Sports Medicine Research: In the Lab & In the Field: To the MOON (and Back) with ACL Rehabilitation (Sports Med Res)


Wednesday, May 13, 2015

To the MOON (and Back) with ACL Rehabilitation

Anterior Cruciate Ligament Reconstruction Rehabilitation: MOON Guidelines

Wright RW, Haas AK, Anderson J, Calabrese G, Cavanaugh J, Hewett TE, Lorring D, McKeznie C, Preson E, Williams G, and the MOON Group. Sports Health. 2015; 7(3): 239-243.

Take Home Message: Rehabilitation programs that incorporate early motion, limit open kinetic chain exercises prior to 6 weeks post surgery with a transition to normal open kinetic chain exercises, and incorporate neuromuscular training throughout are best practices during anterior cruciate ligament (ACL) reconstruction rehabilitation.

Anterior cruciate ligament (ACL) reconstruction rehabilitation programs are constantly being evaluated to determine best practices.  The Multicenter Orthopaedic Outcomes Network (MOON) group consists of 20 clinicians who are investigating many lower extremity injury outcomes.  At the beginning of their prospective cohort study (2005) they created an evidence-based rehabilitation protocol for patients after an ACL reconstruction. The goal was a program that could be performed in multiple clinical sites without expensive equipment.  The authors of this systematic review aimed to review literature from 2005 to 2011 for new evidence behind current ACL rehabilitation guidelines.  The authors determined favorable outcomes from research studies that promoted early weight bearing and motion, utilized open kinetic chain activities (short arc quads until 6 weeks post-surgery then unrestricted), and incorporated neuromuscular training throughout the rehabilitation program.  The authors noted that for many areas of ACL rehabilitation, there are too few studies or not enough high quality studies to determine best practices in certain areas.  For example, there was not enough evidence to support the use of continuous passive motion, postoperative bracing, home-based rehabilitation, neuromuscular electrical stimulation, or accelerated rehabilitation programs.  However, the authors did note that optimal electrical stimulation patterns are largely unknown.  It is important to note that no deleterious effects were found in the studies that investigated these rehabilitation components; however, there were also no determined benefits.

The MOON group reinforces ACL rehabilitation program guidelines that encourage early motion, open kinetic chain post-6 weeks, and neuromuscular training throughout the rehabilitation program.  The authors noted that there are many components of ACL rehabilitation programs that are not standardized (e.g., electrical stimulation parameters, exercise dosing); hence, further investigation is needed in these areas to establish best practices.  It is also interesting to see that accelerated rehabilitation programs have not proven to be superior to traditional programs.  Oftentimes athletes and clinicians get focused on how quickly we can “get them back out there.”  The ACL reconstruction and rehabilitation process has evolved so quickly and it may be that we have achieved optimal outcomes in the 5 to 6 month return to activities.  It would be interesting if the MOON group would continue to follow these cohorts out to various time points longitudinally to get an idea of long-term outcomes in addition to the immediate outcomes.  The MOON group may be able to identify important factors that leave patients susceptible to poorer long-term outcomes.  These findings may aid in the identification of potential therapeutic intervention windows in at-risk populations.  Ultimately, we should continue to implement rehabilitation programs early, include neuromuscular training throughout, and transition from limited to unrestricted open kinetic chain activities after 6 weeks. 
Questions for Discussion:  Are there other rehabilitation components that you think should be considered best practices post ACL reconstruction?

Written by: Nicole Cattano
Reviewed by: Jeffrey Driban

Related Posts:

Wright, R., Haas, A., Anderson, J., Calabrese, G., Cavanaugh, J., Hewett, T., Lorring, D., McKenzie, C., Preston, E., Williams, G., , ., Amendola, A., Andrish, J., Brophy, R., Cox, C., Dunn, W., Flanigan, D., Hettrich, C., Huston, L., Jones, M., Kaeding, C., Lattermann, C., Magnussen, R., Marx, R., Matava, M., McCarty, E., Parker, R., Reinke, E., Smith, M., Spindler, K., Vidal, A., Wolcott, M., & Wolf, B. (2014). Anterior Cruciate Ligament Reconstruction Rehabilitation: MOON Guidelines Sports Health: A Multidisciplinary Approach, 7 (3), 239-243 DOI: 10.1177/1941738113517855


Clint Sanders said...

I just wanted to note that the MOON Group's project information on their website ( notes that they are planning to follow the study cohort at 2, 6, and 10 year post operative intervals. Knowing several of the physicians involved in this study, I'm sure they will provide phenomenal resources for rehabilitation specialists as the data continues to be reported.

Clint Sanders said...

I just wanted to note that the project page for the MOON group notes that they will be following the study cohort at 2, 6, and 10 year intervals. Knowing some of the physicians involved in this study, I am certain that they will provide great resources to rehabilitation specialists of all kinds in the near future as this data continues to be collected.

Nicole Cattano said...

Thanks Clint! I am looking forward to seeing the continued outstanding work from this group.

Stephan Bodkin said...

I agree that the accelerated rehab programs are often pursued, but may not be the most beneficial for the athlete. Information regarding the patient outcomes for the accelerated groups would be interesting to see when comparing injury recurrence, functional questionnaires, and/or progressive cartilage degeneration to the traditional programs. I also agree that early weight bearing and motion of the knee is important, as it may have a limiting effect of muscle inhibition that occurs due to positive feedback. It will be interesting to see what outcomes the MOON group receives in the future!!

Jeffrey Driban said...

Hi Stephan, thanks for the comment! You may be interested in Bruce Beynnon's clinical trial with accelerated rehab for ACL injuries ( The authors found that at two years the groups were similar in terms of "clinical assessment, patient satisfaction, function, proprioception, and isokinetic thigh muscle strength". An earlier pilot study by the group found similar biomarker changes as well ( It will be very helpful to see injury recurrence rates and structural changes down the road. Stay tuned! As more long-term results from the MOON cohort are published we'll have them here.

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