Contact information
Type
Scientific
Primary contact
Prof Christina Stukenborg-Colsman
ORCID ID
Contact details
Orthopädische Klinik Medizinische Hochschule Hannover im Annastift
Anna-von-Borries-Str. 1-7
Hannover
30625
Germany
christina.stukenborg@ddh-gruppe.de
Additional identifiers
EudraCT number
ClinicalTrials.gov number
Protocol/serial number
N/A
Study information
Scientific title
Periprosthetic bone mineral density (BMD) around two different stems in total hip arthroplasty: an observational longitudinal study
Acronym
Study hypothesis
To monitor the bone mineral density (BMD) around a well known approved femoral implant and a new short stem design femoral implant. The data is used to validate a finite element model of both implants.
Ethics approval
Local ethics committee approved on the 23rd May 2006 (ref: 4226)
Study design
Observational longitudinal study
Primary study design
Observational
Secondary study design
Cohort study
Trial setting
Hospitals
Trial type
Screening
Patient information sheet
Not available in web format, please use the contact details below to request a patient information sheet
Condition
Osteoarthritis of the hip
Intervention
In all patients the Metha short stem (monoblock with 130° CCD angle and 0° ante-, retrotorsion) or the Bicontact stem (AESCULAP AG, Tuttlingen, Germany) was implanted by three experienced senior surgeons over a standard lateral approach in supine position. The cementless short stem implant is made of a titanium forged alloy and has a proximal rough titanium micro-porous coating. An additional 20 µm dicalciumphosphate layer is applied electrochemically. The stem is anchored metaphyseally within the closed ring of the femoral neck. The Bicontact stem is designed for proximal fixation and load transfer to bone. According to the implant design and the Plasmapore-coated proximal part the secondary implant stability is achieved by proximal anchoring and cancellous bone ingrowth. Pre-operatively, 1 week after surgery, 6 month and 12 month after implantation the patients were examined clinically (Harris Hip Score) and underwent DXA examinations.
All patients underwent full weight bearing post-operatively. DXA scans were performed using a HOLOGIC Discovery A S/N 80600 device (Hologic Inc., Waltham, MA). The BMD (g/cm2) of the operated hip was measured using the "metal-removal hip" scanning mode. Conventional Gruen's zones were adapted to the short stem design. Each patients individual ROIs were saved on the Hologic system and were used for all following measurements to reduce bias. The images were analyzed using the dedicated Windows analysis software (version 11.2). The patients were placed in supine position with the affected leg in 20° internal rotation. The foot was secured in the Hologic foot positioning device in order to obtain reproducible rotation in all patients to limit measurement errors, since it has been demonstrated that rotation influences the BMD.
DXA precision was assessed on all subjects. The patients underwent sequential DXA examinations of the contralateral unoperated hip and the proximal femur - taken preoperatively and one week later. Additional quality controls were done every morning for the DXA equipment according to the manufacturer's guidelines, to verify the stability of the system, and did not show any shift or drift during the entire study period. The device used in our study was therefore chaacterised as stable. The same observer (ML) analysed all DXA examinations. A Student's t-test was used to test the hypothesis of a difference between the means at the different measurement time points in the Harris hip Score as a normal distribution was ascertained. The Shapiro-Wilk-tests did not show a normal distribution in the DXA measurements, the Wilcoxon signed-ranks test was used to statistically compare the density changes over one year. A p<0.005 was considered significant. Data analysis was performed with SPSS (11.05 SPSS Inc. Chicago, Illinois). After two years the Bicontact branch was ended, but the Metha branch will continue for additional two years.
Intervention type
Other
Phase
Not Applicable
Drug names
Primary outcome measure
BMD (g/cm^2) in Gruen Zones 1 - 7 per DEXA, measured 1 day pre-operatively, and 1 week, 6 months, 1 year, 2 years, 3 years and 4 years post-operatively.
Secondary outcome measures
Harris Hip Score per questionaire and clinical examination, measured 1 day pre-operatively, and 1 week, 6 months, 1 year, 2 years, 3 years and 4 years post-operatively.
Overall trial start date
01/06/2008
Overall trial end date
31/12/2014
Reason abandoned (if study stopped)
Eligibility
Participant inclusion criteria
1. Indication for unilateral implantation of the Bicontact stem or the Metha short stem due to osteoarthritis of the hip
2. Patients' ages between 35 and 70 years of either sex
3. Written informed consent
Participant type
Patient
Age group
Adult
Gender
Both
Target number of participants
25 per implant, 50 in total
Participant exclusion criteria
1. Manifestly overweight (body mass index [BMI] greater than 35 kg/m^2)
2. History of previous surgeries on the same hip
3. Femoral fractures
4. Metabolic bone diseases
5. Use of steroids or other drugs affecting bone metabolism
6. Intraoperative cracks
7. Severe osteoarthritis of the contralateral hip
8. Received total hip arthroplasty (THA) on the contralateral hip during the study period
9. Patients in whom an event leading to restricted weight bearing on the ipsi- or contralateral hip occurred
Recruitment start date
01/06/2008
Recruitment end date
31/12/2014
Locations
Countries of recruitment
Germany
Trial participating centre
Orthopädische Klinik Medizinische Hochschule Hannover im Annastift
Hannover
30625
Germany
Sponsor information
Organisation
German Research Council (Deutsche Forschungsgemeinschaft [DFG]) (Germany)
Sponsor details
Kennedyallee 40
Bonn
53170
Germany
+49 (0)228 885 1
postmaster@dfg.de
Sponsor type
Research council
Website
Funders
Funder type
Research council
Funder name
German Research Council (Deutsche Forschungsgemeinschaft [DFG]) (Germany) (ref: SFB 599, D6)
Alternative name(s)
Funding Body Type
Funding Body Subtype
Location
Results and Publications
Publication and dissemination plan
Not provided at time of registration
Intention to publish date
Participant level data
Not provided at time of registration
Basic results (scientific)
Publication list