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.