The Assessment of Patient Specific Instrumentation for Unicompartmental Knee Replacement
Primary Purpose
Knee Arthritis
Status
Completed
Phase
Not Applicable
Locations
Study Type
Interventional
Intervention
Patient Specific Instrumentation
Conventional Instrumentation
Sponsored by
About this trial
This is an interventional treatment trial for Knee Arthritis focused on measuring Unicompartmental Knee Replacement, Patient Specific Instrumentation
Eligibility Criteria
Inclusion Criteria:
- Both cruciate ligaments functionally intact
- Full thickness cartilage in the lateral compartment
- Correctable intra-articular varus deformity
- Full thickness cartilage loss in the medial compartment
Exclusion Criteria:
- Contra-indication for MRI
- All forms of inflammatory arthritis
Sites / Locations
Arms of the Study
Arm 1
Arm 2
Arm Type
Experimental
Active Comparator
Arm Label
Patient Specific Instrumentation
Conventional Instrumentation
Arm Description
Patients undergoing unicompartmental knee replacement with the additional aid of patient specific instrumentation.
Patients undergoing unicompartmental knee replacement using standard instrumentation.
Outcomes
Primary Outcome Measures
Radiological Assessment of Component Positioning
Radiological assessment of component positioning and alignment based on post-operative knee radiographs.
Secondary Outcome Measures
Assessment of Functional Outcome
Use of the patient reported outcome tool (Oxford Knee Score) to determine functional outcome at one year following surgery.
Total score is 48. Minimum score 0 and Maximum score 48 with higher score indicating better function.
Scores on a scale
Full Information
NCT ID
NCT02748096
First Posted
April 15, 2016
Last Updated
October 18, 2021
Sponsor
Oxford University Hospitals NHS Trust
1. Study Identification
Unique Protocol Identification Number
NCT02748096
Brief Title
The Assessment of Patient Specific Instrumentation for Unicompartmental Knee Replacement
Official Title
The Assessment of Patient Specific Instrumentation for Unicompartmental Knee Replacement
Study Type
Interventional
2. Study Status
Record Verification Date
April 2016
Overall Recruitment Status
Completed
Study Start Date
March 2012 (undefined)
Primary Completion Date
February 2013 (Actual)
Study Completion Date
March 2014 (Actual)
3. Sponsor/Collaborators
Responsible Party, by Official Title
Sponsor
Name of the Sponsor
Oxford University Hospitals NHS Trust
4. Oversight
Data Monitoring Committee
Yes
5. Study Description
Brief Summary
Patient-specific instrumentation guides have previously been used to improving surgical accuracy and ease of implantation during Total Knee Replacement but have received less attention for implanting Unicompartmental Knee Replacement. The aim of this prospective study is to compare the accuracy of implantation and functional outcome of mobile bearing medial Unicompartmental Knee Replacement implanted with and without patient specific instrumentation by experienced knee surgeons.
Detailed Description
The aim of this prospective study is to compare the accuracy of implantation and functional outcome of mobile bearing medial Unicompartmental Knee Replacements implanted with and without patient specific instrumentation by experienced Unicompartmental Knee Replacement surgeons.
This single-centre parallel-design trial was conducted between March 2012 and March 2014 at the Nuffield Orthopaedic Centre, Oxford. Four expert knee surgeons performed all of the procedures in this study. Patients who were being placed on the waiting list for a medial Unicompartmental Knee Replacement, and met the entry criteria for the trial, were asked to see if they would be willing to receive further information about participation in the study. They were provided with a study information leaflet that they could read in their own time. A member of the research team subsequently contacted the patients in order to determine if they would agree to take part in the study and enrolled them onto the study.
Patients were randomized to either Patient Specific Instrumentation, or Conventional Instrumentation group. There were 23 patients (23 knees) in the Patient Specific Instrumentation group and 22 patients (22 knees) in the Conventional Instrumentation group. Randomization was performed using sealed opaque envelopes. Concealment from operating surgeons and patients was not possible owing to the surgeon needing to confirm the Patient Specific Instrumentation plans, and the patients undergoing pre-operative MRI scans. Patient Specific Instrumentation group patients underwent an MRI scan using the protocol outlined by the Patient Specific Instrumentation manufacturers to plan development of the Patient Specific Instrumentation guides. The preliminary plan indicating prosthesis size, positioning, alignment, and proposed bone resection levels was reviewed by the surgeons who accepted the default preoperative plans unless gross errors were present. The patient specific cutting blocks were then manufactured and sent for sterilization.
