Ignite Creation Date:
2024-05-06 @ 6:52 PM
Last Modification Date:
2024-10-26 @ 2:56 PM
Study NCT ID:
NCT05815953
Status:
ACTIVE_NOT_RECRUITING
Last Update Posted:
2023-04-18
First Post:
2022-04-29
Brief Title:
Polarstem Versus Corail a Comparison of Micromotion and Periprosthetic Bone Remodelling of Two Femoral Stems
Sponsor:
Helse-Bergen HF
Organization:
Helse-Bergen HF
Study Overview
Official Title:
The Polarstem Versus Corail a Comparison of Micromotion and Periprosthetic Bone Remodelling of Two Femoral Stems A Randomised Trial of 60 Patients Using Radiostereometric Analysis Dual Energy X-ray Absorptiometry and Computer Tomography
Status:
ACTIVE_NOT_RECRUITING
Status Verified Date:
2023-04
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
None
Brief Summary:
A randomised controlled trial comparing a recently introduced femoral stem with an established stem for total hip arthroplasty THA 60 patients will be randomised into one of the two groups
1 Polarstem uncemented femoral stem Smith Nephew
2 Corail uncemented femoral stem De Puy All patients will receive a 32mm cobalt-chromium CoCr femoral head and an R3 acetabular cup with a 10 Mrad highly cross-linked polyethylene XLPE liner Smith Nephew
Radiostereometric analysis RSA will be used to measure stem migration Dual-energy x-ray absorptiometry DXA measurements will be used to measure bone mineral density Clinical outcome will be assessed at different time point to evaluate satisfaction and function Data from the Norwegian Arthroplasty Register will be used to investigate the risk of revision
1 Polarstem uncemented femoral stem Smith Nephew
2 Corail uncemented femoral stem De Puy All patients will receive a 32mm cobalt-chromium CoCr femoral head and an R3 acetabular cup with a 10 Mrad highly cross-linked polyethylene XLPE liner Smith Nephew
Radiostereometric analysis RSA will be used to measure stem migration Dual-energy x-ray absorptiometry DXA measurements will be used to measure bone mineral density Clinical outcome will be assessed at different time point to evaluate satisfaction and function Data from the Norwegian Arthroplasty Register will be used to investigate the risk of revision
Detailed Description:
The gold standard in THA the last 45 years has been the all-cemented metal-on polyethylene prostheses such as the Charnley low-frictional arthroplasty From 1980 and onwards however uncemented THA have been increasingly popular worldwide especially for the younger patients The reasons for this were reports on poor results of the Charnley cemented THA in young patients and the belief that the cement itself was the cause of periprosthetic osteolysis and loosening of the prostheses Uncemented THA have good results in some reports and poor results in others The modern uncemented femoral stems have proven good or even excellent results at medium to long term follow-up in the register and in other clinical studies The Corail uncemented femoral stem DePuy has dominated the Norwegian market on uncemented stems since the mid 1980ies Its clinical performance is well documented with good results in terms of implant survival5 The Polarstem Smith Nephew was introduced in 2002 by a group of surgeons that believed the Corail stem had certain limitations and the Polarstem is a Corail-like stem with some modifications The basic design philosophy of a straight tapered design is the same for both stems
Unlike drugs medical devices such as orthopaedic implants can be launched on the market without any proof of clinical efficacy In some cases inferior implants have been used in thousands of patients before the inferior results were discovered Some authors propose a stepwise introduction of new implants in order to avoid compromising large numbers of patients The present study is a step in the introduction of a relatively new femoral stem High accuracy measuring tools will be used to measure critical factors such as implant migration and bone remodelling at short-term follow-up The findings will give information on the expected clinical outcome at longer term
The aims of the study are
To compare the migration of the Polarstem and the Corail stem with RSA The null hypothesis is that there is no difference in the early 2 years postoperative migration of these implants Early migration has earlier proved to be a surrogate for implant performance at medium and long term
To compare any remodeling of periprosthetic femoral bone from direct postoperative measures to later time points Periprosthetic bone loss especially in the proximal femur can compromise the longevity of a prosthetic joint This bone loss vary and will be compared between the two designs
To assess and compare clinical outcome measures and radiological outcomes such as signs of loosening and osteolysis
Components
