April 2015

The psychology of returning to sports after ACL surgery

4ACL-iStock9654197-copyBy Trevor A. Lentz, PT, SCS, CSCS

Psychological factors are responsible for delayed return to sports after anterior cruciate ligament reconstruction in a sig­nificant number of patients despite successful physical rehabilitation, but questions remain as to the most effective ways to address these issues.

Anterior cruciate ligament (ACL) rupture is a common sports-related injury, with multiple physical, psychological, economic, and social consequences. Those who suffer an ACL tear often choose to undergo surgical reconstruction, as this is thought to provide the best chance of returning to unrestricted sports participation.1,2 Indeed, the development of arthroscopic reconstruction techniques and the subsequent emergence of accelerated rehabilitation protocols have made return to preinjury levels of sports participation a very realistic possibility for most patients.3-5 But how effective are we as sports medicine professionals at returning patients to preinjury levels of sports participation and performance?

Recent studies have clarified the current state of return to sport following ACL reconstruction, and the results are discouraging. In a large meta-analysis, Ardern et al6 found that, while 81% of people returned to some level of sport after surgery, only 65% returned to their preinjury level of sport and 55% returned to competitive sports after surgery. Many studies have identified potentially modifiable factors as a primary barrier to return-to-sports participation. These potentially modifiable factors often include psychological factors.7-10 In fact, psychological factors are often the most prevalent reason for not returning to sports, with numerous studies reporting that roughly half of those who do not return to sports, or approximately 20% of all patients undergoing ACL reconstruction, cite psychological factors as a primary reason.7,8,10-12

Our ability to consistently provide patients with a strong, stable knee has outpaced our ability to consistently provide them with psychological readiness for sports

Psychological factors as a barrier

The prevalence of psychological factors inhibiting return to sport is not surprising. Across other anatomical regions and diagnoses, psychological factors are regarded as some of the strongest and most consistent predictors of pain and disability, often more so than commonly assessed physical factors.13-16 More surprising, however, is that most established ACL rehabilitation guidelines and return-to-sport criteria fail to include specific assessment or intervention recommendations for psychological factors,17-20 and these factors are not often recognized by clinicians as barriers to sports participation.21

The relatively high prevalence of psychological factors as a barrier to sports participation may be due to many reasons. First, accelerated rehabilitation programs that place a heavy emphasis on early range of motion, weightbearing, quadriceps strengthening, and neuromuscular retraining have reduced the risk of developing physical limitations that impede sports participation. Patients are typically allowed to begin sport-specific training three to four months after reconstruction, and get clearance for return to unrestricted sports participation around six to nine months postsurgery.20 However, as a result of these impairment-focused accelerated rehabilitation programs, our ability to consistently provide patients with a strong, stable knee has outpaced our ability to consistently provide them with psychological readiness, thus leading to a relatively higher prevalence of psychological barriers.

Another reason for the relatively high prevalence of psychological barriers is that surgical success has historically been defined by objective outcomes (eg, knee ligament laxity, graft integrity, knee range of motion, knee strength), with less attention on the ability to return to sports. Presumably, this focus has been the result of inherent difficulties in quantifying return to sports, or the assumption that resolution of objective knee impairments necessarily facilitates a return to unrestricted sports participation. However, multiple studies have now shown that resolution of knee impairments is a poor proxy for return-to-sport status.10,22 For instance, Ardern et al found that, while 90% of people undergoing ACL reconstruction achieved normal or nearly normal knee function postoperatively (mean, 41.5 months) using impairment-based outcomes, only 63% had returned to their preinjury level of participation, and 44% had returned to competitive sports.10

The extent to which variance in return-to-sports outcomes is not explained by physical factors commonly addressed in rehabilitation provides a compelling argument for reevaluating whether our current rehabilitation approaches and return-to-sports criteria that focus on objective outcomes should also include consideration of psychological factors.

