Psychosocial Barriers After Anterior Cruciate Ligament Reconstruction: A Clinical Review of Factors Influencing Postoperative Success

Abstract

Context:

Psychosocial factors arising after anterior cruciate ligament (ACL) injury may have a direct influence on an individual’s decision to return to sport after ACL reconstruction (ACLR). While there is ample evidence to suggest that deficits in quadriceps strength, neuromuscular control, and clinical functional tasks exist after ACLR, the root and contribution of psychological dysfunction to an individual’s success or return to sport after ACLR is still largely uncertain and unexplored. Given the discrepancy between successful functional outcomes and the percentage of athletes who return to sport, it is important to thoroughly address underlying factors, aside from physical function, that may be contributing to these lower return rates.

Evidence Acquisition:

Articles that reported on return to sport, psychological factors, and psychosocial factors after ACLR were collected from peer-reviewed sources available on Medline (1998 through August 2018). Search terms included the following: anterior cruciate ligament OR ACL AND return-to-sport OR return-to-activity, anterior cruciate ligament OR ACL AND psychological OR psychosocial OR biopsychosocial OR fear OR kinesiophobia OR self-efficacy, return-to-activity AND psychological OR psychosocial.

Study Design:

Clinical review.

Level of Evidence:

Level 5.

Results:

Psychosocial factors relative to injury are important components of the rehabilitation process. To fully understand how psychosocial factors potentially influence return to sport, an athlete’s emotions, experiences, and perceptions during the rehabilitation process must be acknowledged and taken into consideration.

Conclusion:

Acknowledgment of these psychosocial factors allows clinicians to have a better understanding of readiness to return to sport from a psychological perspective. Merging of the current ACLR rehabilitation protocols with knowledge related to psychosocial factors creates a more dynamic, comprehensive approach in creating a positive and successful rehabilitation environment, which may help improve return-to-sport rates in individuals after ACLR.

Return to Sport After Anterior Cruciate Ligament Injury

Despite extensive rehabilitation measures, the rates of patients resuming preinjury sporting levels after anterior cruciate ligament (ACL) reconstruction (ACLR) are lower than expected.^33,34,59 Ardern et al⁴ reported that overall 81% of individuals undergoing ACLR returned to some form of sporting activity after surgery. When examining return-to-sport rates based on sporting level, approximately 65% had returned to preinjury level, but only 55% returned to competitive sport. Additionally, while patients often expect to return to sport, between 15% and 20% of athletes are not returning to any sport participation after ACLR.^41,59 Thus, it is clear that the number of athletes returning to preinjury sports is low, despite these athletes’ achieving successful surgical outcomes based on knee laxity measures, tunnel and graft position, and/or subjective reports of knee function.^4,7 Although a larger emphasis is often placed on rehabilitating physical performance, the consideration of psychological factors after ACLR is critical to providing comprehensive patient care.

Psychological Considerations

Mounting evidence supports the effects of psychological dysfunction on recovery outcomes after ACLR.^{3,12,15,24,25,37} Notably, there are several psychosocial constructs that may be predictive of improved outcomes after surgery.^24,53 While there is ample research evaluating physical outcomes after ACLR, the contribution of psychological dysfunction to an individual’s return to sport after ACLR is still largely unexplored. Given that successful functional outcomes do not always equate to successful return to sport, it is important to address underlying factors, apart from physical function, that may be contributing to these lower return rates. Therefore, the purpose of this clinical review is to explore psychosocial factors, using the dynamic biopsychosocial behavioral model, that have the potential to influence an individual’s ability to return to sport and functional activities after ACLR.

Evidence Acquisition

Articles that reported on return to sport, psychological factors, and psychosocial factors after ACLR were collected from peer-reviewed sources available on Medline (1998 through August 2018). Search terms included the following: anterior cruciate ligament OR ACL AND return-to-sport OR return-to-activity, anterior cruciate ligament OR ACL AND psychological OR psychosocial OR biopsychosocial OR fear OR kinesiophobia OR self-efficacy, return-to-activity AND psychological OR psychosocial.

