A patella tendon rupture, also known as a patella tendon tear, occurs when there is a tear (either partial or complete) of the patella tendon. It can make it difficult or even impossible to extend the knee joint or straighten the leg. Thus, impairing a person’s ability to walk, run, or perform other activities which require the use of the knee joint. 

There are 3 types of patella tendon rupture, these are:

• Partial tear: tendon is damaged but not completely separated.
• Complete tear: tendon is fully ruptured and no longer connected to the kneecap (patella) or shinbone (tibia).
• Avulsion tear: tendon torn away from the bone, pulling a fragment of bone along.

A patella tendon rupture is characterised into 3 grades depending on severity, these are:

• Grade 1: tendon is partially torn, but the fibres are still intact enabling the knee to still bear weight, and perform some movements.
• Grade 2: tendon is significantly damaged, with partial tearing of the fibres leading to difficulty in bearing weight and experiencing pain, swelling, and weakness.
• Grade 3: tendon is completely torn or detached from the patella or tibia, resulting in the inability to straighten the leg or bear weight on the affected leg.

The following are some of the most prevalent causes of a patellar tendon rupture:

• Direct blow to the knee, such as a fall or a sports-related collision
• Repetitive stress on the tendon stems from intense knee-related activities
• Degenerative changes lead to weakening of the tendon, making it more prone to injuries
• Pre-existing medical conditions can increase the likelihood of a rupture
• Existing knee injuries can cause a complete rupture of the patella tendon

• A loud “pop” or “snap” when an injury occurs
• Severely impaired walking and standing ability 
• Swelling and bruising around the affected knee
• Inability to bear weight on the affected leg
• Sudden burst of severe pain at the time of injury

In the subsequent hours and days, swelling will develop around the knee, and it will be tender to the touch.

• Athletes: patella tendon ruptures are common among athletes of football, volleyball, and basketball.
• Gender: men are generally more prone to patella tendon rupture than women.  
• Age: people aged 40-60 tend to suffer from this injury as a result of an overall weakened tendon consistently under high levels of stress.
• Steroid use: continuous steroid usage weakens the tendons and thus, increases the likelihood of a rupture.
• Chronic knee problems: individuals with a history of knee issues may be at higher risk of a rupture.

• Physical examination and medical history: inform your orthopaedist of the potential activities that may have led to an injury such as trauma, exercise, or sports. Physically the area of injury will be examined and several motion tests will be conducted to review the injury.

• Imaging tests: magnetic resonance imaging (MRI) or dynamic ultrasonography would be required to provide imaging of the patellar tendon and surrounding structures to confirm the diagnosis and evaluate the extent of the injury. An x-ray would be ordered to rule out fractures if any is suspected.

• Rest: you would be advised to observe complete rest to relieve pain and reduce swelling.
• Medications: non-steroidal anti-inflammatory drugs (NSAIDs) and painkillers are commonly prescribed as the first course of treatment to reduce inflammation and manage pain.
• Brace: to reduce movement of the knee and allow the tendon to heal before treatment and to manage inflammation and pain.
• Crutches: to limit placing weight on the affected knee.
• Physiotherapy: upon discontinuation of the use of the brace, an active range of motion exercise would be administered via physiotherapy to regain mobility and strengthen muscle.
• Surgery: knee arthroscopy surgery would be administered particularly where a second- or third-grade injury is involved.