ACL reconstruction

ACL TEAR TREATMENT AND RECONSTRUCTION

The treatment options following an ACL tear are individualized for each patient depending on age, activity level, and the presence or absence of injury to other structures within the knee. In general, surgery is recommended for young patients who are active and for those in whom the ACL tear is associated with injury to other structures in the knee. Nonoperative (nonsurgical) treatment may be recommended in older or more sedentary patients.

The main reason to have surgery is to restore stability to the knee so it no longer gives out or slides too far forward, which is often painful. The other reason — perhaps the most important reason — is to protect the articular cartilage in the knee from being damaged. It is also important to protect the medial and lateral menisci in the knee.

The meniscus is a fibrous type of cartilage that sits between the ends of the tibia and femur, and is attached to the lining of the joint. There are two separate meniscal cartilages in the knee, each somewhat C-shaped: one on the inner half of the knee (the medial meniscus), and one on the outer half (the lateral meniscus). [Figure 1] The medial and lateral menisci primarily serve as shock absorbers between the ends of the bones to protect the surface or articular cartilage. With recurrent episodes of giving way, the meniscus can be damaged or torn, causing it to lose its shock-absorbing capability. Without a functioning meniscus, the articular cartilage is exposed to increased pressure and “wears” away, leading to arthritis. Additionally, the articular cartilage may be directly injured or damaged with each episode of giving way.

Nonsurgical Treatment

Nonsurgical treatment consists of physical therapy, activity modification and use of a brace. The goal of physical therapy is to strengthen the muscles around the knee to compensate for the absence of the ACL. Specifically, strengthening the muscles in the back of the thigh (the hamstrings) is helpful. Activity modification can be very successful. Sports that do not involve cutting, such as jogging, cycling or swimming, can often be performed successfully.

In addition to therapy and activity modification, use of a hinged sports brace can be attempted. While bracing may be effective in some patients, in others, instability episodes may continue despite their use.

Surgical Treatment and ACL Reconstruction

Once the ACL tears, it has usually sustained enough damage that attempts to surgically repair it are not successful. Consequently, better results are obtained if the ACL is surgically replaced or reconstructed with another tendon from around the knee. [Figure 2]There are a number of surgical options for reconstructing the ACL. The type of procedure done may vary from patient to patient depending on a specific surgeon’s preference as well as factors unique to an individual patient.

The surgical procedure is most commonly performed using arthroscopic techniques. Using one or two small incisions on the knee, the graft is taken from the patellar tendon or hamstring tendons, and a tunnel is drilled into both the tibia and femur. The graft is threaded across the knee, leaving a piece of bone in each of the tunnels and the patellar tendon in the position of the original ACL, thus reconstructing the ligament. [Figure 2] The graft is then secured in this position, most commonly by “wedging” a screw between the side of the bone and the tunnel. [Figure 3] Alternatively, the graft can be secured by other techniques — staples, sutures, buttons, etc. These fixation devices are usually left in place permanently.

In addition to the ACL reconstruction, additional procedures may be done to other structures within the knee if injury is present. A torn meniscus can be either repaired or trimmed (meniscectomy), and other ligaments can be repaired or reconstructed as well.

Figure 3

Allografts most frequently used today are of the bone-patellar tendon-bone type or from the Achilles tendon at the heel, and come from cadavers that have been screened for infectious diseases, e.g., hepatitis and AIDS. The risk of AIDS from one of these grafts is not known, but it is generally believed to be one out of 1 million. All allografts are carefully screened and tested before they are used in surgery.

How long does rehabilitation take after surgery?

The exact course of therapy may vary somewhat depending on the specific type or reconstruction done, particularly if additional meniscus or ligament surgery was done. Physical therapy is done in a supervised setting in conjunction with a trained therapist. Early in the course of recovery, visits may be two to three times per week, but later, once every week or two is often sufficient. Home exercises are done on days not scheduled for a formal therapy session.

The rehabilitation following ACL reconstruction includes essentially three phases. The first phase of rehabilitation consists of controlling the pain and swelling in the knee, regaining knee motion, and getting early return of muscle strength. The operated leg is typically placed into a brace immediately after surgery.