Operative Technique:
All patients received a mobile bearing medial Oxford unicompartmental knee replacement via a minimally invasive approach under general anaesthetic, and high thigh tourniquet. Intra-operatively, the bone cuts were made through the Patient Specific Instrumentation guides without the use of any intra or extra-medullary instrumentation on the femoral side but with a tibial extramedullary guide for some cases. The subsequent milling process and all soft tissue balancing was performed manually in the standard fashion.
Post-operatively, the need to have a blood transfusion, and the change haemoglobin levels were also recorded. Oxygen saturation levels over the first 24 hours post surgery were also recorded. Screened anteroposterior and lateral post-operative radiographs were performed prior to discharge. Patients attended the physiotherapy ward discharge clinic at six weeks. A further clinical review was performed at 12 months at which point Oxford Knee Scores were recorded.
The primary outcome measure was radiological assessment of component positioning. (See Outcome measures section for more detail)
Target sample size:
The sample size was calculated from a previous study that used similar radiological assessments to compare unicompartmental knee replacements performed using conventional instrumentation, with those performed using computer navigation. In this study, the standard deviation of the tibia varus/valgus angle for the control group was 3.6°. Assuming a minimum clinically important difference of 3°, the standard mean difference would be 0.8. Hence with a power of 0.8 and significance level of 0.05, a total sample size of 44 patients (22 in each group) was required.
6. Conditions and Keywords
Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Knee Arthritis
Keywords
Unicompartmental Knee Replacement, Patient Specific Instrumentation
7. Study Design
Primary Purpose
Treatment
Study Phase
Not Applicable
Interventional Study Model
Parallel Assignment
Masking
None (Open Label)
Allocation
Randomized
Enrollment
45 (Actual)
8. Arms, Groups, and Interventions
Arm Title
Patient Specific Instrumentation
Arm Type
Experimental
Arm Description
Patients undergoing unicompartmental knee replacement with the additional aid of patient specific instrumentation.
Arm Title
Conventional Instrumentation
Arm Type
Active Comparator
Arm Description
Patients undergoing unicompartmental knee replacement using standard instrumentation.
Intervention Type
Procedure
Intervention Name(s)
Patient Specific Instrumentation
Intervention Description
Patients will undergo a medial unicompartmental knee replacement. This knee replacement is implanted using patient specific cutting guides that have been produced based on the patient's individual anatomy (using plans from pre-operative MRI scans of the patient's knee).
Intervention Type
Procedure
Intervention Name(s)
Conventional Instrumentation
Intervention Description
Patients will undergo a medial unicompartmental knee replacement using standard conventional instruments.
Primary Outcome Measure Information:
Title
Radiological Assessment of Component Positioning
Description
Radiological assessment of component positioning and alignment based on post-operative knee radiographs.
Time Frame
Within a weeks after surgery
Secondary Outcome Measure Information:
Title
Assessment of Functional Outcome
Description
Use of the patient reported outcome tool (Oxford Knee Score) to determine functional outcome at one year following surgery.
Total score is 48. Minimum score 0 and Maximum score 48 with higher score indicating better function.
Scores on a scale
Time Frame
One year after surgery
Other Pre-specified Outcome Measures:
Title
Post-operative Change in Haemoglobin Between Baseline Baseline and 48 Hours After Surgery
Description
Change in haemoglobin levels between baseline and 48 hours after surgery will be determined
Time Frame
Within the first 48 hours after surgery
Title
Number of Participants With The Need for Blood Transfusion Following Surgery
Description
Number of Participants with The Need for Blood Transfusion within 48 hours of Surgery
Time Frame
Within the first 48 hours after surgery
10. Eligibility
Sex
All
Minimum Age & Unit of Time
18 Years
Accepts Healthy Volunteers
No
Eligibility Criteria
Inclusion Criteria:
Both cruciate ligaments functionally intact
Full thickness cartilage in the lateral compartment
Correctable intra-articular varus deformity
Full thickness cartilage loss in the medial compartment
Exclusion Criteria:
Contra-indication for MRI
All forms of inflammatory arthritis
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
Andrew Price, FRCS PhD
Organizational Affiliation
Nuffield Department of Orthopaedics, Rheumatology & Musculoskeletal Sciences, University of Oxford
Official's Role
Principal Investigator
12. IPD Sharing Statement
Plan to Share IPD
Yes
IPD Sharing Plan Description
Plan to publish in high impact peer reviewed orthopaedic journal
Learn more about this trial
The Assessment of Patient Specific Instrumentation for Unicompartmental Knee Replacement
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