Mechanical vs kinematic alignment in TKR
Research type
Research Study
Full title
A prospective, randomised, controlled study of the outcomes and cost effectiveness of Triathlon CR knee replacement system: traditional instruments versus alternative alignment technique.
IRAS ID
225871
Contact name
Andrew Toms
Contact email
Sponsor organisation
RD+E Hospital NHSFT
Clinicaltrials.gov Identifier
Duration of Study in the UK
8 years, 0 months, 1 days
Research summary
As many as 20% of patients are unhappy with the results of total knee replacement (TKR). Various changes to surgical technique have tried to address this but have not led to a significant improvement in the numbers of patients satisfied with their operation.
Recently, attention has focussed on alignment of the leg. When viewed from the front, a number of people do not start with a straight, mechanically aligned leg. Traditionally, when implanting a knee replacement, the surgeon tries to put the shin bone half of the knee replacement perpendicular to the floor to equalise stresses on the in and outside of the joint. However, this may result in the alignment of the leg changing considerably, straining the soft tissues around the knee and contributing to dissatisfaction with TKR.
There has been a move by some surgeons to change practice, and to implant the TKR in a way that replicates the alignment of the patient’s own original knee- alternative alignment. Studies looking at alternative alignment have not shown any loss of satisfaction with results of TKR and indeed are showing some signs that in the short term, function of the knee may be better with the new technique.
We are planning to run a study comparing the knee replacement we use in Exeter- the Triathlon- when put in place using traditional alignment methods versus using the alternative alignment technique. We will assess the results in various ways including patient satisfaction questionnaires, measuring muscle strength, flexibility around the knee, and by assessments of alignment of the new knee on X-rays and CT scans. We will look at short term results for satisfaction and function of the knee, and in the long term look at wear and survivorship to see if we can improve patient satisfaction with TKR.REC name
Wales REC 2
REC reference
17/WA/0252
Date of REC Opinion
11 Aug 2017
REC opinion
Favourable Opinion