The personalKNEE Trial

June 6, 2025 updated by: Helse Møre og Romsdal HF

Robotic Assisted Surgery Comparing Personalized Alignment Versus Mechanical Alignment of Total Knee Arthroplasty - A Randomized Controlled Trial

Robotic knee surgery makes it possible to adopt different alignment philosophies in total knee arthroplasty. The classical operation where the knee is placed in a neutral manner, the so called mechanical alignment, has been used for decades. The kinematical alignment has recently won popularity. With this technique the focus is to render the natural knee anatomy even if this means to end up with a varus or valgus position. In this study, the investigators will compare the mechanical alignment and kinematical alignment and test the patients clinically and with a special CT scan to see if this technique gives equal or better longevity of the implants.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Mechanical alignment (MA) has for many years been the most used surgical alignment technique in total knee arthroplasty (TKA). This means that regardless of constitutional native anatomy (i.e. valgus or varus), one strives to achieve a neutral coronal knee axis on postoperative x-rays (Hip-Knee-Ankle angle, HKA). To achieve MA, the cuts are made perpendicular to the mechanical axis, and subsequent soft tissue balancing is performed if necessary. However, many patients do not have a neutral knee alignment before they develop osteoarthritis. Several authors therefore advocate the personalized alignment (kinematic, KA or functional alignment, FA), where the aim is to restore the patient's original pre-arthritis anatomy and joint line. This means that tibial component placement in varus or valgus is accepted, despite the possible result of a postoperative non-neutral HKA axis. Studies indicate that good clinical results can be achieved in terms of range of motion (ROM) and patient reported outcome measures (PROMs) with these techniques, but it has not been tested properly in terms of activity measurements, strength testing or migration of implants. There is diversity in the literature regarding whether tibial component with too much deviation from a neutral axis can lead to increased migration and eventually aseptic solution. To date, only a few trials, with diverging results, have assessed migration of the implants implanted with KA or FA. The methods are so far perceived as controversial, despite the widespread use.

KA or FA can be performed by manual conventional surgery; however, the newly introduced robotic assisted surgery probably yields higher accuracy and precision of the cuts during surgery. This makes robotic assisted surgery well suited for personalized surgery. Yet, it is claimed that because of diversity of the different features for planning and executing the surgery, each system should be evaluated separately, and not as a group. The investigators therefore planned this study to assess the efficacy of robotic assisted surgery comparing MA and personalized alignment (PA) techniques.

Aims of the trial

  1. Evaluate the clinical outcomes of patients who have had TKA with PA and compare it with conventional MA.
  2. Analyse and compare the in vivo stability over time of TKA operated with PA vs. MA using CT- based radiostereometric analysis (CT-RSA).
  3. Evaluate the postoperative position of the implants using two different alignment philosophies.

Objective Perform TKAs on patients using ROSA® Knee System (Zimmer Biomet, Warsaw, Indiana USA) robotic assisted surgery and randomize the patients to either PA or MA.

Materials and methods

A multiple blinded randomized controlled parallel superiority trial will be performed, where the patients, study nurse, statistician and physiotherapists are blinded to the surgical method (PA or MA). The study will include 152 patients. The study adheres to the consort statement.

Surgery All surgeons involved in the trial are experienced knee surgeons. The surgeons have received thorough tutoring in the use of the ROSA Knee System and the Persona TKA, and both alignment techniques have now been adopted in our standard treatment of end stage OA. The learning curve of robotic assisted surgery is probably very small, and more related to time spent on the procedure rather than placement of the implants. The placement of the tibial implant will be restricted in the coronal plane to maximum 5 degrees of varus and 2 degrees of valgus. In sagittal plane, the slope will be limited to between 0-10 degrees.

The Persona TKA implant although contemporary, is a well-documented implant with very low migration.

The MA and PA techniques are well known and already used in a widespread fashion all around the world. Several clinics in Norway have also adopted the methods.

Implantation of tantalum markers in bone and polyethylene has been performed for more than 40 years in numerous studies without any known complications.

Known but rare complications to robotic surgery are fractures at the site of insertion of the bone pins, and pin site infections. In elderly or osteoporotic patients, the surgeons will consider using unicortical engagement of the pins. Concerning infections, all the default precautions in the OR will be taken, such as preoperative and postoperative administration of antibiotics, strict sterile procedures etc.

