This is the first blog in a 4 part series looking into successful outcomes following ACL injury.
An ACL injury is generally a stressful time for an individual. Upon seeking professional advice, some people decide that surgical ACL reconstruction is the best option for them whereas others decide to undertake conservative rehabilitation of their knee. Often, entering ACL reconstruction, individuals have a few goals and expectations in mind. These commonly include…
-Return to Sport (RTS) within 12 months
-Return to play at previous level of performance
-Low likelihood of reinjury
……But how realistic are these?
RTS has mny contributing factors in individuals following ACLR- physical and psychological being just two. This blog will review and discuss the current evidence around RTS following ACL injury based on varying levels of participation and varying definitions of RTS. Table 1 shows the RTS rates in athletes at varying levels of competition
Elite/professional athletes (a)
Non Elite (b)
Level of RTS
Pre-injury level of competition or higher. Various sports; mainly male
Return to some form of sport
Return to pre-injury level of sport
Return to competitive sport
RTS rate (time frames inconsistent)
83% (95%CI= 77%-88%). Time frame for RTS between 6-13months depending on sport
81% (95% CI = 74%-87%)
65% (95% CI = 59%-72%
55% (95% CI = 46%-63%)
(a) Lai et al 2018, systematic review and meta-analysis
(b) Ardern et al 2014, systematic review and meta-analysis; time frame non-specific due to systematic review
Why is there a difference in RTS rates (to preinjury levels) between elite and non-elite sports people?? Potential reasons include:
-Better access to high-quality medical and rehabilitation services, and more allocated time with in a week in which to complete rehab
-Elites may have inherently superior athletic skill, proprioception and fitness levels to recreational athletes
-Elite athletes may have different psychological profiles than non-elite athletes
-Elite athletes may be more willing to accept a higher level of reinjury risk at return to sport than non-elites, eg trading off the chance to win Olympic gold
-More financial incentives to return to sport, plus sporting career objectives
Additionally, according to Ardern et al (2014), the following factors have been found to influence RTS rates
Impact: Men 1.4x more likely to return to preinjury sporting level; and 1.7x more likely to return to competitive sport.
Implication: ie. Women often still RTS but possibly to a more recreational level
Impact: Younger age favoured return to preinjury level of sport (p<0.01)
Implication: May reflect greater exposure to sport eg at school, or more time to participate without work/family commitments; or less concern around impact of reinjury to QOL
SUBJECTIVE KNEE RATING
Impact: Approx 2x higher rate of return to preinjury sport with higher subjective (IKDC) knee rating, ‘normal’ compared to ‘nearly normal, abnormal or severely abnormal’
Implication: Reflects importance of progressing physical rehab to achieve a high subjective rating of knee function
Impact: Lower fear of reinjury favoured returning to preinjury lelel of sport (SMD 0.9, p<0.001)
Implication: Reflects importance of physical rehab to a high standard to build foundations for knee confidence, along with targeted mental skills training
Impact: More symmetrical hopping performance on objective testing favoured returning to preinjury sport level (small SMD 0.3, p<0.05)
Implication: Reflects importance of working towards regaining limb symmetry with dynamic maximal tasks, and objective physical testing
Impacl: Greater psychological readiness for RTS favoured returning to preinjury levels of sport (SMD 1.0, p<0.01)
Implication: Reflects importance of mental rehab as appropriate, alongside comprehensive physical rehab
Impact: Odds ration 2.4, but only 5% difference in rates of return to competitive sport favouring hamstring graft over PT autograft
Implication: Most probably reflects bias in surgeon preference, and number of hamstring grafts vs PT grafts in the analysis
Ardern and Osterberg et al (2016) also looked at satisfaction following ACLR and found that at minimum 2years follow up (average 3years)
-While 39% of people who were satisfied with their ACLR outcome hadn’t returned to preinjury activity, 20% of the dissatisfied group had returned to preinjury activity
-People who had returned to preinjury activity and had higher QOL scores and psychological self efficacy scores were more likely to be satisfied with the outcomes of ACLR
So, Are these ACLR outcomes considered successful?
The stats above highlights a few things
1) It may be difficult to impose a generic description of successful outcome following ACLR
2) 55% return to competitive sport is probably lower than most non-elites entering ACLR expect. ie Just because someone has ACLR doesn’t automatically mean they’ll RTS.
Many people undergo ACLR on the false assumption that this will allow them to return to preinjury or competitive sport, however the desire to RTS isn’t in itself necessarily an indicator to undergo ACLR as there are many factors (noted above, and expanded upon in later blogs) which mean that despite ACLR, the goal of RTS is often not met.
3) Some people may still deem their ACLR successful even if they don’t return to their previous level of competitive sport as they may be happy to trade a lower level of competition to offset reinjury risk (81% return to any sporting level)
4) As noted in our previous blog, many people are happy and able to be ‘adapters’ in their post-ACL injury choice of sport. This also reinforces the importance of discussing non-operative ACL management in people who have an otherwise stable knee and are interested in considering alternative sporting options.
Overall- an honest and individualised “shared decision making” discussion with the patient regarding options post-ACL injury (+/- surgery) is critical. This should include sporting expectations as this is imperative to optimize satisfaction and successful outcomes.
-Ardern CL, Glasgow, P, Schneiders A, et al. Br J Sports Med 2016;0:1–12.
-Ardern CL, Osterberg A, Sonesson S, et al. Arthroscopy 2016; 32 (8) 1631-1638
-Ardern CL,Taylor NF, Feller JA, et al. Br J Sports Med 2014;48:1543–1552.
-Lai CCH, Ardern CL, Feller JA, et al. Br J Sports Med 2018;52:128–138.