Keywords

Clinical Scenario

CH is a 50-year-old male pedestrian struck by a car with a chief complaint of right leg pain. Given the mechanism of injury, he was brought in by ambulance as trauma activation and evaluated using the Advanced Trauma Life Support (ATLS) protocol. Subsequent secondary and tertiary surveys were notable for an isolated closed fracture of the right proximal tibia without neurovascular deficit (Fig. 8.1a, b). He was placed in a long-leg splint for stabilization until definitive fixation; his compartments were serially monitored by clinical exam; and a CT scan evaluation for fracture extension into the tibial plateau was negative (Fig. 8.2a, b).

Fig. 8.1
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Injury films (a, b): Injury films demonstrate a proximal third tibial fracture with a long proximal segment amenable to tibial intramedullary nailing. It is important to be familiar with the interlocking hole distances of the nail available at your institution, and preoperative templating is encouraged

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Fig. 8.2
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CT scans (a, b): Preoperative computed tomography is encouraged in proximal third tibial fractures to prevent displacement of an unrecognized tibial plateau fracture during nail insertion

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Treatment Algorithm

With few exceptions, displaced extraarticular proximal tibial shaft fractures are treated operatively due to the poorly tolerated effects of malunion. Evaluation of the status of the soft tissues is the most important factor when selecting treatment options [1]. Fractures with minimal soft-tissue injury, which include closed fractures with minimal swelling, are amenable to plate fixation, multiplanar fine-wire external fixation, or intramedullary fixation. The choice of fixation is determined by the surgeon’s familiarity with the technique and the length of the proximal fragment. Longer proximal fragments that can accommodate three interlocking screws are preferably fixed using intramedullary implants, whereas a very short proximal fragment may require fine wire fixation or plating. Fractures with severe soft-tissue injury, including open fractures, compartment syndrome, or vascular injury repair, should be initially treated with temporizing external fixation until soft-tissue coverage or adequate healing has occurred.

CH has a closed fracture with minimal soft-tissue injury, and the proximal fragment is long enough to accommodate three interlocking screws. Thus, intramedullary fixation is the preferred treatment option.

Treatment Considerations with Proximal Third Tibial Nailing

Intramedullary nailing of proximal third tibial fractures was initially discouraged in favor of plate osteosynthesis or external fixation, due to the observation that proximal tibial nailing commonly resulted in apex anterior and valgus malalignment [2]. Diaphyseal fractures of the tibia are reduced by the isthmal fit of the nail; however, proximal tibial fractures are not corrected this way due to the discrepancy of a relatively small nail within a voluminous soft cancellous metaphysis. Therefore, the reduction of a proximal tibial fracture relies on a perfect start point in line with the anatomic axis of the tibia. A start point that is too medial, resulting in a lateral nail trajectory, often occurs due to the constraints of patellar tendon or a deficient lateral cortex (Fig. 8.3b). A start point that is too anterior, resulting in a posterior nail trajectory, often occurs due to the constraint of the patella or the deforming forces of the extensor mechanism with the knee flexed. As a result, when the nail abuts the posterior and lateral cortices of the distal fragment, the nail “straightens” along the anatomic axis of the tibia, resulting in a vector that levers the proximal fragment into procurvatum (apex anterior) and valgus deformity.

Fig. 8.3
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Technical figures (a): Appropriate trajectory within the proximal segment will prevent varus and valgus malposition during nail insertion. It is important to note that prior to reaming, the fracture must be reduced to prevent eccentric reaming of the cortices at the fracture site, risking malreduction. (b) A lateral trajectory will result in a valgus vector during nail insertion. (c) A Poller screw, as demonstrated by the yellow circle, may be placed distally within a reamed canal with an aberrant lateral trajectory with a correct starting point. This requires removal of the reduction tool or nail. Of note, a Poller screw will correct coronal plane malalignment, but may result in mild translation if the combination of a medial starting point and a lateral trajectory is present

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Intraoperative Tips and Tricks for Reduction/Fixation

Given the advantages of fixation with tibial nailing, several techniques were developed to overcome the difficulties associated with proximal tibial nailing. The use of minifragmentary provisional fixation was described as an adjunct, which facilitated proximal fragment alignment at the expense of an additional incision and disruption of the healing milieu. However, the force vector of a nail with an aberrant trajectory often overcame the reduction achieved with provisional fixation. A lateral parapatellar approach was described to help facilitate an anatomic start point in the coronal plane, but does not address sagittal malalignment. Therefore, techniques which facilitated optimal start point and trajectory became the workhorse for anatomic reduction of proximal tibial fractures with intramedullary fixation.

