Cannabis is effective for treating arthritis pain and for treating the underlying inflammation. CBD is a potent anti-inflammatory and I would reccomend a CBD rich tincture of whole plant cannabis. Experiment with different ratios of CBD:THC. Inhaled cannabis has a more rapid onset, and may be of benefit in treating acute symptoms and for providing immediate relief. Topicals also work rapidly and usually do not cause strong psychoactive effects. Edibles are also a good option, and I would start with a does of around 10 milligrams.