Everhart JS, Best TM, Flanigan DC. Psychological predictors of anterior cruciate ligament reconstruction outcomes: a systematic review. Knee Surg Sports Traumatol Arthrosc. 2015;23:752–762.
Clinical Question: Can baseline psychological factors predict restoration of knee function and return to sport following anterior cruciate ligament (ACL) reconstruction surgery?
Data Sources: PubMed, CINAHL, UptoDate, Google Scholar, Cochrane Reviews, and SportDiscus were searched from 1975 to 2012. The search terms included psychology AND surgery, orthopedic procedures, arthroscopy, rehabilitation, and operative.
Study Selection: Inclusion criteria were: (1) investigated ACL reconstruction outcomes; (2) study population included mean age of 13 to 65 years; (3) prospective study design; (4) predictive assessment of psychological factors as primary or secondary aim of the study; (5) only peer-reviewed publications included, no abstracts, posters, or thesis papers, and (6) English language.
Data Extraction: Surgical procedure, patient demographics, length of follow-up, and before/after outcome measures were extracted from the included studies. Included study results were limited to preoperative psychological factors and their predictive value of postoperative knee outcomes.
Main Results: Eight prospective studies met the inclusion criteria and were analyzed in the final review. Follow-up times ranged from 3 to 60 months after surgery, with a mean of 9 months. Preoperative measures of stress were a negative predictor, whereas social support and sport identity were positive predictors. Self-efficacy, self-motivation, and optimism were positive predictors for multiple factors, including rehabilitation compliance, return to sport, and self-rated knee function. Increased kinesiophobia and pain catastrophizing at the first rehabilitation visit was not a predictor of knee symptoms or function in early rehabilitation phases.
Conclusion: Baseline psychological screenings, specifically for self-confidence, optimism, and self-motivation, can help predict outcomes and return to sport following ACL reconstruction. Lower baseline stress and stronger social support and athletic identity can also predict positive return to sport and self-rated knee function outcomes.
Summary: ACL rupture is a traumatic injury that occurs commonly in young, active populations.1,2 Overall, it is estimated that more than 200,000 ACL injuries occur in the United States each year and most patients elect surgical reconstruction.2 A recent Cochrane review compiled the available literature on surgical procedures, postoperative rehabilitation, and outcomes following ACL reconstruction.3
Despite available evidence, the long-term functional outcomes after ACL reconstruction appear suboptimal, with some patients suffering a second ACL injury or inability to return to pre-injury activity levels.2 A recent study that observed 78 patients after ACL reconstruction found 29.5% sustained a second injury to the contralateral or ipsilateral knee within 2 years.2 ACL reconstruction has also been linked to unsatisfactory knee function and health-related quality of life.1 In a meta-analysis of 5,770 patients, only 63% returned to pre-injury activity levels and only 44% returned to competitive sports at 41 months after reconstruction.1 Patients who report an inability to return to desired activity levels often continue to self-report instability, decreased knee function, difficulty with activities of daily living, fear of re-injury, and pain.1,4
Previous cross-sectional studies have determined the relationship of psychological factors and return to activity in late rehabilitation phases,4 but a recent systematic review aimed to evaluate preoperative psychological factors as a predictive assessment for functional outcomes after ACL reconstruction.5 This systematic review5 included 8 prospective studies that focused on the predictive assessment of psychological factors and concluded that several psychological factors are predictive of postoperative outcomes and return to activity. Pain catastrophizing, fear of re-injury, confidence, motivation, self-efficacy, optimism, and even sport-related identity may be baseline patient data predictive of postoperative outcomes such as knee function and return to activity.5 Fear of re-injury was repeatedly revealed as the most common barrier to return to activity.
Fear of re-injury was greater in participants who were not competing at pre-injury levels.6 Results also showed that a patient's optimism or belief that he or she could perform knee-related tasks in the future was predictive of greater scores on patient-rated outcome measures including the Knee Injury and Osteoarthritis Outcomes Score (KOOS), Tegner activity score, and the hop index score.5 The importance of self-efficacy and optimism was supported by results that showed lower pessimism scores were linked to higher KOOS scores 5 years after ACL reconstruction. Greater self-efficacy also affected postoperative rehabilitation compliance, completion, and effort. Patients who include positive self-talk or goal setting completed their home exercise program more often with higher perceived ratings of motivation and effort.
