Open vs. closed kinetic chain exercises after ACL surgery
Controversy surrounding the use of open kinetic chain (OKC) exercises following anterior cruciate ligament (ACL) reconstruction, especially in the early phases has evolved over many decades.
It is known that the ACL graft is at its most vulnerable during the first 6-12 weeks following surgery, and it has been theorised that OKC exercises lead to increased laxity in the graft, thus placing it at greater risk of of failure.
The current systematic review however, concludes that based upon the current available evidence, there does not appear to be any significant difference in graft laxity, quadriceps strength, patient-report function or physical function.
This systematic review included a thorough meta-analysis, which evaluated the timing of the exercise protocols as well as the graft used, and took into account quality of evidence, clinical and statistical heterogeneity and risk of bias using the GRADE approach.
A total of 10 studies was included in this review. Collectively, this included 485 participants, with a mean age of 24 to 33 years of age with 74% of them males.
Laxity
Laxity was measured in millimetres using arthrometry. Low to moderate quality evidence suggests no statistically significant or clinically important difference (set at 2 mm) in laxity when introducing OKC exercises before 6 weeks even when comparing different graft types. This was also the case when OKC exercises were introduced after 6 weeks.
Strength
Strength of the quadriceps was measured using either an isokinetic system or a dynamometer. Low to moderate quality evidence suggests there was no strength difference at any time point or with any graft with the early introduction of OKC exercises (before 6 weeks) compared to closed kinetic chain (CKC) exercises.
There was only limited evidence of no difference at short and long-term follow-up with late introduction of OKC exercises and low quality evidence to suggest that OKC exercises resulted in a statistically significant improvement in strength at medium-term follow-up.
Patient-Reported Function
The Lysholm score and Hughston Clinic Questionnaires were used for self-reported function. In the studies with early introduction of OKC exercises, there was low to moderate quality evidence that showed no difference in patient-reported function at any time point and limited evidence that showed the same with late introduction of OKC exercises.
Physical Function
The triple crossover hop and single-leg hop were used as outcome measures physical function. No difference was found at any time point with the early addition of OKC exercises. Similarly, no difference was found when OKC exercises were introduced later at the short and medium term follow-ups.
Overall, based on the current low-medium quality evidence, there does not appear to be any significant difference in graft laxity, quadriceps strength, patient-report function or physical function.
It is important to note that a large proportion of participants was male and therefore the results may not be as applicable to females. Furthermore, higher quality randomised controlled trials in the future would be beneficial to further evaluate this topic.
> From: Perriman et al., J Orthop Sports Phys Ther 48 (2018) 552-566. All rights reserved to Journal of Orthopaedic & Sports Physical Therapy. Click here for the online summary.
