One of the most common knee injuries is an anterior cruciate ligament sprain or tear. Athletes who participate in high demand sports like soccer, football, and basketball are more likely to injure their anterior cruciate ligaments.If you have injured your anterior cruciate ligament, you may require surgery to regain full function of your knee. This will depend on several factors, such as the severity of your injury and your activity level.
Normal knee anatomy, front view
Three bones meet to form your knee joint: your thighbone (femur), shinbone (tibia), and kneecap (patella). Your kneecap sits in front of the joint to provide some protection.Bones are connected to other bones by ligaments. There are four primary ligaments in your knee. They act like strong ropes to hold the bones together and keep your knee stable.
These are found on the sides of your knee. The medial collateral ligament is on the inside and the lateral collateral ligament is on the outside. They control the sideways motion of your knee and brace it against unusual movement.
These are found inside your knee joint. They cross each other to form an “X” with the anterior cruciate ligament in front and the posterior cruciate ligament in back. The cruciate ligaments control the back and forth motion of your knee.
The anterior cruciate ligament runs diagonally in the middle of the knee. It prevents the tibia from sliding out in front of the femur, as well as provides rotational stability to the knee.
About half of all injuries to the anterior cruciate ligament occur along with damage to other structures in the knee, such as articular cartilage, meniscus, or other ligaments.
Injured ligaments are considered “sprains” and are graded on a severity scale.
Grade 1 Sprains. The ligament is mildly damaged in a Grade 1 Sprain. It has been slightly stretched, but is still able to help keep the knee joint stable.
Grade 2 Sprains. A Grade 2 Sprain stretches the ligament to the point where it becomes loose. This is often referred to as a partial tear of the ligament.
Grade 3 Sprains. This type of sprain is most commonly referred to as a complete tear of the ligament. The ligament has been split into two pieces, and the knee joint is unstable.
Partial tears of the anterior cruciate ligament are rare; most ACL injuries are complete or near complete tears.
MECHANISM OF TEAR
The anterior cruciate ligament can be injured in several ways:
- Changing direction rapidly
- Stopping suddenly
- Slowing down while running
- Landing from a jump incorrectly
- Direct contact or collision, such as a football tackle
Several studies have shown that female athletes have a higher incidence of ACL injury than male athletes in certain sports. It has been proposed that this is due to differences in physical conditioning, muscular strength, and neuromuscular control. Other suggested causes include differences in pelvis and lower extremity (leg) alignment, increased looseness in ligaments, and the effects of estrogen on ligament properties.
When you injure your anterior cruciate ligament, you might hear a “popping” noise and you may feel your knee give out from under you. Other typical symptoms include:
- Pain with swelling. Within 24 hours, your knee will swell. If ignored, the swelling and pain may resolve on its own. However, if you attempt to return to sports, your knee will probably be unstable and you risk causing further damage to the cushioning cartilage (meniscus) of your knee.
- Loss of full range of motion
- Tenderness along the joint line
- Discomfort while walking
- Patient with torn ACL frequently experience a feeling of “giving Way” (Subluxating) of the knee joint often causing periodic pain. They feel less confident on their injured knee during brisk walking, walking on uneven surface, walking on wet or slippery surfaces. They are also uncomfortable in Jumping down from the small height like few steps and not willing to run or jog even for small distances.
Physical Examination and Patient History
During your first visit, your doctor will talk to you about your symptoms and medical history.
During the physical examination, your doctor will check all the structures of your injured knee, and compare them to your non-injured knee. Most ligament injuries can be diagnosed with a thorough physical examination of the knee.
Other tests which may help your doctor confirm your diagnosis include:
X-rays. Although they will not show any injury to your anterior cruciate ligament, x-rays can show whether the injury is associated with a broken bone.
Magnetic resonance imaging (MRI) scan. This study creates better images of soft tissues like the anterior cruciate ligament. It can evaluate the grade of ACL injury and as well as evaluate for other possible injuries, such as meniscus tears, cartilage injuries and other ligament injuries
Treatment for an ACL tear will vary depending upon the patient’s individual needs. For example, the young athlete involved in agility sports will most likely require surgery to safely return to sports. The less active, usually older, individual may be able to return to a quieter lifestyle without surgery.
A torn ACL will not heal without surgery. But nonsurgical treatment may be effective for patients who are elderly or have a very low activity level. If the overall stability of the knee is intact, your doctor may recommend simple, nonsurgical options.
Non surgical management of isolated ACL tears is likely to be successful or may be indicated in patients:
- With partial tears and NO instability symptoms.
- With complete tears and no symptoms of knee instability during low-demand sports who are willing to give up high-demand sports
- Who do light manual work or live sedentary lifestyles
Bracing. Your doctor may recommend a brace to protect your knee from instability. To further protect your knee, you may be given crutches to keep you from putting weight on your leg.
