The anterior cruciate ligament (ACL) is one of the four key ligaments that ensure passive stability to the knee joint. Anterior cruciate ligament is the most commonly injured ligament of the knee and one of the most common injuries in general. The injury of ACL is known as one of the most severe injuries in sports because it is characterised by long and complex rehabilitation.
The injury occurs due to forced, strong hyperextension of the knee (the knee is “pushed” back) or due to rapid pivoting (rotating the body around the fixed foot and shin). A combination of weak muscles of the thigh, landing many jumps, and poor endurance of the hamstrings along with sports activities, suffering blows, awkward landings and falls all pose a risk of injury to the anterior cruciate ligament.
There are two mechanisms of injury to the anterior cruciate ligament – non-contact and contact mechanisms. 70-80% of ACL injuries are non-contact in nature, which means that the cause of injury is not an external force such as an awkward landing, suffering a blow, or falling.
Non-contact injury is a consequence of ligament failure. A great number of ACL injuries can be prevented with adequate physical preparation.
Symptoms of the ACL injury include strong pain in the knee that can spread down the entire extremity, limited mobility of the knee (knee extension and flexion), oedema or swelling that appears several hours after the injury and gradually grows in size, a feeling of instability in the knee, a wobbly, swaying feeling in the knee and gradual loss of muscle mass in quadriceps muscles, especially on the inner side.
About 40% of patients with an ACL injury report a pop in the moment of injury that occurs due to the rupture of the ligaments.
More than half of anterior cruciate ligament injuries co-occur with meniscal injuries of the knee joint. When the injury happens, it is vital to promptly undergo diagnostic testing, namely x-ray and magnetic resonance imaging (MRI) that confirm or refute the diagnosis of ACL and skeletal fractures.
After an ACL injury, it is important to follow the RICE method of acute condition management.
It is obligatory to intensively perform preoperative rehabilitation up to the day of surgery. It is necessary to stop the swelling of the joint, do away with pain symptoms, recover full flexion and extension of the knee, and prevent or reduce muscle atrophy. The success of preoperative rehabilitation depends on the extent of injury and the patient’s participation.
In the event of a full ACL rupture, surgical ligament transplantation is necessary.
If the ACL rupture is partial, we first perform conservative treatment with special exercises to improve muscle strength and knee joint control during movements. If knee instability or intense pain do not disappear, then partial ACL rupture also requires surgical treatment.
Postoperative rehabilitation of the anterior cruciate ligament lasts from 6 to 9 months, depending on the age, level of sports activity, and the extent of the patient’s injury. The first month of rehabilitation includes therapy sessions that lessen the pain and swelling, and gradually we apply special exercises to activate the thigh muscles and regain the full extent of knee joint flexion and extension.