Initially, weight bearing is allowed with crutches and is progressed to full-weight bearing independent of crutches as swelling, motion and muscle strength allow. Most patients are on crutches for one week, although some may be on crutches longer and some shorter. This phase typically takes six to eight weeks.

The second phase emphasizes recovery of full knee motion and muscle strength. Cycling, running on the treadmill and light jogging are started in this phase. In some patients, a sport brace is obtained to replace the postoperative knee brace. This phase typically lasts from two to four months after surgery.

The final phase consists of graduated return to full activity. Normal muscle strength, coordination and the absence of swelling are required for successful return to activity. A brace may be recommended early in the return to cutting and pivoting sports. This phase occurs at four to eight months after surgery, depending on the particular patient and the nature of his or her activities.

A patient’s rehabilitation is monitored closely by both the therapist and surgeon for evidence of potential problems. Most significantly, patients are cautioned not to attempt a too premature return to full activity, which may cause the knee to be inflamed or reinjured. In every patient, the graft must both heal into place and be incorporated into the knee. Too much stress too soon may increase the risk of graft failure.

What are the potential complications after surgery?

Most patients experience no complications and return to full activity between six and eight months after surgery. However, the most common complications include pain in the front of the knee and loss of knee motion.

Pain in the front of the knee occurs in 10 to 20 percent of patients. Fortunately, it can usually be controlled by modification in the physical therapy protocol. Loss of motion occurs in less than 5 percent of patients and is most common in patients with limited motion before surgery. In some individuals, intermittent pain and swelling occur with activity despite a successful ligament reconstruction. This is often related to the amount of meniscal or cartilage injury that was present and identified at the time of surgery.

In the absence of identifiable causes, a small percentage of patients will end up with a persistent detectable increased amount of motion in their knee (a “loose” graft). This may be related to stretching of the graft over time or due to an additional injury.

Will I be able to return to my previous sporting activities?

Approximately 85 percent of patients return to their previous level of activity without restrictions. In the other 15 percent, full return may be limited by a number of causes: pain, swelling, persistent laxity, change in lifestyle related to age, intentional choice or other unidentifiable causes.

ACL RECONSTRUCTIONS

ACL tears are beginning to get more and more prevalent in today's society.  Many people believe it's in regards to the athletes getting bigger and stronger, younger, and the duration a body must endure physical exhaustion between the start of a career and the end. Then there's the discussion of the shoes, and the courts changing from the old hardwoods to the new, more athletically-inclined sport courts, to the strength of the athletes becoming more sport specific and less functionally based.  For example, a dual-sport athlete who practices both sports year-round still may get winded from walking up a set of stairs, simply because this isn't a part of their routine. This would be considered a functional deficit. 

PREVALENCE

Between winter and spring are when most of our ACL tears come into the clinic, and that usually correlates with those sport-specific seasons. Why not during the fall, you ask?

1.  ACL tears are due to a non-contact injury 70% of the time;

Meaning 70% of the time, the ACL will tear without someone else crashing into the knee joint and causing a rupture due to outside forces.

2.  ACL tears are almost 3x more prevalent in women than in men;

This is due to a number of reasons, including anatomical additives, such as the Q angle (read up on our blog post titled Q Angle), bone structure, hormonal balance, and musculoskeletal relationship that differs between men and women. 

3.  Sport-specific seasons;

Looking at sport seasons in the Kansas City metro area, the fall has football, volleyball, cross country, Men's soccer, etc. which, except volleyball, all fall under the less-at-risk categories.  Football is a contact sport, where ACL tears are just over 2x less likely to occur during a contact sport, and are just over 3x less likely to happen to males - which also decreases the risk for men's soccer.  Distance runners are usually less likely to tear their ACL as compared to sprinters and short distance runners because their stride involves a lesser knee flexion stride, and the majority of the hits the ACL will take is while the knee is extended, or in a nonthreatening position in regards to the ACL. 

Once you get into the winter and spring, where men/women's basketball become the main focus, competitive volleyball takes off, baseball practices start, as does track and field and women's soccer, the risk increases as each of these sports have a higher risk of ACL tears than do those in the fall. 

THE TEAR

Now, ACL tears can either be partial or complete, and the typical orthopedic surgeon is going to perform some type of repair if the tear is >50% (where a complete tear is a 100% tear.) Many physicians will require pre-operational therapy to increase functional strength to help an athlete's chances in recovering successfully. This is dependent upon the athlete, but pre-operational therapy will likely last anywhere from 2-6 weeks. 

