Patient Portal. Iowa Arthritis and Osteoporosis Center. 8421 Plum Drive. Urbandale, Iowa. 50322. Serving patients from the greater Des Moines area, Ames, Fort Dodge, Marshalltown, Newton, Mason City, Ottumwa, Centerville, Atlantic, and more. Specializing in the treatment of osteoporosis and osteopenia in addition to rheumatic diseases such as arthritis, rheumatoid ….