KARAOKE: krill oil versus placebo in the treatment of knee osteoarthritis: protocol for a randomised controlled trial
Laslett, LL and Antony, B and Wluka, AE and Hill, C and March, L and Keen, HI and Otahal, P and Cicuttini, FM and Jones, G, KARAOKE: krill oil versus placebo in the treatment of knee osteoarthritis: protocol for a randomised controlled trial, Trials, 21, (79) pp. 1-14. ISSN 1745-6215 (2020) [Refereed Article]
Background: Knee osteoarthritis (OA) is a common and important cause of pain and disability, but interventions
aimed at modifying structures visible on imaging have been disappointing. While OA affects the whole joint,
synovitis and effusion have been recognised as having a role in the pathogenesis of OA. Krill oil reduces knee pain
and systemic inflammation and could be used for targeting inflammatory mechanisms of OA.
Methods/design: We will recruit 260 patients with clinical knee OA, significant knee pain and effusionsynovitis present on MRI in five Australian cities (Hobart, Melbourne, Sydney, Adelaide and Perth). These
patients will be randomly allocated to the two arms of the study, receiving 2 g/day krill oil or inert placebo
daily for 6 months. MRI of the study knee will be performed at screening and after 6 months. Knee symptoms,
function and MRI structural abnormalities will be assessed using validated methods. Safety data will be
recorded. Primary outcomes are absolute change in knee pain (assessed by visual analog score) and change
in size of knee effusion-synovitis over 24 weeks. Secondary outcomes include improvement in knee pain over
4, 8, 12, 16 and 20 weeks. The primary analyses will be intention-to-treat analyses of primary and secondary
outcomes. Per protocol analyses adjusting for missing data and for treatment compliance will be performed
as the secondary analyses.
Discussion: This study will provide high-quality evidence to assess whether krill oil 2 g/day reduces pain and
effusion-synovitis size in older adults with clinical knee OA and knee effusion-synovitis. If krill oil is effective
and confirmed to be safe, we will provide compelling evidence that krill oil improves pain and function,
changes disease trajectory and slows disease progression in OA. Given the lack of approved therapies for
slowing disease progression in OA, and moderate cost of krill oil, these findings will be readily translated into
Trial registration : Australian New Zealand Clinical Trials Registry, ACTRN12616000726459. Registered on 02
Universal Trial Number (UTN) U1111–1181-7087.
krill oil, osteoarthritis, pain, knee pain, magnetic resonance imaging (MRI)