Cruciate ligament injury or rupture: an overview

By Cristiano Antonino On May 31, 2023

The knee is one of the most complex joints in the human body: it is made up of four fundamental ligaments, including the cruciate ligaments, and in particular the anterior cruciate ligament

It is one of the most important structures of the knee, as it contributes to the stability of the entire joint, performing an essential protective function which consists in preventing hyperextension of the knee and limiting internal rotation of the tibia.

However, traumatic events and continuous stresses can lead to a rupture of this ligament: the cruciate ligament injury is one of the most common knee injuries; it can be total or partial and requires great attention from the medical team.

Depending on the specific case, the age of the patient and the type of lesion reported, the most suitable treatment to cure a cruciate lesion may include conservative and pharmacological therapy, or it may be necessary to intervene surgically to resolve the problem.

What is the cruciate ligament and what is it used for?

The knee is one of the most important synovial joints in the human body; it plays a fundamental role in supporting the weight of the body and allows a wide range of movements of the lower limbs.

This joint is where the three main bones of the leg meet: the femur, tibia, and patella.

The knee is also equipped with four important ligaments, whose main function is to stabilize the entire joint and prevent the bone components from losing their correct alignment: they are the anterior cruciate ligament, the posterior cruciate ligament, the medial collateral ligament and the lateral collateral ligament; the first two ligaments occupy the central part of the joint (intracapsular), while the collateral ligaments are located in the extracapsular area, respectively on the inner and outer side of the knee.

Anterior cruciate ligament: prevents hyperextension of the knee by avoiding excessive forward movement of the tibia.

Posterior cruciate ligament: keeps the ends of the femur and tibia aligned, preventing excessive forward or backward sliding of one of the two bone components.

Medial collateral ligament: Reinforces the inner side of the knee and prevents lateral blows and thrusts from causing misalignment between the femur and tibia.

Lateral collateral ligament: it has a similar function to the medial collateral ligament but operates on the opposite front, therefore it strengthens the external side of the knee and prevents a lateral sliding from misaligning the tibia and femur.

Due to its structural complexity, the knee joint is often subject to injuries that can damage one or more ligaments: a knee sprain can cause injuries of various entities, leading to strains and real lacerations that can compromise the functions stabilization and alignment of ligaments.

This condition can lead to various complications such as fractures, inflammation and bone degeneration.

Knee sprain and cruciate ligament injury

Direct or indirect sprain trauma and stresses that cause excessive extension or forced rotation can cause the injury of one of the ligaments.

In most patients who sustain a cruciate ligament injury, the damage affects the anterior cruciate.

Knee injuries are particularly frequent in elderly patients and in subjects who practice contact sports, such as football, basketball, skiing, tennis, etc.; traffic accidents can also be a frequent cause of cruciate ligament injury. In most cases, the harmful mechanisms that determine a knee sprain are due to:

Unnatural twisting of the knee, in or out while the foot is planted on the ground.

Knee hyperextension, i.e. a malalignment of the joint with longitudinal sliding of the femur or tibia.

Abrupt stop during a run at full speed.

Violent impacts to the leg or foot.

Depending on the extent of the trauma, the cruciate tear is often associated with the injury of other joint structures such as cartilage and menisci, or it can involve other bone segments.

Although it is quite common, the cruciate ligament injury constitutes a serious injury to the knee, which affects the stability of the entire joint and compromises the execution of a large number of activities.

What are the symptoms of cruciate ligament injury?

The symptoms of patients who report a cruciate ligament injury can vary significantly from case to case.

The typical picture involves the immediate appearance of intense pain located in the knee area, combined with the impossibility of using the joint; often following the injury, the patient can hear noises and crunches during movement, which are caused precisely by the laceration of the ligament.

Another typical symptom of cruciate injury is an immediate feeling of instability or failure of the knee.

Sometimes, following particularly violent trauma, a distortion can also involve other joint structures such as the collateral ligaments, the menisci or the cartilage, further aggravating the clinical picture.

