Comparing X-3 To N2vac Polyethylene With the Triathlon Total Knee System

• pain [ Time Frame: 10 years ] [ Designated as safety issue: No ]
• function [ Time Frame: 10 years ] [ Designated as safety issue: No ]
• radiographic outcomes [ Time Frame: 10 years ] [ Designated as safety issue: No ]
• health related quality of life [ Time Frame: 10 years ] [ Designated as safety issue: No ]
• adverse events [ Time Frame: 10 years ] [ Designated as safety issue: Yes ]

Methodology: This study will be a randomized, multi-center evaluation comparing N2vac polyethylene inserts and patellas with X3 inserts and patellas when used in the Triathlon PS total knee system.

Study Duration: 12-18 month enrollment period + 10 year follow-up for each case years total duration

Multi-centre study

Objectives

Primary: To compare the 10 year implant survival of the Triathlon PS total knee system when X3 polyethylene components are used to the same knee system when N2Vac components are used.

Secondary: To compare pain, function, radiographic outcomes, and health related quality of life of subjects in both treatment groups. Safety will be assessed by comparison of adverse events between the groups.

Number of Subjects 384 cases (197 each group)

• Device: X-3 polyethylene
  highly cross-linked polyethylene for knee arthroplasty
• Device: N2Vac polethylene
  conventional polyethylene

• Experimental: X-3
  X-3 polyethylene which is a new highly cross-linked poly that is theorized to be more durable in vivo
  Intervention: Device: X-3 polyethylene
• Active Comparator: N2Vac polethylene
  conventional polyethylene
  Intervention: Device: N2Vac polethylene

Inclusion Criteria:

• The subject requires a primary cemented total knee replacement.
• The subject has a diagnosis of osteoarthritis (OA), traumatic arthritis (TA), or avascular necrosis (AVN).
• The subject has intact collateral ligaments.
• The subject has signed the ethic committee approved, study specific Informed Patient Consent Form.
• The subject is willing and able to comply with post-operative scheduled clinical and radiographic evaluations and rehabilitation.

Exclusion Criteria:

• The subject has inflammatory arthritis.
• The subject is morbidly obese, BMI > 40.
• The subject has a history of total or unicompartmental reconstruction of the affected joint.
• The subject has had a high tibial osteotomy or femoral osteotomy.
• The subject has a neuromuscular or neurosensory deficiency, that would limit the ability to assess the performance of the device.
• The subject has a systemic or metabolic disorder leading to progressive bone deterioration.
• The subject is immunologically suppressed, or receiving chronic steroids (>30 days duration).
• The subject's bone stock is compromised by disease or infection and cannot provide adequate support and/or fixation to the prosthesis.
• The subject has had a knee fusion at the affected joint.
• The subject has an active or suspected latent infection in or about the knee joint.
• The subject is a prisoner.