Ten Year Implant Survivorship of the ANTHEM™ PS Total Knee System (ANTHEM PS)

A Prospective, Multicentre, Cohort Study Assessing the Safety and Efficacy of the ANTHEM™ PS Total Knee System in Patients Following a Total Knee Arthroplasty

The ANTHEM™PS Total Knee System is being conducted to demonstrate non-inferiority of 10 year implant survivorship in patients undergoing total knee arthroplasty for osteoarthritis compared to reported literature

Study Overview

• Status: Active, not recruiting
• Conditions: Arthroplasty, Replacement, Knee
• Intervention / Treatment: Device: ANTHEM™ PS Total Knee System implant

Detailed Description

The ANTHEM PS Study is a prospective, multicentre, cohort study to collect relevant patient reported, clinical, surgical and radiological data from 143 subjects implanted with the ANTHEM™PS Knee System for degenerative joint disease in up to 6 clinical sites globally. Total study duration for study participants will be 10 years with post-operative follow-up visits planned for 6 weeks, 1 year, 2 years, 5 years, 7.5 years and 10 years. The study will evaluate the 10 year implant survivorship and the safety and outcome of the ANTHEM™PS Knee System over 10 years. This is a post-market study of the ANTHEM™PS Total Knee System.

The primary objective of the study is to demonstrate non-inferiority (8% margin) of 10 year implant survivorship of the ANTHEM™PS Total Knee System in patients undergoing total knee arthroplasty for osteoarthritis compared to reported literature.

The secondary objectives of the study are to evaluate shorter and long term safety and outcomes of the ANTHEM™ PS Total Knee System.

• Knee injury and Osteoarthritis Outcomes Score (KOOS)
• 2011 Knee Society Score (2011 KSS)
• EQ-5D - 3L
• Femoral Fit ('Perfect Fit' rate)
• Radiographic Assessment
• Revision for any reason
• Adverse Events (AEs)

• Study Type: Interventional
• Enrollment (Actual): 148
• Phase: Not Applicable

Contacts and Locations

Study Locations

• China
  • Beijing
    • Beijing, Beijing, China, 100035
      • Beijing Jishuitan Hospital, Institute of Orthopedics & Traumatology,
• Italy
  • Milan, Italy, 20149
    • Instituto Clinico Sant'Ambrogio
  • Roma, Italy, 00186
    • Fatebenefratelli Isola Tiberina Gemelli Hospital - Isle of Rome
• Korea, Republic of
  • Hwasan, Korea, Republic of
    • Chonnam National University Hwasun Hospital
  • Seoul, Korea, Republic of
    • Severance Hospital, Yonsei University Health System
  • Gyeongsangnam
    • Yangsan, Gyeongsangnam, Korea, Republic of, 626-770
      • Pusan National University Yangsan Hospital
• South Africa
  • KZN
    • Durban, KZN, South Africa, 3630
      • Westville Hospital
• Thailand
  • Bangkok, Thailand, 10700
    • Siriraj Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 75 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Subject is a candidate for primary total knee arthroplasty due to degenerative joint disease
2. Subject is willing to sign and date an EC-approved consent form
3. Subject is male or female between the ages of 18 and 75 years of age
4. Subject plans to be available through ten (10) years post-operative follow-up
5. Subject agrees to follow the study protocol

Exclusion Criteria:

1. Subject would receive the ANTHEM™ Total Knee System on the affected knee as a revision for a previously failed total or unicondylar knee arthroplasty
2. Subject received TKA on the contralateral knee as a revision for a previously failed total or unicondylar knee arthroplasty
3. Subject has a history of patellar fracture, patellectomy, patello-femoral instability
4. Subject has inflammatory arthritis
5. Subject possesses a contralateral or ipsilateral revision hip arthroplasty
6. Subject has ipsilateral hip arthritis resulting in flexion contracture

7. Subject has one or more of the following arthroplasties that are not fully healed and well-functioning, as determined by the Investigator:

   • Ipsilateral or contralateral primary total hip arthroplasty or hip resurfacing arthroplasty
   • Contralateral primary total knee or unicondylar knee arthroplasty
8. Subject has an active infection or sepsis (treated or untreated)
9. Subject has presence of malignant tumor, either primary or metastatic, or benign tumor on leg with the knee to be treated
10. Subject has conditions that may interfere with the TKA survival or outcome (e.g. Paget's or Charcot's disease, vascular insufficiency, muscular atrophy, uncontrolled diabetes mellitus i.e. not under treatment with oral/injectable medications to control blood glucose levels, fibromyalgia, moderate to severe renal insufficiency or neuromuscular disease)
11. Subject has a chronic, contralateral lower extremity condition causing abnormal ambulation, which is not related to the knee (e.g. ankle fusion, ankle arthroplasty, previous hip fracture).
12. Subject is pregnant or plans to become pregnant during the study
13. Subject has an emotional or neurological condition that would pre-empt their ability or willingness to participate in the study, including mental illness, mental retardation, drug or alcohol abuse
14. Subject has a BMI>40
15. Subject is enrolled in another investigational drug, biologic, or device study
16. Subject is facing current or impending incarceration
17. Subject has an inadequate bone stock to support the device which would make the procedure unjustifiable, including but not limited to: severe osteopenia/osteoporosis or family history of severe osteoporosis/osteopenia

