30 May 2022

The three most common knee injuries

30 May 2022

The three most common knee injuries

The knee is one of the most important joints in the human body. It’s a weight bearing structure and must function correctly to facilitate basic movement, as well as most athletic pursuits. 

Knee pain is a common clinical complaint in the population. Approximately 25% of all adults are impacted by frequent knee pain which limits function and mobility and impairs quality of life, according to an article by Uyen-Sa D. T. Nguyen et al titled ‘Increasing Prevalence of Knee Pain and Symptomatic Knee Osteoarthritis’ published online in the ACP Annals of Internal Medicine

The article examines data from six National Health and Nutrition Examination Surveys over a 33-year period and notes the increasing frequency of knee pain in the population over time:  

“The age and body mass index (BMI)-adjusted prevalence of knee pain and symptomatic knee osteoarthritis approximately doubled in women and tripled in men over a 20-year period.” 

In some instances, knee pain is the result of an acute injury, such as torn cartilage or a damaged ligament. In other cases, knee pain can be the result of ongoing degenerative or medical conditions.  

Using MRI to identify the cause of knee pain

Magnetic Resonance Imaging (MRI) is a particularly useful clinical tool for determining the specific nature of knee pain. A study published in the Journal of Family Medicine and Primary Care titled ‘Descriptive study of knee lesions using magnetic resonance imaging and correlation between medical imaging diagnosis and suspected clinical diagnoses evaluated the medical records of 240 patients who had underwent knee MRI. 

The study was conducted at Prince Mohammad bin Abdul Aziz Hospital in Al Madinah Al Munawarah and relied on data retrieved from the hospital’s Radiology and Medical Imaging Department’s database. 

The study found that the “majority of knee lesions were medial meniscus (MM) lesions (63%) followed by osteoarthritis (48%) and ACL lesions (35%).” 

“The majority of the MM and ACL lesions were tears (54.6% and 69.41%, respectively) followed by degeneration (33.55% and 17.65%, respectively).” 

1. Meniscus tear

The meniscus is a c-shaped disc of cartilage within the knee that absorbs shock from running or playing sports as well as facilitating smooth movement. 

Tears to the meniscus can occur when the knee is twisted suddenly while bearing weight and are particularly common in sports that require jumping, rapid changes in direction such as the various Australian Rules Football codes, soccer, and volleyball. 

The study published in the Journal of Family Medicine and Primary Care referenced above notes that tears of the meniscus are more common in men than in women, they can occur in all age groups but peak in the third decade of life. 

“While clinical history plus physical examination is the preferred diagnostic method for degenerative tears, confirmation by magnetic resonance imaging (MRI) is preferred for traumatic tears.” 

“MRI enables excellent diagnostic accuracy for identifying the ligament, meniscus, tendon, and cartilage lesions of the knee and has been described as the best noninvasive imaging modality for diagnosing the meniscus lesions.”  

Surgery may be required for the treatment of a torn meniscus, depending on the extent of the injury. Surgeons can perform an operation known as arthroscopy to trim away torn cartilage.

2. Anterior cruciate ligament (ACL) tear

The anterior cruciate ligament (ACL), responsible for stabilising the knee, runs between the femoral (thigh) and tibia (leg) bones. It can be torn when the lower leg is twisted or extended too far forward when the ankle is on the ground. 

ACL injuries are one of the most common knee injuries and account for around 40% of all sporting injuries. 

The severity of ACL injuries can vary widely from partial tears in the ligament through to the ligament being torn completely. Less serious tears can be treated without surgery and may heal with rest and physical therapy treatment. Surgery to replace the ligament is required in more serious cases.  

3. Osteoarthritis

Osteoarthritis is the most common joint condition and results from degeneration of the joint cartilage that occurs following injury or ongoing wear and tear to the knee.

Osteoarthritis is a common cause of chronic knee pain.

Risk for osteoarthritis increases with age and it affects women more frequently. Long-term repetitive stress to the knee due to running on hard surfaces or playing high impact sports such as basketball and netball are risk factors for developing the condition, especially if there has been a history of knee injury.

Individuals suffering from obesity are at an increased risk of developing osteoarthritis over time. 


If you’ve experienced an acute knee injury or are suffering ongoing knee pain, it’s important to seek treatment.  

Your GP may be able to diagnose your condition, or otherwise refer you for an MRI scan or to see a specialist for further opinion and diagnosis.

Rehabilitation with a physical therapist is recommended in many cases for follow-up treatment. 

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Our team of content writers create website materials that adhere to the principals set out in content guidelines, to ensure accuracy and fairness for our patients. Dr. Ronald Shnier, our Chief Medical Officer, personally oversees the fact-checking process, drawing from his extensive 30-year experience and specialised training in radiology.