Quadriceps and Patella Tendon Repair Surgery
The quadriceps tendon and the patellar tendon are the two critical links in the knee’s extensor mechanism — the system that allows you to straighten your leg, walk, run, climb stairs, and rise from a chair. The quadriceps tendon connects the powerful quadriceps muscle to the top of the kneecap, while the patellar tendon connects the bottom of the kneecap to the tibial tubercle on the shinbone. When either of these tendons ruptures — typically from a forceful eccentric contraction such as landing from a jump, stumbling, or a sudden deceleration — the extensor mechanism is disrupted and the patient immediately loses the ability to straighten the knee or bear weight on the affected leg. Quadriceps tendon ruptures are more common in patients over 40, while patellar tendon ruptures tend to occur in younger, more active patients. Both injuries are surgical emergencies — the tendons very rarely heal on their own, and the best outcomes are achieved when surgical repair is performed within the first few weeks after injury.
Dr. Jonathan Glashow is a board-certified orthopedic surgeon and Clinical Associate Professor of Orthopedic Surgery at NYU Grossman School of Medicine, with published research on patellar viability and the contribution of the infrapatellar fat pad to the knee’s extensor mechanism — studies that directly inform his understanding of the anatomy, blood supply, and biomechanics involved in tendon repair around the kneecap. With over 30 years of experience, more than 15,000 procedures performed, and roles as Chief Medical Officer for the New Jersey Devils and Philadelphia 76ers, he has managed acute extensor mechanism disruptions in professional athletes where restoring full tendon integrity and knee function is essential for return to competition. Named a Castle Connolly Top Doctor every year since 2000, Dr. Glashow performs quadriceps and patellar tendon repair surgery at his Upper East Side practice in New York City.
Surgical Repair and Recovery
Patients with a quadriceps or patellar tendon rupture typically present with a painful, swollen knee and difficulty walking. The hallmark finding is an inability to straighten the leg against resistance — a clear sign that the extensor mechanism has been disrupted. Seeking orthopedic evaluation quickly is essential, because surgical repair is ideally performed within four weeks of the injury for the best outcomes.
Complete tears of the quadriceps or patellar tendon require surgical repair to restore strength and function to the leg. The procedure involves placing strong sutures through the torn tendon and passing them through tunnels drilled in the kneecap to reattach the tendon securely to the bone. The surgery typically takes approximately one hour and is performed on an outpatient basis under general anesthesia.
After surgery, patients wear a knee brace to protect the repair and may use crutches for several weeks — though weight can typically be placed on the leg as long as the knee is kept straight. Early range-of-motion exercises are often introduced under the supervision of a physical therapist, particularly for athletes who need an accelerated rehabilitation timeline. The knee brace is generally discontinued around three months, and most patients return to full activity between four and six months after surgery depending on the tendon involved and their individual healing progress.
If you have sustained a sudden injury to the front of your knee and are unable to straighten your leg, you may have ruptured your quadriceps or patellar tendon — and early surgical repair produces the best outcomes. Dr. Glashow offers urgent evaluation with same-day imaging at his Upper East Side practice and can proceed to surgical repair with minimal delay when needed. Contact our office to schedule an emergency consultation.
Frequently Asked Questions About Quadriceps and Patellar Tendon Repair
What is the difference between a quadriceps tendon tear and a patellar tendon tear?
Both tendons are part of the knee’s extensor mechanism, but they are located on opposite sides of the kneecap and tend to rupture in different patient populations. The quadriceps tendon connects the quadriceps muscle to the top of the kneecap and is more commonly ruptured in patients over 40, often in the setting of degenerative tendon changes. The patellar tendon connects the bottom of the kneecap to the shinbone and is more commonly ruptured in younger, active patients — frequently during high-force jumping or landing activities. Both injuries produce the same functional result: an inability to straighten the knee.
How do I know if I ruptured my quadriceps or patellar tendon?
The most common presentation is a sudden, severe pain at the front of the knee during a forceful activity such as jumping, landing, or stumbling — often accompanied by a popping or tearing sensation. Rapid swelling develops, and the patient is unable to straighten the leg or perform a straight leg raise. A visible gap or depression may be palpable at the top of the kneecap (quadriceps tendon rupture) or at the bottom of the kneecap (patellar tendon rupture), and the kneecap may appear to have shifted higher or lower than normal. Any of these signs warrants urgent evaluation.
Why is early surgery important for tendon ruptures?
When the quadriceps or patellar tendon ruptures, the torn ends begin to retract — pulled apart by the muscle above and the weight-bearing forces below. The longer the delay between injury and repair, the more the tendon retracts, the more scar tissue forms in the gap, and the more difficult it becomes to bring the ends back together with adequate tension. Repairs performed within the first two to four weeks after injury consistently produce better functional outcomes than delayed repairs, which is why Dr. Glashow recommends urgent evaluation for any suspected extensor mechanism disruption.
Can a partial tendon tear be treated without surgery?
Small partial tears — where the majority of the tendon remains intact and the patient can still actively straighten the knee — may be managed conservatively with bracing, activity modification, and a structured physical therapy program. However, the tendon must be monitored closely, because partial tears can progress to complete ruptures if they are subjected to further stress before healing. Dr. Glashow evaluates each injury with clinical examination and MRI to determine whether the tear is stable enough for conservative management or whether surgical repair is indicated to prevent progression.
How long does recovery take after tendon repair surgery?
Most patients wear a knee brace for approximately three months while the repaired tendon heals. Crutches are typically used for four to six weeks, with weight-bearing permitted as long as the knee remains in extension. Physical therapy begins within the first one to two weeks and progresses through range-of-motion recovery, progressive strengthening, and functional training over the following months. Most patients return to daily activities within two to three months and to full sports or high-demand physical activity between four and six months. Dr. Glashow tailors the rehabilitation pace to each patient’s tendon quality, repair strength, and functional goals.
Can the tendon re-rupture after repair?
Re-rupture is uncommon when the repair is performed properly and the rehabilitation protocol is followed — published re-rupture rates after primary repair are generally below 5 percent. The most common risk factors for re-rupture are premature return to heavy loading before the tendon has healed adequately, non-compliance with bracing restrictions, and poor tendon tissue quality at the time of initial repair. Dr. Glashow uses strong suture fixation through bone tunnels to maximize repair strength and monitors each patient’s healing progress closely before advancing the rehabilitation timeline.
