Tibial fractures, suprapatellar intramedullary nail technique

Intramedullary nailing technique for tibial fractures: through a suprapatellar, transarticular approach with the knee flexed at 20-30° and a specific protective tube to protect the intra-articular structures.

01.Tibial Intramedullary Nailing: access and alignment, anterior knee pain

Surgical access for intramedullary nailing of tibial fractures is important in order to insert the intramedullary nail through the correct entry point, to minimize damage to the intra-articular knee structures, and to achieve optimal fracture repositioning and proper nail entry.

The classic approaches for tibial stem fractures are the median infrapatellar or parapatellar approaches. Although these approaches are indicated for mid-portion fractures, postoperative valgus, anterior, or syndesmotic deformities frequently occur in more proximal fractures.

The main cause of malalignment in proximal tibial fractures is deformity caused by pulling of the quadriceps tendon during knee flexion and mechanical conflict between the nail tip and the posterior tibial cortex during implant insertion. The patella also prevents axial entry of the nail in the sagittal plane (Fig. 1a, b). Therefore, another common method of entering the point is through a medial parapatellar incision, which results in slightly medial-to-lateral nail insertion (Figs. 1c and 2). As the nail enters the intramedullary canal distal to the fracture, the proximal portion is tilted into an exostosis (Fig. 2). Finally, the resting tension of the anterior chamber muscles contributes slightly to the ectropion (Fig. 3).

Figure 1 a,b Using the conventional infrapatellar approach, the patella prevents axial entry of the nail, resulting in the common deformity of anterior apical sagittal alignment and ectropion coronal alignment.c Intramedullary nail alignment was performed using the parapatellar approach.

Figure 2 Approaching the entry point through a medial parapatellar incision leads to slightly medial to lateral nail insertion. As the nail enters the medullary canal distal to the fracture (a), the proximal portion is tilted into a flare (b)

Fig. 3 Resting tension of the anterior muscle compartment ( a ) produces a subtle ectopic arrangement ( b )

Nailing the tibia into a more extended position helps to avoid complications associated with severe intraoperative knee flexion.The technique was described by Gelbke, Jakma et al. in 2010 and has gained popularity in recent years because nailing the tibia in a nearly straight limb position simplifies fracture manipulation and repositioning. Fluoroscopy has become technically easier to perform. The fluoroscopy time for suprapatellar nailing has been reported to be significantly shorter than for infrapatellar nailing . In addition, the nail insertion angle (in the sagittal plane) is more parallel to the longitudinal axis of the tibia with this approach than with infrapatellar nailing; this prevents mechanical clash between the nail tip and the posterior cortex, thereby facilitating fracture reduction.

Postoperative anterior knee pain is a relevant problem. Anterior knee pain has been reported in 50-70% of patients with fractures, with only 30% of patients experiencing pain relief after removal of the endplate. Access-related scar formation of the patellar tendon and Hoffa's fat pad has been estimated to be a potential source of postoperative knee pain. In addition, the suprapatellar approach avoids the traditional incision of severing the branch of the patellar branch of the saphenous nerve, which avoids anterior knee numbness and dulled sensation (Figure 4). Passing the nail through the quadriceps tendon, thereby leaving the patellar tendon intact, appears to significantly reduce the rate of postoperative knee pain.

Fig. 4 Relationship between the saphenous nerve and different accesses to the tibialis obliqua nail

Due to the favorable outcome of proximal fractures, the indications in clinical practice have been extended to all fractures.

Potential problems with intramedullary nailing in the suprapatellar approach:

- May leave reaming debris in the knee joint. However, clinical experience with retrograde femoral nailing has not shown any short- or long-term adverse effects.

- How is the implant removed after the fracture has healed? Although it is technically feasible to remove an intramedullary nail through a suprapatellar approach, the technique is demanding and most surgeons prefer to remove an intramedullary nail through an infrapatellar approach.

02.When should a suprapatellar intramedullary nail be used?

Advantages

- Semi-extended knee position facilitates fracture manipulation and reduction by relaxing muscle forces and retention during nail insertion.

- Lower risk of postoperative malalignment of proximal, segmental, and distal fractures compared to traditional techniques

- Nailing is technically easier to perform

- Nailing is feasible as a “single surgeon procedure”.

- Reduced fluoroscopy time

- No damage to the patellar tendon and less incidence of post-nailing anterior knee pain

- Easier to perform in a multi-team procedure, as with polytrauma.

Disadvantages

- Risk of damage to knee cartilage and other intra-articular structures

- Increased risk of knee infection

- Removal of the implant may require a different approach

Indications

- Extra-articular fractures of the proximal tibia (Type AO 41A)

- Simple comminuted fractures of the tibial diaphysis (type AO 42A-C)

- Segmental tibial diaphysis fracture (type AO 42C)

- Extra-articular and simple intra-articular distal extension fractures of the distal tibia (types AO 43A and C1)

- Floating knee

Contraindications

- Gustilo grade 3C open fractures of the tibia due to increased risk of joint infection, although an increased risk of joint infection has not been reported in open fractures

- Severe soft tissue tear, contamination or infection in the suprapatellar region

- Ipsilateral knee prosthesis (relative contraindication)

- Knee fusion

- Knee hyperextension >20°

- Ipsilateral tibial plateau fracture involving the nail entry point is a relative contraindication

- Implants obstructing the nail entry point

- Ipsilateral patella fracture (relative contraindication)

03. Surgical methods

① Body position and perspective

Fig. 5 The patient lies supine on a radiolucent table that allows a split-leg position. The fractured limb is left hanging freely and a scroll is placed under the knee joint (a) to achieve 10-30° of knee flexion 

(b). The C-arm is placed on the opposite side. The unaffected leg is lowered 10-30° from horizontal to ensure proper imaging in the lateral position.

②Find the right needle entry point

Figure 6 This approach is marked by the shaft of the patella, tibial tuberosity, and anterior tibial cortex. A 2 cm longitudinal skin incision is made 1-1.5 cm proximal to the superior base of the patella. The quadriceps tendon is exposed and a midline longitudinal incision is made in the direction of the tendon fibers. The suprapatellar recess is opened and the surgeon's fingers enter the knee joint from below the patella to assess ease of access. Slight extension of the limb may facilitate access to the kneecap. Insertion of a Langenbeck retractor for slight elevation of the patella may also enhance access. If the joint space is very narrow and instrumentation is difficult, the medial or lateral support band may be incised proximal to it in order to semi-dislocate the patella to one side.

③Protection of cartilage

Figure 7 Protection of the patellofemoral cartilage from surgical-related injury is one of the main goals of the surgical procedure. Therefore, protective sleeves must be used during instrument and nail insertion.a Instruments for transarticular access include insertion handles, external (soft) and internal (metal) protective sleeves, trocar pins, and porous wire guides.b The insertion handles are assembled with a protective sleeve and an external (soft) and internal (metal) protective sleeve, a trocar pin, and a porous wire guide. The trocar needle is assembled with the protective sleeve and insertion handle.b Mounting handle with lateral ventilation holes. The knob on top of the insertion handle prevents accidental disengagement of the handle assembly

④ Insert the guidewire and adjust the position

Figure 8a The handle assembly is inserted underneath the patella through the patellofemoral joint toward the desired entry point on the tibia (Figure 9). In most cases, the patella will move slightly medially or laterally during instrument insertion. The groove in the patellofemoral joint usually guides the trocar needle to the correct position automatically.

Fig. 8b Position was confirmed in both planes using fluoroscopy and corrected where necessary. The trocar needle is then replaced by a porous guidewire, a guidewire that passes through the center hole of the guidewire and whose tip is inserted into the proximal tibial metaphysis to ensure correct position.

Figure 8c When the guidewire is in a suboptimal position, a second guidewire can be used to make slight adjustments in a better position through the porous guidewire, up to a maximum of 4.3 mm As an alternative, it may be easier to start with the guidewire and place it unaided at the optimal point of entry. The insertion instrument with the guidewire is then slid over the guidewire.

