Bespoke vs Standard Instrumentation in TKR

Knee Osteoarthritis Clinical Trial

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

Status Recruiting

Clinical Trial Summary

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.

Clinical Trial Description

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. ;

Study Design

Allocation: Randomized, Intervention Model: Parallel Assignment, Masking: Single Blind (Outcomes Assessor), Primary Purpose: Health Services Research

Related Conditions & MeSH terms

• Knee Osteoarthritis
• Osteoarthritis
• Osteoarthritis, Knee

• NCT number: NCT02845206
• Study type: Interventional
• Source: NHS Lothian
• Contact: Susan Shepherd
• Email: susan.shepherd@nhslothian.scot.nhs.uk
• Status: Recruiting
• Phase: N/A
• Start date: February 2016
• Completion date: February 2020