Due to the traumatic shock and intense pain caused by the injury, patients prone to cruciate injury may also experience fatigue and fainting, palpitations, or nausea.

In the later stages, a knee injury can also cause it

Swelling, especially during the acute phase of the injury.
Joint stiffness and reduced mobility, both due to pain caused by movement and due to structural damage to the joint.
Instability and joint blocks, specifically the patient may feel that the knee assumes an unnatural position outside its original anatomical site.
Ecchymoses and bruises located in the affected area.
Joint effusion and hemarthrosis with evident swelling.

Diagnosis

Due to the rather acute symptoms reported by patients who suffer a knee injury, the diagnosis of the injury is generally made a few hours after the trauma, after the subject has received immediate first aid treatments.

The diagnostic process first of all includes a careful physical examination, during which the orthopedist analyzes the sore knee, evaluates the stability and motility of the joint, and establishes the dynamics of the accident that gave rise to the trauma.

During the visit, the doctor carries out a series of manual tests which include the Lachman test to verify the elasticity and motility of the knee, a Jerk test to detect the presence of crunches and joint blocks, and the anterior drawer test.

If the results indicate a cruciate ligament injury, the orthopedist prescribes a series of instrumental tests to identify the location and type of the injury, assess the extent of the damage and establish the most suitable therapeutic approach.

To this end, an X-ray of the leg is essential, especially if bony involvement is suspected, and an ultrasound or MRI of the knee.

Care and treatment

The most suitable therapy to treat a cruciate lesion may depend on the age and degree of activity of the patient, the extent of the damage reported, the instability of the lesion and the involvement of other joint structures.

Conservative therapy

In the case of minor partial injuries or in elderly patients, it is possible to opt for a conservative therapy, combined with a rehabilitation physiotherapy course for a partial recovery of knee functionality; sometimes it may be necessary to resort to external guardians to immobilize the area.

Cryotherapy and the administration of anti-inflammatory and pain-relieving drugs can also help keep pain and discomfort under control.

Although with conservative therapy it is possible to obtain good results and allow the patient to carry out normal daily activities, it does not in any way allow recovery from the injury: the affected knee still remains compromised from a functional point of view and involves various limitations of movement.

This is due to the fact that the cruciate ligament is almost completely devoid of blood supply, and is therefore unable to regenerate in the event of injury.

Reconstructive surgery in cases of cruciate ligament injury

In the case of young and still active patients, especially in the case of athletes, surgical therapy is the most frequently adopted approach: an unrepaired cruciate lesion, in fact, exposes the joint to the risk of new distortions which can cause extensive damage and lead to the early development of osteoarthritis.

The reconstructive surgery of the cruciate ligament is performed arthroscopically, a micro-invasive technique that allows you to reach the knee joint through small incisions of a few centimeters.

During the operation, first of all, the residuals of the damaged tissue are removed, after which a tunnel is made in the femur and tibia to house the new ligament; this can be taken from the central portion of the patella of the same patient (graft), it can come from an organ donor (transplant) or it can be synthetic.

Recovery times from surgery can range from 4 to 6 months, during which absolute rest and abstention from physical activity are recommended; in most cases the use of crutches during the post-operative phase, and the use of an external brace for a more or less prolonged period of time, can be prescribed.

After surgery, it is essential that the patient scrupulously follow a rehabilitation program to fully recover knee function.

Rotator Cuff Injury: What Does It Mean?

Dislocations: What Are They?

Tendon Injuries: What They Are And Why They Occur

Elbow Dislocation: Evaluation Of Different Degrees, Patient Treatment And Prevention

Cruciate Ligament: Watch Out For Ski Injuries

Meniscus, How Do You Deal With Meniscal Injuries?

Meniscus Injury: Symptoms, Treatment And Recovery Time

First Aid: Treatment For ACL (Anterior Cruciate Ligament) Tears

Anterior Cruciate Ligament Injury: Symptoms, Diagnosis And Treatment

Patellar Luxation: Causes, Symptoms, Diagnosis And Treatment

Arthrosis Of The Knee: An Overview Of Gonarthrosis