Intramedullary Nailing of Metaphyseal Proximal and Distal Fractures

Robert Ostrum

Michael Quackenbush

ANATOMY

Proximal metaphyseal fractures of the tibia are those that occur proximal to the isthmus of the tibia (FIG 1A).
Distal metaphyseal fractures of the tibia are those that occur distal to the isthmus of the tibia (FIG 1B).

PATHOGENESIS

Common causes of tibial fractures include high-energy collisions (pedestrian vs. car bumper) such as an automobile or motorcycle crash.

FIG 1 • A. AP view of synthetic tibia model. Shading of the proximal tibial metaphysis is shown. B. AP view of synthetic tibia model. Shading of the distal tibial metaphysis is shown.
Lower energy injuries, such as certain sports injuries or falls, can also cause fractures of both the proximal or distal tibial metaphysis.

NATURAL HISTORY

Fractures of the tibia can occur in all age groups and from a variety of mechanisms.
Goals of treatment should include restoration of length, rotation, and alignment of the tibia with a return to previous level of activity and function.
Recognition and treatment of associated injuries including those to nerves, blood vessels, or compartment syndrome should be an integral part of the assessment and treatment to prevent complications.

PATIENT HISTORY AND PHYSICAL FINDINGS

Patients will often present with a recent history of trauma.
Tibial fractures may present with a variety of findings:
- Pain in the affected extremity with an inability to bear weight
- Leg length inequality
- Visual deformity including tenting of the skin
- Contusions/abrasions
- Nerve injury
- Open fractures
- Compartment syndrome
- Sensory deficits in the foot (less common)

IMAGING AND OTHER DIAGNOSTIC STUDIES

Diagnosis of a proximal or distal tibia (FIG 2A,B) fracture can usually be made with standard orthogonal anteroposterior (AP) and lateral x-rays.
- Dedicated knee and ankle x-rays are necessary to decrease the chance of missing a fracture at the articular surface.
Fractures that extend proximally or distally into the articular surface may require a computed tomography (CT) scan to evaluate joint involvement and/or displacement to aid in preoperative planning (FIG 3A,B).

NONOPERATIVE MANAGEMENT

Nonoperative management is normally reserved for lower energy injuries with minimal or no displacement.
Patients with low functional demands (ie, paraplegic) or significant medical comorbidities can be successfully treated without surgical intervention.
Nonoperative management of the proximal or distal tibia often involves a long-leg splint with conversion to a long-leg cast once swelling has resolved.
- Distal fractures may be converted to a short-leg cast or brace once there is radiographic evidence of healing.
Non-weight bearing for the first 6 weeks with progression to full weight bearing, with or without a brace, once there is physical evidence of healing (decrease in pain) and/or radiographic evidence of healing (callus formation)

FIG 3 • A. CT of distal tibia with axial cut demonstrating intra-articular extension of distal tibia fracture. B. CT of distal tibia with sagittal cut demonstrating intra-articular extension of distal tibia fracture.

SURGICAL MANAGEMENT

Proximal Tibia Fractures

The proximal tibia presents a challenge for intramedullary (IM) nailing due to deforming forces from the patella and the eccentric starting point for the IM nail.
Flexion of the knee past 60 degrees to allow access to the tibial nail starting point causes the quadriceps, patella, and patellar tendon to extend the proximal fracture fragment leading to an extreme procurvatum deformity.
- In addition, starting the IM nail at the “usual” starting point, just medial to the lateral tibial spine, in the coronal plane will produce a valgus deformity. Techniques to prevent these deformities include the following:
  - Judicious use of blocking screws
  - Suprapatellar IM nailing
  - Semiextended IM nailing
  - Clamps, plates for reduction prior to IM nailing

Preoperative Planning

A review of all images will help to plan the surgical a pproach.
Fractures that extend into the proximal plateau or across the distal plafond may require closed or open reduction and fixation prior to IM nailing.
- Cancellous screws (6.5 mm) placed posteriorly in the tibial plateau will be out of the way of the tibial nail and its entry site.
- Depending on the fixation required, small fragment screws and/or plates should be readily available for distal fractures.
Obtaining and maintaining the reduction may require additional equipment. Planning ahead of time will avoid unnecessary delays in the operating room.
- Some examples of other items you may wish to have available include (FIG 4A,B) the following:
  - Clamps, “spike” pushers, K-wires
  - Small fragment set (for provisional plate fixation)
  - Large fragment (6.5, 7.3 mm) cannulated cancellous screws
  - External fixator/universal distractor
  - Skeletal traction tray (calcaneal traction)

FIG 4 • A,B. Preoperative planning may include additional equipment. This may include small fragment plates and screws (Synthes, Paoli, PA), specific clamps, or traction sets.

Positioning

Patients are positioned in the supine position on a radiolucent table. A bolster may be placed under the ipsilateral hip.
Radiolucent triangles may be used to assist with hyperflexion of the knee for standard nailing (FIG 5), whereas smaller bumps may be placed under the knee for semiextended approaches (FIG 6).

FIG 5 • Standard tibial nailing requires hyperflexion of the knee. Radiolucent triangles may help with positioning.

FIG 6 • Patient positioning for semiextended or suprapatellar nailing. Notice a small bump under the knee to provide 30 to 40 degrees of knee flexion. Suprapatellar nailing requires specific instruments seen here.

Approach