Psychological contributors

The concept of psychological factors as barriers to return to sports is not new.23,24 In the mid-1980s, researchers applied grief and loss and cognitive appraisal models to sports-related injury to describe psychological adjustments and emotional responses throughout recovery.23 In the mid-to-late 1990s, specific considerations emerged for psychological responses to ACL injury and reconstruction.23 Since then, our understanding of psychological factors as they contribute to poor sports performance and the ability to return to sports following injury has grown considerably.25

Fear-avoidance beliefs. “Fear-avoidance beliefs” is a broad term referring to the avoidance of activities based on fear.26 In patients who have undergone ACL reconstruction, the most common fear-avoidance beliefs are those regarding fear of movement (kinesiophobia) and fear of pain. The fear avoidance model has been proposed to describe the development of fear of pain, anxiety, and disability as the result of a painful experience or injury.27 A full description is beyond the scope of this article; interested readers are referred to reviews by Vlaeyen and Linton and Leeuw et al.27,28

While the fear-avoidance beliefs model was initially developed to describe the transition from acute to chronic pain in patients with low back pain, the inherently painful and destabilizing nature of an ACL injury lends itself to the theoretical application of this model in patients who have undergone ACL reconstruction, and recent studies provide empirical and statistical evidence to support the validity of the fear avoidance model in this population.29,30

Empirical support for the fear avoidance model is found in numerous studies reporting on self-described reasons for not returning to sports. Many of these have found that fear of reinjury is the most common reason for not returning to sports, more common than knee instability or pain.2,7,8,10 Other studies have identified fear avoidance beliefs as a significant contributor to knee function in multivariate analysis. Ross et al31 showed that fear avoidance beliefs related to physical activity contributed significantly to knee function and sports-related activity after ACL reconstruction, even after accounting for injury-related variables and physical impairment measures.

A similar study by our research group found that kinesiophobia was a significant contributor to self-reported function in a multivariate analysis, after accounting for common physical impairment and demographic variables in patients who had been cleared for return to sports at six months and one year post-ACL reconstruction.32 In a cross-sectional study of patients within the first year of ACL reconstruction, Chmielewski et al found higher levels of kinesiophobia in the first three months after surgery than after six months; however, kinesiophobia after six months was significantly associated with knee function.33 This study included patients in both the early postoperative and late return-to-sports stages of rehabilitation and did not distinguish between patients who had and had not been cleared to return to sports in the late stage. Collectively, these findings suggest that fear-avoidance beliefs contribute to functional limitations following ACL reconstruction and should be considered a target for rehabilitation after surgery.

Pain catastrophizing. Knee pain typically decreases over time following ACL reconstruction, and is generally low in the late postsurgical stages of rehabilitation.9,33 However, despite relatively low levels of pain following surgery, the presence of pain is a common impairment-related barrier to sports participation and a significant predictor of function throughout rehabilitation.9,11,33 In addition to fear of pain, pain catastrophizing may be one mechanism by which even low levels of pain can contribute to significant functional limitations following ACL reconstruction.

Pain catastrophizing is an exaggerated response to actual or anticipated pain.34 Catastrophizing behavior as it relates to pain is one of the central mechanisms driving avoidance behavior in the fear-avoidance model and may be a significant factor for people following ACL reconstruction who have pain or anticipate pain as the result of a functional activity. Clinical studies have identified pain catastrophizing as a significant predictor of pain intensity in the early postsurgical phases of rehabilitation; however, its influence on function in later stages of rehabilitation, including return to sports, is not as clear.30,35 Pilot data suggest early postoperative and one-year differences in pain catastrophizing between patients who return to sports after ACL reconstruction and those who do not due to fear of reinjury, but those data require confirmation in larger studies.36

4ACL-iStock6360635-copyPsychological resilience. While most studies have focused on negative factors that confer psychological vulnerability to injury or pain, less attention has been paid to positive factors that enable patients to adaptively cope with their injury or pain. Positive psychological resources, such as self-efficacy or optimism, may have a significant influence on return to sports after ACL reconstruction and should be considered an important adaptive psychological factor. Chmielewski et al,30 for example, found that early improvements in self-efficacy following surgery were associated with greater reductions in pain and function, while other studies have linked preoperative resilience factors—such as psychological readiness to return to sports (measured with the ACL-Return to Sport after Injury [ACL-RSI] scale, internal locus of control, and positive expectations—with significantly higher odds of returning to sports.37

In a systematic review of psychological predictors of ACL outcomes, Everhart et al38 found that early measures of self-efficacy, self-motivation, and optimism were predictive of return to sports and knee function. Resilience factors are independent of negative psychological factors, such as fear avoidance and catastrophizing, and therefore should be assessed and addressed independently in the clinical encounter.

Identifying patients at risk

Recovery of function and sports performance following ACL reconstruction is a multidimensional, complex process. For some patients, psychological factors may represent a significant barrier to regaining knee function or sports performance. Others will not have any significant psychological barriers. One of the most important limitations in our current knowledge is how to prospectively identify patients who are at risk for poor return-to-sports outcomes due to psychological factors.