SURGERY

Surgical procedures are going to range from 45-180 minutes, depending on the type of reconstruction and the surgeon - and of course - whether or not there are any complications. The surgical risks are minimal, as risks decrease with age and overall health. Since usually these ACL tears are more prevalent with athletes, they are typically younger in age and in excellent health. 

The surgical procedure chosen between the patient and their surgical team is likely to differ based on the surgeon, and the patient's condition. 

For example, we currently have a patient, who is also a close friend of our staff, who is here recovering from his third ACL rupture. This is the second tear on the knee he's currently working on, so the procedure chosen was going to be a different approach than the first. 

TYPES

Allograft v. Autograft

An autograft is going to be harvesting the necessary portion of the tendon and using the host as a donor. In other terms, the hamstring graft will be harvested from the patient the ACL reconstruction is being performed on - or using their own hamstring tendon.  

An allograft is harvesting a portion of the hamstring tendon from a separate, nonliving donor, or a cadaver. 

Allograft repairs have a lesser recovery time, as only the knee joint and ACL have to heal, whereas an autograft would likely be slightly more painful, as well as take longer to heal.  Allografts, however, have had recent research come out that states the likelihood of a second rupture is increased by almost 60% in comparison to an autograft tear. The reason behind this is usually because the body recognizes the new ACL as it's own, and therefore, heals faster. 

Hamstring Graft

There are 4 hamstring muscles on the back side of the thigh. Their primary function is going to be flexion (bending) at the knee, and extension at the hip, and they insert on the knee joint via a tendon, on both sides. A surgeon would take a portion of one of these hamstring tendons, typically the semitendinosus for increased stability and recreate an ACL with that graft.  Doubling over the tendon by folding it in half is proven to increase tensile strength, but does require harvesting a larger portion of the tendon, but is associated with greater range of motion discrepancies, as well as a slower recovery. 

BTB Patellar Graft

A BTB, or Bone-Tendon-Bone, Patellar Graft would be taking a portion of the patellar tendon, as well as portions of the bony attachments. The patellar tendon is the distal half of the quadriceps tendon. The quadriceps, more commonly known as the "quads", are a group of 4 muscles on the front of thigh that extend (straighten) the knee, and assist to flex the hip (i.e. doing high knees). The insert on a common tendon, the quadriceps tendon, and head distally. This tendon envelopes the patella, or the knee cap, a sesamoid bone that is otherwise not attached to the body. Distal to the patella, the quadriceps tendon now becomes the patellar tendon before inserting on the shin bone.  This portion of the quadriceps tendon will be the graft.  Bone-tendon-bone means the surgeon will not only harvest the middle 1/3 of the patellar tendon, but will also harvest small pieces of the patella and shin bone to serve as bony attachments to enhance recovery, as the small pieces of the bone will start to regrow into the bone they're going to be surgically attached to. 

Hamstring v. Patellar Tendon

Both surgical procedures have a 90-95% success rate, meaning the likelihood of a second rupture is only around 5-10%. Done correctly and given no extraneous circumstances, either option is going to be enough to get back to doing what you love.  Hamstring repairs are now done in Kansas City entirely arthroscopically, meaning the incisions are going to be very minimal - and recovery is faster, and less painful because the incisions will heal before the patient is out of the post-surgical brace. Patellar tendon repairs, however, are typically a little stronger, but take longer to recover from. The incision is typically about 4 inches long, which will take weeks to heal properly - potentially even after the post-surgical brace is removed. 

When an athlete decides, it will be up to them to choose a surgeon to will give them the best chance of a successful surgery, whilst limiting them to as little time as possible out of the game. Hamstring tendon repairs typically get patients back to doing what they love a little faster, by maybe a few weeks, but do come with a slightly higher risk, inching closer to that 90% success rate, respectfully, compared to the impressive 95% success rate of the patellar tendon repair. Both will take around 6 months to be cleared from therapy and return to sports, and will take around 12 months for the patient to feel back to 100%.  Surgeons will likely recommend athletes wear an ACL supporting brace, but are worn at the discretion of the athlete.