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Completed

NCT Number: NCT02145455

Unity Total Knee Replacement Using Two Different Surgical Techniques

This study will compare two different surgical methods used in total knee replacement with the Unity Total Knee Replacement System. The study will evaluate these two methods based on patients' ability to perform various tasks prior to surgery and at 4 time points during the first 12 months after surgery.

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Key information

Conditions

Arthritis of the Knee

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Exeter Knee Reconstruction Unit at the Princess Elizabeth Orthopaedic Centre

Exeter, Devon, EX2 5DW, United Kingdom

About this study

This study will be conducted at a single centre. The study has two treatment groups. One group of 50 knees (approximately 50 subjects) will have a surgical method that uses mechanical alignment (alignment based on how the leg and knee joint move) to determine the proper position of the knee replacement device. The other group of 50 knees (approximately 50 subjects) will have a surgical method that uses anatomical alignment (alignment based on how the anatomy/structure of the leg and knee joint) determine the proper position of the knee replacement device. Subjects will be randomly assigned to one of the two groups. Clinical and functional tests will be conducted pre-operatively and at 6 weeks, 3 months, 6 months and 12 months to determine overall knee function. In addition, a CT scan will be completed pre-operatively and at 6 weeks to assess changes in alignment.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • The patient must be listed for a primary total knee replacement using the Corin Unity Total Knee Replacement System, according to the product 'Instructions For Use'
  • The patient must give signed informed consent to participate in the study
  • The patient must be able to understand all that is expected of them and be able to comply with the study protocol
  • Male and female patients who are skeletally mature

Exclusion criteria

  • Any patient with a total knee replacement not implanted with a Corin Unity Total Knee Replacement
  • Any patient with a revision total knee replacement or conversion of a Unicondylar replacement to a total knee replacement on the operative knee
  • Any patient with fixed flexion contracture greater than 20 degrees
  • Any patient with varus/valgus deformity greater than 15 degrees
  • Any case not described in the inclusion criteria
  • Any patient who cannot or will not provide signed informed consent for participation in the study
  • Any patient whose prospects for a recovery to independent mobility would be compromised by known co-existent, medical problems
  • Any patient with a known sensitivity to device material
  • Any patient who is pregnant
  • Any patient currently a prisoner
  • Any patient known to be a drug or alcohol abuser, or have a psychological disorder that could affect follow-up care or treatment outcomes
  • Any patient currently involved in any personal injury litigation, medical-legal or worker's compensations claims
  • Any patient unable to read and understand English

Treatment and study plan

Unity Total Knee Replacement System

Device

Other names: Unity Total Knee Replacement System (Cruciate Retaining), Unity Total Knee Replacement System (Posterior Stabilised)

Primary outcomes

  1. Power of knee extension

    Time frame: 12 months post-operative

    Power of knee extension via peak torque of quads measured on a digital myometer.

Secondary outcomes

  1. Timed up and go test

    Time frame: 12 months post-operative

    The test measures the length of time it takes the subject to rise from a chair, walk 10 feet, turn around, and sit back down in the chair. The subject may rest or use walking aids during the test.

  2. Single leg stance (SLS) test

    Time frame: 12 months post-operative

    The test measures the length of time the subject can stand on their operative leg.

  3. 6 minute walk test

    Time frame: 12 months post-operative

    The test measures the length of distance a subject can walk in 6 minutes at a pace that does not cause them to become short of breath. Patient may stop and rest if needed, then resume.

  4. Timed stairs test

    Time frame: 12 months post-operative

    The test measures the length of time it takes a subject to climb up a stair block and down the other side. The subject is asked how difficult the test was on a scale of 0 to 10. The subject can use the rails, if needed.

  5. Wii Fit balance test

    Time frame: 12 months post-operative

    The subject is asked to stand on a Wii Fit balance board while the "Deep breathing" exercise in the Yoga section is selected. The subject is instructed to follow the instructions on the screen. The subject's score is recorded and the subject is asked how difficult the test was on a scale from 1 to 10.

  6. Ability to kneel

    Time frame: 12 months post-operative

    The subject is asked to kneel on a mat on the floor and then rise to a standing position. The subject may use a bench or the floor for balance. After the test, the subject is asked how difficult the test was on a scale of 1 to 10. The subject is allowed to refuse to do the test if he/she feels unable to do so.

  7. Sloped treadmill test

    Time frame: 12 months post-operative

    The subject is asked to walk on a level treadmill at a comfortable walking speed. The incline of the treadmill is increased until the subject says stop or the limit of the treadmill is reached. The test is repeated with the treadmill in reverse and the subject facing backwards to simulate walking downhill. The subject is asked how difficult the test was on a scale of 1 to 10.

  8. Walking on uneven ground

    Time frame: 12 months post-operative

    The subject is asked to walk from one end to the other on a specialized track topped with fist-sized pebbles. The subject is allowed to use walking aids. The subject is asked how difficult the test was on a scale of 1 to 10.

  9. CT evaluation

    Time frame: 6 weeks post-operative

    CT scan will be done to assess the following anatomical items:

    • Medial joint line position
    • Overall limb alignment
    • Joint obliquity
    • Rotation

  10. Power of knee flexion

    Time frame: 12 months post-operative

    Power of knee flexion via peak torque of quads measured on a digital myometer.

  11. Oxford Knee Score (OKS)

    Time frame: 12 months Post-operative

    A questionnaire about your ability to perform daily functions.

  12. Knee Injury and Osteoarthritis Score (KOOS)

    Time frame: 12 months Post-operative

    A questionnaire to assess your ability to perform activities of different difficulty levels.

  13. EuroQoL 5-dimension Health State (EQ-5D)

    Time frame: 12 months Post-operative

    A questionnaire to assess your health and well-being.

  14. Patient Satisfaction Score

    Time frame: 12 months Post-operative

    A questionnaire to assess your satisfaction with your knee implant.

Sponsors and collaborators

Lead sponsor

Corin

Industry

Registry information

Official study title

Unity Total Knee Replacement: Prospective Single-centre Clinical Study

Important dates

Study start
2015
Primary completion
2020
Study completion
2020
First posted
May 23, 2014
Registry last updated
Jul 14, 2020

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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