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The knee is the most common area injured in downhill skiing. This is likely in part due to the ankle biomechanics are changed due to the rigid nature of the ski boot and that the ski allows for more torque to be directed into the knee. One of the more severe injuries that a skier can experience is an anterior cruciate ligament (ACL) tear. Approximately one in twenty World Cup ski racers will experience an ACL injury within a single season. Racers are at a greater risk for injury due to increased speed on the slopes. There are a few ways that skiers tear their ACL’s. The least common is a boot induced anterior drawer, which is when a skier lands off balance to the rear. The second most common way is a backward twisting fall. The most common way is a forward twisting fall. If you or a friend just tore an ACL skiing, there are a ton of questions that will flood your mind. In this blog post, I’ll lay out these questions in a timeline.
Questions we will cover:
Do I need surgery?
I’ve decided on surgery. What things do I need to take into consideration?
What does rehab look like?
What else should I be thinking about?
Do I need surgery?
The answer to that question depends. Some people can do fine and return to their prior level of sport without having ACL reconstruction and some people need to have surgery. In the United States, almost everyone opts for surgery, but that doesn’t mean that it is always the right option. In the scientific literature, they describe two different groups, copers (no surgery) and non-copers (surgery needed). Nearly everyone has difficulty right after the injury for a short period. It is common to have swelling, reduced range of motion, and weakness. Surgeons typically won’t operate right after injury because they want the individual to have minimal swelling, near full range of motion, and decent quadriceps control because these factors help with a better surgical outcome. During this time, some people who fall into the coper group start doing pretty well. They have more normal movement patterns, their knee doesn’t give away, and better quadriceps control.
When people realize that there is the possibility that they may fall into the coper group, the next thing they often wonder is if I choose a non-surgical route will I get to the same level if I had chosen surgery. The research shows that the general population copers and choose a non-surgical option have better knee function at 3, 6, and 12 months than those that undergo surgery.
Sometimes it can be difficult to figure out if you are coping well without surgery. What happens if I choose to delay surgery? The research shows that the general population all end up with about the same knee function after two years whether they choose a non-surgical route, surgery, or delayed surgery. One drawback to note with delayed surgery is that if you aren’t strength training, then it may be more difficult to muscle mass and strength later on because of deconditioning.
If skiing is your primary sport, then it may be worthwhile to think about what the big picture looks like when determining which option you might pursue. Let’s look at two contrasting examples. Scenario one, let’s say that it is early June and you were skiing corn on the Washington volcanoes when you tore your ACL. In this scenario likely surgery wouldn’t happen until early to middle July, which would mean that full return to skiing wouldn’t likely happen until middle March to early April the following year. With missing the majority of next winter it may be easier to almost forfeit next season and see how a more conservative approach would be. Scenario two, Washington winter started a little early in late October and you ended up tearing your ACL in middle November. Likely surgery would happen just before or after the December holiday season. This would result in you being able to have a full recovery before next winter even starts. In this scenario, if you aren’t falling into the coper category quickly then it may make more sense to choose the surgical option more quickly. These are just two examples and you need to weigh all the options for yourself.
I’ve decided on surgery. What things do I need to take into consideration?
If you decide that surgery is the best option for you, one of the next considerations is graft choice. During ACL reconstruction surgeons essentially use some other tissue to “replace” the ACL and mimic its function for knee stability. Surgeons can choose between four different options. What graft you and your surgeon decide to use choose is a matter of preference and what will provide the best outcome.
Grafts can initially be classified as allograft or autografts. Allografts are harvested from a cadaver. Allografts are typically more likely to be used when someone is not that active as they have a higher rate of re-tearing. Due to this not usually being the optimal choice for active individuals I’m not going to discuss it in the rest of this article. Autografts are when the surgeon uses the person’s tissues for the replacement of the ACL. The three options for autographs are patellar tendon, quadriceps tendon, and hamstring tendon. Each of these has pro’s and con’s
Patellar tendon: This is graft is harvested by taking part of the tendon and small chunks of the bone from your patellar tendon (this is the spot that a physician would tap when they are checking your reflexes). It is ever so slightly stronger than the hamstring tendon graft and has slightly lower re-rupture rates. One of the drawbacks is that quadriceps function can be affected for some time after. Also, it is more likely that someone will have anterior (front) knee pain, especially when kneeling.
Quadriceps tendon: Very similar to the patellar tendon graft except that it is taken from above the knee cap and does not require any bone to be removed. Some of the physical properties of the graft may be closer to that of the ACL, so it may better match its function. There may still be some quadriceps deficits associated with this option, but kneeling is less likely to cause an issue.
Hamstring tendon: For this graft, they harvest the semitendinosus (a muscle of one of the hamstring group) tendon. An advantage of this option is that quadriceps strength is not as likely to be affected and will likely improve ability especially in the earlier stages of rehab. One of the disadvantages is that it can take up to two years to regain full strength of the hamstring, even though the vast majority is returned by the end of the year.
When deciding on graft type you need to consider what are your primary outdoor activities. Activities like skiing, hiking, and mountaineering all require really good quadriceps function and place less demand on the hamstrings. On the other hand, if you primarily rock climb, especially in styles that require heel hooks or more overhanging, you place a higher demand on hamstrings and less on your quadriceps. Make sure to discuss primary activities and what you want to return to with your surgeon.
