hole, with the drill held in an oblique position out of the intensifier beam (1.), and the position checked with the image intensifier.

Once the tip of the drill bit is in the centre of the hole, the drill is moved to a position parallel to the intensifier beam.
Drilling is performed carefully so that the position is not lost- starting the drill at low speed allows the bit to grip without slipping.
A minimum of 2 distal locking bolts should be used. For nail diameters over 10mm the locking bolts have a 5mm thread diameter, smaller nails use a 4mm locking bolt (I generally try to avoid using smaller diameter nails as these locking bolts are significantly weaker and more prone to early failure).
In distal fracture patterns I use 3 bolts, 2 medio-lateral and 1 antero-posterior to give better control of the distal fragment.
The blocking wire can be replaced with a screw if desired however in our experience multi-plane locking bolts in the distal segment give sufficient stability and the routine placement of blocking screws is not needed.

Once distal locking is complete the proximal end of the nail can be locked.
The aiming jig is attached to the nail introducer (1.).
In some fracture patterns (eg transverse) it may be desirable to ‘backslap’ the nail to improve the apposition of the fracture ends.
There is specific attachment for the introducer and hammer to do this, though in this case it wasn’t required.

A trocar is placed through the aiming jig (1).
An incision is made in the skin and the trocar advanced down to bone.
The longer 4.2mm drill bit is used- this allows direct reading of the screw length from marks on the drill bit and the near end of the trocar (as long as the trocar is contacting bone!). In this case I used 2 static 5mm locking bolts, I very rarely (if ever) use dynamic locking bolts, for more proximal fracture patterns placing locking bolts in multiple planes is desirable.

The half frame can now be removed.
First the wires are loosened from the half ring with spanners before they are cut (we avoid cutting tensioned wires in bone due to the risk of fracture as the wire very rapidly detentions). The wires can then simply be pulled from the bone.
Final X-rays are now taken.

The supra-patella pouch is thoroughly lavaged with saline via the silicone protection sleeve.
To repair the quadriceps tendon I use a 1- vicryl on a J shaped needle to get a good hold in the tendon with my suture throws. The remaining wounds are closed in layers with interrupted nylon for skin.

Non-adhesive dressings are applied and a wool and crepe bandage.

Post-operative imaging shows satisfactory alignment.