What kind of regulatory pathway would be required for an antibiotic-releasing hip stem?
CDRH Regulatory. Class 2 – Special Controls

Is it a device, drug, biologic, or combination?
Combination

What is its “primary mode of action?
Treatment of hip joint infection with hip stem. Releasing antibiotics on a fully weight-bearing implants

Is it Class I, II, II?
Class II

What claims would you recommend we make for it? An example of a claim is “fights infection in bone (osteomyelitis) and reduces incidence of hip implant failure”. Any claim that you say, you have to lay out a plan to prove it.
Suffering from hip pain due to common injuries, hip arthritis, avascular necrosis or osteonecrosis.

Drawing on some of your experience from the week we did pre-clinical research, what pre-clinical research studies would you recommend be done to prove the claims?
Preclinical in vivo and vitro studies would be recommend. Also, biocompatibility testing of a material prior to clinical studies will be required.

Guessing as best you can, what sorts of clinical trials would you recommend in the IDE? Does it need an IDE at all?
CDRH ->Class 1,2 ->510(k). Investigational Device Exemption (IDE) is not need at all for clinical trial.