Intramedullary Nailing of Diaphyseal Tibial Fractures

Clifford B. Jones, MD, FACS

Dr. Jones or an immediate family member has received royalties from Lippincott and OsteoConcentric; is a member of a speakers’ bureau or has made paid presentations on behalf of Stryker; serves as a paid consultant to or is an employee of OsteConcentric and Stryker; and serves as a board member, owner, officer, or committee member of the Arizona Orthopaedic Society, Banner University Medical Center – Phoenix, the Center Chief Orthopaedic Spine Institute, and the Orthopaedic Trauma Association.

PATIENT SELECTION

Indications

Most displaced tibial fractures benefit from surgical stabilization to enhance earlier return to function and to avoid prolonged casting; stiffness; and delayed/malunion/nonunion.¹ Most tibial diaphyseal fractures are optimally treated with a reamed, locked intramedullary nail. Metaphyseal-diaphyseal junctional fractures at the proximal or distal ends are more problematic to treat secondary to the metaphyseal flare, need for perfect entry site, muscle tendon site pull, noncanal fit, and increased risk of malalignment secondary to fluoroscopic parallax. Semiextended tibial nailing has lessened the risks of metaphyseal-diaphyseal nailing.

Contraindications

Contraindications to tibial intramedullary nailing that hinder nail insertion include preexisting osseous deformity, lack of a tibial canal (osteopetrosis, prior metabolic process), stemmed total knee arthroplasty (relative), and knee ligament repair (screws). Relative contraindications include morbid obesity, which hinders knee flexion and guide insertion. In open fractures with gross contamination, which require repeat excisional debridements, intramedullary nailing should be delayed until debridements are completed and a stable wound environment is present.

PREOPERATIVE IMAGING

Preoperative imaging requires AP and lateral radiographs to determine fracture pattern, comminution, and bone loss. The images should include the knee and ankle joints to detect intra-articular extension. When intra-articular extension is inconclusive or pattern undiagnosed, CT imaging can be beneficial. If bone loss is present, contralateral tibial images may predict symmetrical tibial length.

PROCEDURE

Patient Positioning and Room Setup

The patient is positioned supine on a radiolucent operating table (diving board or pelvic table). A radiolucent small bump (rolled towel or blanket, but not a beanbag, which is not radiolucent) is placed under the ipsilateral buttock to neutralize the normal lower extremity external rotation. The ipsilateral arm is placed out to the side or across the body. With extended surgical time and an obese patient, a bump under the buttock can increase the risk of shoulder hyperextension and/or brachial plexopathy. Placing a pad under the elbow and flexing the elbow can relieve this tension.

The surgeon should try to avoid tourniquet application or use. With an open fracture with venous injury and exposed cancellous surfaces, however, limited or transient application of a sterile tourniquet can reduce blood loss.

The patient is prepared and draped to the mid portion of the ipsilateral thigh. If warranted, the ipsilateral toes can be covered with a sterile impervious drape to avoid additional contamination.

Fluoroscopy

The monitor should be at the end of the bed or angled 20° to 30° to enhance visualization. The fluoroscopy imaging arm and base should be placed at a 90° angle to the surgical limb and table to facilitate consistency and mobilization. The fluoroscopy imaging base should be placed on the contralateral side of the table.

For AP imaging, the C-arm should be nearly parallel to the tibial diaphysis (Figure 1). The amount of knee flexion and length of the extremity hinder true proximal lateral imaging, which is achieved when the proximal tibia overlays approximately 50% of the fibula. Increased knee flexion and length of the tibia hinder lateral imaging because the arc of the C-arm will impinge on the table.

FIGURE 1 Fluoroscopic imaging for intramedullary nailing of the tibia. For AP imaging, the C-arm is positioned parallel to the tibial diaphysis. (Courtesy of Eben Carroll, MD.)

Four nonpenetrating towel clamps are used to attach the large drape or commercially available drape to the operating table during lateral imaging. For AP imaging, the drape is folded in half and attached to the side of the operating table.

Leg Positioning

The surgical leg is positioned in a flexed position over a radiolucent triangle. The size of the triangle should allow for knee flexion of 100° to 120°. The foot should be suspended (Figure 2, A) and not rest on the table (Figure 2, B).

