“The Other Cruciate Ligament”

I was, am, and always will be a fast-pitch softball catcher. I love this sport and this position! I was drawn to this sport and position at the age of 11 after growing up watching baseball. My start came when I decided to take a break from soccer to try my hand at the “female version”. Not only did I find that I had a natural talent for this sport, it soon turned out that I had a natural talent for being a catcher which made "the want" easy. When it seemed that many parents were trying to make their daughters pitchers, I wanted to be on the other side of the pitcher.  Sometimes we have the tendency to see the pitcher as the key player on the field. We tend to focus our eye on the one who is throwing the ball. Yet, there is always someone throwing the ball back to the pitcher; that's the catcher. The role a catcher plays is key to the team as well as the pitchers success! A catcher is a leader on the field both in communication but also with directing and guiding flow of the game. A catcher must have strong relationship with her pitcher. She must know when to give her pitcher a break, when to walk out to the mound and check in when it seems things are not going as intended. She must also be able to direct other position players based on the current play. She must be flexible, agile, strong, speedy, and willing to give herself to the dirt!

Back in 1999, I was a 20-year-old and in my second year as a collegiate softball athlete. I played at a school in North Dakota and our team had an away game playing Valley City State University. We were on the field and I was behind the plate. “Crack” of the bat as a ball was sent to right field. I yelled out to my first basemen to shift left. I am watching the runner on second base begin to turn third and head in my direction. I would protect my home plate with my body as I had been trained so I set up with my left foot on the black edge of home plate. I was set to receive the ball that would soon be coming in my direction. As this runner began running in my direction, the first basemen, turns and throws the ball.  Inches from my glove, “Bam” I felt this base runner hit me and very soon after I felt a sharp pain in my left knee. I began to hobble because I could not bend my knee.  It was just too painful however I was able to get back down but my left knee is straight out to my side. Our pitcher pitches the ball and strike three is called. I head back to the dugout. “Heather, you are up first”. I grab my helmet, bat, and gloves. As I set up in the batter’s box, I feel ok. In comes the ball and I step and throw my hands toward the ball resulting in a line drive toward mid right field. As the ball sails to the outfield and proceeds to bounce over the fence, I step from the batter’s box and “snap”! I feel a disarticulating sensation in my left knee and down to the ground I go. I very literally crawled to second base since the ball had bounced over the fence. After arriving at second base, a pinch runner comes in and I am soon taken from the field and assessed by the athletic trainer. He assumed and assessed the worst for a female athlete; an anterior cruciate ligament tear, ACL. I would soon find out, he was wrong. It was the other cruciate ligament. The posterior cruciate ligament, or PCL.

The posterior cruciate ligament! Also called the PCL, this ligament is one of two ligaments that are intra-articular (inside the knee joint) to the knee and therefore play a key role in helping to stabilize the knee. In the case of the PCL, its role is to help prevent a posterior or backwards translation(movement) of the tibia on the femur or to prevent an anterior translation(movement) of the femur on the tibia whereas the anterior cruciate ligament (ACL) plays a role in preventing an anterior translation(movement) of the tibia on the femur or a posterior translation(movement) of the femur on the tibia(1,2).  In my case, I sustained an isolated PCL tear, meaning no other structure was injured.

We tend to hear a lot less about the PCL, especially an isolated PCL tear.  The rates of an isolated PCL tear are rare with an incident rate of about three percent. (3) When the PCL is torn, it typically is during a multi-ligamentous injury that involves the ACL and one or both of the collateral ligaments. The mechanism of injury is due to what is called a dashboard injury, a direct fall onto a bent knee, or when the knee is hyperextended with an axial rotation or varus-valgus force with the foot firmly planted when the knee is flexed. This was very likely what happened to me. My left foot was firmly planted, my knee was in a bent position and I was hit from a left to right direction which likely resulted in a valgus force to my knee. The moment I tried to run from the batter’s box was the finalizing force.

If we choose to look on the bright side of a knee injury, in the case of an isolated PCL tear, it is common to non-surgically manage the knee. That was the case with me. I followed the surgeon and sports medicine doctors’  orders and rehabbed the hell out of my knee. In the case of a multi ligament knee, surgery very likely will be needed to help reestablish stability for the knee.

In rehabilitation of the PCL, it is important to avoid applying excessive stress to the injured structures and therefore it is important in minimizing active hamstring contraction. Just the opposite, it is important to activate the quadriceps to help draw the tibia forward. There may be some therapists or practitioners who avoid, minimize, or simply don’t like resisted leg extension machines or long arc quads however, this was and still is an exercise I perform as a means of  maintaining a strong quadricep. Given the time that has elapsed since the injury, I do much more than just these at this time however I still love doing low load, high repetition leg extensions. It has helped keep my quads strong over the years and since my injury I have not had any issues with my left knee. Exercises in my post PCL rehab plan included: loaded leg extensions, wall ball squats with the tibias vertical, heel raise(seated and standing), low height step ups. Exercises to avoid with a PCL tear may include: hamstring curls, bridges, rear dead lifts, or any exercise that isolates and loads the hamstrings.

Resources/References:

1) Dutton Orthopedics: Examination, Evaluation, and Intervention., 5th Ed.

2) Neumann DA. Kinesiology of the musculoskeletal system: Foundations for Rehabilitation. 3rd Ed.

3) Vaquero-Picado A, Rodríguez-Merchán EC. Isolated posterior cruciate ligament tears: an update of management. EFORT Open Rev. 2017 Apr 27;2(4):89-96. doi: 10.1302/2058-5241.2.160009. PMID: 28507781; PMCID: PMC5420825