What could be causing this butt implant pain 9 months post-op?

Thank you for the question dear @LRJ. The reason can be a lot of them it's hard to let you know one of the reason without testing. Please make an appointment with your surgeon and have run test and evaluation. Your safety is always first.

The majority of plastic surgeons in the United States, do not offer gluteal implants. There’s probably good reason for this. The procedure is known to have high complication rates and high failure rates. Typically infected foreign bodies should be removed and the tissues allowed to heal without foreign bodies. The textbook answer is generally that any contaminated foreign body will remain contaminated until removed. There are certain exceptions to highly vascular areas like in the face. There have been attempts of salvaging, infected implants for breast surgery and surgeons have tried this with mixed success in the past, including gluteal implants. The first line of having an affection is tenderness. This could very well be a recurrence infection, and I would guess that is the most likely underlying explanation. I think you need to get yourself checked out ASAP. Infections can spread rapidly become more serious and potentially cause major health issues, including potential fatality.
Even if you don’t have an inspection, do you need to make sure that there isn’t something more serious going on. I suggest you follow up with your provider immediately.
Best,
Mats Hagstrom, MD