The foot can be mobilized to enhance AP visualization or stabilized with towels and smaller triangles used as bumps to correct for coronal and sagittal plane deformities. A cushion should be placed under the knee and calf of the contralateral leg. Also, if required, the limb should be secured to prevent it from falling off the table during the procedure.

FIGURE 2 The foot should be suspended over the appropriately sized radiolucent triangle, not impinging or lying on the table. Photographs show correct (A) and incorrect (B) positioning. (Courtesy of Eben Carroll, MD.)

Special Instruments/Equipment/Implants Required

Complete intramedullary nail set of choice
Complete reamer set of choice
Radiolucent table
Large, medium, and small radiolucent triangles for limb positioning
Multiple small and large retractors
Multiple large and small Weber bone reduction clamps
Dental picks
Large universal distractor (in room, unopened)
Multiple Schanz pins (2.5 and 5.0 mm)
Small fragment plate and screw set (in room, unopened) for provisional stabilization of open fractures and/or blocking screws
Additional large drapes for coverage of fluoroscopy machine during lateral visualization and coverage of the end of the table when the knee is flexed

Surgical Technique

Approach and Start Site

With the knee in flexion, the start site can be determined by fluoroscopic analysis.² The correct start site is based on surgeon experience and published cadaveric studies. In general, the best anatomic start site is along the medial aspect of the lateral tibial spine on the AP view (Figure 3, A) and on the apex of the anterior tibial slope on the lateral view³^,⁴ (Figure 3, B). To determine this start site, the guide pin is placed on the skin (Figure 4) and the position is confirmed with fluoroscopy. The pin site is marked on the skin. Some surgeons prefer a parapatellar approach to avoid violation of the patellar tendon. If the mark described above and shown in Figure 4 is closer to the medial edge of the patellar tendon, a medial parapatellar incision is used, and if it is closer to the lateral edge of the patellar tendon, a lateral
patellar incision is used. That said, the surgeon should keep in mind that the lateral patellar approach may be advantageous for proximal third fractures to facilitate nail placement along the lateral tibial cortex.

FIGURE 3 The medial aspect of the lateral tibial spine on the AP view (A) and the apex of the anterior tibial slope on the lateral view (B). (Courtesy of Eben Carroll, MD.)

Medial Parapatellar Approach

A 3- to 4-cm incision is made along the medial border of the patellar tendon. The paratenon is reflected, and the patellar fat pad is separated from the posterior aspect of the patella. The surgeon should exercise caution to avoid entrapment of the medial meniscus and coronary ligament.

FIGURE 4 Photograph shows a guide pin placed on the skin to determine the start site for the intramedullary nail. The position is then confirmed with fluoroscopy. (Courtesy of Eben Carroll, MD.)

Lateral Parapatellar Approach

This approach is useful for proximal third fractures, to facilitate nail placement along the lateral tibial cortex. A 3- to 4-cm incision is made along the lateral border of the patellar tendon. The paratenon is reflected, and the patellar fat pad is separated from the posterior aspect of the patella. The surgeon should take care to avoid entrapment of the lateral meniscus and coronary ligament.

Patellar Tendon Splitting Approach

The patellar split incision or approach provides the most consistent and accurate start site. A 2-cm incision is made on the middle proximal portion of the patellar tendon and over the distal portion of the patella. A percutaneous guide pin is then inserted without further dissection. The paratenon is split, and the patellar fat pad is separated from the posterior aspect of the patellar tendon. The surgeon must take care to avoid entrapment of the coronary ligament.

Suprapatellar Approach

For proximal or distal third, metaphyseal-diaphyseal tibial fractures, a 3- to 4-cm incision is created about 2- to 3-cm proximal to the proximal pole of the patella centrally; the subcutaneous tissue and fascia is dissected to the level of the rectus. The rectus is split in line with the fibers, and the dilating and instrument cannula is inserted.⁵^,⁶^,⁷^,⁸ Fully extending the knee or tilting the proximal pole of the patella will facilitate cannula insertion.

Medial Parapatellar Approach With Eversion of the Patella

This approach is used with periarticular scarring, patella baja, and/or knee contracture. An 8- to 10-cm incision is made over the medial half of the patella and patellar tendon with the knee in extension or slight flexion. An incision is made through the medial retinaculum. With a large enough retinacular incision, the patella is everted laterally. The knee is then flexed to the desired angle to facilitate pin insertion.

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