Postmarketing Study to Determine Performance of the SIGMA HP® PARTIAL KNEE SYSTEM

This is an interventional treatment trial for Osteoarthritis focused on measuring Osteoarthritis, Knee, Knee replacement, Knee implant, Knee arthroplasty, Unicompartmental, Primary, Partial, Patellofemoral, Medial, Lateral, Bicompartmental, Cemented, Post-traumatic arthritis of the tibio-femoral and/or patellofemoral articular surfaces, History of Gout or pseudo-gout. Read More

Inclusion Criteria:

• Male or female subjects, aged at least 21 years.
• Subjects who are able to give voluntary, written informed consent to participate in this clinical investigation and from whom consent has been obtained.
• Subjects, who, in the opinion of the Clinical Investigator, are able to understand this clinical investigation, co-operate with the investigational procedures and are willing to return to the hospital for all the required post-operative follow-ups.
• Subject has non-inflammatory degenerative joint disease (NIDJD), including: osteoarthritis, posttraumatic arthritis, avascular necrosis and chondrocalcinosis.
• Subject has a functional stable knee.
• Subject, in the opinion of the Investigator, is suitable for either a single or bicompartmental knee replacement.

• Subject meets the following selected radiographic parameters:

  • X-ray evaluation confirms the presence of NIDJD
  • Disease location: 1 to 2 compartments, maximum. Disease can be present in the patellofemoral compartment, the medial tibiofemoral compartment, lateral tibiofemoral compartments alone or in any two compartments.
  • Disease severity: Kellgren and Lawrence44 Grade II or greater for all compartments replaced.

Exclusion Criteria:

• Subjects who, in the opinion of the Clinical Investigator, have an existing condition that would compromise their participation and follow-up in this clinical investigation.
• Women who are pregnant.
• Subjects who are known drug or alcohol abusers or with psychological disorders that could affect follow-up care or treatment outcomes.
• Subjects who have participated in a clinical investigation with an investigational product in the last 3 months.
• Subjects who are currently involved in any injury litigation claims.
• Multiple joint involvement that will compromise rehabilitation (for example: advanced hip, ankle or spine disease).
• Known to be a prisoner, mentally incompetent, an alcohol / drug abuser, involved in medical-legal case or worker's compensation
• Previous knee arthroplasty (any type) in any one of the three compartments of the knee.
• Requires more than a lateral soft tissue release or an anterior cruciate ligament reconstruction.
• Uncorrectable anatomical tibio-femoral angle.
• Bone deficiency requiring structural bone grafts to support the implants.
• Previous patellectomy.
• For Subjects indicated for a patellofemoral arthroplasty, Subject has uncorrected patella baja (Caton-Deschamps ratio less than or equal to 0.6).
• Tri-compartmental disease process (patella-femoral, medial tibio-femoral and lateral tibio-femoral).
• Active bacterial infection that may spread to other areas of the body (e.g., osteomyelitis, pyogenic infection of knee joint, urinary tract infection, etc.).
• Significant neurological or musculoskeletal deformity or a disease that may affect gait or weight bearing, (e.g., muscular dystrophy, multiple sclerosis, amputation).
• Known allergy to implant materials.