Quadriceps Tendon Tears

The quadriceps tendon connects the quadriceps muscles on the front of the thigh to the top of the kneecap (patella). When the muscles contract, they pull on this tendon to help straighten the leg at the knee joint. A quadriceps tendon tear occurs when the tendon is partially or completely torn, separating the muscle from the kneecap. This injury disrupts the ability to extend the knee and can make even basic movements like walking or climbing stairs very difficult.

Quadriceps tendon tears vary in severity. In a partial tear, some of the tendon fibers are damaged but not completely severed. This may cause pain and weakness but may still allow some movement. In a complete tear, the tendon is fully detached from the kneecap, often accompanied by a noticeable gap above the patella and an inability to straighten the leg. These tears typically require surgical repair to restore normal function.

The symptoms of a quadriceps tendon tear can appear suddenly, especially following a traumatic injury or fall. Common signs include:

• A sudden, sharp pain at the front of the knee
• Swelling and bruising that develop rapidly
• A tearing or popping sensation at the time of injury
• Difficulty walking or standing
• Inability to straighten the knee or raise the leg
• A noticeable indentation or gap just above the kneecap
• The kneecap appears lower than normal (since the tendon is no longer holding it in place)

In cases of partial tears, symptoms may be milder, but ongoing pain and weakness can make it difficult to perform normal activities or engage in sports.

Quadriceps tendon tears often result from a sudden, forceful stress on the tendon, especially when the knee is bent and under load. Common causes include:

• Falls or trauma: Landing awkwardly from a jump, stumbling on stairs, or slipping can cause the tendon to overstretch or tear.
• Direct impact: A blow to the front of the knee, such as from a sports collision or car accident, can damage the tendon.
• Sudden load on the leg: Attempting to stop abruptly or change direction during sports can place excessive strain on the quadriceps tendon.
• Chronic overuse: Repetitive stress from running, jumping, or weightlifting can weaken the tendon over time, making it more prone to tearing.

Certain medical conditions can also make the tendon more fragile. These include chronic kidney disease, diabetes, rheumatoid arthritis, or previous corticosteroid use. In older adults, tendons naturally lose elasticity and strength, increasing the risk of tears even from minor injuries.

Several factors can increase the likelihood of a quadriceps tendon tear. Age is a major contributor—people over 40 are more prone to this injury due to gradual tendon weakening. Individuals involved in sports or physically demanding activities, especially those requiring jumping or sudden movements, face a higher risk.

Other risk factors include:

• Chronic illnesses: Conditions such as diabetes, gout, or systemic lupus can interfere with tendon health.
• Previous knee injuries or surgeries: Scar tissue or prior damage can make the tendon more susceptible to tearing.
• Steroid or certain antibiotic use: Long-term use of corticosteroids or fluoroquinolone antibiotics can weaken tendon fibers.
• Lack of proper conditioning: Weak thigh muscles, limited flexibility, or imbalanced leg strength can strain the quadriceps tendon.
• Obesity: Excess body weight increases the load on the knee joint and surrounding tendons, raising injury risk.

Diagnosis typically begins with a detailed physical examination. Dr. Kevin Collon will assess knee movement, strength, and tenderness to identify whether the tendon has been compromised. During the exam, patients with a complete tear are often unable to actively straighten the leg or perform a straight-leg raise.

Imaging tests such as ultrasound or MRI are often ordered to confirm the diagnosis and determine the extent of the tear. X-rays may also be taken to rule out associated injuries, such as fractures or displacement of the kneecap. Prompt diagnosis is essential, as early treatment improves the chances of a full recovery and minimizes long-term weakness or stiffness.