What is the purpose of rooster comb injections?

Doctors use rooster comb injections to treat the pain of mild or moderate knee osteoarthritis in people who don't respond to more common treatments, such as heat, ice and store-bought pain relievers, according to WebMD. Also known as hyaluronan injections, these shots lubricate the knee and allow bones greater agility.

Because rooster comb injections are made from actual chicken combs, they are not suitable for patients who are allergic to poultry or eggs, states WebMD. Possible side effects for any person receiving this treatment include redness, joint swelling and pain, which can be severe in come cases. Patients typically experience pain relief within 12 weeks of the first injection.