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How Important is ‘Prehab’ Before ACL Surgery?

“Everyone has a plan until they get punched in the mouth.” – Mike Tyson

I’ve decided to keep this inspirational boxing quote thing going…at least for now. So, just for a moment, let’s forget that Mike Tyson bit some dude’s ear off in the third round of their heavyweight rematch, and take a look at his message.

I’m a planner. I always have been. And throughout the course of my life, I have been forced to come up with contingency plans over and over and over again. Adaptability is a nice skill to have, as you can’t always control what happens to you. You can, however, always control how you react. We talked a little bit about the psychological side of injury in a previous blog, so you may recall that grieving is totally normal. However, once you’ve come to terms with what an ACL injury means and you’ve digested the situation (or in my case 50 Trader Joe’s dark chocolate peanut butter cups and a bottle of mango wine juice), you have to come up with a “Plan B.”

My last blog talked a little bit about conservative vs. surgical management of an ACL tear. If you’ve decided to go the surgical route, you will need to find a doctor you trust; one who understands your athletic goals and aspirations. Like a good consumer, you will have to explore all of the options and weigh the pros and cons of each graft choice. After deciding which option is best for you, you’ll set a surgery date and start a very long nine to twelve month journey.

I often get asked the question, “How long should I wait before having ACL surgery?” I certainly have my opinion, but first let’s look at the evidence. Some research advocates for a delayed reconstruction due to increased risk of arthrofibrosis (or the formation of excessive scar tissue) when surgery is performed within one week of rupture. Other research supports a “sooner-the-better” approach, as there is increased meniscal and chondral damage associated with delayed repair. You might recall that the odds of cartilage damage increase by 1% for every month that elapses after injury in between surgery. And still other research claims that there is no difference between “early” (<3 weeks) and “delayed” (>6 weeks) ACL reconstruction. So what’s actually the truth?

From an anecdotal standpoint, I had my first primary ACL reconstruction within two weeks of injury and had no complications in terms of arthrofibrosis or impaired range-of-motion. My second and third injuries occurred while I was a UConn athlete (go Huskies!), so I was fortunate enough to get on the operating table within five days of injury. With these surgeries, I noticed minimal quadriceps atrophy (or muscle wasting) and had no complications associated with early reconstruction. My last ACL-R was the most difficult of them all. Due to my life circumstances at the time, I had to delay surgery for approximately 8 weeks. I was working 40+ hours/week and was unable to give my knee the time and attention it deserved. It was my hardest rehabilitation to date, and I am still working towards my prior level of function.

For ACL’s one through three, I also participated in something called “prehabilitation,” or “prehab.” Prehab can be defined as “the process of enhancing functional capacity of the individual to enable him/her to withstand the stressor of inactivity.” Prehab commonly includes range-of-motion exercises, neuromuscular activation and strength training, as well as proprioceptive/balance drills. Unfortunately, there is a paucity, or lack, of literature examining the effect of prehabilitation on outcomes associated with ACL reconstruction. While reviewing the literature, I stumbled across a study by Shaarani et al. (2013) that compared outcome measures between a group of subjects that completed six weeks of prehab versus a control group who did almost nothing prior to surgery. The prehab group performed both strength and balance exercise, with a prescription of 3 sets of 12 repetitions, increasing by 10-15% volume-load each week.

The authors found that patients who underwent the six weeks of prehab actually scored significantly higher on the single-legged hop test (one of the best functional tests for lower extremity strength), as well as on their self-reported assessment using something called the Modified Cincinnati Knee Rating System. These effects were sustained at the 12 week point post-operatively. The mean return to sport timeframe was 34.18 weeks for the prehab group and 42.5 weeks for the control group. Although statistically insignificant (*nerd alert* p=0.055), that’s still a potential 8-week difference when talking about returning to the sport you love. While this study certainly had its limitations, it is one of the few that examines the effects of prehab on ACL reconstruction. That’s got to be worth something, right?

Not only are you statistically more likely to have a favorable outcome, but you will also be afforded the opportunity to establish a relationship with a physical therapist. Building good rapport with someone you can trust is essential during the recovery process and allows you to seamlessly transition into your post-op rehab. While many of your exercises will be awkwardly similar to your early post-op program, you will familiarize yourself with some of the essentials to succeed. You will work on reducing swelling, restoring full knee extension, improving knee flexion, and regaining quadriceps control/preventing muscular atrophy.

Personally, prehab was the last thing I wanted to be doing after blowing out my knee. So much so that I consciously chose not to prehab for my last injury – even with my training as a PT. Let me tell you that stubbornness is an awful, awful thing. It’s okay to feel sad and fed-up. Just remember that your knees are your knees for life. And if you put the work in now, you’ll probably have a better outcome in the long-run. Always control the controllables. Wouldn’t you want to do everything in your power to ensure a successful recovery?




  1. Shelbourne KD, Wilckens JH, Mollabashy A, DeCarlo M. Arthrofibrosis in acute anterior cruciate ligament reconstruction: the effect of timing of reconstruction and rehabilitation. Am J Sports Med. 1991;19(4):332–336.
  2. Wasilewski SA, Covall DJ, Cohen S (1993) Effect of surgical timing on recovery and associated injuries after anterior cruciate ligament reconstruction. Am J Sports Med 21: 338–342.
  3. Granan LP, Bahr R, Lie SA, Engebretsen L. Timing of anterior cruciate ligament reconstructive surgery and risk of cartilage lesions and meniscal tears: a cohort study based on the Norwegian National Knee Ligament Registry. Am J Sports Med 2009;37:955-61.
  4. Smith TO, Davies L, Hing CB (2010) Early versus delayed surgery for anterior cruciate ligament reconstruction: a systematic review and meta-analysis. Knee Surg Sports Traumatol Arthrosc 18:304–311.
  5. Shaarani SR, O’Hare C, Quinn A, Moyna M, Moran R, O’Byrne JM. Effect of Prehabilitation on the Outcome of Anterior Cruciate Ligament Reconstruction. Am J Sports Med. 2013;41(9):2117-2127.