⑤ Expansion of the medulla oblongata

Fig. 9a Opening the medullary cavity from the ideal entry point is a critical step in the surgical procedure. In the anteroposterior plane, this is the medial aspect of the lateral tibial spur. In the lateral plane, the correct entry point is located at the transition between the articular surface and the anterior cortex.

Fig. 9b The correct position of the guidewire is in line with the tibial axis in the anteroposterior plane and as close to parallel to the anterior cortex as possible in the lateral projection. The guidewire tends to move posteriorly.

Figure 9c In cases where a pin or nail cannot be inserted correctly, blocking the nail or pin helps to guide the nail into the correct position. 

Blocking nails are used in the wider metaphyseal region when the guidewire or nail cannot be centered parallel to the longitudinal axis of the bone or when fracture misalignment in one or both planes remains during nail insertion.

Figure 10 At this stage, it is recommended that the handle assembly be secured to the femoral condyle using a 3.2 mm guide wire. This prevents the assembly from exiting the tibia.

Figure 11 The 12.0 mm hollow drill bit is placed through the internal protective sleeve and down through the guidewire to the bone. The medullary canal is opened by drilling to a depth of 8-10 cm and a ball-ended guidewire is inserted into the proximal tibia.

⑥ Fracture reduction

Figure 12a At this stage, we reset the fracture.

Figure 12b Depending on the location of the fracture and its morphology, a variety of reduction tools such as percutaneous clips, retractors, small fragment plates, and blocking screws can be used to achieve proper alignment. In proximal tibial fracture reduction, sometimes even with the help of additional implants, before opening the medullary canal by drilling. The reaming rod is advanced distally and inserted into the center of the distal tibial metaphysis. After repositioning, the length and diameter of the nail are determined. If necessary, enlarge the tibial canal to the desired diameter by reaming in 0.5 mm increments. The opening in the protective sleeve handle allows for flushing and suctioning of debris from the joint during reaming. If possible, it is recommended that a nail with a minimum diameter of 10 mm be used. The 5.0 mm Locking Bolt for this type of nail is more resistant to failure than the 4.0 mm Locking Bolt used for finer nails. The length of intramedullary nails is usually determined with a fluoroscopic ruler.

⑦Insert intramedullary nail

Fig. 13a Nail insertion through the reaming rod under fluoroscopy. Note that the insertion handle for the suprapatellar nail is longer than that for the infrapatellar nail because the distance from the skin incision to the tibial nail entry point is also longer.

Figure 13b Please note that the bend (Herzog curve) at the proximal end of the intramedullary nail cannot be inserted through the internal metal protective sleeve. Therefore, the internal protective sleeve must be removed from the handle assembly prior to insertion of the nail (b; see section “Errors, Dangers and Complications”). Check the final position of the intramedullary nail in the anterior-posterior and lateral views. Remove the reaming rod. If the nail needs to be replaced, leave the reaming rod in place and insert the new nail into the rod. 5 mm markings on the insertion handle indicate the depth of insertion of the implant in the proximal tibia (Fig. 14). (Figure 14)

⑧ Distal and proximal locking

Figure 14a Proximal and distal locking configurations depend on specific fracture characteristics. Proximal locking can be accomplished with an aiming arm. Distal locking is accomplished freehand or through the use of a radiopaque drill guide. Optionally, an end cap may be used, which prevents bone from growing into the proximal end of the intramedullary nail and facilitates later removal of the implant. In particular, over-inserted nails are easier to remove when end caps of appropriate length are used. The desired length of the end cap is measured by inserting a mark on the handle or by inserting a guide wire through the aiming arm.

Figure 14b The tip of the guidewire indicates the proximal position of the intramedullary nail. The screw connecting the aiming arm to the nail needs to be removed to insert the end cap. The end cap passes through the barrel of the insertion handle. The insertion handle remains in place. This aligns the end cap with the top of the intramedullary nail and prevents it from being lost in the knee. Inserting the guidewire through the barrel end cap into the proximal end of the nail also helps guide the end cap to its proper position in the proximal end of the intramedullary nail. At the end of the procedure, a sterile saline solution should be rinsed to wash away any remaining debris particles.