The Dynamic Biopsychosocial Model as a Framework to Success After ACLR

Numerous psychosocial factors have been identified and attributed to the failure of persons returning to sport.⁵⁰ These factors range from a general loss of interest in sport and change in level of play (high school to college) to the fear of reinjuring the involved or contralateral extremity.^1,15 Other factors such as lifestyle changes, occupational demands, loss of motivation, and perception of self-efficacy, as well as the age of the athlete, may contribute to whether or not he or she returns to play at any level.^5,15,22 The ability of clinicians to understand psychosocial factors and how they relate to physical factors during recovery after ACLR is imperative to addressing these factors and their potential to influence return to sport. To this end, numerous outcome instruments have been developed in an attempt to improve evaluation techniques of psychosocial factors after ACLR (Table 1).

Table 1.

Subjective outcomes assessing psychosocial factors after injury

Scale	Psychosocial Responses Assessed	Suggested Intervention/Talking Points
ACL-RSI 60	Risk appraisal, patient confidence, perceived readiness to return to functional activities	Talk to the individual and assess what his/her goals after ACLR are; whether that be return to some form of functional activities or not
TSK 27,28	Fear of pain/reinjury with associated movement patterns, kinesiophobia	Graded exposure to activities or movements that elicit a sense of fear
K-SES 52,53,55	Certainty regarding performance of daily activities, sports and leisure activities, physical activities, future knee function	Early and continuous exposure to tasks that the individual feels comfortable completing and progressing in difficulty as he/she becomes more confident and exhibits more perceived self-efficacy
PRSII 23	Feelings of devastation, dispirited, reorganization, feeling cheated, and restlessness, emotional response	Early education on the healing process and risk factors for reinjury may help relieve fears that develop. Correct any false expectations on the length and requirements of rehabilitation
KOOS-QOL 49	Awareness of knee, modifications to lifestyle, lack of confidence, difficulties with knee	Talk to the individual and assess what his/her goals after ACLR are; whether that be return to some form of functional activities or not. Graded exposure to tasks requiring varying levels of confidence and awareness of the knee

ACLR, anterior cruciate ligament reconstruction; ACL-RSI, Anterior Cruciate Ligament–Return to Sport After Injury Scale; KOOS-QOL, Knee injury and Osteoarthritis Outcome Scale–Quality of Life; K-SES, Knee Self-Efficacy Scale; PRSII, Psychological Response to Sport Injury Inventory; TSK, Tampa Scale of Kinesiophobia.

To fully understand how psychosocial factors potentially influence return to sport, an athlete’s emotions, experiences, and perceptions during the recovery process must be acknowledged.^13,36,48 Using the “dynamic biopsychosocial model”⁶³ (which deals with post–sport injury response and recovery) may be particularly useful for health care providers working with an athlete who desires to resume functional sporting activities (Figure 1). The term biopsychosocial incorporates biological, behavioral, and social attributes, providing a comprehensive understanding of the complexity and abundant responses that transpire after traumatic injury, such as an anterior cruciate ligament (ACL) injury.⁶² The psychological response is composed of 3 major components: cognition, affect, and behavior.^51,62 Cognition refers to the thoughts and appraisals that athletes have after an injury. The affect component focuses on how an athlete feels after an injury. Behavior, which is influenced by both cognition and affect, involves the actions of an athlete. All 3 of these components influence the fourth component of the model, outcome, which comprises the results, the effects, and the consequences after an injury.^51,62

Figure 1.

Dynamic biopsychosocial cycles of post–sport injury response and recovery.⁶² Copyright 2010 by D. M. Wiese-Bjornstal. Reprinted by permission of the author.

