Hop tests and psychological PROs provide a demanding and clinician-friendly RTS assessment of patients after ACL reconstruction, a registry study

Piussi et al. BMC Sports Science, Medicine and Rehabilitation https://doi.org/10.1186/s13102-020-00182-z (2020) 12:32 RESEARCH ARTICLE Open Access Hop tests and psychological PROs provide a demanding and clinician-friendly RTS assessment of patients after ACL reconstruction, a registry study Ramana Piussi1, Susanne Beischer1,2, Roland Thomeé1,2 and Eric Hamrin Senorski1,2* Abstract Background: There is growing interest in assessing psychological well-being in patients after anterior cruciate ligament (ACL) reconstruction. It is unknown whether an assessment of psychological outcome in addition to tests of muscle function can facilitate decisions on return to sport (RTS). Therefore, the aim of this study was to evaluate passing rates in different physical RTS test batteries, with and without the inclusion of psychological outcome measures 1 year after ACL reconstruction. Method: In this cross-sectional cohort study a total of 320 patients (51% men) aged 18–65 years were included 1 year after ACL reconstruction. Passing rates on different muscle function (MF) test batteries (with results presented as Limb Symmetry Index (LSI)), consisting of knee extension and flexion strength tests, 3 hop tests, and 2 psychological patient-reported outcomes (PROs); Quality of Life subscale from the Knee injury and Osteoarthritis Outcome Score (KOOS QoL) and ACL Return to Sport after Injury (ACL-RSI), were evaluated 1 year after ACL reconstruction. Muscle function test batteries comprised: 2 MF tests (vertical hop and hop for distance; pass = 90% LSI); 2 MF tests and 2 PRO (pass = 90% LSI, 62.5 points on KOOS QoL and 76.6 points on ACL-RSI), 5 MF tests (2 strength and 3 hop tests, pass = 90% LSI), and 5 MF tests and 2 PRO (pass = 90% LSI, 62.5 points on KOOS QoL and 76.6 points on ACL-RSI). Results: Passing rates in the different test batteries were 47% for 2 MF tests, 19% for 2 MF tests and 2 PROs, 29% for 5 MF tests and 13% for 5 MF tests and 2 PROs. The use of psychological PROs together with tests of muscle function gave the lowest passing rate (13%). There was a very strong correlation between passing 2 hop tests and 2 PROs and passing 5 MF tests (rφ = 0.41) as well as passing 5 MF tests and 2 PROs (rφ = 0.79). Conclusion: The use of hop tests together with psychological PROs provides a clinician-friendly RTS test battery for assessment 1 year after ACL reconstruction as the passing rate was 19% when using 2 hop-tests combined with 2 PROs, compared with 29% when using 5 tests of MF requiring advanced testing equipment. Keywords: Knee, Evaluation, Test batteries, Anterior cruciate ligament * Correspondence: 1 Sportrehab Sports Medicine Clinic, Stampgatan 14, SE-411 01 Gothenburg, Sweden 2 Unit of Physiotherapy, Department of Health and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Box 455, SE-405 30 Gothenburg, Sweden © The Author(s). 2020 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data. Piussi et al. BMC Sports Science, Medicine and Rehabilitation (2020) 12:32 Introduction After an anterior cruciate ligament (ACL) reconstruction, up to 30% of patients suffer a second knee injury within 5 years from surgery [1]. Consequences associated with a second ACL injury are for instance lower level of physical activity, knee pain and kneejoint osteoarthritis [2, 3]. Reaching return to sport (RTS) criteria based on objective assessments of muscle function (MF) in the lower extremity, prior returning to sport, can reduce the risk of a second ACL injury [4, 5]. Since a safe RTS after an ACL injury is a milestone for a majority of patients, it recieves much attention [6, 7]. A proper assessment of MF after ACL injury and reconstruction should comprise measures of quadriceps and hamstring strength as well as measures of functional performance, such as hop tests [8]. As an athletic injury always is followed by a psychological response, psychological outcome measures have become more common in the assessment of patients with an ACL injury [9–11]. In a recent systematic review of clinical practice guidelines (CPG) for rehabilitation after ACL reconstruction, the evaluation of psychological measures was recommended in 2 out of 5 CPGs [12]. Despite that the importance of psychological factors during rehabilitation and RTS has been widely recognized [13, 14], its implementation in the evaluation prior to RTS is scarce. Time and tests of physical performance, are the most common used RTS criteria [15]. Results from only hop performance can be insufficient as RTS criteria. Furthermore, as demands increase by adding more MF tests, the passing rate (the proportion of patients reaching a given cut-off value) is reduced [16–18]. It is, however, unknown if adding an assessment of psychological outcome to MF tests will result in different passing rates, resulting in a better foundation for decisions on RTS. The aim of this study was therefore to evaluate passing rates in different physical RTS test batteries, with and without the inclusion of psychological outcome measures 1 year after ACL reconstruction. Methods This cross-sectional study was based on data extracted from a rehabilitation outcome registry, Project ACL, on 8 February 2019. Project ACL was established in 2014 and aims to improve the care of patients with an ACL injury through the use of regular assessments as well as to provide patients and clinicians with treatment feedback. Data are collected prospectively at predefined follow-ups with ACL injury or ACL reconstruction as baseline [19–21]. The follow-up data consist of validated tests of MF and patient-reported outcomes (PROs). The Page 2 of 9 patients undergo individualized rehabilitation under supervision of a registered physical therapist. Ethical approval has been obtained from the Regional Ethical Review Board (registration numbers: 265–13, T023–17). In the present study, data from the 1-year follow-up were extracted for analy (...truncated)