Clinical Trial Details
— Status: Active, not recruiting
Administrative data
NCT number |
NCT02177227 |
Other study ID # |
Attune TruMatch |
Secondary ID |
|
Status |
Active, not recruiting |
Phase |
N/A
|
First received |
|
Last updated |
|
Start date |
August 2014 |
Est. completion date |
August 2024 |
Study information
Verified date |
May 2023 |
Source |
Lawson Health Research Institute |
Contact |
n/a |
Is FDA regulated |
No |
Health authority |
|
Study type |
Interventional
|
Clinical Trial Summary
The purpose of our study is to determine, using a prospective, randomized-controlled trial,
the economic viability and clinical outcomes associated with patient-specific instrumentation
(PSI) for total knee arthroplasty in an obese patient population.
Description:
This is a randomized, blinded study. Following REB approval, eligible patients electing to
undergo TKA will be identified by either the PI or co-investigators, and approached in an
orthopaedic outpatient clinic to discuss enrolment into the study. Patients will be enrolled
if they meet the prerequisite inclusion criteria and have signed an informed consent.
Patients will then be randomized to undergo a TKA using PSI, or a conventional TKA. The
randomization sequence will be computer generated using blocks of five. Preoperative
Assessment At baseline, patients will complete a Knee Society Score (KSS), Short-Form 12
(SF-12) Questionnaire, and Western and McMaster University Osteoarthritis Index (WOMAC)
questionnaire, and the European Quality of Life Scale Index (EQ-5D). The EQ-5D is a
validated, reliable, and feasible outcome measure that provides a utility index. This utility
index allows quality adjusted life years to be calculated following an intervention. The
questionnaire is a 5-item standardized generic measure of health related quality of life that
includes domains of mobility, self-care, usual activities, pain and discomfort, and anxiety
and depression. Each item is scored using a 3-point response scale and each combination of
response choices describes a health state (resulting in 243 possible health states). Each
health state can then be converted to a utility value ranging from 0 (worst) to 1.0 (best)
using existing preference valuation data[22]. It has been valuated in both Canadian and
American populations for use in assessing health-related quality of life [23, 24]. We will
then calculate each patient's quality-adjusted life year (QALY). QALYs incorporate both
length of life and quality of life into a single measure and are calculated by multiplying
the utility value by the length of time spent in that health state. Additionally, a clinical
assessment will be completed, including knee range of motion, ligamentous assessment, and
evaluating for soft tissue contractures. Finally, patients will have 3-foot coronal and
sagittal standing radiographs of their lower extremities at our institution. The standing
mechanical axis of the involved limb will then be calculated. Skyline views will also be
performed as part of the radiographic analysis. In order for appropriate preoperative
planning, patients randomized to PSI will undergo a computed tomography (CT) scan of the
surgical limb using the TruMatch TM scanning protocol. Following modifications made by the
treating surgeon, the personalized patient instruments will be manufactured in standard
fashion. Intraoperative Assessment On the day of surgery, patients will receive either a
spinal or general anesthetic based on recommendations from an anesthetist, or personal
preference. A non-sterile tourniquet will be applied to the operative limb. A mid-line skin
incision followed by a medial parapatellar arthrotomy will be used for exposure. The femoral
and tibial cuts will be made using conventional instrumentation in the control group, or the
TruMatch TM Personalized Solutions Instruments in the treatment group. Soft tissue balancing,
including releases and removal of osteophytes, will be performed at the discretion of the
surgeon. The Attune TM components will be implanted using cement fixation. At the time of
cementing the implants, patients will receive a parenteral weight-based dose of tranexamic
acid (20 mg /kg), provided that there are no contra-indications. Prior to closure, patients
will receive an intra-articular injection of an anesthetic cocktail. The parapatellar
arthrotomy and subcutaneous tissue and skin will be closed in standard fashion.
Post-operatively, patients will receive deep-vein thrombosis prophylaxis for 14-days
post-operatively. They will also receive 24 hours of post-operative parenteral antibiotics.
They will be assessed by physiotherapy, with weight-bearing and range of motion exercises
beginning on post-operative day 0. Patients will be discharged from hospital once they have
reached appropriate rehabilitative milestones outlined by our institution. Postoperative
Assessment Patients will have routine follow-up with their surgeon at 2-, 6-, and 12-weeks,
followed by 1-year and every other year thereafter. Three-foot coronal and full-length
sagittal standing radiographs, as well as skyline views of the involved knee, will be taken
at the 1-year postoperative visit. We will calculate the mechanical axis of the operative
limb based on this postoperative radiographic assessment. The patients will complete the KSS,
SF-12, WOMAC, and EQ-5D questionnaires at their 6-week, 12-week, and 1-year visits. These
outcome questionnaires will be collected prospectively at 5-years and 10-years
post-operatively through our institution's database. Assessors of both clinical outcomes and
mechanical axis will be blinded to surgical intervention (conventional instrumentation versus
PSI TKA). Patients will also receive a health care resource use diary to complete between
follow-up intervals in order to collect outpatient direct and indirect costs associated with
TKA. Costs Our institution's costs-accounting department will provide information regarding
operating room costs, implant costs, and costs associated with routine care such as nursing,
medications, and investigations. Physician-related costs will be acquired through Ontario
Health Insurance Plan billing protocols. The outpatient cost analysis diary will capture
direct, non-medical costs associated with TKA (see Appendix C). The data will be reported in
Canadian dollars for the fiscal year in which the in-hospital cost data was derived. A sample
database we are currently employing in an unrelated study can be provided if required.
Cost-Utility Analysis Incremental Cost-Utility Ratio (ICUR) The ICUR represents the ratio of
incremental cost to incremental utility. The incremental cost represents the additional cost
of the PSI group compared to the conventional group. The costs will include all direct
(operating room, hospital stay, rehabilitation, medications, investigations) and indirect
costs (informal care, time lost to productivity). Similarly, the incremental utility is the
mean difference in QALY between groups. Net Benefit Regression We will use the net benefit
regression (NBR) framework to estimate the incremental net benefit (INB) of PSI [25]. An
intervention is considered to be cost-effective if the INB is greater than zero. The net
benefit regression method also provides a means to adjust for any potentially confounding
factors and therefore allows greater statistical efficiency and provides a more precise
estimate of the INB. We will include the following covariates in our regression models:
baseline utility score, severity of osteoarthritis, age and number of comorbidities. To
characterize the statistical uncertainty around our estimate of INB we will calculate 95%
confidence intervals, and a cost-effectiveness acceptability curve (CEAC). Modeling To
determine the cost-effectiveness of a new intervention, an economic decision model is
appropriate when there are multiple existing sources of evidence to answer a question (e.g.
randomized trials, cohort studies, registries, etc.) or to forecast the costs and/or outcomes
beyond the follow-up period of the clinical trial. Given that PSI is a relatively new
technology, there is no long-term data available to accurately determine the survival of the
implant or the rate of revision. To accurately answer this question, we will prospectively
follow the cohort long-term to determine survival rates of the implant.