The 3DKnee™ System: A Post-Market Study

The purpose of this study is to evaluate the survivorship and efficacy of the Encore 3DKnee™ system in a group of patients who will receive the 3DKnee™ as a primary (first) orthopedic implant in the knee. Each knee will be designated as a separate subject and followed for a period of 2 years.

Study Overview

• Status: Completed
• Conditions: Osteoarthritis; Rheumatoid Arthritis; Avascular Necrosis; Varus Deformity; Post Traumatic Arthritis
• Intervention / Treatment: Device: 3DKnee

• Study Type: Interventional
• Enrollment (Actual): 71
• Phase: Phase 4

Contacts and Locations

Study Locations

• United States
  • Missouri
    • St. Peters, Missouri, United States, 63376
      • St. Peter's Bone & Joint Surgery

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• This must be a primary knee replacement on this knee.

• Have knee joint disease related to one or more of the following

  • degenerative joint disease, including osteoarthritis or traumatic arthritis
  • Avascular necrosis of the femoral condyles
  • Post-traumatic loss of joint configuration, particularly when there is patellofemoral erosion, dysfunction or prior patellectomy
  • Moderate valgus, varus, or flexion deformities
  • Rheumatoid arthritis
• Patient is likely to be available for evaluation for the duration of the study
• Able and willing to sign the informed consent and follow study procedures
• Patient is not pregnant
• Patient must be over 18 years of age

Exclusion Criteria:

• If there has been a total knee replacement on this knee in the past (no revisions allowed in study)
• Infection, or history of infection, acute or chronic, local or systemic
• Alcoholism or other addictions
• Muscular, neurological or vascular deficiencies which compromise the affected extremity
• Obesity
• Insufficient bone quality
• Loss of ligamentous structures
• High levels of physical activity
• Materials sensitivity
• Prisoner
• Mental conditions that may interfere with the patient's ability to give an informed consent or willingness to fulfill the study requirements
• Patient is pregnant
• Is younger than 18 years of age

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Non-Randomized
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: Primary; Post market study	Device: 3DKnee; Subjects with knee osteoarthritis and willing to participate in the study

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Safety Assessment	Number of device related adverse events and device failures at the 2 year time frame.	2-year
Knee Society Score Evaluation	The Knee Society Score includes a knee rating and function score. This evaluation covers the knee rating score with three main parameters of pain, stability and range of motion and that flexion contracture, extension lag and misalignment should be dealt with as deductions. Thus, 100 points will be obtained by a well-aligned knee with no pain, 125 degrees of motion, and negligible anteroposterior and mediolateral instability. 50 points are allotted for pain, 25 for stability, and 25 for range of motion. Grading for KS Score: Excellent (90-100), Good (80-90), Fair (70-79) and Poor (<70).	2 year
Knee Society Function Score	The Knee Society Score includes a knee rating and function score. Patient function considers only walking distance and stair climbing, with deductions for walking aids. The maximum function score, which is also 100, is obtained by a patient who can walk an unlimited distance and go up and down stairs normally. Walking ability is expressed in blocks (approximately 100 meters). Stair climbing is considered normal if the patient can ascend and descend stairs without holding a railing. A score of > or = to 60 on the function score is considered success.	2-year
Number of Participants With >2mm Wide at the Bone/Cement Interface or a >3 Degree or >3 mm Migration (Shift) of the Component.	Radiographic failure is defined as a complete radiolucent line > 2mm wide at the bone/cement interface or a >3 degree or >3 mm migration (shift) of the component.	2-year

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Oxford Knee Score	Questionnaire on the perceptions of patients about a total knee replacement. Score between 0 and 48 where: 0 to 19 may indicate severe knee arthritis, 20 to 29 may indicate moderate to severe knee arthritis, 30 to 39 may indicate mild to moderate knee arthritis and 40 to 48 may indicate satisfactory joint function.	2-year

Collaborators and Investigators

• Sponsor: Encore Medical, L.P.
• Investigators: Principal Investigator: John McAllister, M.D., St. Peter's Bone and Joint Surgery

Publications and helpful links

Helpful Links

• Sponsor company home page

Study record dates

Study Major Dates

• Study Start: October 1, 2006
• Primary Completion (Actual): October 1, 2010
• Study Completion (Actual): October 1, 2010

Study Registration Dates

• First Submitted: September 30, 2008
• First Submitted That Met QC Criteria: October 1, 2008
• First Posted (Estimate): October 2, 2008

Study Record Updates

• Last Update Posted (Estimate): March 2, 2011
• Last Update Submitted That Met QC Criteria: February 8, 2011
• Last Verified: February 1, 2011

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathologic Processes; Joint Diseases; Musculoskeletal Diseases; Arthritis; Necrosis
• Other Study ID Numbers: PS - 703