The knee is the junction of three bones: the femur (thighbone), tibia (shinbone), and patella (kneecap). These are held together by muscles, cartilage, and ligaments – including the anterior cruciate ligament, or ACL.
Ligaments are strong bands of connective, slightly flexible tissue that attach bones to one another and act as stabilizers for a joint. The other ligaments in the knee include the posterior cruciate ligament (PCL), the medial collateral ligament (MCL), and the lateral collateral ligament (LCL).
Because the ACL is connected to the lower back of the femur and the upper front of the tibia, and because it stretches in front of the PCL, the ACL is particularly vulnerable to injury. After all, the knee joint must bear the full weight of the human body while walking, running, twisting, turning, jumping, or landing.
How Does a Torn ACL Happen?
The most commonly injured ligament of the knee is the ACL, which can be injured any time a person is moving rapidly or suddenly changes direction. When a ligament is injured or torn – even partly – it can cause pain, swelling, and weakness in the joint.
The knee is built to bear weight and to twist and turn in a limited fashion. However, certain conditions place a person at a greater risk for an ACL injury:
- Being Female – A woman is naturally built with wider hips for childbearing, but this places the knees at a slightly skewed angle as compared to men’s knees.
- High-Impact Sports – Participation in sports like basketball or football require planting the foot and making rapid changes in direction.
- Not Warming Up – A lack of stretching, warming up, or poor conditioning increases the risk of injuring the ACL.
- Hard Surfaces – Playing sports on artificial turf or exercising on pavement will increase the stress placed on the knee joint. It is better to play and exercise on natural grass, which is more pliable and creates less of an impact on the knees.
- Improper Footwear – The foot can shift inside a shoe that’s too large and cause the knee to give way.
How Do I Know if I Have a Torn ACL?
Usually, a person realizes instantly that they have suffered an ACL injury, because it is usually accompanied by a popping sensation and sound in the knee. Tearing the ACL also causes an immediate swelling of the knee joint, a loss of motion, and severe pain.
Treating a Torn ACL
If your ACL injury is minor, your physician may recommend home treatment with the RICE method:
This may be followed by physical therapy for several weeks.
When an ACL Tear Requires Surgery
If the RICE method, physical therapy, and other conservative methods are not lessening the pain of an ACL injury, the orthopedist may order an MRI of the affected knee. If the MRI shows no improvement in the torn ACL, surgery may be required to repair the damage.
If surgery is necessary, the doctor will remove the damaged ligament and replace it with a grafted tendon taken from another portion of the person’s knee. If this is not possible, it may be replaced with a donor tendon.
Surgery is followed by physical therapy to restore full function to the knee. Full recovery can take up to a year, depending on the severity of the injury to the ligament.
How to Prevent Knee Injuries
Strengthening the legs helps the knees stay strong. Stronger muscles can help reduce the pressure and impact placed on the knee, which helps to protect the knee from injury.
Training the knees by actively practicing proper form with a coach or athletic trainer can help correct things like incorrect form or posture while engaging in certain movements. Learning how to quickly change direction or to land from a jump can help prevent ACL injuries.
Knee Doctor in San Antonio
If you have suffered an injury to your knee and it is accompanied by rapid swelling, pain, and the inability to walk, chances are it is an injury to the ACL. Visit an orthopedic surgeon promptly, as this is one injury that normally will not improve with time.
Contact us today at the Center for Orthopaedic Surgery and Sports Medicine by calling (210) 692-7400 or schedule an appointment online, and take that first step toward healing today!