Skip to main content
OpenTrials
Completed

NCT Number: NCT02845206

Bespoke vs Standard Instrumentation in TKR

Total knee replacement (TKR) is an established treatment for knee osteoarthritis and leads to a satisfactory outcome in over 75% of patients. The pain and function after TKR can be dependent on the accuracy of initial implantation, as deviation of more than 3 degrees from the normal alignment of the limb can lead to abnormal stresses on the implant and accelerated failure. Patient specific cutting blocks may result in a more individualised implant placement, improved pain and function following surgery, and a long-lasting implant.

This trial is designed to investigate if there is any benefit to bespoke instrumentation in terms of pain and function to the patient, and an economic benefit to the NHS.

Completed

Looking for future studies?

Notify Me

Key information

Conditions

Knee Osteoarthritis Arthritis Joint Diseases Musculoskeletal Diseases Osteoarthritis Osteoarthritis, Knee Rheumatic Diseases

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Royal Infirmary of Edinburgh

Edinburgh, Lothian, EH16 4SA, United Kingdom

About this study

Total knee replacement (TKR) is an established treatment for 'wear and tear' arthritis and leads to a satisfactory outcome in over 75% of patients. However, this means that up to 25% of patients are not entirely satisfied with their TKR. The longevity and stability of a TKR is greatly dependent on the accuracy of the initial surgery. Deviation of more than 3 degrees from the normal axis can lead to abnormal stresses causing the implants to fail. 'Patient specific' technology involves preoperative computer assessment of the patients' knee and allows for a 'patient specific' cutting block to be manufactured. This will allow for individual bony cuts specific to the patients own anatomy.

'Patient specific' implants and cutting blocks may allow a more optimal implant positioning and are implanted without the need for instrumentation of the femoral medullary canal (thigh), so lower blood loss may result. This could result in improved early range of movement and decreased pain following surgery. The total knee replacement used in this study will be the GMKSphere (Medacta International) TKR. It has a specific design which more closely resembles a natural unreplaced knee than any other knee replacement. It may help address the phenomenon of 'mid flexion instability', which is where the patient perceives their replaced knee to be unsteady on stairs and slopes.

Patient specific technology may also result in a cost saving, as it potentially reduces the number of sterilised trays required during the surgery.

This study will allow for comparison in knee function and patient outcomes between patients who have undergone their TKR with patient specific cutting blocks compared to conventional cutting blocks. The scans obtained following the surgery could lead to world leading methodology for the assessment of knee replacements and would set a blue print for the evaluation of other knee implants in the future.

Who can participate

Healthy volunteers accepted: No

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

Inclusion criteria

  • Patients with osteoarthritis ('wear and tear') of the knee which is sufficiently symptomatic to require knee arthroplasty as assessed by their consultant orthopaedic surgeon

Exclusion criteria

  • Patients with inflammatory arthropathy, patients requiring bone augmentation, ligament incompetence, values deformity > 5 degrees

Treatment and study plan

Patient specific cutting blocks

Procedure

'MyKnee' Instrumentation

Conventional cutting blocks

Procedure

Standard Instrumentation

Primary outcomes

  1. Limb alignment

    Time frame: 1 years

    Measured in degrees from Hip-Knee-Ankle radiographs from centre of femoral head to midpoint of the ankle

Secondary outcomes

  1. Difference between baseline pre-op and one year post-op change in gait measured using a bespoke clinic-appropriate motion analysis system.

    Time frame: 1 year

    Knee range of motion, strength and gait analysis assessments will be carried out on a bespoke clinic-appropriate motion analysis system. This system consists of 8 Vicon B10 Bonita cameras (Vicon Systems, Oxford) which immediately surround a self-paced N-Mill treadmill (Motekforce Link, Amsterdam).

  2. Difference in patient reported knee pain level as measured by Oxford Knee Score between baseline and one year and also between study groups.

    Time frame: 1 year

    Validated patient reported knee pain questionnaires as measured by Oxford Knee Score (out of 48 points) pre-operation and at one year post-operation. Difference between baseline and one year scores for each patient and also analysed between groups (patient specific cutting blocks compared to conventional cutting blocks).

  3. Difference in patient reported knee function between baseline and one year and also between study groups.

    Time frame: 1 year

    Validated patient reported knee function questionnaires as measured by EQ-5D pre-operation and at one year post-operation. Difference between baseline and one year scores for each patient and also analysed between groups (patient specific cutting blocks compared to conventional cutting blocks).

  4. Difference in patient reported quality of life questionnaires between baseline and one year and also between study groups.

    Time frame: 1 year

    Validated quality of life questionnaires as measured by SF-12 score pre-operation and at one year post-operation. Difference between baseline and one year scores for each patient and also analysed between groups (patient specific cutting blocks compared to conventional cutting blocks).

  5. Healthcare cost

    Time frame: 1 year

    Healthcare cost measured in pounds sterling (GBP). Total cost of performing knee replacement using conventional cutting blocks compared to using bespoke cutting blocks and disposable instrumentation. The measurable contributors to the costs of healthcare include operating time (minutes), number of instrument trays requiring sterilisation (number of trays), length of hospital stay (days), patient transfusion requirement (number of units of packed cells required), cost of bespoke disposable instrumentation (GBP).

Sponsors and collaborators

Lead sponsor

NHS Lothian

Other Gov

Registry information

Official study title

Randomised Controlled Trial of Patient Specific Instrumentation vs Standard Instrumentation in Total Knee Arthroplasty

Important dates

Study start
2016
Primary completion
2018
Study completion
2020
First posted
Jul 27, 2016
Registry last updated
Sep 23, 2024

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.

Related clinical trials

Published trials that share one or more normalized conditions with this study.