Wellsandt et al (2017) Limb Symmetry Indexes Can Overestimate Knee Function After Anterior Cruciate Ligament Injury
Comparison between single leg hop and quad strength – in two different ways.
Who - Non professional cutting athletes, 14-55 yrs old(Excluded other significant injuries).
Limb Symmetry Index (LSI) = comparison between Left and Right during an assessment.
Estimated pre-injury capacity (EPIC) = measuring uninvolved limb pre-operatively then comparing to the involved side at 6 months post-op.
Results
57% achieve 90% LSI at 6 months post-op
29% achieve 90% EPIC criteria at 6 months post-op
34% who meet all LSI standards at 6 months post-op, DIDN’T reach 90% EPIC criteria
2 year post-op follow up: 11 re-ruptures (3 of those didn’t meet LSI or current standard) leaving a further 8 participants (4 ipsilateral and 4 contralateral ie. opposite leg). 6 of which meet LSI at 6 months but did not meet EPIC!
Recommendation
An isokinetic dynamometry assessment of the un-injured leg pre-op is appropriate to measure EPIC and it seems this could reduce the risk of further ACL by not returning to sport to early
We are lucky enough at the Melbourne Knee Clinic to have an affiliation with Swinburne University to do all our isokinetic testing. See our referrers page so you can also assess this service for your patients to get quality data to make good decisions.
If this is not feasible then limb symmetry of 110% is a more appropriate figure for strength considering the above findings.
Consideration needs to be given to the fact that this testing was done at 6 months post operative which is significantly early to return to sport even in an elite population.
Melbourne Knee Clinic has a two staged Return to Sport guideline (see website for further details)