The Polarstem uncemented femoral stem Smith Nephew Orthopaedics AG Baar Switzerland is a straight titanium alloy Ti6Al4V tapered fully hydroxyapatite HA coated uncemented implant HA is used to enhance on-growth of bone to the implant surface and is put on top of a plasma spray porous coating titanium in a 150 75µm layer The stem was introduced onto the market in 2002 and no documentation on the clinical efficacy beyond 5 years existed when this study was planned The design philosophy however is similar to other implants that have good results at long term
The Corail uncemented femoral stem De Puy Int Ltd Leeds UK is a straight tapered fully hydroxyl-apatite coated stem that was introduced in 1986 in Norway It has been the most commonly used uncemented stem since and by 2014 more than 60 of THA patients in Norway received this stem The 15 year survival was 97 according to a study from 2007
R3 uncemented acetabular cup Smith Nephew Orthopaedics AG Baar Switzerland is a fourth-generation hemispheric porous coated cup intended for press-fit fixation The cup is based on the well-documented Reflection cup also Smith Nephew and has a locking mechanism that has proved better stability of the liner in laboratory studies Further a new asymmetric coating made of titanium powder StikTite with higher porosity and friction has been added The stability of this cup was found to be excellent in a series of patients measured by RSA The R3 cup was approved by the European Commission CE in 2007 and the Food and Drug Administration FDA in 2008 In some countries such as Australia the implant is one of the most frequently used and according to the Australian Orthopaedic Association National Joint Replacement Registry AOANJRR the results with up to 5 years of follow-up are promising
Radiography
Radiostereometric analysis RSA is a highly accurate and precise method of evaluating implant migration and polyethylene wear The precision usually is about 01-04 mm translational migration and 01-1 degrees rotation The radiation dose is low compared to plain x-rays 10-20 During surgery tiny spheres of Tantalum are implanted in periprosthetic bone The metal implants will be measured with markerless RSA On day 1-6 postoperatively two simultaneous exposures of the hip and a co-ordinate system are taken These films allow three-dimensional definition of the implant and bone relative to the co-ordinate system Implant migration and rotation is measured on repeat examinations over time The high precision allows us to detect small differences between groups and also means that the number of subjects in each group can be restricted The precision repeatability of the measurements in this study will be evaluated by double examinations at the 1-year RSA-visit Limits for significant differences are calculated as the 99 confidence intervals of the absolute mean values of the double examinations
Plain x-rays At all follow-up consultations plain x-rays of the pelvis and an AP and lateral view of the hip will be taken On postoperative pelvic views the varusvalgus position of the stem and cup inclination will be measured Later these values will be evaluated together with migration- and wear values Osteolysis will be measured
Computed tomography In order to investigate the incidence and to quantify periprosthetic osteolysis investigators will perform CT scanning of the patients at 10 years
Dual x-ray absorptiometry DXA Periprosthetic femoral bone mineral density BMD will be measured with DXA The load transmission to periprosthetic bone differs according to the mechanical properties and design of the implant Stress-shielding stress-protection of periprosthetic bone results in local osteopenia bone loss and may contribute to loosening periprosthetic fractures and complex revision procedures Most contemporary hip implant designs aim to reduce stress shielding as much as possible
Our departments standard surgical approach the posterolateral approach will be used on all patients The operations will take place in an operation theatre with laminar airflow the patients will receive prophylactic antibiotics Cephalotin 2gx4 or Clindamycin 06gx3 if Penicillin allergy perioperatively and prophylactics against thromboembolism Dalteparin 5000 international units for 2 weeks Implantation of the prosthetic components will be done according to preoperative planning and the manufacturers advice 6-10 tantalum beads Ø1mm will be inserted into the proximal femur The holes are then covered with bone wax
The patients are allowed immediate weight bearing as tolerated Walking aids at demand Physiotherapy is started on day 1 postoperatively and is continued at dismission
The results of the RSA- and DXA-examinations and clinical outcome measures will be collected in electronic files under the respective patient numbers Data obtained on previous occasions will not be accessible when examining the patient
According to the Data Inspectorate the requirements for a simple melding are
The responsible medical doctor investigator is employed by the organization in which the patient is being registered
The patient gives hisher written consent to participation in the study
The end of the study is determined at its start
The gathered data are deleted or anonymized at the end of the study