Unfortunately, no threshold values have been firmly established for psychological questionnaires when determining risk for failure to return to sports after ACL reconstruction. Some studies, however, have reported questionnaire means for groups of patients who do not return to sport, and these provide some direction for identifying patients with elevated fear of reinjury.

Our research group found that patients who were unable to return to sports had mean scores of 20 points on the Tampa Scale for Kinesiophobia (TSK-11), while their counterparts who were able to return to sports reported mean scores of 15 points.8 Those who were unable to return to sports due to fear of reinjury, specifically, scored slightly higher, with a mean of 21.5 points.9 A small pilot study examining TSK-11 cut-off scores found that decreased odds of returning to sports after ACL reconstruction were associated with TSK-11 scores greater than 19 points; this threshold, however, should be confirmed in larger studies.39 In addition to the TSK-11,40 other questionnaires that may be used to assess psychological factors include the Pain Catastrophizing Scale (PCS),34 Knee Self-Efficacy Scale (K-SES),41 and ACL-RSI scale.42 Based on available evidence, psychological factors should be evaluated early on in rehabilitation, tracked throughout the rehabilitation process, and assessed as a criterion for return to sports.

4ACL-iStock46911580-copyThere is limited information specific to ACL injury populations that can be used to drive evidence-based recommendations for psychological treatment approaches. However, extensive research on treatment of patients with low back pain may provide some guidance. In low back pain populations, psychologically informed practice has been presented as a secondary prevention approach for the development of chronic pain and disability. Briefly, this approach incorporates screening for psychological factors and implementation of cognitive behavioral approaches into activity-based interventions. Interested readers may refer to a review by Nicholas and George for more information on this approach.43

Psychologically informed prac­tice has shown promise for improving function in patients with low back pain who display clear signs of fear of pain or reinjury,44 and may be beneficial for patients demonstrating similar issues following ACL reconstruc­- ­tion. However, this approach has not been examined in the published literature involving clinical trials of ACL reconstruction. Unfortunately, researchers and clinicians have a limited understanding of when negative psychological factors emerge and how they change over time. It stands to reason, however, that psychologically informed practice approaches may be most beneficial if started early in rehabilitation and continued through return-to-sports stages for patients with high levels of fear-avoidance beliefs, high levels of catastrophizing, or low psychological resilience.

Perhaps the most important aspect of evaluating and managing psychological factors following ACL reconstruction is for clinicians simply to talk with patients about this potential barrier. For some patients, early education on the healing process and risk factors for reinjury may help relieve fears that develop shortly after surgery. Discussing pain mechanisms and the expectation that recovery can take many months may help to reduce the early catastrophizing that often accompanies the experience of pain.

Often, the best way to assess specific psychological barriers is to ask. Most patients will discuss activities or movements that elicit fear, and graded exposure to these movements may be a good way to reduce those fears and improve self-efficacy. For other patients, return to sports may not be a priority. In fact, a sizeable percentage of patients do not return to sports after ACL reconstruction due to a change in lifestyle or a change in priorities.2,7,8 Ultimately, establishing realistic goals and expectations, as well as maintaining open communication between patient and clinician, can go a long way toward assessing and managing psychological barriers in rehabilitation.

Trevor Lentz, PT, SCS, CSCS, is a physical therapist specializing in sports and postoperative rehabilitation at the University of Florida Health Orthopaedics and Sports Medicine Institute in Gainesville. His research focuses on the psychosocial influences of treatment effectiveness in patients with musculoskeletal pain.

