Glucosamine sulfate effect on the degenerated patellar cartilage: preliminary findings by pharmacokinetic magnetic resonance modeling.

Normal and degenerated cartilages have different magnetic resonance (MR) capillary permeability (K(trans)) and interstitial interchangeable volume (v(e)). Our hypothesis was that glucosamine sulfate treatment modifies these neovascularity abnormalities in osteoarthritis. Sixteen patients with patella degeneration, randomly distributed into glucosamine or control groups, underwent two 1.5-Tesla dynamic contrast-enhanced MR imaging studies (treatment initiation and after 6 months). The pain visual analog scale (VAS) and American Knee Society (AKS) score were used. A two-compartment pharmacokinetic model was used. Percentages of variations (postreatment-pretreatment/pretreatment) were compared (t-test for independent data). In the glucosamine group, pain and functional outcomes statistically improved (VAS: 7.3 +/- 1.1 to 3.6 +/- 1.3, p < 0.001; AKS: 18.6 +/- 6.9 to 42.9 +/- 2.7, p < 0.01). Glucosamine significantly increased K(trans) at 6 months (-54.4 +/- 21.2% vs 126.7 +/- 56.9%, p < 0.001, control vs glucosamine). In conclusion, glucosamine sulfate decreases pain while improving functional outcome in patients with cartilage degeneration. Glucosamine sulfate increases K(trans), allowing its proposal as a surrogate imaging biomarker after 6 months of treatment.