After Breast Augmentation with Saline 7 months ago, I need a Capsulectomy. Is it necessary to replace the implants?

The risk of recurrence of capsular contracture is quite high without implant replacement. If the implants are not under the muscle then that should be considered also. In my experience the best protection against recurrent CC is Strattice in addition to capsulectomy and implant replacement.

There is no certain answer to this question. Despite lots of research, we still do not know for certain what causes capsular contractures. A popular theory is that there is a biofilm on the implant that contributes to the inflammatory response that causes the contracture. Surgeons that believe this theory might suggest doing everything possible to remove anything that might be associated to this biofilm. This would include complete removal of the capsule and anything touching the capsule which would include the implant. Even if this is done, there is no guarantee that you will not develop another contracture. My rule of thumb is that if the implant pocket appears to be contaminated, has areas of calcification, spilled gel implants, etc., then implant replacement should be done. If the pocket looks clean, but just the wall of the capsule is thickened, I tend to complete a capsulotomy or change the implant pocket and often use the same implants after bathing them in an antibiotic solution.

This is a very complex question and we don't have enough information to answer this fully. You may benefit from implant exchange because some implants have less of a chance of recurrent capsular contracture. You may also benefit from pocket change, acellular dermal matrix, etc.  You need a full consultation. If your previous surgeon is a board certified plastic surgeon who specializes in revisional breast surgery, speak to him/her. If not, seek another opinion. If this is not treated appropriately, you can be in for a long haul of repeat surgeries and medical bills.