A semiextended medial parapatellar arthrotomy, an adoption of the approach used for total knee arthroplasty, facilitates the appropriate lateral and high start point, because it allows for lateral subluxation of the patella. This removes the constraint of the patella and tendon against the starting wire, allowing the surgeon to place the start point more posteriorly and laterally and direct the starting wire more anteriorly and medially, respectively [3]. This technique has been modified so as to be performed via an extraarticular approach [4], thus reducing the risk of cartilage damage and preventing retained intraarticular reamings. Lateral retraction of the patella is performed following parapatellar retinacular incision to the level of the quad tendon with care not to violate the synovium. The infrapatellar fat pad is then sharply detached at its inferior margin, exposing the anatomic start point.

The semiextended suprapatellar approach, which requires the use of special instrumentation, was developed to capitalize on the advantages of the open semiextended techniques without the theoretic morbidity of a larger incision. Though long-term functional outcomes are not established, short-term results indicate minimal risk of damage of the patellofemoral joint with the use of the suprapatellar guide [5].

Pöller, or blocking screws, can be used as an adjunct to guide nail trajectory by reducing the volume within the metaphysis through which the nail can pass, and also prevent late malalignment by preventing nail migration [6]. The screws are positioned posteriorly and laterally within the proximal segment adjacent to the nail path. More simply, blocking screws are placed on the concavity of the deformity. Interlocking screws or 3.2 mm pins may be used to prevent bending or breakage associated with the use of drill bits or smaller diameter screws.

A combination of techniques is sometimes required for very proximal tibial fractures or those with proximal extension. The surgeon should use any of the techniques to ensure proper nail start point and trajectory if he/she is to prevent the typical pitfalls associated with intramedullary nailing of proximal tibial fractures.

Given the advantages of semiextended approaches for proximal tibial shaft fractures, the operative surgeon chose to utilize a medial parapatellar arthrotomy in the case of CH. After the start point was selected, and the opening reamer was used with care to protect articular surface, a reduction tool was used through the proximal segment to pass the guide wire. Subsequently, it was noted that the opening reamer trajectory was oriented more laterally than desired, with the concern that nail insertion would force the proximal segment into valgus. Therefore, a Pöller, or blocking screw, was inserted laterally to prevent valgus malalignment (see Fig. 8.4a, b). It is important to note that a blocking screw used to correct an incorrect nail trajectory must be within the aberrant path, and therefore the nail or reduction tool must be drawn back before placement of the Pöller screw (Fig. 8.3c). This is in contrast to a blocking screw used to prevent late migration, which can be done adjacent to a well-placed nail.

Fig. 8.4
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Intraoperative photos/flouros (a, b): Intraoperative fluoroscopy demonstrating lateral and distal placement of a Poller screw in the sagittal plane

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Postoperative Protocols

Proximal third tibial fractures are axially unstable due to the lack of interference fit. Although Poller screws and interlocking screws oriented orthogonally may help prevent late migration, it is unclear if they provide enough multiplanar stability in the cancellous metaphysis for early weight bearing. Therefore, weight-bearing is restricted for 4–6 weeks until early callous appears, and then advanced as tolerated. Range of motion exercises are begun and encouraged immediately postoperatively (Fig. 8.5).

Fig. 8.5
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Postop films (a, b): Immediate postoperative films demonstrating anatomic coronal alignment achieved by correction of a lateral trajectory with a lateral Poller screw, and anatomic sagittal alignment facilitated by a semiextended approach

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Follow-Up with Union/Complications

Postoperatively, CH went on to clinical and radiographic union at 5 months. Of note, CH had late migration in the sagittal plane resulting in mild procurvatum deformity, which was within acceptable alignment and was not expected to affect the clinical outcome (Fig. 8.6a, b). Prevention of late migration could have been accomplished via positional screws adjacent to the nail following nail placement laterally, and in CH’s case, posteriorly. Anecdotally, and in the case of CH, anterior knee pain is reduced using semiextended techniques for reasons that are unclear. The nailing of proximal tibial third fractures, though more technically challenging, can result in superior outcomes if done appropriately using any combination of techniques used to ensure proper alignment and prevention of late nail migration.

Fig. 8.6
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Follow-up films (a, b): Note maintenance of varus and valgus alignment with mild late procurvatum deformity at 3 months. Placement of a posterior positional Pöller screw may have prevented this late deformity

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Pearls/Salient Points

  • Proximal third tibial fractures are difficult to nail and have a high percentage of malunion (varus and extension of the proximal fragment) if not reduced

  • Reduction before nailing and maintenance until locking screws are inserted is important to achieve optimal outcomes

  • Multiple techniques including lateral starting point, semiextended, suprapatellar nailing, use of blocking screws or plates and/or ex ternal fixators for provisional fixation may be utilized

  • Proximal articular extension, if present, should be fixed using either supplemental screws or plate along with nailing.