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Other: ANTHEM™ PS Total Knee System implant; The ANTHEM™ PS Total Knee System will demonstrate non-inferiority of 10 year implant survivorship in patients undergoing total knee arthroplasty for osteoarthritis compared to reported literature

Device: ANTHEM™ PS Total Knee System implant; The ANTHEM™ PS Total Knee System is a comprehensive system which allows surgeons to address simple to complex knee arthroplasties. The ANTHEM™ PS Total Knee System consists of the following components: Cobalt-Chrome (Co-Cr) femoral components - Posterior stabilised; Titanium primary tibial components; Posterior-stabilised ultra-high molecular weight polyethylene (UHMWPE); Polyethylene patella components The resulting product is sufficient to accommodate a wide range of clinical applications.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Ten year Anthem knee implant survivorship	The ANTHEM™ Total Knee System will demonstrate non-inferiority of 10 year implant survivorship in patients undergoing total knee arthroplasty for osteoarthritis compared to reported literature	Study participants will be followed for 10 years

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Knee injury and Osteoarthritis Outcomes Score (KOOS)	Participant Questionnaire to assess the patients opinion about their knee and associated problems.	Participant questionnaire completed at the Baseline timepoint, 6 weeks, 1,2, 5 and 10 years
2011 Knee Society Score (2011 KSS)	Participant questionnaire including a pre-operative section supplying information relating to the current symptoms, knee function, satisfaction with their pre-operative functional activities, and the expectations they have of the results of the total knee arthroplasty. The surgeon then completes information on objective measures such as joint alignment, instability, motions and symptoms.	Participant questionnaire completed at the Baseline timepoint, 6 weeks, 1,2, 5 and 10 years
EQ-5D-3L	Participant Questionnaire_ The EQ-5D-3L questionnaire is a self-rating evaluation questionnaire made up of health status measurements of mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. The participants also evaluate their overall health status using a visual analogue scale.	Participant questionnaire completed at the Baseline timepoint, 6 weeks, 1,2, 5, 7.5 and 10 years
Femoral Fit ('Perfect Fit' rate)	For each individual knee, 'overall femoral component fit' across the combined three femur levels; condylar, junctional and trochlear will be characterised under three classifications: Perfect Fit: just fit at all three levels or just fit at two levels and underhang at one; Overhang: overhang observed on at least one of the three levels; Underhang: underhang at all three levels or underhang at two and just fit at one	Femoral Fit will be measured at surgery, assessed for an estimated 1 hour
Radiographic Assessments to adequately assess the component position, prosthesis-bone interface, and the knee alignment.	The Knee X Rays taken during the course of the study will include Full leg weight-bearing, bilateral anteroposterior (AP), lateral and patellar radiographs. The knee assessments to be made from radiographs will include: Radiographic findings; Component orientation; Radiolucencies; Migration; Osteolysis and Stress shielding.	Radiographic assessments to be conducted at Pre-operation timepoint (Baseline), post-operative (Day 1), 6 weeks, 1,2, 5, and 10 years
Revision for any reason	Anthem implant revision done for any reason	Anytime during the 10 year study period
Adverse Events	All adverse events captured during the entire study period to provide patient safety oversight	Adverse events are collected at any time during the study with formal timepoints being at surgery, 6 weeks, 1,2, 5, 7.5 and 10 years

Collaborators and Investigators

• Sponsor: Smith & Nephew, Inc.
• Investigators: Study Director: Alison Walker, Smith & Nephew, Inc.

Study record dates

Study Major Dates

• Study Start (Actual): June 28, 2017
• Primary Completion (Estimated): December 30, 2028
• Study Completion (Estimated): December 30, 2029

Study Registration Dates

• First Submitted: February 6, 2017
• First Submitted That Met QC Criteria: March 7, 2017
• First Posted (Actual): March 13, 2017

Study Record Updates

• Last Update Posted (Estimated): February 22, 2024
• Last Update Submitted That Met QC Criteria: February 21, 2024
• Last Verified: February 1, 2024

More Information

Terms related to this study

• Other Study ID Numbers: 14-4065-09; OREM-ANTHEM-PMCFU (Other Identifier: Smith & Nephew)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: Yes