Tension Band Wiring Procedure for Patellar Fracture: Step-by-Step Technique
Tension band wiring is the most widely accepted surgical technique for treating patellar fractures, providing superior biomechanical stability that allows for early functional rehabilitation and optimal fracture healing. 1
Patient Selection and Preoperative Assessment
- Tension band wiring is indicated primarily for displaced transverse patellar fractures and can be used for almost every type of patellar fracture pattern 1
- Preoperative radiographs should include anteroposterior and lateral views to assess fracture pattern, displacement, and articular congruity 2
- CT may be used when radiographs are inconclusive, especially when using metal artifact reduction techniques to detect occult fractures 2
Surgical Procedure Steps
Step 1: Patient Positioning and Preparation
- Position patient supine with a bolster under the affected knee to maintain 20-30° flexion 3
- Prepare and drape the knee in standard sterile fashion 3
- Apply tourniquet to the proximal thigh and inflate after limb exsanguination 3
Step 2: Exposure and Fracture Reduction
- Make a midline longitudinal incision over the patella, extending from 2 cm above the superior pole to 2 cm below the inferior pole 4
- Incise the extensor retinaculum on both sides of the patella 4
- Evacuate hematoma and debris from the fracture site 3
- Identify and protect the articular surface 3
- Reduce the fracture anatomically using reduction forceps to restore articular congruity 4
Step 3: Kirschner Wire Placement
- Insert two parallel 1.6-2.0 mm Kirschner wires (K-wires) from inferior to superior pole 1
- Place K-wires approximately 5 mm deep to the anterior surface of the patella 5
- Ensure K-wires are parallel and do not penetrate the articular surface 3
- Leave the ends of K-wires protruding at the inferior pole for later bending 4
Step 4: Tension Band Wire Application
- Pass an 18-gauge stainless steel wire in a figure-of-8 pattern 5
- Thread the wire through the quadriceps tendon proximally and the patellar tendon distally 3
- Cross the wire over the anterior surface of the patella 4
- Tighten the wire with pliers while maintaining fracture reduction 3
- Twist the wire ends together on the lateral side to secure fixation 4
Step 5: Securing the Construct
- Bend the protruding ends of the K-wires 180° at the inferior pole 4
- Cut the bent K-wires, leaving approximately 5-8 mm of bent wire 5
- Ensure the bent ends are embedded in the soft tissue to prevent skin irritation 5
- For additional stability in comminuted fractures, consider adding cerclage wires or using a modified technique with additional wires 3, 6
Step 6: Wound Closure
- Repair the extensor retinaculum with absorbable sutures 4
- Close the subcutaneous tissue and skin in layers 3
- Apply sterile dressing and a hinged knee brace 3
Postoperative Management
- Begin passive range of motion exercises on the second postoperative day 4
- Allow weight-bearing as tolerated with brace support after five days, unless contraindicated by associated injuries 4
- Remove the brace when quadriceps control is adequate 3
- Gradually increase active range of motion and strengthening exercises 6
Potential Complications and Considerations
- Hardware-related complications are common, with implant removal rates of up to 40% in patients younger than 60 years due to skin irritation 5
- Other complications include infection (5%), hardware loosening (10%), malunion (4.5%), and nonunion (4%) 4
- Consider modified tension band techniques with multiple wires to enhance stability and reduce complications 3, 6
- For comminuted fractures where tension band wiring may not be suitable, partial patellectomy may be necessary as a salvage procedure 1