Physical therapy. As the swelling goes down, a careful rehabilitation program is started. Specific exercises will restore function to your knee and strengthen the leg muscles that support it.
In non surgical treatment, progressive physical therapy and rehabilitation can restore the knee to a condition close to its pre-injury state and educate the patient on how to prevent instability.This may be supplemented with the use of a hinged knee brace. However, many people who choose not to have surgery may experience secondary injury to the knee due to repetitive instability episodes.
Importantly, there is a risk of damage to the menisci (the cartilage shock absorbers) and articular cartilage (the slippery gliding surface on the ends of the bones) with each subluxation event. This damage can lead to degenerative arthritis and subsequent meniscus tears. These tear of meniscus and damage to articular cartilage is largely irrecoverable even when patient opt for surgery at the later date. Because of these concerns a majority of active and young patients elect to undergo ACL surgery when the ligament tears.
Timing of surgery
Few important criteria must be met before the ACL can be surgically reconstructed:
1, Swelling in the knee should be minimal
2, Range-of-motion (bending and straightening) of the injured knee must be nearly 50% of the uninjured knee.
3, Good Quadriceps muscle strength must be present.
Usually it takes 4-6 weeks after injury before ACL reconstruction can be performed.
It is very tailor made decision, considering various diverse factors such as the injury mode and other associated injuries in the knee which dictate the time of the surgery.
We usually prefer Regional anaesthesia as it provides postoperative pain control and also allows the patient to visualise the procedure on the monitor. We place an arthroscope into the joint. Small 5mm incisions called portals are made in the front of the knee to insert the arthroscope and instruments and we examine the condition of the knee.
Meniscus and cartilage injuries are trimmed or repaired and the torn ACL stump is then removed. In the most common ACL reconstruction technique, bone tunnels are drilled into the tibia and the femur to place the ACL graft in almost the same position as the torn ACL. The harvested graft is then inserted into the tunnels and fixed to the femur and tibia bones with a combination of special buttons, screws and sometimes with staples depending upon the need condition of the bone and graft
Grafts for ACL reconstruction
The graft tissue can either be an autograft (from one own’s body) or allograft (cadaveric donor tissue).
Autograft options include different tendons from different muscles: Hamstrings Tendons, Quadriceps Tendon, and Patellar Tendon (BTB), peroneus longus tendon, hamstring tendon from opposite knee.
Advantages to autograft include no risk of disease transmission and potentially quicker healing of the new ACL.
Allograft (Tissues harvested from Dead people) options also include a variety of different tendons from different muscles: Hamstrings Tendons, Tibialis Anterior Tendon. Patellar Tendon, Quadriceps Tendon, Achilles Tendon, and the Tensor Fascia Lata. It also has inherent risk of disease transmission like hepatitis and HIV as Ill as prolonged healing time of ACL.
How does the new ACL heal after my surgery?
Typically the graft heals to the bone through bleeding created by drilling the tunnels.The type of fixation material also helps newly reconstructed ACL to heal in the tunnels. It generally takes approximately 3 months for it to completely behave like a normal native ACL.
Physical therapy is a crucial part of successful ACL surgery, with exercises beginning immediately after the surgery. Much of the success of ACL reconstructive surgery depends on the patient’s dedication to rigorous physical therapy. With new surgical techniques and stronger graft fixation, current physical therapy uses an accelerated course of rehabilitation .
In the first 10 to 14 days after surgery, the wound is kept clean and dry, and early emphasis is placed on regaining the ability to fully straighten the knee and restore quadriceps control. The knee is iced regularly to reduce swelling and pain. We use a postoperative brace Weight bearing status (use of crutches to keep some or all of the patient’s weight off of the surgical leg) is also determined by physician preference, as well as other injuries addressed at the time of surgery.
After anatomic ACL reconstruction, rehabilitation guidelines are usually as follows:
0-14 days use crutch to walk and discontinue by end of 2 weeks
14-30 days No long brace during day, start knee bending and walking with stick outdoors. Attend partly table work
1m- 2m stair climbing, walking outdoors, attending table work, more knee bending, almost 75% recovery of movements, driving 4 wheeler by 6 weeks.
2m-3m walking normally, climbing stairs normally, almost full knee bending
3m-4m jogging and straight line running, start cross leg sitting and if advised start squatting
6months sport specific training with hinge knee cap
9m- 12m gradual return to sports after function training is over
12months returns to sports initially with functional brace
In general, these guidelines should be followed after ACL reconstruction. However, it is very important to realize that these guidelines may change depending on each patient. Your doctors may tailor a specific, individualized rehabilitation program depending on the number of surgeries you have had, accompanying ligament and meniscal injuries, your individual progress, and other factors that may impact the healing of you graft.