Cognition

Cognition is made up of conscious assessments and thoughts that athletes have after an injury. A subcomponent of cognition that may play a role in ability to return to sport after ACL injury is self-efficacy.^40,51,62 Self-efficacy, along with numerous other psychosocial influences (ie, health locus of control [HLOC], kinesiophobia, anxiety, mood, patient willingness, commitment) can contribute to the success or failure of an ACLR rehabilitation.¹² Self-efficacy is an individual’s judgment of his or her ability to carry out a task, regardless of whether or not the individual can or does complete it.^{12,18,34,51,52} After ACLR, many athletes are functionally capable of completing a task; however, because of low self-efficacy they may perceive themselves as unable to complete the task.^51,52 Higher levels of self-efficacy are not only predictors of improved physical activity and knee symptoms/function after ACLR^18,51 but may also increase the athlete’s likelihood of returning to sport due to improved levels of rehabilitation adherence.^12,52 Self-efficacy may be influenced by factors such as ability to cope with pain, HLOC, quality of life, and physical function.⁵⁴ Furthermore, it may be important to consider a patient’s degree of self-efficacy prior to deciding whether or not to undergo ACLR. Specifically, the Knee Self-Efficacy Scale (K-SES)⁵⁵ can be used to prospectively evaluate an individual’s perception of his or her ability to perform a task or sport specific function.⁵⁴ Preoperative K-SES scores are predictive of an individual’s ability to return to preinjury activity intensity and frequency of physical activity 1 year post-ACLR.^2,53 Determinants of self-efficacy after ACLR are mostly dependent on how athletes interpret their knee function and how strongly they believe that their recovery and outcome after surgery is a result of their own actions and behaviors.¹² As self-efficacy can lead to enhanced rehabilitation outcomes and may be increased over the span of rehabilitation, improving self-efficacy in the earlier stages of rehabilitation or prior to surgery may be important for successful recovery and return to sport after ACLR.

A subsequent construct similar to self-efficacy that can influence outcomes after ACLR is HLOC, which describes the belief that one’s health status is controlled by either one’s own behaviors or by outside factors, such as fate.⁵⁸ Internal HLOC has been defined as the degree to which individuals perceive to control decisions or life events.^47,48,51 Evidence has suggested that after ACLR, athletes may experience situations where they believe they have no control over the outcome of specific actions. Those who have a high internal HLOC compared with a low internal HLOC (perceiving events to be a consequence of one’s actions, rather than an event occurring due to fate or chance) are more satisfied with their knee function, both in activities of daily living and in sports activities after ACLR.⁵¹ Athletes who demonstrate higher internal HLOC report greater satisfaction with their knee function, activities of daily living, and sports activities after ACLR compared with those with lower sense of HLOC. Both constructs of HLOC and self-efficacy encompass factors related to successful task completion and may promote increased physical outcomes after ACLR.^33,51

Affect

Affect, the second component of the dynamic biopsychosocial model, is concerned with the way an athlete feels after an injury. Affective responses are made up of emotions, feelings, and moods, including depression, anxiety, low vigor, fatigue, grief, and burnout. Of these, mood, pain, and personality factors can potentially influence outcomes after ACLR. Negative moods throughout recovery adversely affect rehabilitation outcomes.^24,43 Individuals who report less presurgical knee joint pain demonstrate increased readiness to return to functional activities and overall more positive emotions throughout recovery after ACLR.³⁸

A specific feature of affect observed after ACLR is fear of reinjury. Fear of reinjury and kinesiophobia (irrational and debilitating fear of physical movement due to feelings of vulnerability to painful injury or reinjury³⁴) are commonly observed after ACL injury^17,26,51,62 and can negatively influence return-to-sport outcomes.^3,34,57 Fear of reinjury can present clinically as hesitance or wariness toward certain activities or movements and is a unique predictor for return to sport.^3,15 Individuals reporting greater fear of reinjury were less likely to return to sport and preinjury level of participation,^17,33,35,57 and upward of 24% of athletes did not return to play due to fear of reinjury.³⁴ Regardless of pain, fear of reinjury predicted the likelihood of returning to sport. In a study by Flanigan et al,²⁶ factors such as persistent knee issues, life events, or personal factors that may have influenced a person’s decision to return to sport were examined. Apart from persistent knee issues (ie, pain, swelling, instability, weakness), fear of reinjury was the most common “personal” reason for not returning to sport.²⁶ With over half of participants citing fear of reinjury as the reason for not returning to sport, it is important to address interventions and strategies that manage the fear patients may be feeling after ACLR. In addition to physical fear of reinjury, patients have identified nonphysical fears associated with the ACL injury process, such as fear of loss of income, fear of repeating rehabilitation, and fear of sporting incompetence.⁵⁶ Identifying and addressing physical and nonphysical fears is an important step in decreasing patients’ overall fear and hesitation in the hopes of combating the low percentages of those patients returning to sport after ACLR.

