A Prospective Study to Evaluate the ConforMIS iTotal® (PS) Knee Replacement System

This is a prospective clinical study designed to observe the long-term clinical outcomes of total knee arthroplasty using a patient-specific, posterior stabilized implant in patients with osteoarthritis.

Study Overview

• Status: Terminated
• Conditions: Osteoarthritis, Knee
• Intervention / Treatment: Device: iTotal PS KRS

Detailed Description

The study is prospective. Subjects will be implanted with an iTotal® PS Knee Replacement System. The study will include a minimum of 100 subjects across up to 10 sites. The patients enrolled in this study may represent the first cases of the iTotal PS KRS implanted at a particular site; data collected for the first 15 patients at each site will be analyzed separately from the rest of the enrolled population. This will provide visibility towards determining if there exists a learning curve in the implantation process of the iTotal PS KRS. The study sites will be located in the United States.

• Study Type: Observational
• Enrollment (Actual): 102

Contacts and Locations

Study Locations

• United States
  • North Carolina
    • Chapel Hill, North Carolina, United States, 27599
      • UNC Orthopedics
  • Texas
    • Austin, Texas, United States, 78751
      • Texas Institute for Hip & Knee Surgery
  • Vermont
    • Morrisville, Vermont, United States, 05661
      • Mansfield Orthopaedics
  • West Virginia
    • Huntington, West Virginia, United States, 25702
      • Scott Orthopedic

Participation Criteria

Eligibility Criteria

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

• Sampling Method: Non-Probability Sample

Study Population

Patients with osteoarthritis of the knee

Description

Inclusion Criteria:

• Clinical condition included in the approved Indications For Use for the iTotal® PS
• Osteoarthritis, as confirmed by the investigator's assessment of disease status at screening visit that warrants a TKR procedure. Disease status is assessed by Clinical and Radiographic assessment.
• Willingness to participate in the clinical study, to give informed consent, and to attend all follow-up visits
• > 18 years of age

Exclusion Criteria:

• Simultaneous bilateral procedure required
• BMI > 40
• Active malignancy (defined as a history of any invasive malignancy - except non- melanoma skin cancer), unless patient has been treated with curative intent and there have been no clinical signs or symptoms of the malignancy for at least 5 years
• Poorly controlled diabetes
• Neuromuscular conditions which prevent patient from participating in study activities
• Active local or systemic infection
• Immunocompromised
• Fibromyalgia or other general body pain related condition
• Rheumatoid arthritis or other forms of inflammatory joint disease
• Loss of bone or musculature, osteonecrosis, neuromuscular or vascular compromise in the area of the joint to be operated on, to an extent that the procedure is unjustified
• Diagnosed with or receiving treatment for Osteoporosis
• Other physical disability affecting the hips, spine, or contralateral knee
• Severe instability due to advanced loss of osteochondral structure
• Prior arthroplasty of the affected knee, including High Tibial Osteotomy (HTO)
• Unwilling or unable to comply with study requirements
• Participation in another clinical study which would confound results
• Allergy to any of the implant materials

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Baseline from 1-Year in KSS	Change in Knee Society Scores from the pre-operative visit to the 1-year post-operative visit. The Knee Society Score (KSS) includes an Objective Knee Score, Function Score, Satisfaction Score, and Expectation Score. The objective knee score, completed by the surgeon, includes a VAS score of pain walking on level ground and on stairs or inclines, as well as an assessment of alignment, ligament stability, and ROM, along with deductions for flexion contracture or extensor lag. Patients then record their satisfaction, functional activities, and expectations (Scuderi et al., 2012).	2 Years