04. Cautions

Precautions for Surgical Operations

- In cases of preexisting osteoarthritis, restricted patellar motion may prevent joint access. Incision of the proximal portion of the medial or lateral support band from the medial side facilitates insertion of the trocar pin.

- An ipsilateral knee prosthesis is not a strict contraindication to suprapatellar pinning. Note, however, that it may not be possible to access the usual starting point of the proximal tibial nailing procedure.

- In fractures with articular extension, additional screws may be inserted to immobilize the articular fracture component. It is recommended that these screws be placed prior to nail insertion to avoid secondary displacement of the articular fracture.

Proximal Tibia Fracture Considerations

Proximal tibial fractures are the most difficult tibial fractures to nail and require precise entry points (as described above). These fractures should be reduced prior to nailing to counteract any deforming forces and maximize success. In some cases, correctly positioning the affected limb in a semi-extended position and obtaining a precise entry point and placing the nail with the medullary canal in the coronal and sagittal axes will result in proper alignment of the tibia after nailing.

However, in most cases, some reduction maneuver is required to obtain and maintain satisfactory repositioning of these fractures. If the fracture line is simple and angled, simple pointed resetting clamps or coaptation clamps, placed percutaneously, can be used to obtain and maintain reset during nailing. If the clamp is inadequate or the fracture plane does not lend itself to clamping, pollen or blocking screws can help prevent displacement and malposition (Figure 15). These screws are placed posterior to the desired nail position on the lateral view and lateral to the desired nail position on the anterior-posterior view. Proper placement of these screws for good reset can be challenging.

Fig. 15 Locking screws placed on the outside of the desired nail path in the front and rear views (a) and behind the desired nail path in the side view (b) counteracting the deformation forces

Another very effective technique is temporary fixation of the fracture in an anatomic position (Fig. 16). Usually a small fragment tubular plate with two or three single cortical locking screws will hold the fracture reduced during root canal preparation and nail insertion. The plate will control both displacements. The plate should be left in place as long as there is no fixed gap to prevent the loss of reduction that usually occurs after plate removal. This plate with a single cortical screw is not rigid and will not affect the relative stability of the nail. The reset plate technique can be used for both open and closed fractures.

Figure 16 A small locking plate with a single cortical screw can be obtained and maintained in anatomic reposition. In most cases, the plate should be left in place after nailing. a Initial valgus deformity of a proximal tibial fracture. b A small fracture plate with a single cortical screw is placed medially to obtain and maintain fracture repositioning during nailing. c The plate is not removed after nailing because it provides additional stability

Misalignment, Dangers and Complications

- Intraoperative displacement of the Protective Sleeve may result in damage to the cartilage and intra-articular knee structures (Figure 17). The protective sleeve must be fully reinserted.

- Slight tilting of the Protective Sleeve can exacerbate reamer head extraction. Fluoroscopy helps to identify the problem. Re-adjustment of the protective sleeve will solve the problem (Fig. 18)

- Nail Lock-Up: The implant may become stuck in the metal sleeve at the proximal bend (Herzog curve). For final nail insertion, the metal tube needs to be removed, leaving only the outer soft plastic sleeve. When the nail is stuck, it needs to be completely removed again and the implant reinserted after removing the metal cannula through the plastic cannula only.

Figure 17 Protective sleeve withdrawal without fluoroscopic observation may lead to knee injury

Figure 18 a Tilting or accidental tilting of the protective casing may interfere with reamer removal, as the reamer head may jam. b A fluoroscopic inspection with alignment correction allows removal of the reamer head. c The reamer head can be removed if the reamer head is not in place. d The reamer head can be removed if the reamer head is not in place.

References

Hessmann MH, Buhl M, Finkemeier C, Khoury A, Mosheiff R, Blauth M. Suprapatellar nailing of fractures of the tibia. Oper Orthop Traumatol. 2020 Oct;32(5):440-454.