Constructs related to fear of reinjury, kinesiophobia, and fear avoidance–type behaviors are often discussed together within the context of another psychological model, the fear avoidance model. The fear avoidance model is a cognitive behavioral theory that encompasses behaviors where patients experience a painful stimulus and subsequent negative psychological responses due to an anticipation of pain with certain movements, also commonly referred to as pain catastrophizing, leading to avoidance of these movements.²⁴ Ultimately, movement compensation then leads to decreased strength and range of motion, altered movement patterns,²⁰ and lack of confidence in the stability of the involved extremity.^34,57 Because these components of the fear avoidance model have been suggested to affect function after injury, specifically ACLR, a clinical measurement tool, the Tampa Scale of Kinesiophobia (TSK)³² was developed to objectively identify kinesiophobia. The TSK examines somatic sensations regarding pain experienced during movement, as well as activity avoidance. After ACLR, kinesiophobia levels have been shown to generally decrease through the early to late phases of rehabilitation, and higher TSK scores have been associated with lower self-reported knee function and a lower rate of return to sport after ACLR.^26,31,32 Utilization of the TSK as a measurement of kinesiophobia can allow clinicians to better understand how individuals cope with fear of movement and associated pain.

In addition to the TSK, utilization of psychological assessment scales that have the ability to objectively quantify an individual’s readiness for resumption of functional activities is imperative. The Anterior Cruciate Ligament Return to Sport after Injury (ACL-RSI) scale⁶⁰ can help clinicians objectively identify an athlete’s level of perceived readiness to return to functional and sport-related activities (Table 1). Thus, recognition and acknowledgement of the aforementioned emotional mood responses, personality traits, fear avoidance–type behaviors, and readiness to return to functional activities can provide clinicians with an improved understanding of an individual’s psychological well-being and may ultimately help improve successful outcomes after ACLR.

Behavior

Behavior is greatly influenced by both cognitive and affective responses. Behavior attributes include actions, efforts, and activities after an injury and are notable in rehabilitation attendance and adherence, exercise dependence, malingering, and supplement abuse.^51,62 After ACL injury and reconstruction, avoidance coping and rehabilitation adherence have been identified as central factors influencing postoperative outcomes.⁵¹ Coping is defined as “a constantly changing cognitive and behavioral effort to manage specific external and/or internal demands that are appraised as taxing or exceeding the resources of the person.”¹⁶ Athletes use strategies of avoidance coping to manage stressful situations and emotions that they may be feeling at the time. More commonly seen after ACLR is behavioral avoidance coping where an athlete makes a conscious decision to avoid a certain environment that he or she may perceive as threatening.^16,51 Avoidance coping strategies may inhibit the rehabilitation process because of the athlete’s removal of oneself from the situation or the avoidance of dealing with the injury, thus prolonging the rehabilitation process. Athletes who deny or avoid certain aspects regarding their injury and rehabilitation may feel that they have limited control or no control over the outcome of their situation. These avoidance behaviors and perceived lack of control may be a manifestation of an external HLOC, further serving as a barrier hindering successful return to sport after ACLR.

During lengthy periods of rehabilitation, athletes may become frustrated with the amount of time it is taking to return to sport. In some cases, athletes will decide to discontinue rehabilitation or not fully adhere to their assigned program.^13,51 Adherence to a rehabilitation program has been shown to improve knee symptoms and functional outcomes and has a positive effect on the recovery process after ACLR.¹³ Understanding common behavior responses after injury is important for addressing potential barriers affecting optimal rehabilitation outcomes. Decreasing avoidance coping and increasing rehabilitation adherence may lead to more successful results during and after rehabilitation.

Outcome

Cognition, affect, and behavioral responses of the biopsychosocial model are modifiable and interrelated. These psychological responses all play a role in the outcome or success of recovery after injury.⁵¹ For example, those who demonstrate lower levels of confidence and less optimism (cognition) exhibit greater fear of reinjury (affect), which may result in decreased compliance with rehabilitation (behavior) and may overall influence whether or not the individual makes a successful return to sport (outcome).⁵¹ Through this model, it is evident that both physical and mental aspects of rehabilitation are vital for a “successful” and optimized return to sport. Oftentimes, success of a rehabilitation program is determined by whether or not an athlete returns to functional activities or to his or her preinjury level of sport.^8,51 Recent research indicates that only a limited number of individuals are achieving this goal.^4,9,29,30 Furthermore, upward of 30% of patients who undergo primary ACLR sustain a subsequent reinjury in the years after returning to sports.^45,61 These outcomes clearly demonstrate that there is significant room for improvement in current ACLR.