  1. Swirtun LR, Eriksson K, Renström P. Who chooses anterior cruciate ligament reconstruction and why? A 2-year prospective study. Scand J Med Sci Sports 2006;16(6):441-446.
  2. Heijne A, Axelsson K, Werner S, Biguet G. Rehabilitation and recovery after anterior cruciate ligament reconstruction: patients’ experiences. Scand J Med Sci Sports 2008;18(3):325-335.
  3. Shelbourne KD, Nitz P. Accelerated rehabilitation after anterior cruciate ligament reconstruction. J Orthop Sports Phys Ther 1992;15(6):256-264.
  4. De Carlo MS, McDivitt R. Rehabilitation of patients following autogenic bone-patellar tendon-bone ACL reconstruction: A 20-year perspective. North Am J Sports Phys Ther 2006;1(3):108-123.
  5. Malone TR, Garrett WE. Commentary and historical perspective of anterior cruciate ligament rehabilitation. J Orthop Sports Phys Ther 1992;15(6):265-269.
  6. Ardern CL, Taylor NF, Feller JA, Webster KE. Fifty-five percent return to competitive sport following anterior cruciate ligament reconstruction surgery: an updated systematic review and meta-analysis including aspects of physical functioning and contextual factors. Br J Sports Med 2014;48(21):1543-1552.
  7. Lee DYH, Karim SA, Chang HC. Return to sports after anterior cruciate ligament reconstruction – a review of patients with minimum 5-year follow-up. Ann Acad Med Singapore 2008;37(4):273-278.
  8. Lentz TA, Zeppieri G Jr, Tillman SM, et al. Return to preinjury sports participation following anterior cruciate ligament reconstruction: contributions of demographic, knee impairment, and self-report measures. J Orthop Sports Phys Ther 2012;42(11):893-901.
  9. Lentz TA, Zeppieri G, George SZ, et al. Comparison of physical impairment, functional, and psychosocial measures based on fear of reinjury/lack of confidence and return-to-sport status after ACL reconstruction. Am J Sports Med 2015;43(2):345-353.
  10. Ardern CL, Webster KE, Taylor NF, Feller JA. Return to sport following anterior cruciate ligament reconstruction surgery: a systematic review and meta-analysis of the state of play. Br J Sports Med 2011;45(7):596-606.
  11. Flanigan DC, Everhart JS, Pedroza A, et al. Fear of reinjury (kinesiophobia) and persistent knee symptoms are common factors for lack of return to sport after anterior cruciate ligament reconstruction. Arthroscopy 2013;29(8):1322-1329.
  12. Tjong VK, Murnaghan ML, Nyhof-Young JM, Ogilvie-Harris DJ. A qualitative investigation of the decision to return to sport after anterior cruciate ligament reconstruction: to play or not to play. Am J Sports Med 2014;42(2):336-342.
  13. Flor H, Turk DC. Chronic back pain and rheumatoid arthritis: predicting pain and disability from cognitive variables. J Behav Med 1988;11(3):251-265.
  14. Jensen MP, Turner JA, Romano JM. Correlates of improvement in multidisciplinary treatment of chronic pain. J Consult Clin Psychol 1994;62(1):172-179.
  15. Piva SR, Fitzgerald GK, Wisniewski S, Delitto A. Predictors of pain and function outcome after rehabilitation in patients with patellofemoral pain syndrome. J Rehabil Med 2009;41(8):604-612.
  16. Piva SR, Fitzgerald GK, Irrgang JJ, et al. Associates of physical function and pain in patients with patellofemoral pain syndrome. Arch Phys Med Rehabil 2009;90(2):285-295.
  17. Smith MA, Smith WT, Kosko P. Anterior cruciate ligament tears: reconstruction and rehabilitation. Orthop Nurs 2014;33(1):14-24.
  18. Della Villa S, Boldrini L, Ricci M, et al. Clinical outcomes and return-to-sports participation of 50 soccer players after anterior cruciate ligament reconstruction through a sport-specific rehabilitation protocol. Sports Health 2012;4(1):17-24.
  19. Waters E. Suggestions from the field for return to sports participation following anterior cruciate ligament reconstruction: basketball. J Orthop Sports Phys Ther 2012;42(4):326-336.
  20. Adams D, Logerstedt DS, Hunter-Giordano A, et al. Current concepts for anterior cruciate ligament reconstruction: a criterion-based rehabilitation progression. J Orthop Sports Phys Ther 2012;42(7):601-614.
  21. McVeigh F, Pack SM. An exploration of sports rehabilitators and athletic rehabilitation therapists’ views on fear of re-injury following anterior cruciate ligament reconstruction. J Sport Rehabil 2015 Jan 5. [Epub ahead of print]
