Importance of Hollow or Solid Centralizer for Polished, Collarless and Tapered Stems in Total Hip Arthroplasty

Comparing Hollow and Solid Centralizer Designs When Using a Polished, Collarless, Tapered Hip Prosthesis Stem (MS30). A Prospective, Randomized, Multicenter Study Evaluated by RadioStereometric Analysis (RSA).

Status

Completed

Phases

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT01918540

Enrollment

Registered

2013-08-07

Start date

2003-02-28

Completion date

2014-11-30

Last updated

2014-11-26

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Total Hip Arthroplasty

Keywords

Radiostereometry, Total Hip Arthroplasty, Stem design

Brief summary

The study aims at comparing the effect of hollow or solid centralizer designs on the long time fixation behaviour of hip prosthesis stems that are polished, tapered and collarless. In a prospective, controlled and randomized study comprising two groups of 30 patients/hips each, the patients will be followed up by RadioStereometric Analysis (RSA) for ten years. In completion general health questionnaires as well as hip specific scoring instruments will be used to evaluate patient satisfaction and outcome.The hypothesis of the study is that the different centralizers will result in different migration patterns of the stems, which might affect the risk for late aseptic loosening.

Interventions

PROCEDUREHollow Centralizer

The stem used (MS30)was originally designed with a solid centralizer but has been redesigned to be used with a hollow centralizer. The patients are randomized to either solid or hollow centralizer

PROCEDURESolid Centralizer

The stem used (MS30)was originally designed with a solid centralizer but has been redesigned to be used with a hollow centralizer. The patients are randomized to either solid or hollow centralizer

DEVICEMS-30 femoral stem

This is the stem used in the study.

Study design

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

TREATMENT

Masking

SINGLE (Subject)

Eligibility

Sex/Gender

ALL

Age

60 Years to 85 Years

Healthy volunteers

Inclusion criteria

* Primary osteoarthritis of the hip necessitating primary hip replacement * Charnley classification group A and B * Age 60 - 85 years old at the inclusion time of the study.

Exclusion criteria

* Secondary osteoarthritis * Rheumatoid arthritis * Malignant disease * Severe osteoporosis * Earlier fracture or operation in the hip to be operated on * Peroperative fracture * Ongoing corticosteroid (oral) or immunosuppressive medication * Personal disorders (dementia, alcohol or drug abuse etc) suspected of making completion of the trial uncertain.

Design outcomes

Primary

Measure	Time frame	Description
Radiostereometric Analysis (RSA)	The first postoperative day, 6 months, 1, 2, 5 and 10 years	This will measure the change in stem migration over time and be indicative of long term result.

Secondary

Measure	Time frame	Description
x-ray	The first postoperative day, 6 months, 1, 2, 5 and 10 years	On standard x-rays the progress of radiolucent lines or other signs of loosening will be measured
Hip specific questionnaire	Preoperatively, 1, 2, 5 and 10 years	Hip disability and Osteoarthritis Score (HOOS) - this is a hip specific questionnaire that will measure how the operation has affected the patients hip function and pain situation
General health questionnaire	Preoperatively, 1, 2, 5 and 10 years	EuroQol (EQ-5D) - a standardized instrument for use as measure of general health outcome

Countries

Sweden

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026