Original article written by Adam Culvenor, Michael Girdwood, Carsten Juhl and colleagues
Background
It is no secret that Anterior Cruciate Ligament (ACL) and meniscal injuries lay a heavy burden on sports medicine teams working in professional sport – they are both highly prevalent and result in significant time loss away from competitive sport. There is a growing acceptance that a non-surgical approach to these injuries may be equally successful, if not more successful (when considering time-loss) than surgical intervention. Nevertheless, regardless of the chosen management pathway, it is widely accepted that the rationale and delivery of the subsequent rehabilitation programme following these injuries, is of critical importance when optimising return-to-sport outcomes.
The authors of this systematic review, which was published in the British Journal of Sports Medicine, felt there was little in the form of consensus, regarding the ‘optimal components of ACL rehabilitation’. The author’s aim was to critically appraise and synthesise all available high-quality evidence, assessing ACL or meniscal injury rehabilitation to allow some evidence-based guidelines to be formulated.
What the authors did
Systematic reviews up to June 2021 were reviewed. Twenty-two systematic reviews, including 142 RCTs were included. Mean age of participants in each study was <30 years old. These all focused-on ACL populations and none of which were exclusive to meniscal injuries alone. As we know, meniscal injuries can often happen in conjunction with an ACL injury.
What the authors found
Neuromuscular electrical stimulation (NMES)
A total of 16 RCTs evaluated the effect of NMES following ACL reconstruction. ‘Moderate-certainty’ evidence indicates a ‘large-effect size for the addition of NMES (2-6 sessions per week) to standardised rehabilitation to improve quadricep strength in the first 4-12 weeks post-op. No consistent dosage was stipulated in these reviews.
Open kinetic chain exercises
Eleven RCTs compared open versus closed kinetic chain exercises following ACL reconstruction and with ‘moderate certainty’ found no significant difference in knee laxity, muscle strength, self-reported function, and physical function, regardless of graft type. There was also no difference in laxity or muscle strength with open kinetic chain exercises when starting early (<4 weeks) versus delayed (>12 weeks). It was therefore recommended both open and closed kinetic chain exercises should be feature in early rehabilitation programmes.
Bracing
Moderate-certainty evidence from 7 RCTs indicates that post operative knee bracing following ACL reconstruction provided no benefit to improving knee laxity and physical function.
Cryotherapy
There was low-certainty evidence from 11 RCTs that cryotherapy during the first 48 hours post-op can reduce postoperative pain. Although cryotherapy did not increase the risk of adverse-events, there is no evidence for it effect on outcomes beyond 1-week.
Blood flow restriction (BFR) Training
Very low-certainty evidence from 4 RCTs that indicated blood flow restriction during low-intensity resistance training in the first 2–16 weeks post- ACLR (ranging from two times per day to two times per week) results in greater improvements in quadriceps size and lean muscle mass compared with low-intensity resistance training alone.
What this means for coaches
Following ACL and meniscal injury, the interventions which are likely to be of greatest significant clinical benefit (highest level of supporting evidence) are NMES and open kinetic chain lower limb training. The review also showed significant level of evidence to negate the need for post operative bracing following surgery.
Asides from the above however, the overview concluded that there was a ‘disappointingly low level of evidence for the effectiveness of rehabilitation interventions’ to improve outcomes following ACL and meniscal surgery.
I personally find this a common theme amongst many systematic reviews published within the field of sports medicine within the past 5-10 years or so – especially when it comes down to evaluating clinical research specific to a younger or athletic population. I think it is extremely difficult to perform large studies with tight academic and methodological rigour. There are many, many moving variables within a rehabilitation programme, that can be influenced/changed at a given time point, which makes it very difficult to carry out a well-designed RCT. This may be a result of the ’art’ aspect of rehabilitation – whereby programmes can change or altered based on a clinician’s experience, or ‘feeling’ in each clinical scenario. Likewise, situational pressures and contextual factors can heavily vary between athletes, as can individual and cultural preferences towards certain exercises (!!) and treatments.
It is for the above reasons, I think it is important to also consider our collective experiences (both positive and negative) to help inform our practice, as well as scientific research. Matt Jordan (University of Calgary), Matt Taberner (Recently Orlando Magic) and Matthew Buckthorpe (Isokinetic Group) have previously done an awesome job in summarising their positive rehabilitation experiences, workflows, and systems within academic journals. These types of reviews and mini case-series have allowed practitioners to gain invaluable insight into positive experiences within a high-performance setting. I think these types of publications are going to be part of the future for informing best practice within our field, in conjunction with scientific research.
Reviewer’s comments
- NMES and open-kinetic chain strengthening of the quadriceps and hamstrings should be used following ACL or meniscal surgery.
- There is not a need for post-operative bracing following ACL or meniscal injury.
- Appreciate the ‘art’ side of devising successful rehabilitation programmes – draw on collective experiences when devising rehabilitation programmes to help guide success, whilst there continues to be a lack of high-quality evidence to help inform our practice.
Recommended resources
Listen – Landing and deceleration training, gymnastics and return to play from ACL – Bill Knowles