Currently, there is no consensus on criteria to progress a patient through the return-to-sport phase, with many studies reporting time from surgery as the biggest indicator for readiness to return to sport.^10,21 Consideration of patient perceived function through the use of patient-reported outcomes provides clinicians with subjective data to supplement physical performance when deciding whether an individual is ready to return. To this point, in a review by Lepley,³⁹ only 1 study¹¹ reported clinically acceptable rates of self-perceived physical function at 6 months after ACLR. However, patients who report greater perceived knee function and psychological readiness at the time of return to sport exhibit greater levels of quadriceps strength³⁸ and earlier resumption of functional activities.¹⁴ While passing stringent physical return-to-sport criteria can reduce the risk of secondary ACL injury by 84%,³⁰ recent research evaluating psychological readiness and reinjury observed that individuals who sustained a secondary ACL injury exhibited lower psychological readiness at 12 months postoperatively.⁴¹ Studies that evaluate both physical and psychological function also demonstrate superior postoperative results and reduced risk of reinjury^10,30,44 compared with studies only evaluating 1 or 2 postoperative outcomes (ie, time from surgery, quadriceps strength).^9,21 Physical and patient-perceived function both play a role in influencing rehabilitative success, highlighting the importance of considering both during recovery after ACLR.

Potential Psychosocial Intervention Strategies

While it is well established that certain physical outcomes are modifiable throughout the rehabilitation process (ie, strength, neuromuscular control, limb asymmetries), psychosocial responses to injury are also measurable and modifiable and can be influenced after ACLR. Since poor psychosocial responses are potential barriers hindering successful return to sport and functional activities post-ACLR, it may be beneficial to use interventions aimed at correcting maladaptive psychological responses.⁶ The components of the dynamic biopsychosocial model may be used as a way to group specific intervention strategies together for targeting specific psychosocial constructs arising after ACLR. Cognitive behavioral therapies such as imagery, mindfulness, guided relaxation, and breathing techniques^19,42 could be used to improve constructs such as fear-related emotions, motivation, and self-efficacy (cognition and affect). These strategies decrease negative emotions and may allow for a more positive rehabilitation environment (affect).^18,42,43 Additionally, creating realistic expectations⁵⁹ for patients experiencing fear and other psychological hindrances after ACLR, by using goal-reprioritization and readjustment, may be beneficial in decreasing negative emotions during the recovery process (affect).⁴⁶ Keeping patients satisfied with their progress through the use of goal-readjustment will help create a more stable and positive rehabilitation environment for patients because they continue to feel on track for a successful recovery (behavior). This may further increase intrinsic motivation and HLOC as well as create a more positive outlook on return to sport and functional activities (behavior and outcome). All aspects of the dynamic biopsychosocial model should be addressed and personalized to fit the needs of an individual in order to create an optimal environment for rehabilitation and recovery.

Conclusion

Although some individuals after ACLR are meeting current clinical criteria for clearance to return to sport, other individuals demonstrate suboptimal performances on strength testing, dynamic functional movements, and neuromuscular control tasks and ultimately may not return to preinjury level of activity. Additionally, within the context of the dynamic biopsychosocial model, psychosocial factors related to cognition, affect, behavior, and outcome may have a direct influence on an individual’s decision and ability to return to sport after ACLR. Psychosocial influences, such as fear of reinjury, lifestyle changes, occupational demands, loss of motivation, and perceived self-efficacy, all appear to play a role in an individual’s recovery and, moreover, their decision of whether or not to return to sport. Acknowledgment of these psychosocial factors allows clinicians to have a better understanding of readiness to return to sport from a psychological perspective. Merging of the current ACLR rehabilitation protocols with knowledge related to psychosocial factors creates a more dynamic, comprehensive approach in creating a positive and successful rehabilitation environment, which may help improve return-to-sport rates in individuals after ACLR.