Anterior cruciate ligament injury is one of the most common knee injuries that occurs in athletes, engaged in high demand sports like soccer, football, basketball, skiing and gymnastics. The injury happens when the bio mechanical limits of the ligament exceeds its normal limit (is overstretched) or when excessive pressure is put on the knee joint resulting in its tear. ACL tears normally do not occur in isolation they are usually associated with damage to other knee structures such as cartilage or collateral ligaments.
ACL is one of the four main ligaments of the knee that connects femur to tibia. The knee is essentially a hinge joint held together by few ligaments. The ACL runs diagonally in the middle of knee. It helps to stabilize the knee during dynamic movements such as bending (flexion), straightening (extension) and provides rotational stability to knee.
Most ACL injuries occur in combination with injury or tear to other soft tissues,of which Meniscus(shock absorbing cartilage in the knee) is most common. ACL tears most frequently in the middle of ligament or the ligament can be pulled off the thighbone (femur).Patients often complain about the audible pop or crack at the time when they are injured. They may feel instability in the knee and swelling usually develops rapidly, though not always.
- It is estimated that 70% of ACL injuries occur through ‘non-contact mechanism’, such as:
- random change of direction combined with sudden stopping,
- awkward landing from a jump
- pivoting when the knee is hyperextended.
Rest 30% result from ‘Direct contact’ with another player or object (football, basketball, etc.)
- Women are at higher risk of ACL injuries than men. The apparent reasons for this increased risk may include differences in anatomy, training and activity experience.
Other factors, which can cause ACL injuries are:
- Shoes: Attention should be paid to the shoes worn by athletes as shoes with increased friction coefficient may enhance performance but adversely affects the ACL. Shoes with cleats and high-heels may injure ACL.
- Playing surface: Playing surface having lower friction have lower incidence of injuries.
- Weather (climate): The risk of knee and ankle sprains are less in colder months of the season.
The best way to prevent non contact ACL injuries is through proper training. It includes in identifying and targeting weak muscle areas (e.g., weak front and back muscles of the knee that is quadriceps and hamstrings) and working out on ways to strengthen these weak areas. This can be done with the help of an athletic trainer, physical therapist, or sports medicine specialist.
At present, these training emphasis on injury awareness,injury avoiding techniques and ACL strengthening exercises in which athletes are taught stretching,strengthening,balancing, jumping and landing safely.These types of exercises and training programs are most effective when started at a young age.
In case, if injury has already occurred, another injury can be prevented by implementing rehabilitation exercises in which athletes are taught to reduce the stress placed on ACL.
Wearing a knee brace is advisable during vigorous athletic activity. In severe cases knee ligament Surgery with rehabilitation is the suggested treatment. In elderly sedentary patients, a non-operative treatment approach is also possible.