Suprapatellar tibial intramedullary nailing

Key concept

Stepwise operative approach

1. Preoperative planning

• Confirm fracture pattern, extension into the plateau or ankle, open injury status, and associated ligamentous or knee injury.
• Select nail length, diameter, proximal and distal interlocking strategy, and possible adjuncts:
  • temporary reduction clamps
  • Poller or blocking screws
  • external distractor or temporary plate
  • percutaneous lag screws for a spiral fracture, ensuring they do not obstruct the nail path
• Check patellar mobility before choosing this route. A stiff patella or scarred suprapatellar pouch may make sleeve passage unsafe or difficult.

2. Positioning and imaging

• Place the patient supine on a radiolucent table.
• Put a bump under the ipsilateral hip to avoid external rotation.
• Support the leg on a radiolucent foam ramp or bolster, maintaining the knee in a semi-extended position. Ensure the C-arm can obtain true AP and lateral views from knee to ankle.
• Prep and drape widely enough to permit manipulation, reduction clamps, and distal locking.

3. Skin incision and arthrotomy

• Make a short longitudinal midline incision proximal to the superior pole of the patella. AO describes an incision approximately 4 cm proximal to the superior pole.
• Split the quadriceps tendon in line with its fibers.
• Enter the suprapatellar pouch carefully.
• If patellar excursion is limited, a small medial or lateral parapatellar extension may be required to pass the sleeve without scraping the patellar or trochlear cartilage.

4. Insert the protective cannula

• Introduce the blunt trocar and outer protective sleeve under the patella toward the proximal tibia.
• Under AP and lateral fluoroscopy, confirm that the sleeve is fully seated on the anterior proximal tibia.
• Keep the sleeve in position throughout entry preparation, reaming, and nail insertion. If the system allows fixation of the sleeve, this may help prevent it from migrating proximally during reaming.

5. Establish the starting point

6. Open the proximal tibia

• Pass the entry reamer or cannulated drill over the guidewire, always through the protective sleeve.
• Open only enough proximal cortex and canal to allow passage of the ball-tipped wire.
• Avoid excessive depth or an off-axis reamer trajectory, which can breach the posterior cortex.

7. Reduce the fracture and pass the ball-tipped guidewire

• Achieve reduction before advancing the ball-tipped wire.
• Advance the wire across the fracture and into the distal metaphysis.
• In a metaphyseal fracture, center the wire in the distal fragment on both AP and lateral views.
• Use percutaneous clamps, manual traction, a temporary unicortical plate, a femoral distractor, or blocking screws when needed.

8. Measure, ream, and choose the nail

• Measure nail length from the guidewire.
• Sequentially ream over the ball-tipped wire using the protective entry sleeve.
• Ream gently, usually in 0.5 mm increments. Do not force the reamer and intermittently withdraw it to clear debris.
• Select a nail with appropriate length and diameter according to fracture location, canal size, and the implant system.

9. Insert the nail

• Maintain the reduction while advancing the nail over the guidewire.
• Prefer hand insertion or gentle blows only. If the nail will not advance, reassess reduction, entry point, canal preparation, and nail size rather than force it.
• Seat the proximal nail end sufficiently below the bony entry surface to reduce prominence-related symptoms.

10. Interlock and verify alignment

• Place proximal and distal interlocking screws according to fracture pattern and implant design.
• For proximal or distal metaphyseal fractures, use the number and configuration of interlocks needed to control alignment.
• Before final locking, verify:
  • coronal alignment
  • sagittal alignment
  • rotation clinically and fluoroscopically
  • fracture length
  • nail depth
  • screw lengths and absence of joint penetration

11. Irrigation and closure

• Remove the instrumentation and protective sleeve.
• Irrigate the knee joint and wound thoroughly to remove reaming debris.
• Repair the quadriceps tendon split with absorbable sutures and close in layers.
• Obtain final AP and lateral images of the knee, fracture, and ankle.

Reduction strategies by fracture location

Proximal-third tibial shaft fracture

• Semi-extended positioning
• Accurate high starting point
• Consider medial-to-lateral blocking screw(s) to control coronal alignment
• Consider anterior-to-posterior block if procurvatum persists
• Temporary plate or clamp reduction may be helpful

Midshaft fracture

Distal-third tibial fracture

• Center the guidewire in the distal segment on both views
• Use temporary clamp, reduction aid, or Poller screws when the distal segment is wide
• Confirm enough distal fixation before committing to final nail length

Common errors and prevention

Advantages and limitations

• Semi-extended positioning helps reduction and imaging.
• Particularly useful for proximal and distal tibial fractures.
• Avoids pressure directly over the tibial tubercle/patellar tendon used in many infrapatellar techniques.
• A 2025 systematic review of randomized trials found shorter operative and fluoroscopy time, lower pain scores, and better reported knee-function scores with suprapatellar versus infrapatellar nailing, with no significant difference in union time or major complication rates in the included studies. See the RCT meta-analysis.

• It traverses the knee joint, so meticulous sleeve use is required.
• Prior knee infection, severe patellofemoral disease, restricted patellar mobility, prior quadriceps tendon surgery, or an unsuitable soft-tissue envelope may favor another approach.
• The appropriate starting point and instrumentation details vary by nail manufacturer, so the implant-specific surgical technique should take priority.