Quadriceps tendon rupture

Tendons are strong bands of tissue that connect muscles to the bones. The quadriceps tendon is crucial in straightening the knee from a bent position. Small tears in this tendon can cause pain or make walking or other things we do every day difficult. A complete quadriceps tendon tear is a severe injury that can not be fixed.

Last Updated: February 23, 2024

A quadriceps tendon rupture happens 1.37 times per 100,000 people. Most tears upon extension tend to occur on one side. But there have been several reports of this injury happening on both sides after the exact cause.

Causes of quadriceps tendon rupture might come from an injury or tendon weakness. A quadriceps tear often happens when the leg carries a heavy load, the foot is planted, and the knee is only slightly bent. Tendinitis or tendon inflammation can also weaken the tendon; a common cause of this inflammation is playing sports involving running and jumping. Tendinitis can also be brought by chronic illnesses such as chronic kidney disease.

There is usually a ripping or snapping sound when the quadriceps tendon ruptures. It's common to have pain, swelling, and the inability to straighten the knee after an injury. Among the other signs are:

  • A depression above the kneecap at the site of the tendon rupture
  • Bruising
  • Tenderness
  • Cramping
  • If the tendon is torn, the knee  cap may sag or hang down
  • Knee pain that makes it hard to walk because it buckles or gives way

Ruptures of the quadriceps tendon may usually be diagnosed with just a patient's medical history and a physical exam. Imaging is generally unnecessary; however, the most reliable imaging is ultrasound. With the knee bent, it can help spot a tendon problem and gauge how much of a separation there is. 


Treatment options can be nonsurgical or surgical, depending on the severity of the tear. Surgery is usually indicated in a complete tear. 

Your doctor may recommend a knee brace or immobilizer for acute tears. This brace will help the knee heal by keeping it straight, which may be needed for 3 to 6 weeks for immobilization.

Physical therapy could also be initiated after the pain and swelling have gone down. Specific exercises can help regain the leg's strength and range of motion.

Most people with complete tears will need surgery to repair the torn tendon, including when there is a big partial tear or a partial tear combined with tendon degeneration.

After recovering from a quadriceps tendon tear, most people can return to their old jobs and hobbies. 

However, more than half of people continue to have pain and weakness in their thigh at the location of the tear. People who need surgery tend to do better if the surgery is done soon after the injury.

A competitive athlete can undergo extensive evaluation from their surgeon before being given the green light to resume their sport. The surgeon will perform functional knee tests to see how strong the injured legs are (like hopping). The aim is to have the injured leg perform at a strength of 85-90% of that of the healthy leg. The surgeon will look at more than just how strong the legs are; they will also check balance and see if there is any swelling. 



Pope JD, El Bitar Y, Mabrouk A, et al. Quadriceps Tendon Rupture. [Updated 2022 Nov 17]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK482389/ 

Ortho Infor (2022). Kaposi Sarcoma. Retrieved December 16, 2022, from https://orthoinfo.aaos.org/en/diseases--conditions/quadriceps-tendon-tear/


Last Updated: February 23, 2024