Primary- To evaluate the initial and long-term clinical results in terms of function, quality of life and pain/satisfaction of the Signature* procedure compared to the standard operation instruments.- To evaluate the alignment of the Signature*…
ID
Source
Brief title
Condition
- Joint disorders
- Bone and joint therapeutic procedures
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
-Oxford knee score at 1 Year.
-Alignment of the femoral and tibial prosthesis 6 W in the frontal plane.
Secondary outcome
-Questionnaires
o American Knee Society Score, WOMAC, Oxford Knee - 12, EQ-5D, VAS: at 3
months, 1 year, 2 years, 5 years and 10 years.
-Efficacy
o Operation time
o Length of hospital stay
o Fit, form and practical use of the Signature* alignment guides.
-Safety
o Adverse events/complications: Intra-operative, post-operative during trial
o Needed change of plans per-operative: change of size of prosthesis,
conversion Signature procedure to conventional procedure for any reason
-Survivorship at 10 years post-operative
-Cost-effectiveness
o All material costs of both procedures
-Shape-matching
o Occurrence (and percentage) of outliers in alignment in the frontal, sagittal
and horizontal plane of femoral and tibial components.
o Occurrence (and percentage) of outliers in alignment of the mechanical axis
of the leg.
o Difference in thickness of the in vivo inserted polyethylene compared to
pre-operatively calculated thickness of this insert.
Background summary
Signature* for unicompartmental knee arthroplasty (UKA) is a patient specific
alignment guide based on MRI-images. This type of guiding makes conventional
guiding unnecessary.
The principle aims of this study are:
- to investigate whether the new device, Signature* for UKA, is at least as
effective in clinical outcome as the widely used current method for UKA
- to investigate whether Signature* results in a larger percentage of
prosthesis placed correctly (within guidelines of 3 degrees varus and 3 degrees
valgus).
- to compare the preoperatively planned alignment of the prothesis with the
actual alignment in vivo.
Study objective
Primary
- To evaluate the initial and long-term clinical results in terms of function,
quality of life and pain/satisfaction of the Signature* procedure compared
to the standard operation instruments.
- To evaluate the alignment of the Signature* procedure compared to the
standard operation instruments.
Secondary
- To evaluate the efficacy of the Signature* procedure in terms of operation
time and length of hospital stay compared to the standard operation instruments.
- To evaluate the safety of the Signature* procedure in terms of
complications/adverse events and needed change of plans compared to the
standard operation instruments.
- To evaluate the survival of the Oxford UKA, placed with Signature* alignment
guide compared to the Oxford UKA, placed with standard operation instruments.
- To evaluate the cost-effectiveness of the Signature* procedure compared to
the standard operation instruments.
- Verify the fit, form and practical use of the Signature* alignment guides.
Shape matching:
- To determine the occurrence (and percentage) of outliers in alignment in the
frontal, sagittal and horizontal plane of femoral and tibial components.
Outliers are defined as deviations > 3 degrees from preoperative planning.
- To determine the occurrence (and percentage) of outliers in alignment of the
mechanical axis of the leg. Outliers are defined as deviations > 3 degrees from
preoperative planning.
- Verify to what extend the thickness of the in vivo inserted polyethylene
corresponds with the pre-operatively calculated thickness of this insert.
Study design
A Prospective, Multi-centre, Randomized, Double blind study
Patients will be randomized to be operated on with the use of the conventional
alignment method (control group), or Signature* (trial group). Patients have an
equal opportunity of being assigned to the trial group or control group. The
randomization will occur via a random number generator. The surgeon or clinical
researcher does not choose the participants for each group. The patients are
not informed on the type of prosthesis placement that has been carried out.
The outcome assessor is blinded to the treatment allocation of the patients.
Only the patients in the trial group will participate in the Shape-matching
part of the study, for which a real CT-scan will be made preoperatively and
postoperatively. Patients operated on by means of the standard intramedullar
technique will undergo sham-CT-scanning in order to maintain patient blinding
to treatment allocation.
Study burden and risks
1. Long-leg X-rays (standard)
Prior to surgery (< 6 weeks) standing, weight-bearing long-leg X-rays will be
made. These X-rays serve to determine the mechanical axis of the leg and the
varus/valgus deformity of the knee.
2. MRI scanning (standard)
A MRI-scan of hip, knee and ankle will be made 6 weeks before surgery. This
scan will be conducted according to a scanning protocol (see appendix 3). With
the aid of this scan, the guides and bone models will be manufactured, as
described in the former. All patients undergo scanning in order to maintain
patient blinding to treatment allocation.
3. Shape matching (not Standard)
- A low dose CT-scan of the total leg of the patient will be made
pre-operatively and postoperatively. To maintain blinding of all patients to
treatment allocation, the rest of participating patients will undergo
sham-CT-scanning (* hour on scanning machine without actual scanning).
- Purpose of these scans is to assess alignment of the prosthesis and the
components of the prosthesis in frontal, transverse and sagittal plane and to
compare this alignment with preoperatively determined position of the
prosthesis. The comparison will be done using software of materialise NV
(Materialise NV, Leuven, Belgium). This software is the same software that is
being used for quality checking by Materialise.
- Calculations have been made by Materialise to allow for a minimal radiation
exposure, while maintaining sufficient quality of the imaging. With parameters
120 kVp and 100 mAs and with slice increment 1,25 mm it is possible to generate
images with sufficient accuracy and resolution for performing measurements. For
patients, the radiation exposure will be 2 x 5,69 mSv = 11,38 mSv. This is
comparable with one CT-pelvis or one CT-thorax.
Dr. H. van der Hoffplein 1
Sittard-Geleen 6162 BG
NL
Dr. H. van der Hoffplein 1
Sittard-Geleen 6162 BG
NL
Listed location countries
Age
Inclusion criteria
•Painfull and disabled knee joint resulting from osteoarthritis of the medial
knee compartment.
•High need to obtain pain relief and improve function,
-Above 18 years old (full skeletal maturity).
-Body-mass-index (BMI) <35
-Ablility and willingness to follow instructions, including control of weight
and activity level, and to return for follow-up evaluations.
-Consent form read, understood and signed by patient.
Exclusion criteria
-Patients with osteoarthritis of more than only the medial knee compartment
-Active infection in knee
-General infection
-Distant foci of infections which may spread to the implant site
-Failure of previous joint replacement
-Pregnancy
-Previous major knee surgery, except for arthroscopic meniscectomy.
-Metal near knee joint (MRI-scan not possible)
-Not able or willing to undergo MRI-scan and CT-scan
-Reumatoid arthritis
-Extension deficit of more than 15 degrees
-Flexion less than 110 degrees
-Non-correctable varus axis
-Cruciate ligament insufficiency
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
| Register | ID |
|---|---|
| CCMO | NL38336.096.12 |