Effects of Native Type II Collagen Treatment on Knee Osteoarthritis: A Randomized Controlled Trial

Objective: The aim of this randomized controlled study was to evaluate the efficacy of oral native type II collagen treatment on the symptoms and biological markers of cartilage degradation, when given concomitantly with acetaminophen in patients with knee osteoarthritis. Materials and Methods: Thirty-nine patients diagnosed with knee osteoarthritis were included and randomly distributed into two groups: one treated with 1500 mg/day of acetaminophen (group AC; n=19) and the other treated with 1500 mg/day of acetaminophen plus 10 mg/day of native type II collagen (group AC+CII; n=20) for 3 months. Visual Analogue Scale (VAS) at rest and during walking, Western Ontario McMaster (WOMAC) pain, WOMAC function, and Short Form-36 (SF-36) scores, were recorded. Coll2-1, Coll2-1NO2 and Fibulin-3 levels were quantified in urine as biomarkers of disease progression. ClinicalTrials.gov: NCT02237989. Results: After 3 months of treatment, significant improvements compared to baseline were reported in joint pain (VAS walking), function (WOMAC) and quality of life (SF-36) in the AC+CII group, while only improvements in some subscales of the SF-36 survey and VAS walking were detected in the AC group. Comparisons between the groups revealed a significant difference in VAS walking score in favour of the AC+CII group as compared to AC group. Biochemical markers of cartilage degradation in urine did not significantly improve in any of the groups. Conclusion: All in all, these results suggest that native type II collagen treatment combined with acetaminophen is superior to only acetaminophen for symptomatic treatment of patients with knee osteoarthritis.