Worse knee confidence, fear of movement, psychological readiness to return-to-sport and pain are associated with worse function after ACL reconstruction

Highlights

• Lack of knee confidence and fear of movement due to re-injury are common one-year after anterior cruciate ligament reconstruction.

• Worse fear of movement due to re-injury is related to poorer patient-reported function.

• Worse task-specific knee confidence and pain are related to poorer patient-reported and performance-based function.

• Positive psychological readiness to return-to-sport is associated with better function and higher odds of returning to pivoting sport.

Abstract

Objectives

To determine whether knee confidence, fear of movement, psychological readiness to return-to-sport or pain are associated with patient-reported and performance-based function and return to pivoting sport in individuals one-year after anterior cruciate ligament reconstruction (ACLR).

Design

Cross-sectional study.

Setting

University-laboratory.

Participants

118 individuals one-year post-ACLR.

Main outcome measures

The KOOS-sport/recreation and IKDC and three hopping tasks were used to assess patient-reported and performance-based function, respectively. Questions regarding return to pivoting sport assessed return-to-sport status. Fear of movement (Tampa Scale), knee confidence (an item from KOOS, Visual Analogue Scale-VAS confidence during hopping tasks), knee pain (KOOS-pain, VAS pain during hopping tasks) and psychological readiness to return-to-sport (ACL-RSI) were also assessed.

Results

Worse fear of movement (p = 0.019), KOOS-pain (p < 0.001), ACL-RSI (p < 0.001), task-specific knee confidence and pain were associated with poorer patient-reported function. Worse task-specific knee confidence (p < 0.001) and pain (p < 0006) and ACL-RSI (p < 0.016) were associated with poorer performance-based function. Higher ACL-RSI scores were associated with higher odds of returning to pivoting sport one-year post-ACLR (p < 0.001).

Conclusion

Individual’s fear of movement, knee confidence, psychological readiness to return-to-sport and pain are related to function. Evaluating and considering knee confidence, fear of movement, and psychological readiness should be an important part of comprehensive post-ACLR rehabilitation.

Introduction

Anterior cruciate ligament (ACL) injuries frequently affect young active adults, particularly those involved in pivoting sports. Although surgical reconstruction (ACLR) is often performed to restore mechanical stability of the knee, longer-term outcomes appear to be driven by physical function deficits, irrespective of treatment (Ericsson, Roos, & Frobell, 2013). Quadriceps muscle strength is a key determinant of lower-limb physical function following ACL injury. However, there is emerging appreciation of the extent and potential impact of psychological characteristics on physical function in ACL injured athletes (Ageberg & Roos, 2016; Cozzi, Dunn, Harding, Valovich Mcleod, & Welch Bacon, 2015; Hartigan, Lynch, Logerstedt, Chmielewski, & Snyder-Mackler, 2013; Lentz et al., 2009).

Psychological characteristics such as lack of knee confidence, fear of movement due to re-injury and negative psychological readiness to return-to-sport are often reported following ACL injury and ACLR and have been linked to poorer patient-reported and performance-based function and the decision to not return-to-sport 2–7 years post ACL injury/ACLR (Ageberg & Roos, 2016; Ardern, Taylor, Feller, & Webster, 2012; Kvist, Ek, Sporrstedt, & Good, 2005; Tjong, Murnaghan, Nyhof-Young, & Ogilvie-Harris, 2014). However, patients typically expect to return to unrestricted sport within 12 months of ACLR (Feucht et al., 2016), and the success of surgery and rehabilitation programs are judged on achieving this goal (Lynch et al., 2015). It is therefore important to identify potential contributing psychological characteristics limiting a return to optimal function and return-to-sport 12 months post-ACLR so that management approaches to optimize these characteristics can be incorporated into rehabilitation programs.

Given that knee function can be measured with patient-reported outcomes (e.g. Knee Injury and Osteoarthritis Outcome Score, KOOS) and performance-based outcomes (e.g., hop distance) and that psychological characteristics may be non-specific (e.g. patient-reported outcome measure over the last seven days) or specific to a particular task (e.g. hop test), this study explored relationships between the different constructs of knee function and psychological characteristics. We aimed to determine whether knee confidence, fear of movement due to re-injury, psychological readiness to return-to-sport, or pain are related to patient-reported and performance-based function and return to pivoting sport one-year after ACLR.