Clinical trial NCT00214760: Polymethyl Methacrylate and (PEGT/PBT) Centralizer by the Uncemented BIHAPRO THP
Official title: Phase 3 Randomised, Prospective Study Comparing the PMMA and the Resorbable PEGT/PBT Centralizer by the Uncemented BIHAPRO Total Hip Prosthesis
Study type: INTERVENTIONAL
Overall status: TERMINATED
Phase: PHASE3
Conditions: Osteoarthritis
Keywords: Hip prosthesis
Centralizer
Uncemented
Lead sponsor: Biomet Nederland BV
Sponsor class: INDUSTRY
Collaborators: name: Atrium Medical Center
First posted: 2005-09-22
Enrollment: 70
Sex: ALL
Minimum age (years): 18
Maximum age (years): 75
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: The purpose of this study is to analyse if the alignment of the stem and the number of complications of the new resorbable PEGT/PBT centralizer are comparable to the standard PMMA centralizer during the placement of an uncemented Bihapro hip prosthesis.

Detailed description: For a correct placement and early fixation of an uncemented hip prosthesis, a centralizer is used. Normally, the centralizer is made of PMMA, the same material as bone cement. When a revision is needed, PMMA is difficult to remove, which is one of the reason not to use a cemented hip prosthesis. With a PMMA centralizer, still PMMA will remain in the bone and needs to be removed in case of a revision. PEGT/PBT is a reabsorbable material, which gives stability during the first month after the placement of the hip prosthesis. However, PEGT/PBT is reabsorped afterwards and, therefore, will not interfere with a revision procedure.

The goal of this study is to analyse if the PEGT/PBT is as safe as PMMA in terms of alignment, direct postoperative complications and clinical results.

Therefore, 100 patients indicated for a cementless Bihapro hip prosthesis which have signed an informed consent are included and randomised over the used centralizers using a weighted randomisation method. All patients will be treated equally. The patients are examined preoperatively, 1 day, 6 weeks, 3, 6, 12, 24 en 48 months postoperatively using an X-ray, the Harris hip score and a patient questionnaire, the Womac and SF36.

Eligibility criteria: Inclusion Criteria:

* Age between 18 and 75 years
* Diagnosis: Osteoarthritis
* Indicated for a primary hip prosthesis

Exclusion Criteria:

* Previous hip surgery
* No informed consent
* Active infection in hip
* Immature skeleton
* Rheumatoid arthritis, M. Paget

Primary outcomes:
measure: Alignment
timeFrame: 0,3,6,12,24 months
measure: Complications
timeFrame: all time points
Secondary outcomes:
measure: Pain
timeFrame: 0,3,6,12,24 months
measure: Function
timeFrame: 0,3,6,12,24 months
Other outcomes:
Locations:
city: Heerlen
country: Netherlands
facility: Atrium medical centre
Study officials:
affiliation: Biomet Nederland
name: Joanne Bloemsaat-Minekus, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Hernandez-Vaquero D, Murcia-Mazon A, Paz-Jimenez J, Alegre-Mateo R, Martinez-Garcia J, Pena-Vazquez J. Behavior of the femoral stem in the Bihapro hip prosthesis. Orthopedics. 1999 Nov;22(11):1049-53. doi: 10.3928/0147-7447-19991101-13.