All Polyethylene Versus Metal Backed Tibial Components in Knee Replacement

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details. Identifier: NCT02482493
Recruitment Status : Recruiting
First Posted : June 26, 2015
Last Update Posted : March 24, 2017
Information provided by (Responsible Party):
Helen Samuel, Maidstone & Tunbridge Wells NHS Trust

Brief Summary:

Total knee arthroplasty (TKA) is one of the most commonly performed orthopaedic procedures. Approximately 84,000 knee replacement procedures were recorded in the UK in 2012. The main goal of TKA is to relieve the disabling pain of arthritic disease.

Patient satisfaction following TKA is related to quick recovery and return to daily activities. This can be dependent on the design of the implant used in the knee. Improvements in implant design and surgical technique mean many modern designs offer implant survival rates beyond 10 - 15 years.

As cost pressure increases in the NHS the unit cost of implants is now being scrutinised, particularly with regard to cost effectiveness. The Press-Fit Condylar (PFC) Sigma implant can be used with either a conventional metal backed or alternatively an all polyethylene tibial component (part fitted to the shin bone), the latter considerably cheaper to manufacture. Four small prospective randomised trials and one large regional registry study with long follow up support the safe use of all polyethylene tibial components in TKA. The investigators will therefore undertake a prospective randomised controlled trial comparing the results of all polyethylene tibial components with those of conventional metal backed tibial components in patients aged 75 or over, comparing both clinical outcome and radiological survivorship.

The type of knee replacement used for each patient (metal-backed or polyethylene) will be chosen at random once a patient has agreed to take part in the study.

Data will be collected by means of follow-up appointments and questionnaires and clinical tests both before the operation 1 year, 2 years and 5 years postoperatively. This will allow us to see how both types of knee replacement perform over time and if one performs better than the other in terms of patients movement, pain and functional activities.

Condition or disease Intervention/treatment Phase
Osteoarthritis, Knee Device: Sigma PFC Not Applicable

Detailed Description:

Summary of design and methodology.

When a patient who is appropriate for the study is added to the waiting list for a Total Knee replacement they will be given (or if missed, posted) an information sheet about the study. This will allow patients several weeks to read the information and telephone the Orthopaedic research department, if they wish, with any questions they may have.

The Patients will then come to preassessment clinic as usual. At this point the study will be explained again in person, the patient will be given time to ask questions and will be asked if they wish to consent to participating.

If the patient consents to taking part they will complete preoperative measures and questionnaires There are 3 questionnaires on how the patient is functioning. 2 are completed by the patient and 1 with the help of the Researcher

The questionnaires are:

Oxford Knee Score American Knee Society Score (AKSS) Medical Outcomes Study Short Form-36 Health Survey (MOS SF-36) All questionnaires will be performed preoperatively, 1 year, 2 years and 5 years postoperatively.

Six weeks postoperatively the patient will attend a follow-up clinic. This is standard for all patients undergoing knee replacement surgery at the Tunbridge Wells Hospital. Routine wound checks and postoperative care will take place and any patient's concerns dealt with. At this point the patient will be booked in for another routine follow up appointment 3 months postoperatively. No study data will be collected at these visits besides adverse events or lost to follow-up where appropriate.

At one year post-operatively the patient will be asked to attend for an appointment. The knee will be assessed clinical and same series of clinician and patient questionnaires completed. A series of x-rays will also be taken to allow the position of the implant to be recorded. Measurements will be taken to be taken from the x-rays Similarly the patient will be invited to attend a further 2 appointments at 2 year and 5 years post-operatively. At these appointments the questionnaires will be repeated along with the x-rays.

Should the patient wish to withdraw at any point they are free to do so and will not then be contacted for any subsequent appointments unless they are due routine clinical appointments .

Any patient undergoing total knee replacement and not in the study will attend routine 6 week and 3 month and one year follow-up appointments, as routine but will be discharged when appropriate and will not be subject to long term follow-up.

Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 88 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary Purpose: Treatment
Official Title: A Prospective Randomised Control Trial to Compare Clinical and Radiological Outcomes of the Press-Fit Condylar All-Polyethylene Tibial Component With Metal-Backed Tibial Component Implant, in Patients Aged 75 Years or Over
Actual Study Start Date : January 2017
Estimated Primary Completion Date : July 2023
Estimated Study Completion Date : July 2023

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Active Comparator: All-polyethylene Tibial component
Sigma PFC All polyethylene Tibial component will be implanted
Device: Sigma PFC
patients will receive either an all polyethylene tibial component or a metal- backed component

Active Comparator: Metal Backed Tibial component
Sigma PFC metal-backed tibial component will be implanted
Device: Sigma PFC
patients will receive either an all polyethylene tibial component or a metal- backed component

Primary Outcome Measures :
  1. American Knee Society Score [ Time Frame: 5 year outcomes ]

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

Ages Eligible for Study:   75 Years and older   (Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Patients suitable for simple cemented primary knee arthroplasty
  • Patients presenting with osteoarthritis of the knee
  • Patients with inflammatory arthropathy, requiring total knee arthroplasty
  • Patients must be ambulatory at time of preoperative assessment clinic
  • Patients must be able to understand instructions and be willing to return for follow up
  • Patients aged 75 years or over at the time of surgery

Exclusion Criteria:

  • Previous knee surgery (except arthroscopic / open meniscectomy)
  • Patients with significant medical co-morbidity
  • Disorders causing abnormal gait or significant pain
  • Patients unable to consent
  • Severe visual impairment

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT02482493

Contact: Helen Samuel 01892 635488

United Kingdom
Trauma & Orthopaedic Dept, Tunbridge Wells Hospital Recruiting
Pembury, Kent, United Kingdom, TN2 4QJ
Contact: Helen Samuel    01892 635488   
Principal Investigator: Paul Gibb         
Sponsors and Collaborators
Maidstone & Tunbridge Wells NHS Trust
Principal Investigator: Paul Gibb Maidstone and Tunbridge Wells NHS trust

Responsible Party: Helen Samuel, Mr Paul Gibb - Consultant Orthopaedic Surgeon, Maidstone & Tunbridge Wells NHS Trust Identifier: NCT02482493     History of Changes
Other Study ID Numbers: 14/01/282 version 1.3
First Posted: June 26, 2015    Key Record Dates
Last Update Posted: March 24, 2017
Last Verified: March 2017

Additional relevant MeSH terms:
Osteoarthritis, Knee
Joint Diseases
Musculoskeletal Diseases
Rheumatic Diseases