Retrospective Observational Cohort Study of SYMBOL CUP DM 2

Study Overview
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Brief Summary
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This is a single-center retrospective observational cohort study of consecutively operated patients who underwent total hip arthroplasty with a SYMBOL CUP DMR HA or a SYMBOL CUP DM CEM hemispherical dual mobility acetabular implant. The purpose of this study is to estimate the safety and efficacy of those two implants at two-year follow-up.

Detailed Description
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Description according to PICOS framework: Patients: - Adult men and women requiring a total hip arthroplasty Intervention: - THA with SYMBOL CUP DMR HA or SYMBOL CUP DM CEM hemispherical dual mobility acetabular implants. Comparator: None Outcomes: Safety 1: Implant survival over 2-year follow-up. Safety 2: All adverse events, with focus on implant dislocation, infections, revision surgery Efficacy 1: Harris Hip Score (HHS) at baseline and 1-year follow-up. Efficacy 2: Modified HHS consisting of pain + functional subscores at baseline, 1-year and 2-year follow-ups. Efficacy 2: Devane score at baseline, 1-year and 2-year follow-ups. Efficacy 3: Charnley classification at baseline, 1-year and 2-year followups. Study design: single-center retrospective observational cohort study of consecutively operated patients who underwent total hip arthroplasty 2 years prior to study start. Prospective 2-year follow-up letter and phone questionnaire.

Official Title
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Etude de Cohorte Observationnelle Rétrospective SYMBOL CUP 2

Conditions
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Revision Total Hip Arthroplasty, Primary Total Hip Arthroplasty

Intervention / Treatment
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* Device: THA with SYMBOL CUP DMR HA
* Device: THA with SYMBOL CUP DM CEM


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: All patients with total hip implant using hemispheric dual-mobility SYMBOL CUP DMR HA or SYMBOL CUP DM CEM Operation performed by the primary investigator Delay between index operation and March 1 2018 has reached 2 years Exclusion Criteria: patient refusal to participate in the study minors (age < 18 years) patients under guardianship

Ages Eligible for Study
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Minimum Age: 18 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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| HMB-DMR-HA<br>Total hip arthroplasty with hemispherical metal-back dual-mobility acetabular cup with tripod fixation consisting of a hydroxyapatite-coated outer surface as well as two pegs and one screw. | Device: THA with SYMBOL CUP DMR HA<br> <br> |
| HMB-DM-CEM<br>Total hip arthroplasty with hemispherical metal-back dual-mobility acetabular cup with tripod fixation consisting of a bare metal outer surface to be covered with bone-compatible cement. | Device: THA with SYMBOL CUP DM CEM<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Implant survival: Ratio of the number of participants alive with the complete index hip prosthesis in position at 2-year follow-up, over their initial number | This is a the ratio of the number of participants who are alive with the complete index hip prosthesis in position at a given follow-up time (numerator) over the initial number of those participants from the date they received the index hip prosthesis (denominator). The cumulative ratio is recalculated at each event using the Kaplan-Meier method from the date of each participant index operation through the date of each participant's death or prosthetic removal surgery or loss-to-follow-up or last assessment alive with the hip prosthesis in place. The longest duration between the index operation and the final assessment is 2 years. | 2 years as of index operation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of patients with one or several post-operative adverse events and count of each Serious adverse event and aggregate count of adverse events | All serious post-operative adverse events are taken into account including implant dislocation, infections, revision surgery. | 2 years as of index operation | 
| Harris Hip Score (HHS) at baseline and 1-year follow-up | The score is measured at each assessment in each patient. The mean and confidence interval of the score is measured at each assessment as well as for the within-patient difference between assessments | 1 year as of index operation | 
| The modified Harris Hip Score (modified HHS) at baseline, 1-year and 2-year follow-up | The modified Harris Hip Score (modified HHS) is the sum of pain subscore and functional subscore of the Harris Hip Score. The score is measured at each assessment in each patient. The mean and confidence interval of the score is measured at each assessment as well as for the within-patient difference between assessments | 2 years as of index operation | 
| Devane classification at baseline, 1-year and 2-year follow-up | The class is measured at each assessment in each patient. The mean and confidence interval of the score is measured at each assessment as well as for the within-patient difference between assessments | 2 years as of index operation | 
| Charnley classification | The class is measured at each assessment in each patient. The mean and confidence interval of the score is measured at each assessment as well as for the within-patient difference between assessments | 2 years as of index operation | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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total hip arthroplasty, complex, revision, hemispherical dual-mobility acetabular cup, safety, efficacy, implant survival, prosthetic dislocation