The study does not electronically merge data from different person registers
These requirements are fulfilled in the present study and a melding will be submitted to the Data Inspectorate when the administrative details concerning the study are ready
A patient list will be made coupling patient name and personal identification number to a number on the patient list 1 through 60 The project leader is responsible for the safe handling of the list Other forms with patient information are labelled with the patient number only for identification The sponsors of the study will have access to the anonymised data The study is reported to Personvernombudet through Norsk samfunnsvitenskapelig datatjeneste i Bergen
Analysis of variance on repeated measurements ANOVA will be used on the RSA- and on the clinical data if the data are normally distributed In our earlier RSA studies the data have displayed normal distribution If however the data are not normally distributed non-parametric tests Mann-Whitney U-test Wilcoxon matched-pairs test will be used
Adverse effects side effects and unfortunate effects of the surgery will immediately be reported to the project leader and to the sponsors Abortion or abruption of the study will be considered in the case of unexpected complications
Funding will be applied for from
The Regional Health Services Helse Vest Regionale helseforetak Det regionale samarbeidsorganet Helse Bergen Haukeland Universitetssykehus 5021 BERGEN Norway
Smith Nephew Orthopaedics AG Baar Switzerland
The study will be performed at the Department of Orthopaedic Surgery Haukeland University Hospital Bergen Norway
Unlike drugs medical devices such as orthopaedic implants can be launched on the market without any proof of clinical efficacy In some cases inferior implants have been used in thousands of patients before the inferior results were discovered Some authors propose a stepwise introduction of new implants in order to avoid compromising large numbers of patients The present study is a step in the introduction of a relatively new femoral stem High accuracy measuring tools will be used to measure critical factors such as implant migration and bone remodelling at short-term follow-up The findings will give information on the expected clinical outcome at longer term
The aims of the study are
To compare the migration of the Polarstem and the Corail stem with RSA The null hypothesis is that there is no difference in the early 2 years postoperative migration of these implants Early migration has earlier proved to be a surrogate for implant performance at medium and long term
To compare any remodeling of periprosthetic femoral bone from direct postoperative measures to later time points Periprosthetic bone loss especially in the proximal femur can compromise the longevity of a prosthetic joint This bone loss vary and will be compared between the two designs
To assess and compare clinical outcome measures and radiological outcomes such as signs of loosening and osteolysis
Components
The Polarstem uncemented femoral stem Smith Nephew Orthopaedics AG Baar Switzerland is a straight titanium alloy Ti6Al4V tapered fully hydroxyapatite HA coated uncemented implant HA is used to enhance on-growth of bone to the implant surface and is put on top of a plasma spray porous coating titanium in a 150 75µm layer The stem was introduced onto the market in 2002 and no documentation on the clinical efficacy beyond 5 years existed when this study was planned The design philosophy however is similar to other implants that have good results at long term
The Corail uncemented femoral stem De Puy Int Ltd Leeds UK is a straight tapered fully hydroxyl-apatite coated stem that was introduced in 1986 in Norway It has been the most commonly used uncemented stem since and by 2014 more than 60 of THA patients in Norway received this stem The 15 year survival was 97 according to a study from 2007
R3 uncemented acetabular cup Smith Nephew Orthopaedics AG Baar Switzerland is a fourth-generation hemispheric porous coated cup intended for press-fit fixation The cup is based on the well-documented Reflection cup also Smith Nephew and has a locking mechanism that has proved better stability of the liner in laboratory studies Further a new asymmetric coating made of titanium powder StikTite with higher porosity and friction has been added The stability of this cup was found to be excellent in a series of patients measured by RSA The R3 cup was approved by the European Commission CE in 2007 and the Food and Drug Administration FDA in 2008 In some countries such as Australia the implant is one of the most frequently used and according to the Australian Orthopaedic Association National Joint Replacement Registry AOANJRR the results with up to 5 years of follow-up are promising
Radiography
