Periprosthetic bone mineral density (BMD) around two different stems in total hip arthroplasty

ISRCTN ISRCTN54967983
DOI https://doi.org/10.1186/ISRCTN54967983
Secondary identifying numbers N/A
Submission date
06/08/2010
Registration date
18/08/2010
Last edited
18/08/2010
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Musculoskeletal Diseases
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data
Record updated in last year

Plain English summary of protocol

Not provided at time of registration

Contact information

Prof Christina Stukenborg-Colsman
Scientific

Orthopädische Klinik Medizinische Hochschule Hannover im Annastift
Anna-von-Borries-Str. 1-7
Hannover
30625
Germany

christina.stukenborg@ddh-gruppe.de

Study information

Study designObservational longitudinal study
Primary study designObservational
Secondary study designCohort study
Study setting(s)Hospital
Study typeScreening
Participant information sheet Not available in web format, please use the contact details below to request a patient information sheet
Scientific titlePeriprosthetic bone mineral density (BMD) around two different stems in total hip arthroplasty: an observational longitudinal study
Study objectivesTo 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(s)Local ethics committee approved on the 23rd May 2006 (ref: 4226)
Health condition(s) or problem(s) studiedOsteoarthritis of the hip
InterventionIn 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 patient’s 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 typeOther
Primary outcome measureBMD (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 measuresHarris 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 study start date01/06/2008
Completion date31/12/2014

Eligibility

Participant type(s)Patient
Age groupAdult
SexBoth
Target number of participants25 per implant, 50 in total
Key inclusion criteria1. 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
Key exclusion criteria1. 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
Date of first enrolment01/06/2008
Date of final enrolment31/12/2014

Locations

Countries of recruitment

  • Germany

Study participating centre

Orthopädische Klinik Medizinische Hochschule Hannover im Annastift
Hannover
30625
Germany

Sponsor information

German Research Council (Deutsche Forschungsgemeinschaft [DFG]) (Germany)
Research council

Kennedyallee 40
Bonn
53170
Germany

+49 (0)228 885 1
postmaster@dfg.de
http://www.dfg.de
ROR logo https://ror.org/018mejw64

Funders

Funder type

Research council

German Research Council (Deutsche Forschungsgemeinschaft [DFG]) (Germany) (ref: SFB 599, D6)

No information available

Results and Publications

Intention to publish date
Individual participant data (IPD) Intention to shareNo
IPD sharing plan summaryNot provided at time of registration
Publication and dissemination planNot provided at time of registration
IPD sharing plan
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