BMX TODAY
October 2006



This month's column focuses on another common injury in the BMX sport, anterior cruciate ligament (ACL) injuries. The ACL of the knee endures a tremendous amount of strain in this sport, particularly when an athlete loses control of the bike. An advanced state of aerobic fitness and balanced strength training can go a long way in helping the BMX athlete avoid knee injuries, because injury often occurs when one muscle group is better conditioned that its opposing muscles-such as the quadriceps and the hamstrings.

Despite the best training and conditioning, though, sometimes a serious injury can occur. One of the most common knee injuries I see in athletes of action sports is an ACL tear.

An ACL tear in an athlete must be handled differently than an ACL tear in the non-athlete because following recovery the limb is going to be subjected to the same stresses that resulted in the injury. It isn't a one-time incident unlikely to be repeated.

The first phase of ACL recovery starts immediately after the injury. The athlete may need crutches for a time, and he/she needs to stay off it, keeping it elevated and iced for a couple of days. An X-ray is necessary to be sure that a fracture has not occurred.

After a few days, a program of rehabilitation, we call reconditioning, must occur. This is a program comprised of stationary biking, at least one hour per day everyday, in which the athlete gets his/her heart rate up to the target heart rate for their age. It continues with exercises developed to regain a normal gait, normal range of motion of the knee, and restored strength in the quads and hamstrings. All of this is designed to get the athlete and the leg as strong as possible before surgery.

The next phase involves reconstruction of the ACL, necessary for someone who plans to return to BMX. At Sanders Clinic, we believe that the best way to repair an athlete’s ACL is with an autograft (live tissue) as opposed to an allograft, which is a dead person’s tissue that is frozen, thawed and required to come back to life (revascularize). Compared to the dead person’s tissue, the living tissue of the autograft is stronger. Furthermore, living tissue from the patient's own body has a far greater chance of adjusting to the relocation and being accepted in the new environment than that which is foreign. The chance of disease transmission from one’s own tissue is nil.

Since the dead graft must be revascularized, or brought back to life, and then repopulated with live cells, it takes approximately a year away from sports. And even after a year, it may never strengthen enough to resume the activity that initially prompted the injury. That's why there are articles in the American Journal of Sports Medicine that advocate its use in "non high risk athletes and sedentary people over the age of 40." The quintessential opposite of that description stated in the journal is a BMX rider

For this reason, we only use an athlete's own tissue when we perform ACL reconstructions. We believe that the best place to harvest this graft is from the patella tendon from the opposite, healthy leg. It is live tissue. It is strong. It does not further compromise the already injured and vulnerable ACL deficient knee. There are other reasons for this approach, as well. These reasons include a reduction in postoperative pain and an ability to walk normally without crutches from the first day. And taking this tissue from the patients opposite, healthy leg distributes the stress of the surgery and facilitates a more rapid recovery, typically allowing the athlete to return to competition in three months.

Following surgery, the next phase is rehabilitation. During this time, an athlete rehabs both knees at the same time. In the first few days, athletes are encouraged to take it easy, trying to stay in bed or in the house while exercises are preformed at home. On the fourth day, the stationary bike is reintroduced and used one hour per day. Gait training isn't really necessary at this point, as athletes were never put on crutches and are therefore able to take full weight on their knee from just a few days after the initial injury.

Sport specific exercises are introduced after about six weeks, and athletes may return to competition by three months. We have found that improvements continue over the remainder of the first year. We have had several professional BMXers go back to winning competitions by six months after surgery.

"Dr. Sanders definitely offers an aggressive and extensive approach to the recovery of a surgically repaired knee. He recommended that I undergo a patella tendon graft from my opposite (healthy) knee to correct my damaged knee because he believes this procedure corrects damage in a more natural way and is more durable than donor or artificial remedies. To my surprise, I walked the very next day after surgery-including walking up stairs! The rehab program included many range of motions recovery exercises immediately following surgery. I was on a stationary bike 4 days after surgery and followed his extensive rehab specific to my recovery. Within six months, I was back to winning events and continue on a winning path today."
Jason Carnes, National & World Champion BMX Racer

Send any questions to bmxtoday@nbl.org and get advice from the Jackal's personal orthopedic surgeon, one of the country's best.