Overview
The patellar tendon connects the kneecap to the tibia and carries every ounce of force the quadriceps produces. A complete rupture — typically from a sudden eccentric load during a missed step or a jump landing — breaks the extensor mechanism, and the patient cannot actively extend the knee. Early repair restores continuity before the tendon retracts and scars.
How the Procedure Works
We expose the tear through a midline incision and pass heavy locking sutures through the torn tendon end, then drill two or three bone tunnels through the patella from inferior to superior pole. The sutures are pulled through and tied over the superior patella, drawing the tendon back to its insertion. The critical intraoperative check is patellar height: we compare the repaired side to the contralateral knee on a lateral fluoroscopic view and adjust tension so the patella sits at its normal position — too distal (patella baja) limits flexion postoperatively, too proximal means the repair is loose and extensor lag will persist. A cerclage augmentation suture from the patella to the tibial tubercle protects the repair during early healing in attenuated tissue. Repair within the first week or two, before retraction becomes fixed, produces the best outcomes.
When to Consider Patellar Tendon Repair
Patellar tendon repair is generally offered when symptoms, imaging, and a trial of non-operative care together point to surgery as the next step. The typical picture includes:
Acute patellar tendon rupture
Sudden inability to extend the knee, with a palpable gap below the kneecap and a high-riding patella on X-ray.
Chronic rupture with functional loss
An older rupture that was not repaired initially and leaves the patient with persistent extensor lag.
Conditions This Treats
Physicians Who Perform Patellar Tendon Repair
Providers Who Surgically Assist with Patellar Tendon Repair
Risks & Why We Still Recommend It
Every operation carries risk. The reason we offer this procedure is that the condition, left untreated, causes a knee that cannot actively straighten — walking, stairs, and standing from a chair all depend on an intact extensor mechanism. That is the trade we are managing — not eliminating risk, but choosing the smaller of two unfavorable trajectories.
The risks we discuss with patients before patellar tendon repair include:
- bleeding and infection
- anesthesia risk
- stiffness, particularly loss of flexion
- re-rupture
- patella alta or baja from imperfect tensioning
- suture-anchor or hardware issues
- blood clot (DVT/PE)
The indication to proceed is an acute rupture of the patellar tendon with loss of active knee extension. Patients who don't need this operation don't get it.
Further Reading
External patient-education references and related OSI pages for additional background: