Retrospective Observational Cohort Study of SYMBOL CUP DM 2

Completed

Interventions: Device: THA with SYMBOL CUP DMR HA
Device: THA with SYMBOL CUP DM CEM

Brief Summary: This is a single-center retrospective observational cohort study of consecutively operated patients who underwent total hip arthroplasty (THA) 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: Description according to PICOS (Patient, Intervention, Comparator, Outcomes, Study design) 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 (mHHS) 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.

Recruitment & Eligibility

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

Arm && Interventions

Group	Intervention	Description
HMB-DMR-HA	THA with SYMBOL CUP DMR HA	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.
HMB-DM-CEM	THA with SYMBOL CUP DM CEM	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.

Primary Outcome Measures

Name	Time	Method
Implant Survival: Acetabular Cup Survival at 2-year Follow-up	2 years as of index operation	This is a the ratio of the number of patient joints surviving with the acetabular prosthesis in position at a given follow-up time (numerator) over the initial number of those joints from the date they received the acetabular prosthesis (denominator). The cumulative ratio is recalculated at each event using the Kaplan-Meier method from the date of each joint 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 acetabular prosthesis in place. The longest duration between the index operation and the final assessment is 2 years.

Secondary Outcome Measures

Name	Time	Method
Number of Patients With One or Several Post-operative Adverse Events and Count of Each Serious Adverse Event and Aggregate Count of Adverse Events	2 years as of index operation	All serious post-operative adverse events are taken into account including implant dislocation, infections, revision surgery.
Harris Hip Score (HHS) at Baseline and 1-year Follow-up	1 year as of index operation	Harris Hip Score (HHS) is measured at each assessment in each patient. HHS is a physician-completed instrument that consists of subscales for pain severity (1 item, 0-44 points), function (7 items, 0-47 points), absence of deformity (1 item, 0-4 points), and range of motion (2 items, 0-5 points). Scores range from 0 (worse disability) to 100 (less disability). The mean and confidence interval of the score is measured at each assessment as well as for the within-patient difference between assessments
The Modified Harris Hip Score (Modified HHS) at Baseline, 1-year and 2-year Follow-up	2 years as of index operation	The modified Harris Hip Score (modified HHS) is the sum of pain subscore and functional subscore of the Harris Hip Score. It consists of subscales for pain severity (1 item, 0-44 points), function (7 items, 0-47 points). Scores range from 0 (worse disability) to 91 (less disability)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