One of the most important issues in the studies of chondroprotection is to be able to extrapolate a decrease in structural evolution into a delay in knee surgeries such as joint replacement, as studies are usually not long enough to provide this answer. Nevertheless, rapid progressors on a short period of time (Group for the Respect of Ethics and Excellence in Science (GREES) criteria) could help providing an answer as these patients have been shown to be at higher risk of surgeries. Objective(s): The aim of this post hoc analysis is to describe the efficacy of Strontium Ranelate (SrRan) on rapid radiological progression, from the first year, in patients from SEKOIA study (randomised study with 3 years of treatment by 2 doses of SrRan versus placebo in knee osteoarthritis). Material and methods: 1683 patients suffering from symptomatic primary knee osteoarthritis (Kellgren and Lawrence [KL] score of 2 or 3, joint space width (JSW) of 2.5 to 5 mm and pain assessed on a visual analogue scale of at least 40 mm) have been included and randomised to receive SrRan 1 g/day, 2 g/day or placebo during 3 years. Knee X-rays were performed yearly during 3 years, with a validated semi-automated method of joint space narrowing (JSN) assessment. During the first year, radiological progressors (defined as having a JSN >= 0,3 or >= 0,5 mm; over the SDD), have been compared between groups using a Chi2 test in the ITT population. Results: ITT set included 1371 patients (82% of the randomized set; 445 patients in SrRan 1g group, 454 patients in SrRan 2g group and 472 patients in placebo group) with a mean age of 63 +/- 7 years, a mean BMI of 30 +/- 5 kg/m2 and a mean JSW of 3.5 +/- 0.8 mm. 61% of patients were KL II and 69% were female. A significantly lower proportion of patients in SrRan1g and 2g groups had radiological progression during the first year compared to placebo: 12% and 13% versus 30%. The estimate of the between groups difference E (SE) was -8.07 (2.42), 95% CI [-12.81; -3.33] with p < 0.001 for SrRan 1g/d versus placebo and E (SE) was -6.91 (2.45), 95% CI [-11.71; -2.10] with p = 0.005 for SrRan 2g/d versus placebo. It corresponds to a decrease of the risk of rapid progression by 40% and 35% in the SrRan 1g and 2g groups compared to placebo Conclusion: In patients suffering from primary knee OA, SrRan at the dose of 1g or 2g/d decreases the number of rapid radiological progressors from the first year of treatment suggesting that the beneficial structural effect could be clinically relevant.
Chevalier, X., Richette, P., Bruyère, O., Chapurlat, R., Cooper, C., & Reginster, J. (2014). Strontium ranelate decreases the number of rapid radiological progressors from the first year in sekoia study. Osteoarthritis and Cartilage, 22, S461. https://doi.org/10.1016/j.joca.2014.02.878