Assurance of Safety and Function
Zimmer advertised the Durom Cup as deformation resistant with durable fixation and reliable bone on-growth. The Durom Cup experienced a high incidence of early failure and unacceptably high revision rates. The Durom Cup was voluntarily removed from the market by Zimmer under the pretense of inadequate instructions for use/surgical technique instructions. The FDA determined the cause for the recall as "Misbranding: Labeling False and Misleading".
A company that designs, manufactures, or offers any product for sale has a responsibility to protect patients from hazards that may be present in their products. The design process must take into account the types of actions that people make under reasonably foreseeable conditions of service, including intended use and reasonably foreseeable misuse. Hazards should be designed out of the product through engineering means. If the hazard cannot be eliminated, guards must be provided. In all cases in which the hazard cannot be eliminated or guarded against, clear and prominent warnings or instruction as to the dangers of the product must be provided. These are the three steps of the fundamental principles and rules of practice for safe and appropriate engineering of products. Hazard analysis and harm mitigation rests with the manufacturer.
Medical device manufacturers have a responsibility to characterize the mechanical performance of a device in typical and foreseeable worst-case clinically relevant conditions. In products like hip implants, the manufacturer has a responsibility to educate the users (surgeons, patients and other caretakers) concerning the device limitations including methods users can adopt to assure effectiveness and prevent injury. Implant safety and efficacy is greatly affected by the ability of the design withstand reasonably foreseeable physiologic forces at physiologic load rates.
Zimmer failed to investigate:
- The stability of the implant within bone
- Deformation/repeatability of placement/appropriate seating of the cup using their recommended preparation and installation techniques
- Biologic proof of fixation with the fixation surface used
Zimmer should have:
Helping Defective Hip Replacement Recipients In Wisconsin
- Performed sufficient testing to ascertain the performance characteristics of this device to assure adequate performance in patients like Ms. Bowers
- Changed the product and/or the instruction techniques to assure adequate performance prior to sale or
- Appropriately warned against use in specific patient types likely to have premature loosening prior to sale in the USA