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Table 5: Summary of Original and Revision Groups’
“Revision Free” Rates
Original Surgery
Group
Revision Surgery
Group
Relative Risk Reduction
[absolute reduction]
16.0%
[0.3%]
27.6%
[0.9%]
MECHANICAL MALFUNCTION (only) REVISION
Malfunction Free Patients
96.6%
95.2%
• IZ devices Revision
Free
96.7%
95.8%
• Non-IZ devices
Revision Free
96.0%
93.9%
Relative Risk Reduction
[absolute reduction]
18.6%
[0.7%]
30.9%
[1.9%]
Study Strength and Weaknesses
As a voluntary registration, there was a relatively high PIF return
rate (strength), but there was not 100% compliance (weakness).
Additionally, the PIF return did not guarantee that all requested
data fields were completed (weakness). The PIF system collects
data when a surgical revision occurs (strength). However, two (2)
limiting factors (weaknesses) include:
1. The PIF database does not record events (e.g., infection) that
are successfully treated without a surgical explant procedure,
i.e., if no implanted system component changes occur, or no
surgical device adjustment occurs, then no PIF is completed
and the event (infection) is not recorded in the database.
2. There are currently no mechanisms for removing patients
from the database who have died (or lost to follow-up) and
therefore lack any reported follow-up data. AMS expects the
“lost to follow-up” occurrence to be similar and consistent
between groups; regardless of over (or under) reporting the
reported rates would remain comparable.
Final Safety Findings (key endpoints)
The study demonstrated the IZ antimicrobial impregnation
did not affect the mechanical performance of the device. The
study demonstrated the IZ antimicrobial impregnation devices
in both original and revision surgery groups consistently had
slightly higher revision free rates, overall, for infection and
mechanical malfunction. In addition, the corresponding relative
risk reduction for the original surgery IZ group demonstrated
a 16.0% relative risk reduction for Infection and a 18.6%
relative risk reduction for mechanical malfunction. The data
demonstrate that the AMS 800 (IZ and Non-IZ) device is and
remains safe and effective.
Patient Counseling Information
Patients should be counseled in order to have a realistic
expectation of the physical, psychological and functional
outcome of the implantation. The risks, benefits and potential
adverse events of all available treatment options should be
discussed with the patient and considered by the physician and
patient when choosing a treatment option.
An appropriate patient history, including history of personality
disorders, and diagnostic work-up should be a part of the patient
decision making process.
Some patients may become dissatisfied by the presence of the
prosthetic device in their body. This issue should be discussed
with the patient prior to the surgery. Patient dissatisfaction may
lead to device removal. Patients should also be aware that the
AMS 800 is not considered to be a lifetime implant.
It is also important that the physician discusses with the patient
