What is my legal recourse if my knee implant has failed?

You could sue the manufacturer of the knee implant.  This area of law is product liability.  You could sue the manufacturer for negligence and strict liability.  Negligence is based on the failure to exercise due care (that degree of care that in this case a reasonable manufacturer of this product would have exercised to prevent foreseeable injury).  In order to prove negligence, you would have to prove duty of care (discussed above), breach of duty (product was defective), actual cause, proximate cause and damages.  Actual cause means but for the failure of the knee implant, would you have sustained the injuries you have received?  If the answer is no, which appears to be the case, you have established actual cause.  Proximate cause means were there any unforeseeable intervening events which would relieve the manufacturer of liability?  If the answer is no, you have established proximate cause.  Damages (monetary compensation) you are seeking would be based on your medical bills, medical reports, and any wage loss.  Compensation for the medical bills and wage loss is straight reimbursement.  The medical reports will document the nature and extent of your injuries and will be used to determine compensation for pain and suffering.  Compensation for pain and suffering is an amount in addition to your medical bills.

You would only file one lawsuit with separate causes of action (claims) for negligence and strict liability.  Strict liability means the manufacturer is liable for the defective product whether or not the manufacturer exercised due care.

The manufacturer could assert the defense of assumption of the risk with regard to strict liability and negligence.  Assumption of the risk means you recognized and understood the danger and voluntarily chose to encounter it.  For example, if the knee implant had various limitations and you engaged in some activity beyond those limitations which resulted in your injury.  Most likely, this does NOT apply in your case, but I am just mentioning it in case the manufacturer raises the defense of assumption of the risk.

 In addition to your causes of action (claims) for negligence and strict liability, you may have a claim for breach of warranty.  Breach of warranty would apply to express warranties and implied warranties.  An express warranty would be a written warranty such as the knee implant was to last a certain number of years. 

There are two types of implied warranties.  There is an implied warranty of merchantability which means the implant is of a quality acceptable in the trade.  The other type of implied warranty is the implied warranty of fitness for a particular purpose which means the  implant had to meet the standards necessary for use as a knee.

Medical malpractice is negligence, but is separate from product liability.  Unless your doctor's negligence caused the problems with the knee implant, your claim would be against the manufacturer of the defective product and not the doctor.

A class action would have to be approved by a court and requires numerous plaintiffs with similar claims and the named representatives of the class would have to have claims common to those of the class members.

It would be advisable to speak with a personal injury.

You will need to file your lawsuit against the manufacturer for negligence, strict liability, and possibly breach of warranty prior to the expiration of the applicable statute of limitations or you will lose your rights forever in the matter.