Comparison of Conventional and Large Diameter Femoral Heads for the Prevention of Hip Dislocation

Study Overview
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Brief Summary
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About ten percent of revision hip replacements will dislocate. Although dislocation is not a life-threatening problem, it is stressful and costly and requires hospitalization to treat. Subjects who have repeated dislocations live with the constant fear of another dislocation. The purpose of this study is to test the effectiveness of a large ball prosthesis in preventing post-surgical dislocation. A large diameter ball has greater freedom of movement before it impinges; therefore, theoretically, it should not dislocate as easily.

Official Title
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A Randomized Multi-Centre Controlled Trial of Large Diameter (36/40 mm) Versus Conventional Diameter (32 mm) Femoral Heads for the Prevention of Post Revision Arthroplasty Dislocation

Conditions
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Hip Dislocation

Intervention / Treatment
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* Device: Large Diameter Femoral Head


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Eligible patients will be those undergoing revision hip arthroplasty, either first revision or subsequent re-revision. Revision must require replacement of both the acetabular component and femoral component, except when revising femur only with well-fixed Trilogy socket. The acetabular component must have a minimum outer diameter of 50 mm. The femoral component inserted should be a Zimmer Versys™ beaded full-coated stem or Zimmer ZMR™ stem or collarless polished taper (CPT™) Patients must be able to reply to questionnaires in either French or English. Exclusion Criteria: Patients who are undergoing revision for recurrent dislocation. Revision of the acetabulum requiring structural allograft or reconstruction ring. Revision of the acetabulum requiring the use of cemented all-polyethylene cups. Revision of the acetabulum using a liner cemented into an existing metal shell. Intra-operative decision to use a constrained liner.

Ages Eligible for Study
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Minimum Age: 19 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Intervention/Treatment |
| --- |
|Device: Large Diameter Femoral Head|nan|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To compare the difference in dislocation rate between those receiving a large ball (36/40 mm femoral head) versus those receiving a 32 mm femoral head in patients who undergo revision hip arthroplasty |  | at two years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To compare polyethylene wear in the two groups |  |  | 
| To compare the difference in functional and quality of life measures in the two groups |  | at 3, 12 and 24 months post surgery | 
| To compare radiographic findings in the two groups |  |  | 
| To estimate the rate of re-revision in the two groups |  |  | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Post-Arthroplasty Hip Dislocation