A Study Using Metaphyseal Cones Versus a Cemented Stem Construct in Revision TKR

Summary

Lay Person's Summary:

Knee replacement surgery has been successfully carried out for many years. However, in time, some knee replacements will fail-usually either because of wear or loosening of the replacement parts. This may mean the patient has to undergo further surgery-this is known as revision total knee replacement (rTKR). This revision surgery is often more complex than the original operation and presents the operating surgeon with several technical challenges. Of particular concern, is that when the old knee replacement is removed, a large cavity can be left in the bone. The new knee replacement has to be placed into this, but it is essential that it is immediately stable and secure. The large cavity has to be somehow either filled in or bypassed to ensure the new knee replacement is secure enough for early weight-bearing and long term survival.

Different techniques have been used for many years to overcome this problem. Firstly, it may be possible to simply cement another knee replacement into the cavity- probably needing more cement than was previously used.

An alternative option to this is use a device called a "cone" which sits into the bony cavity created by removing the original knee replacement, and a new knee replacement can be cemented into this.

Bone grows onto the cone to ensure its stability. The new knee replacement can have either short stemmed components like the original Total Knee Replacement (TKR), or long stemmed components.

All of these types of rTKR are presently in use throughout the United Kingdom (UK). At this point in time, no-one knows which type is best. The research team are planning to run this study to see if it is possible to identify which type of rTKR gives the best outcome for patients. The research team will examine the results in different ways including questionnaires to measure how well the patients feel their knee is performing, specific tests to measure knee function, and by using x-rays and scans.

The investigators will identify patients suitable for inclusion in the study from their medical notes, x-rays and scans. If patients consent to be in the study, the research team will randomly allocate them to receive one of the 3 rTKR options (no cone and new knee replacement only, cone with short stemmed components or cone with long stemmed components) and monitor their progress for 5 years after the operation.

The investigators will identify patients suitable for inclusion in the study from their medical notes, x-rays and scans. If patients consent to be in the study, the investigators will randomly allocate them to receive one of the 3 rTKR options (no cone and new knee replacement only, cone with short stemmed components or cone with long stemmed components) and monitor their progress for 5 years after the operation.

A preliminary analysis of the data generated by the study will be carried out 2.5 years after recruitment of the 1st participant to assess compliance with the study protocol.

Conditions

• Total Knee Arthroplasty

Interventions

PROCEDURE

short or long stemmed rTKR cemented

An evaluation of the outcomes of different ways of performing revision total knee replacement surgery

PROCEDURE

Cone with short stem

Revision knee replacement using a metaphyseal cone and then a knee replacement with short stems is cemented in to it

PROCEDURE

Cone with long stem

Revision knee replacement using a metaphyseal cone and then a knee replacement with long stems is cemented in to it

Sponsors & Collaborators

• Royal Devon and Exeter NHS Foundation Trust

  lead OTHER

Principal Investigators

• Andrew Toms, MSc FRCS · RD+E Hospital NHSFT

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

90 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2017-06-21

Primary Completion

2028-06-21

Completion

2028-09-30

Countries

• United Kingdom

Study Locations