The effectiveness of preoperative rehabilitation programmes on postoperative outcomes following anterior cruciate ligament (ACL) reconstruction: a systematic review

INTRODUCTION: The anterior cruciate ligament (ACL) is the most commonly injured ligament in the knee with annual incidence rates of ruptures reported at 68.6 per 100,000. ACL ruptures are commonly treated with surgical reconstruction which aims to restore knee stability and maximise functional capacity to allow individuals to return to their preinjury level of physical activity. Prior to ACL reconstruction (ACLR), preoperative rehabilitation, commonly termed prehabilitation (PreHab), has been suggested to physically and mentally prepare patients for surgery and postoperative rehabilitation. No previous systematic review has specifically evaluated the effectiveness of PreHab on postoperative outcomes. A 2017 systematic review did investigate prehabilitation, but of the included eight RCTs only two included post-operative outcomes and not all RCTs included surgery in the treatment pathway. HYPOTHESES: To explore the effectiveness of preoperative rehabilitation programmes (PreHab) on postoperative physical and psychological outcomes following anterior cruciate ligament reconstruction (ACLR). METHODS: A systematic search was conducted from inception to November 2019. Randomised controlled trials (RCTs) published in English were included. Risk of bias was assessed using Version 2 of the Cochrane risk-of-bias tool, and the Grading of Recommendations Assessment system was used to evaluate the quality of evidence. RESULTS: The search identified 739 potentially eligible studies, three met the inclusion criteria. All included RCTs scored ‘high’ risk of bias. PreHab in all three RCTs was an exercise programme, each varied in content (strength, control, balance and perturbation training), frequency (10 to 24 sessions) and length (3.1- to 6-weeks). Statistically significant differences (p<0.05) were reported for quadriceps strength (one RCT) and single leg hop scores (two RCTs) in favour of PreHab three months after ACLR. One RCT reported no statistically significant between-group difference for pain and function. No RCT evaluated post-operative psychological outcomes. CONCLUSION: Low-quality evidence suggests that PreHab that includes muscular strength, balance and perturbation training offers a small benefit to quadriceps strength and single leg hop scores three months after ACLR. There is no consensus on the optimum PreHab programme content, frequency and length; this requires future consideration including the development of PreHab programmes that consider psychosocial factors and the measurement of relevant post-operative outcomes such as psychological readiness.