Tendons are strong cords of fibrous tissue that attach muscles to bones. The quadriceps tendon attaches the quadriceps muscles (in front of the thigh) to the kneecap and helps straighten your knee. Small tears of the tendon can make it difficult to walk and participate in other daily activities. A large tear of the quadriceps tendon is a disabling injury.

How common: These tears are not common. Males in their 40ies and 50ies are at risk.

Average patient: A 45-year-old man who falls going downstairs after missing a step.

Cause: It occurs when there is a heavy landing on the leg with the foot planted and the knee partially bent. Tears can also be caused by falls, direct force to the front of the knee, and lacerations (cuts). Chronic diseases that disrupt blood supply to the tendon and inflammation (quadriceps tendinitis) weaken the tendon, making it susceptible to a tear. High risk conditions include chronic renal failure, Gout, Rheumatoid arthritis, Leukemia, Diabetes mellitus, chronic steroid use, and prolonged immobilization of the knee.

Symptoms: When quadriceps tendon tears, there is often a tearing or popping sensation. Pain and swelling typically follow, and you may not be able to straighten your knee. Additional symptoms include an indentation at the top of the kneecap (where the tendon tore) and difficulty walking due to the knee buckling or giving way.

Severity of injury: Quadriceps tendon tears can be either partial or complete. Partial tears do not completely disrupt the soft tissue (similar to a rope stretched such that some fibers are frayed, but the rope is still in one piece). A complete tear will split the soft tissue into two pieces (the muscle is no longer anchored to the kneecap). Without this attachment, the knee cannot straighten when the quadriceps muscles contract.

Treatment options: Mild and partial tears respond well to bracing-immobilization and physical therapy. Complete tears usually need to undergo surgical repair. Earlier done, the better! We attach the torn tendon to the bone (patella) using small implants (called suture anchors). If your tendon has shortened too much before surgery (those who seek treatment after a month), extra tissue graft may have to be added to lengthen the tendon.

Expected result:Patients may have some continued pain at the tear-site but usually are able to have majority of their quadriceps strength restored. The most common complications of quadriceps tendon repair include weakness and loss of knee motion.

Return-to-activity timeline: After surgery, patients are advised to bear minimal to no weight for 6-8 weeks. A return to normal activities usually requires a significant return of strength, which can take about 6-9 months after surgery.