Ouch! So sorry your Molly's going through this ... and you and your wife as well. It must be the season of hip dysplasia around here.
If you have any questions about it, one of our mods @sheshistory has been through hip and knee issues with her boys. She'll be more than happy to answer any of your questions. Her youngest, Truman, had to go through hip surgery when he was a very young pup. He's about 2 now, and as rambunctious as ever.