Patellar Fracture and Extensor Mechanism Repair

Indications

Patellar Fractures, tension band wiring of a transverse patella fracture
Tension band wiring of a transverse patella fracture. Image by Hellerhoff, Wikimedia Commons, CC BY-SA 3.0.
  • Patellar fracture with extensor lag, step over 2 mm or gap over 3 mm
  • Complete quadriceps or patellar tendon rupture
  • Undisplaced fractures with an intact straight leg raise are treated in a brace
  • Open fractures need urgent debridement

Position

  • Supine, thigh tourniquet
  • Image intensifier for fracture fixation
  • Bump under the ipsilateral hip to correct external rotation

Operative Steps

  1. Longitudinal midline incision
  2. Transverse patellar fractures, tension band wiring or cannulated screws with a tension band
  3. Comminuted lower pole, partial patellectomy with transosseous reattachment of the patellar tendon
  4. Quadriceps tendon rupture, locking sutures through vertical patellar tunnels or anchors
  5. Patellar tendon rupture, transosseous repair protected by a cerclage wire or suture
  6. Repair the retinacula
  7. Check patellar height against the other side
  8. Clear haematoma and inspect the articular surface through the retinacular tear
  9. Reduce with pointed reduction clamps and check the joint surface by palpation and imaging
  10. Suture fixation reduces hardware irritation

Postoperative Care

  • Hinged brace locked in extension, then progressive flexion
  • Early quadriceps activation
  • Flexion limits increase by about 30 degrees every 2 weeks
  • Avoid resisted extension for 12 weeks after tendon repair

Complications

  • Extensor lag and weakness
  • Stiffness and patella baja
  • Symptomatic hardware
  • Re-rupture
  • Hardware irritation is common and often leads to removal
  • Patellofemoral arthritis after articular fractures
  • Infection and wound breakdown

Related Pages

Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 10 October 2026.