Study Type

Interventional

Enrollment (Estimated)

152

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • Norway
    • Møre And Romsdal
      • Kristiansund, Møre And Romsdal, Norway, 6508

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

• femoro-tibial or patello-femoral osteoarthritis (Kellgren-Lawrence, K-L) grade 2-4 with persistent pain, referred to Kristiansund Hospital for primary TKA

Exclusion Criteria:

  • serious psychiatric disorders
  • dementia
  • drug abuse
  • patients not able to speak and read Norwegian language making them noncompliant or unable to perform an informed consent
  • Patients with ongoing cancer therapy
  • Patients with ASA (The American Society of Anesthesiologists physical status class risk stratification system) classification >3
  • Patients in the need of walking aid devices
  • Patients in need of primary revision arthroplasty or more than 15 degrees of varus or 5 degrees of valgus on preoperative HKA images.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Mechanical alignment
Patients are operated with ROSA robot and mechanical alignment
Procedure: Total knee replacement
Mechanical or Personalized alignment
Experimental: Personalized alignment
Patients are operated with ROSA robot and kinematic alignment
Procedure: Total knee replacement
Mechanical or Personalized alignment

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
MTPM
Time Frame: 2 years
Maximum Total Point Motion measured by CT -based RSA in millimeters.
2 years

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
XYZ translation
Time Frame: 2 years
Translation of implant measured by CT -based RSA in millimeters
2 years
XYZ rotation
Time Frame: 2 years
Rotation of implant measured by CT -based RSA in degrees
2 years
Steps per day
Time Frame: 1 year and 2 years
ActivePAL accelerator registration of mean steps per day measured 24/7 for a week
1 year and 2 years
Walking speed
Time Frame: 1 and 2 years
ActivePAL accelerator registration of mean meter per second measured 24/7 for a week
1 and 2 years
Stair climbing
Time Frame: 1 and 2 years
Standardized climbing and descending of stairs up and down. Time in seconds measured up, down and total.
1 and 2 years
Maximal voluntary contraction flexion
Time Frame: 1 and 2 years
Isometric contraction at 90 degrees knee flexion measured in Newtons with Tindeq force cell
1 and 2 years
Maximal voluntary contraction extension
Time Frame: 1 and 2 years
Isometric contraction at 90 degrees knee extension measured in Newtons with Tindeq force cell
1 and 2 years
Maximal voluntary contraction
Time Frame: 1 and 2 years
Isometric contraction at 90 degrees knee flexion measured in Newtons with Tindeq force cell
1 and 2 years
Sit to stand test
Time Frame: 1 and 2 years
Maximum number of repetitive transitions from sitting on a chair to standing without the use of hands during 30 seconds
1 and 2 years
KOOS score
Time Frame: 1 and 2 years
Knee Injury and Osteoarthritis of 5 dimensions measuring activity of daily living (ADL), Quality of life, Sport and recreation, pain and symptoms. From 0 (bad) to 100 (excellent)
1 and 2 years
FJS
Time Frame: 1 and 2 years
Forgotten Joint Score is a 12 item scale assessing the ability to forget the operated joint as artificial during activities of daily living. Ranges from 0 (bad) to 100 (excellent)
1 and 2 years
Eq-5D
Time Frame: 1 and 2 years
EuroQol 5 Dimensions is a generic patient reported outcome measure measuring quality of life. The scale ranges from 100 ('the best imaginable health state') to 0 ('the worst imaginable health state' ).
1 and 2 years
VAS
Time Frame: 1 and 2 years
The Visual Analogue Scale (VAS) measures pain intensity. The VAS consists of a 10cm line, with two end points representing 0 ('no pain') and 10 ('pain as bad as it could possibly be')
1 and 2 years

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Helse Møre og Romsdal HF

Collaborators

University of Oslo
Oslo University Hospital
National Taiwan Normal University
Sectra AB

Investigators

  • Study Director: Frank-David Øhrn, MD, PhD, Møre og Romsdal Hospital Trust
  • Study Chair: Kirsti Sevaldsen, MD, PhD, Møre og Romsdal Hospital Trust

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

August 25, 2024

Primary Completion (Estimated)

May 1, 2027

Study Completion (Estimated)

May 1, 2035

Study Registration Dates

First Submitted

July 8, 2024

First Submitted That Met QC Criteria

July 16, 2024

First Posted (Actual)

July 18, 2024

Study Record Updates

Last Update Posted (Actual)

June 11, 2025

Last Update Submitted That Met QC Criteria

June 6, 2025

Last Verified

June 1, 2025

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 738578

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Upon proper request to the corresponding author data will be shared anonymously.

IPD Sharing Time Frame

After publication and for 2 years

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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