A 70-year-old man with diabetes and long-term osteoarthritis in his knees is presenting for follow-up. He reports that his pain has become much more severe, and says he is having difficulty with ambulation and is becoming fairly inactive. In the past, he tried ibuprofen and naproxen, but those offered limited improvement and he developed secondary ulcers. He says that taking acetaminophen is like “taking a sugar pill”—it offers no help. He had some relief from steroid injections 3 months ago, and again 1 month ago, but they were short-lived. A recent x-ray is shown below:

Which of the following is the next most appropriate step in the treatment of his condition?

a. Use oral steroids

b. Try another steroid injection

c. Inject the knee joint with ketorolac (Toradol)

d. Inject hyaluronic acid into his knee joints

e. Refer for knee replacements