Finally, there appears to be an association between both stress and social support with knee surgery outcomes. Higher levels of stress were associated with increased knee laxity, and a patient's athletic identity was associated with decreased knee laxity. Higher levels of stress may decrease rehabilitation compliance, whereas a greater social support system and athletic identity may increase compliance. The importance of social support was age dependent because athletic identity becomes less important for surgical outcomes with increased age and social support becomes more important.5
Although more research is needed, these results might support psychological screenings being used as a preoperative tool to predict outcomes and the implementation of psychological interventions to improve ACL reconstruction outcomes. Clinicians should consider the inclusion of positive self-talk, goal setting, and imagery as interventions to reduce the impact of psychosocial barriers to recovery.5,7 Imagery has been previously used to improve psychological skills such as confidence, self-efficacy, and motivation. Mental imagery used after injury can also improve muscle function and strength after immobilization or ACL reconstruction. Goal setting, imagery, and positive self-talk can be implemented both before and after injury to improve readiness for surgical intervention and return to activity.5,7
Although the authors did identify some predictive factors, there appeared to be no relationship between kinesiophobia and pain catastrophizing at the first rehabilitation appointment of patients reporting knee symptoms at 12 weeks.5 It might be hypothesized that patients who have not experienced functional movement or a significant amount of knee motion at all by the first rehabilitation appointment would not have experienced kinesiophobia or pain catastrophizing yet.
Although fear avoidance may not be useful to measure at baseline, there may be tools to use throughout postoperative treatment that can still influence clinical decision-making. The Tampa Scale of Kinesiophobia (TSK-11) is a form used to measure pain-related fear of movement/re-injury, which may be heightened after diagnosis of an ACL rupture or post-surgical intervention. In the previous cross-sectional study,4 the TSK-11 score was significantly lower in patients who specifically reported a fear of re-injury. Furthermore, the systematic review showed that implementing the TSK-11 later in the rehabilitation process may reveal psychological barriers to functional progressions and return to activity.5
The causes for variance in the success after ACL reconstruction are purported to be multifactorial, including psychological differences among patients.5 Patients often self-report decreased function despite restoration of clinical measures such as range of motion and strength. Therefore, there appears to be a discrepancy between postoperative restoration of knee function and a patient's self-reported knee function and return to sport. Addressing psychological factors and interventions may help improve these outcomes.5
Because surgical intervention is often traumatic, time-consuming, and expensive, it is important for clinicians to be able to assess a patient's lifestyle and psychological factors to determine psychological interventions that will improve the likelihood of success after surgical intervention.5 When preparing for surgical intervention, pre-injury activity level, desire for return to sport, occupational demands, commitment to long-term rehabilitation, motivation, and expectations for knee function should all be discussed with the patient.5 Given all of these potential barriers to successful ACL reconstruction outcomes, it is important for clinicians to understand options available to measure psychological factors prior to surgical intervention, as well as throughout rehabilitation.
Current literature suggests that baseline psychological factors can predict outcomes and rehabilitation success in patients who undergo ACL reconstruction. Because many patients with ACL reconstruction never return to pre-injury activity levels, it is useful for clinicians to have tools to determine whether surgical intervention is appropriate and which psychosocial interventions can be integrated into postoperative care to improve outcomes.
The reason that patients do not return to pre-injury activity is multifactorial, and including mental health or psychological predictors may help us understand the whole patient-centered image, rather than just the physical impairments expected postoperatively. Currently, patient-rated outcome measures are often implemented in later stages of rehabilitation, but baseline measures show promise in guiding clinical decisions and treatment approaches for patients following an ACL rupture. Development of a validated tool that integrates items from patient-rated outcome measures that focus on self-efficacy, confidence, optimism, and motivation could be the most beneficial based on the current evidence.
- Frobell RB, Roos HP, Roos EM, Roemer FW, Ranstam J, Lohmander LS. Treatment for acute anterior cruciate ligament tear: five year outcome of randomised trial. BMJ. 2013;346:f232. doi:10.1136/bmj.f232 [CrossRef]
- Paterno MV, Rauh MJ, Schmitt LC, Ford KR, Hewett TE. Incidence of second ACL injuries 2 years after primary ACL reconstruction and return to sport. Am J Sports Med. 2014;42:1567–1573. doi:10.1177/0363546514530088 [CrossRef]
- Monk AP, Davies LJ, Hopewell S, Harris K, Beard DJ, Price AJ. Surgical versus conservative interventions for treating anterior cruciate ligament injuries. Cochrane Database Syst Rev.2016;4:CD011166.
- Lentz TA, Zeppieri G Jr, 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;43:345–353. doi:10.1177/0363546514559707 [CrossRef]
- Everhart JS, Best TM, Flanigan DC. Psychological predictors of anterior cruciate ligament reconstruction outcomes: a systematic review. Knee Surg Sports Traumatol Arthrosc. 2015;23:752–762. doi:10.1007/s00167-013-2699-1 [CrossRef]
- Ardern CL, Taylor NF, Feller JA, Webster KE. Fear of re-injury in people who have returned to sport following anterior cruciate ligament reconstruction surgery. J Sci Med Sport. 2012;15:488–495. doi:10.1016/j.jsams.2012.03.015 [CrossRef]
- Slimani M, Tod D, Chaabene H, Miarka B, Chamari K. Effects of mental imagery on muscular strength in healthy and patient participants: a systematic review. J Sports Sci Med. 2016;15:434–450.