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NCT Number: NCT04095637

RCT: Mako Medial Unicondylar Knee Arthroplasty vs Oxford Unicondylar Knee Arthroplasty

The overall aim of this prospective, randomised, single-blinded, controlled trial is to compare clinical outcomes and accuracy of implant positioning in Mako robotic UKA versus jig-based Oxford UKA with navigation control. Patients receiving the Mako robotic UKA (Stryker Ltd) will form the investigation group and those undergoing the jig-based Oxford UKA (Zimmer-Biomet Ltd) with navigation control will form the control group.

The primary objective in this study is to compare accuracy of component positioning as assessed by postoperative low radiation dose CT scan between conventional Jig-based Oxford UKA with navigation control and Mako robotic UKA.

Recruiting

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Key information

Age range

40 year–80 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

UCL Hospital NHS Foundation Trust

London, NW1 2BU, United Kingdom

Location status: Recruiting

Location contact

Jenni Tahmassebi

CONTACT

[email protected]

02034479413

Who can participate

Healthy volunteers accepted: Yes

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

Inclusion criteria

  • • Patient has medial unicompartmental knee osteoarthritis requiring primary UKA
  • Patient and Surgeon are in agreement that UKA is the most appropriate treatment
  • Patient is fit for surgical intervention following review by surgeon and anaesthetist
  • Patient is between 40-80 years of age at time of surgery
  • Gender: male and female
  • Patient must be capable of giving informed consent and agree to comply with the postoperative review program
  • Patient must be a permanent resident in an area accessible to the study site
  • Patient must have sufficient postoperative mobility to attend follow-up clinics and allow for radiographs to be taken

Exclusion criteria

  • • Patient is not suitable for primary UKA e.g. multi-compartmental knee osteoarthritis, anterior cruciate ligament rupture
  • Patient is not medically fit for surgical intervention
  • Patient requires revision surgery following previously failed correctional osteotomy or ipsilateral UKA
  • Patient is immobile or has another neurological condition affecting musculoskeletal function
  • Patient is less than 40 years of age or greater than 80 years of age
  • Patient is already enrolled on another concurrent clinical trial
  • Patient is unable or unwilling to sign the informed consent form specific to this study
  • Patient is unable to attend the follow-up programme
  • Patient is non-resident in local area or expected to leave the catchment area postoperatively

Treatment and study plan

Medial knee arthroplasty

Device

Surgical intervention where the medial portion of the knee is replaced by an artificial metal and polyethylene implant

Primary outcomes

  1. Accuracy of component positioning

    Time frame: 6 weeks post-op

    Comparison of accuracy of component positioning as assessed by postoperative low radiation dose CT scan

Secondary outcomes

  1. Lower limb alignment

    Time frame: Pre-op then 6 weeks, 6 months, 1 and 2 years post-op

    Lower limb alignment in the coronal, axial, and sagittal planes as assessed by postoperative low radiation dose CT scan at 6 weeks after surgery.

  2. Femoral implant alignment

    Time frame: Pre-op then 6 weeks, 6 months, 1 and 2 years post-op

    Femoral implant alignment in the coronal, axial, and sagittal planes as assessed by postoperative low radiation dose CT scan at 6 weeks after surgery.

  3. Tibial implant alignment

    Time frame: Pre-op then 6 weeks, 6 months, 1 and 2 years post-op

    Tibial implant alignment in the coronal, axial, and sagittal planes as assessed by postoperative low radiation dose CT scan at 6 weeks after surgery.

  4. Operating time

    Time frame: Intraoperative

    Length of time of operation in minutes

  5. Time to discharge

    Time frame: 6 weeks post op

    Length of hospital admission from admission date to documented discharge from hospital

  6. Oxford Knee Score (OKS)

    Time frame: Pre-op; 6 weeks post-op; 6 months post-op; 1 year post-op; 2 years post-op

    Patient recorded outcome measure via questionnaire; cumulative score with best being 48, worst being 0

  7. Short form SF-12

    Time frame: Pre-op; 6 weeks post-op; 6 months post-op; 1 year post-op; 2 years post-op

    Patient recorded outcome measure via questionnaire; cumulative score via 12 questions pertaining to perception of current physical and mental health; higher score best score, lower score worse score

  8. Western Ontario and McMaster Universities Arthritis Index (WOMAC)

    Time frame: Pre-op; 6 weeks post-op; 6 months post-op; 1 year post-op; 2 years post-op

    Patient recorded outcome measure via questionnaire; cumulative score with 0 being best score

  9. Knee injury and Osteoarthritis Outcome Score (KOOS) Osteoarthritis Outcome Score (KOOS)

    Time frame: Pre-op; 6 weeks post-op; 6 months post-op; 1 year post-op; 2 years post-op

    Patient recorded outcome measure via questionnaire; 6 domains contribute to overall percentage; 100% being best score

  10. European Quality of Life questionnaire with 5 dimensions for adults (EQ-5D)

    Time frame: Pre-op; 6 weeks post-op; 6 months post-op; 1 year post-op; 2 years post-op

    Health-related quality of life via 5 domains; score -1 to 1 with 1 being best score

  11. Mobilisation distance (metres)

    Time frame: Pre-op; 6 weeks post-op; 6 months post-op; 1 year post-op; 2 years post-op

    How far patient can walk in metres

  12. Use of mobility aids

    Time frame: Pre-op then 6 weeks post-op; 6 months post-op; 1 year post-op; 2 years post-op

    Documenting the use of any mobility aid to assist with ambulation; can include wheelchair, walker, crutches, sticks or no aid required

  13. Range of movement

    Time frame: Pre-op then 6 weeks post-op, 6 months post-op, one year post-op; 2 years post-op

    Range of movement of knee joint in degrees, typically from 0 to 140 degrees; higher number is better score

  14. Complications

    Time frame: during inpatient admission and postoperatively at 6- weeks, 6 months, 1 year and 2 years

    Complications as relating to surgery; to include pain; fracture; neurovascular injury; blood clots; infection of wound; infection of artificial joint; pain; heart attack; stroke; pulmonary embolus; return to operating theatre; revision surgery; death

Study contacts

Contact information is provided by the study sponsor or research team.

Jenni Tahmassebi

CONTACT

[email protected]

02034479413

Sponsors and collaborators

Lead sponsor

University College, London

Other

Collaborators

  • Stryker Instruments

Registry information

Official study title

A Prospective Randomised Control Trial of Mako Medial Unicondylar Knee Arthroplasty Versus Jig-based Oxford Unicompartmental Knee Arthroplasty With Navigation Contro

Important dates

Study start
2017
Primary completion
2025
Study completion
2026
First posted
Sep 19, 2019
Registry last updated
Jul 9, 2025

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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