Sprains and tears to the anterior cruciate ligament are among the most common knee injuries, particularly in high-impact sports like football and basketball.
Causes of anterior cruciate ligament injuries
Rapid changes of direction when running, stopping suddenly, a collision or landing heavily after jumping… all of these can lead to injuries of the anterior cruciate ligament, which runs diagonally along the inside of the knee joint.
It forms an X shape with the posterior cruciate ligament – the anterior at the front of the knee joint with the posterior at the back. The role of the anterior cruciate ligament is to give the knee rotational stability and to protect the tibia. The posterior cruciate ligament keeps the shinbone in place. Because the latter is stronger, it is less prone to injury.
If you are unfortunate enough to injure your anterior cruciate ligament, you’re most likely to sustain a grade 3 sprain. This is where the ligament is completely torn in half or pulled off the bone. It is the most serious type of injury and can leave the knee joint prone to instability. It may also be accompanied by damage to the meniscus, articular cartilage and other ligaments.
Treating anterior cruciate ligament injuries
Surgery is often needed to repair the most serious anterior cruciate ligament tears and those that occur alongside other knee injuries. Patients who sustain partial anterior cruciate ligament tears or who have a less active lifestyle may choose a non-surgical route involving physiotherapy and rehab. This can be effective in some cases although not for those who hope to return to competitive sport.
Researchers study the risk of total knee replacement after cruciate ligament surgery
A team of researchers from Washington University in St Louis, Missouri, set out to examine whether people who have cruciate ligament surgery are at greater risk of needing a total knee replacement in the future, and also whether there are clinical and genetic risk factors that increase the risk. Their findings were published in The Bone and Joint Journal, 2024.
The researchers used the UK Biobank to identify people who’d undergone cruciate ligament surgery. Data from verbal history and procedural codes recorded through the NHS was used to identify those who’d subsequently had a total knee replacement. Of the 2,576 with a history of cruciate ligament surgery, 290 (11.25%) had undergone a total knee replacement. The prevalence of total knee replacement surgery in patients who’d previously had a surgical repair of their cruciate ligament was 0.75% at age 45, 9.10% at 65 and 20.43% at age 80.
Findings confirm increased risk
The study showed patients who’d previously had cruciate ligament surgery were 4.6 times more likely to have had a total knee replacement by age 55 than those who’d never had cruciate ligament surgery. They concluded that a history of prior cruciate ligament surgery meant a substantially higher risk of total knee replacement at a relatively younger age.
Certain clinical and genetic factors – such as obesity, a job that requires constant walking or standing, or heavy manual labour – were also found to increase the risk. No single-nucleotide polymorphism (SNP) – a genomic variant at a single base position in the DNA – was associated with an increased risk of total knee replacement following cruciate ligament surgery.
Preventing cruciate ligament injuries
Clearly, it is important to minimise the chances of sustaining anterior cruciate ligament injuries if you play high impact sport or have a job that carries a high risk of injury. An effective warm-up and cool-down routine, good technique and wearing the correct footwear can all help to lower your injury risk. If you do injure yourself and need surgery to repair your cruciate ligament, it is essential to follow the advice of your clinical team.
An effective rehabilitation programme after surgery can help rebuild strength and function in the affected knee. Making lifestyle adjustments can also lower your risk of future knee replacement. For example, regular low impact exercise and maintaining a healthy body weight can help you remain fit and active and reduce the strain on your knee joint.
Contact us for information about diagnosing and treating anterior cruciate ligament injuries, as well as advice on total or partial knee replacement surgery.
