Prospective Multicenter Post Approval Study of the LPS-Flex Mobile Bearing Knee

The NexGen LPS-FLex Mobile Bearing Knee received FDA approval for commercial distribution in
the US on December 10, 2007. The approval was in accordance with a "condition of approval" to
perform a 10-year post approval study to evaluate the longer-term safety and effectiveness of
the LPS-Flex Mobile Bearing Knee. The post approval study will consist of patients from the
investigational device exemption study arm (Group 1) as well as patients who are eligible for
a total knee replacement and have been chosen to receive the LPS-Flex Mobile Knee (Group 2).
Group 1 will be followed through a total of 10 years from the date of surgery and has
completed t his portion of the study. Group 2 will be followed through a total of 5 years
from the date of surgery.

Inclusion Criteria:

- Osteoarthritis

- Primary and secondary traumatic arthritis

- Avascular necrosis of the femoral condyle

- Moderate varus, valgus, or flexion deformities (i.e. valgus/varus deformity of less
than or equal to 15 degrees, fixed flexion deformity of less than or equal to 10
degrees)

Exclusion Criteria:

- Previous history of infection in the affected joint and/or local/systemic infection
that may affect the prosthetic joint

- Insufficient bone stock on femoral or tibial surfaces

- Skeletal immaturity

- Neuropathic arthropathy

- Osteoporosis or any loss of musculature or neuromuscular disease that compromises the
affected limb

- A stable, painless arthrodesis in a satisfactory functional position

- Severe instability secondary to the absence of collateral integrity

- Total knee arthroplasty is contraindicated in patients who have rheumatoid arthritis
(RA) and an ulcer of the skin or a history of recurrent breakdown of the skin because
their risk of postoperative infection is greater. RA patient using steroids may also
have increased risk of infection. Late infections in RA patients have been reported
24+ months postoperative.

- Patient is a poor compliance risk, i.e., history of ethanol or drug abuse, or mental
handicap that would compromise patient compliance with respect to rehabilitation or
follow-up

- Patient is not willing or able to give informed consent to participate in the
follow-up program

- Patient is not willing to return for all scheduled follow-up appointments as defined
by this protocol.