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change from baseline in KSS at years 2, 5 and 10 post-implantation	The Knee Society Score includes an Objective Knee Score, Function Score, Satisfaction Score, and Expectation Score. The Knee Society Score (KSS) includes an Objective Knee Score, Function Score, Satisfaction Score, and Expectation Score. The objective knee score, completed by the surgeon, includes a VAS score of pain walking on level ground and on stairs or inclines, as well as an assessment of alignment, ligament stability, and ROM, along with deductions for flexion contracture or extensor lag. Patients then record their satisfaction, functional activities, and expectations (Scuderi et al., 2012).	Up to 10 years
Change from baseline in KOOS at years 1, 2, 5 and 10 post-implantation	The Knee Injury and Osteoarthritis Outcome Score (KOOS) is a 42 question knee-specific instrument, developed to assess the patients' opinion about their knee and associated problems.	Up to 10 years
Post-operative limb alignment if long leg x-rays available	Comparison of limb alignment between pre-operative and post-operative x-rays.	2 years
Length of hospital stay in hours	How long the patient is in the hospital from the time of admission to the time of discharge.	1 year
Blood loss during surgery	Estimated blood loss during surgery (mL)	1 year
Transfusion rate	Rate of patients who require blood transfusions during surgery	1 year

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Revision rates post-implantation	Rate of patients that require a revision of the total knee replacement for any reason.	Collected from the date of implantation to the end of the study. Up to 10 years.
Length of procedure: Skin to Skin	The duration of the knee arthroplasty starting from the time the surgeon makes the first incision and ending when the surgeon sutures the initial incision.	1 year

Collaborators and Investigators

• Sponsor: Restor3D
• Investigators: Study Director: Marc Quartulli, Restor3D

Publications and helpful links

General Publications

• Kurtz S, Ong K, Lau E, Mowat F, Halpern M. Projections of primary and revision hip and knee arthroplasty in the United States from 2005 to 2030. J Bone Joint Surg Am. 2007 Apr;89(4):780-5. doi: 10.2106/JBJS.F.00222.
• Rougraff BT, Heck DA, Gibson AE. A comparison of tricompartmental and unicompartmental arthroplasty for the treatment of gonarthrosis. Clin Orthop Relat Res. 1991 Dec;(273):157-64.
• Fitzpatrick C, FitzPatrick D, Lee J, Auger D. Statistical design of unicompartmental tibial implants and comparison with current devices. Knee. 2007 Mar;14(2):138-44. doi: 10.1016/j.knee.2006.11.005. Epub 2006 Dec 22.
• Fitz W. Unicompartmental knee arthroplasty with use of novel patient-specific resurfacing implants and personalized jigs. J Bone Joint Surg Am. 2009 Feb;91 Suppl 1:69-76. doi: 10.2106/JBJS.H.01448.
• Bourne RB, Chesworth BM, Davis AM, Mahomed NN, Charron KD. Patient satisfaction after total knee arthroplasty: who is satisfied and who is not? Clin Orthop Relat Res. 2010 Jan;468(1):57-63. doi: 10.1007/s11999-009-1119-9.
• Noble PC, Conditt MA, Cook KF, Mathis KB. The John Insall Award: Patient expectations affect satisfaction with total knee arthroplasty. Clin Orthop Relat Res. 2006 Nov;452:35-43. doi: 10.1097/01.blo.0000238825.63648.1e.
• Scuderi GR, Bourne RB, Noble PC, Benjamin JB, Lonner JH, Scott WN. The new Knee Society Knee Scoring System. Clin Orthop Relat Res. 2012 Jan;470(1):3-19. doi: 10.1007/s11999-011-2135-0. No abstract available.

Study record dates

Study Major Dates

• Study Start (Actual): May 1, 2017
• Primary Completion (Actual): November 1, 2022
• Study Completion (Actual): November 1, 2022

Study Registration Dates

• First Submitted: May 8, 2017
• First Submitted That Met QC Criteria: May 11, 2017
• First Posted (Actual): May 12, 2017

Study Record Updates

• Last Update Posted (Actual): October 25, 2023
• Last Update Submitted That Met QC Criteria: October 23, 2023
• Last Verified: October 1, 2023

More Information

Terms related to this study

• Keywords: osteoarthritis; total knee replacement; knee replacement; knee arthroplasty; TKA; patient-specific; posterior stabilized
• Additional Relevant MeSH Terms: Joint Diseases; Musculoskeletal Diseases; Rheumatic Diseases; Arthritis; Osteoarthritis; Osteoarthritis, Knee
• Other Study ID Numbers: 14-003

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