  22. Thomeé R, Kaplan Y, Kvist J, et al. Muscle strength and hop performance criteria prior to return to sports after ACL reconstruction. Knee Surg Sports Traumatol Arthrosc 2011;19(11):1798-1805.
  23. Doyle J, Gleeson NP, Rees D. Psychobiology and the athlete with anterior cruciate ligament (ACL) injury. Sports Med 1998;26(6):379-393.
  24. Morrey MA, Stuart MJ, Smith AM, Wiese-Bjornstal DM. A longitudinal examination of athletes’ emotional and cognitive responses to anterior cruciate ligament injury. Clin J Sport Med 1999;9(2):63-69.
  25. Te Wierike SCM, van der Sluis A, van den Akker-Scheek I, et al. Psychosocial factors influencing the recovery of athletes with anterior cruciate ligament injury: a systematic review. Scand J Med Sci Sports 2013;23(5):527-540.
  26. Lethem J, Slade PD, Troup JDG, Bentley G. Outline of a fear-avoidance model of exaggerated pain perception—I. Behav Res Ther 1983;21(4):401-408.
  27. Vlaeyen JW, Linton SJ. Fear-avoidance and its consequences in chronic musculoskeletal pain: a state of the art. Pain 2000;85(3):317-332.
  28. Leeuw M, Goossens ME, Linton SJ, at al. The fear-avoidance model of musculoskeletal pain: current state of scientific evidence. J Behav Med 2007;30(1):77-94.
  29. Kvist J, Ek A, Sporrstedt K, Good L. Fear of re-injury: a hindrance for returning to sports after anterior cruciate ligament reconstruction. Knee Surg Sports Traumatol Arthrosc 2005;13(5):393-397.
  30. Chmielewski TL, Zeppieri G Jr, Lentz TA, et al. Longitudinal changes in psychosocial factors and their association with knee pain and function after anterior cruciate ligament reconstruction. Phys Ther 2011;91(9):1355-1366.
  31. Ross MD. The relationship between functional levels and fear-avoidance beliefs following anterior cruciate ligament reconstruction. J Orthop Traumatol 2010;11(4):237-243.
  32. Lentz TA, Tillman SM, Indelicato PA, et al. Factors associated with function after anterior cruciate ligament reconstruction. Sports Health 2009;1(1):47-53.
  33. Chmielewski TL, Jones D, Day T, et al. The association of pain and fear of movement/reinjury with function during anterior cruciate ligament reconstruction rehabilitation. J Orthop Sports Phys Ther 2008;38(12):746-753.
  34. Sullivan MJL, Bishop SR, Pivik J. The Pain Catastrophizing Scale: Development and validation. Psychol Assess 1995;7(4):524-532.
  35. Pavlin DJ, Sullivan MJL, Freund PR, Roesen K. Catastrophizing: a risk factor for postsurgical pain. Clin J Pain 2005;21(1):83-90.
  36. Lentz T, Zeppieri G Jr, Tillman SM, et al. First-year recovery patterns differ among return to sport status groups following ACL reconstruction. J Orthop Sports Phys Ther 2014;44(1):A51.
  37. Ardern CL, Taylor NF, Feller JA, et al. Psychological responses matter in returning to preinjury level of sport after anterior cruciate ligament reconstruction surgery. Am J Sports Med 2013;41(7):1549-1558.
  38. Everhart JS, Best TM, Flanigan DC. Psychological predictors of anterior cruciate ligament reconstruction outcomes: a systematic review. Knee Surg Sports Traumatol Arthrosc 2015;23(3):752-762.
  39. Lentz TA, Tillman SM, Zeppieri G Jr, et al. Identification of factors that predict return to pre-injury level of sport participation 1 year following ACL reconstruction. J Orthop Sports Phys Ther 2010;40(1):A41.
  40. Woby SR, Roach NK, Urmston M, Watson PJ. Psychometric properties of the TSK-11: a shortened version of the Tampa Scale for Kinesiophobia. Pain 2005;117(1-2):137-144.
  41. Thomeé P, Währborg P, Börjesson M, et al. A new instrument for measuring self-efficacy in patients with an anterior cruciate ligament injury. Scand J Med Sci Sports 2006;16(3):181-187.
  42. Webster KE, Feller JA, Lambros C. Development and preliminary validation of a scale to measure the psychological impact of returning to sport following anterior cruciate ligament reconstruction surgery. Phys Ther Sport 2008;9(1):9-15.
  43. Nicholas MK, George SZ. Psychologically informed interventions for low back pain: an update for physical therapists. Phys Ther 2011;91(5):765-776.
  44. Macedo LG, Smeets RJEM, Maher CG, et al. Graded activity and graded exposure for persistent nonspecific low back pain: a systematic review. Phys Ther 2010;90(6):860-879.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.