One of the big unknowns about surgery for people is often about when will things return to “normal” life for them. I will dive deeper into timelines later, but some reference points can be helpful. Usually, people get clearance from their surgeon to start running in 12-16 weeks and return to sport full sports sometime around 9 months after surgery.
Something that you should be aware of is how a graft's strength changes over time. It would be really easy to assume that the graft gets stronger as time passes, but this is not the case. The graft weakens after surgery until about the three-month mark and continues to get stronger from that point on. Even though the graft is weakest at three months, your ability to tolerate activity will be better due to improved muscle function.
What does rehab look like?
Before we discuss what rehab looks like, I think it will be beneficial to understand the importance of return to sport testing and what tests might be performed. Utilizing a good battery of return to sport testing is crucial because it can help us to ensure that the risk of re-injuring the ACL is lower. If someone returns to sport before meeting proposed guidelines have a four times more likely risk of subsequent ACL rupture. Return to sport testing is comprised of hop testing (with single-limb hop testing being the most predictive), sometimes sport-specific measures like the Vail Sport test for skiing, and psychological questionnaires. These all have specific cutoff criteria associated with them, for example, a passing score on the hop test requires that you score at least 90% of the uninvolved limb.
ACL rehab has changed over the years and it is now considered best practice to use criterion-based phases. Researchers don’t ever quite have the same phases, yet they are all relatively similar. I like to think of ACL rehabilitation in the following three phases; functional, work capacity, and return to sport. Even though we exclusively go by timelines, I’m including them to help give estimates for better understanding. I’m not going to list any specific exercises as individual therapists may have different exercise selection preferences and will tailor your program to you.
Functional: (after surgery - ~8-10 weeks)
Goals – minimize swelling, improve range of motion, improve quadriceps control, return to normal walking pattern
Description – During this phase, we are all about getting your knee to function well for every day, non-sporting movements. Achieving near full ROM and good quadriceps control is key. Something to note is that icing can be incredibly helpful for pain, but contrary to popular belief, it does not help with swelling. I would much rather someone use ice for pain management than anti-inflammatories or narcotics.
Criterion to pass to next phase – 0 degrees of knee extension (or within 2 degrees of hyperextension from the uninvolved leg), 90% of knee flexion,
Work Capacity: (~8-10 weeks – ~6-7 months)
Goals – Be able to start with a graded return to sport, improve strength, improve endurance, have full range of motion
Description – This phase is trying to build a big base of general physical preparedness, which will then transfer to sport-specific tasks. There is a significant focus on building strength as this is the basis for the expression of power (single-limb hop test). Biomechanics will be corrected. It is important to continue to train the uninvolved limb hard (discussed later), so often there are single limb exercises included. Typically, individuals are allowed to start jogging around the 3-4 month timeframe.
Criterion to pass to next phase – Single limb hop test of greater than 80%, psychologically ready to return to sport
Return to Sport: (~6-7 months – full return to sport)
Goals – Return to sport
Description – This will have more explosive training and sport-specific tasks incorporated into rehab. High-intensity low repetition strength will still be included. As you near the end of this phase a graded return to slopes can be taken. A great example of this was outlined by Kokmeyer in the Journal of Orthopedic Sports Physical Therapy for ski racers.
Criterion to pass phase– Single limb hop test greater than 90% and full completion of the graded return to activity
When determine who you want to partner with your rehab professional, you should essentially interview the. Ask them about how long they usually work with patients, how often they see the patients, if they know the demands of skiers or outdoor athletes, how they determine if an individual is ready to return to sport. You need to be your own best advocate. Choose the person that can help you the most and serve you the best.
Other things to think consider
I want to make a point of it that during, and especially early on, it is important to be training the non-involved side as heavy as you can. This is important for a couple of reasons. First, it helps prevent de-training. Losing strength can have an impact on the future ability and also can make return to sport testing more challenging to interpret if you are ready to return. For example, if you were able to single-leg hop 48 inches on your uninvolved leg at the time of injury, but then you experience detraining and at six months after surgery, your ability is now only 42 inches, then how you interpret what is 90% for the involved leg changes dramatically. The second reason to keep training the uninvolved leg is that through some funky neurobiology, you can retain more strength on the injured leg even if you aren’t training it.
Blood flow restriction (BFR) training can be an important addition to your recovery process. This can be especially true during the early stages of rehab. On average an individual will lose about a fist size amount of muscle out of their thigh after ACL reconstruction. This atrophy happens quickly after surgery but slowly returns with training. If someone is using BFR they can nearly completely avoid any muscle loss, which will help the recovery process. Ask your provider if they know about BFR and best practices for post-surgical cases.
Finally, think about the big picture. Figure out if skiing is a possibility next season or what type of skiing you will be doing. Think about ways to improve your abilities, use your return to the slopes progression to dial in a technique that you have been neglecting. If you are a backcountry skier, now is the perfect time to research a progression of tours, both old and new. You could improve your ability to understand avalanche science or take time learning to use programs like Google maps to better understand how to design your tours and lay down skin tracks.
As always, thank you for reading! I appreciate you taking the time to get this far. If know someone that would benefit from reading this post, please share. To subscribe to blogs that are directed at outdoor athletes fill out the form below. If you have any questions you can email me at dan@arrowptseattle.com or if you are interested in scheduling an appointment click here. If you are in the Seattle area and looking for a surgeon, please email me. There is a surgeon that I have never met personally, but have worked with a few of his patients and they all seem to do exceptionally well. If I ever needed knee surgery, this is the provider that I would seek out personally.