Radiostereometric analysis RSA is a highly accurate and precise method of evaluating implant migration and polyethylene wear The precision usually is about 01-04 mm translational migration and 01-1 degrees rotation The radiation dose is low compared to plain x-rays 10-20 During surgery tiny spheres of Tantalum are implanted in periprosthetic bone The metal implants will be measured with markerless RSA On day 1-6 postoperatively two simultaneous exposures of the hip and a co-ordinate system are taken These films allow three-dimensional definition of the implant and bone relative to the co-ordinate system Implant migration and rotation is measured on repeat examinations over time The high precision allows us to detect small differences between groups and also means that the number of subjects in each group can be restricted The precision repeatability of the measurements in this study will be evaluated by double examinations at the 1-year RSA-visit Limits for significant differences are calculated as the 99 confidence intervals of the absolute mean values of the double examinations
Plain x-rays At all follow-up consultations plain x-rays of the pelvis and an AP and lateral view of the hip will be taken On postoperative pelvic views the varusvalgus position of the stem and cup inclination will be measured Later these values will be evaluated together with migration- and wear values Osteolysis will be measured
Computed tomography In order to investigate the incidence and to quantify periprosthetic osteolysis investigators will perform CT scanning of the patients at 10 years
Dual x-ray absorptiometry DXA Periprosthetic femoral bone mineral density BMD will be measured with DXA The load transmission to periprosthetic bone differs according to the mechanical properties and design of the implant Stress-shielding stress-protection of periprosthetic bone results in local osteopenia bone loss and may contribute to loosening periprosthetic fractures and complex revision procedures Most contemporary hip implant designs aim to reduce stress shielding as much as possible
Our departments standard surgical approach the posterolateral approach will be used on all patients The operations will take place in an operation theatre with laminar airflow the patients will receive prophylactic antibiotics Cephalotin 2gx4 or Clindamycin 06gx3 if Penicillin allergy perioperatively and prophylactics against thromboembolism Dalteparin 5000 international units for 2 weeks Implantation of the prosthetic components will be done according to preoperative planning and the manufacturers advice 6-10 tantalum beads Ø1mm will be inserted into the proximal femur The holes are then covered with bone wax
The patients are allowed immediate weight bearing as tolerated Walking aids at demand Physiotherapy is started on day 1 postoperatively and is continued at dismission
The results of the RSA- and DXA-examinations and clinical outcome measures will be collected in electronic files under the respective patient numbers Data obtained on previous occasions will not be accessible when examining the patient
According to the Data Inspectorate the requirements for a simple melding are
The responsible medical doctor investigator is employed by the organization in which the patient is being registered
The patient gives hisher written consent to participation in the study
The end of the study is determined at its start
The gathered data are deleted or anonymized at the end of the study
The study does not electronically merge data from different person registers
These requirements are fulfilled in the present study and a melding will be submitted to the Data Inspectorate when the administrative details concerning the study are ready
A patient list will be made coupling patient name and personal identification number to a number on the patient list 1 through 60 The project leader is responsible for the safe handling of the list Other forms with patient information are labelled with the patient number only for identification The sponsors of the study will have access to the anonymised data The study is reported to Personvernombudet through Norsk samfunnsvitenskapelig datatjeneste i Bergen
Analysis of variance on repeated measurements ANOVA will be used on the RSA- and on the clinical data if the data are normally distributed In our earlier RSA studies the data have displayed normal distribution If however the data are not normally distributed non-parametric tests Mann-Whitney U-test Wilcoxon matched-pairs test will be used
Adverse effects side effects and unfortunate effects of the surgery will immediately be reported to the project leader and to the sponsors Abortion or abruption of the study will be considered in the case of unexpected complications
Funding will be applied for from
The Regional Health Services Helse Vest Regionale helseforetak Det regionale samarbeidsorganet Helse Bergen Haukeland Universitetssykehus 5021 BERGEN Norway
Smith Nephew Orthopaedics AG Baar Switzerland
The study will be performed at the Department of Orthopaedic Surgery Haukeland University Hospital Bergen Norway
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
False
Is a FDA Regulated Device?:
False
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None