"True Incidence of Hip Dislocation After Primary THA - a Nationwide Population Study"

• ClinicalTrials.gov Identifier: NCT03859791
• Recruitment Status: Active, not recruiting
• First Posted: March 1, 2019
• Last Update Posted: March 1, 2019
• Sponsor: University of Southern Denmark
• Information provided by (Responsible Party): Lars Lykke Hermansen, University of Southern Denmark

Study Description

Brief Summary:

The primary objective is to report the true incidence of hip dislocations in primary THA patients within 2 years of index surgery.

Secondary, patient and component characteristics (age, sex, comorbidity, cemented/uncemented, approach, head diameter) are analyzed as potential risk factors for dislocation. Specific components may be analyzed based on number.

Condition or disease	Intervention/treatment
Hip Dislocation	Other: THA

Detailed Description:

Based on published literature and personal experience, most hip surgeons have an assumption of the degree of hip dislocation. This will be the first study to reveal the actual extent of this specific complication in a large population. It will give surgeons knowledge of the current standards -both on a national and hospital level. Depending on the results and comparisons to relevant countries, the investigators will be able to either substantiate or forced to rethink current procedures. This applies to both surgical access and use of specific components.

Since the vast majority of dislocations appear within 1-2 years after primary surgery (29), the follow-up period will be 2 years. By applying the National Patient Registry the investigators are able to identify any type of patient contact with the hospital system throughout Denmark in these 2 years. Patients assigned with correct diagnostic and procedural codes for dislocation and reduction are identified. However, the investigators will also find the cases of dislocation that are incorrectly coded in the registry. Therefore, the investigators will manually look in all the patient files from orthopedic contacts regardless of assigned diagnostic and procedural codes. Additionally, emergency room and internal medicine contacts are scanned with a broad and comprehensive range of relevant hip- and dislocation-related codes to identify episodes of hip dislocation, which are incorrectly coded. These patient files will also be manually reviewed.

If a patient is revised within the first 2 years, the follow-up period ends on the revision date. Revisions are also registered in the Danish Hip Arthroplasty Registry. However, the completeness is 93-95% and therefore lower than for primary operations. In order to have the complete set of revisions, the investigators will enrich our data with an extraction from the National Patient Registry by applying all approved hip revision codes

Study Design

• Study Type: Observational
• Actual Enrollment: 32500 participants
• Observational Model: Cohort
• Time Perspective: Retrospective
• Official Title: "True Incidence of Hip Dislocation After Primary THA - a Nationwide Population Study"
• Actual Study Start Date: January 1, 2018
• Estimated Primary Completion Date: June 1, 2019
• Estimated Study Completion Date: October 1, 2019

Groups and Cohorts

Intervention Details:

• Other: THA
  Study participants have received a total hip arthroplasty due to arthritis. We do not make further intervention.

Outcome Measures

Primary Outcome Measures :

1. Hip dislocation [ Time Frame: 2 years. ]
   The true incidence of hip dislocation calculated as proportion presented with 95% confidence intervals (CI).

Secondary Outcome Measures :

1. Age [ Time Frame: 2 years. ]
   Potential risk factor found by logistic regression analysis
2. Sex [ Time Frame: 2 years. ]
   Potential risk factor found by logistic regression analysis
3. Comorbidity [ Time Frame: 2 years. ]
   Potential risk factor found by logistic regression analysis
4. Fixation of components [ Time Frame: 2 years. ]
   Potential risk factor found by logistic regression analysis
5. Surgical approach [ Time Frame: 2 years. ]
   Potential risk factor found by logistic regression analysis
6. Head diameter of prosthesis [ Time Frame: 2 years. ]
   Potential risk factor found by logistic regression analysis
7. Time to dislocation [ Time Frame: 2 years. ]
   Time to first dislocation presented by Kaplan-Meier plot.
8. Development in complication (dislocation) over time. [ Time Frame: 5 years. ]
   Incidence each year (2010-2014) calculated as proportion presented with 95% confidence intervals (CI) and compared statistically depending on distribution.

Eligibility Criteria

• Ages Eligible for Study: 40 Years and older (Adult, Older Adult)
• Sexes Eligible for Study: All
• Accepts Healthy Volunteers: Yes
• Sampling Method: Non-Probability Sample

Study Population

Retrospective, we include patients with the diagnosis "primary/idiopathic hip OA". Patients are identified by data extraction from the Danish Hip Arthroplasty Registry. From 2010-2014 an average of 9000 hips/year received a primary THA and about 80% of these patients were diagnosed with idiopathic/primary arthritis. Therefore, we tend to include approximately 36.000 hips. We also include the second hip, if a patient undergoes 2 primary operations in our inclusion period and this is adjusted for in the analysis.

Criteria

Inclusion Criteria:

• patients with the diagnosis "primary/idiopathic hip OA and inserted THA from 01.01.2010 - 31.12.2014.

Exclusion Criteria:

• patients receiving a resurfacing hip arthroplasty and hip revisions
• patients with incomplete registry data
• patients with previous hip surgery

Contacts and Locations

Locations

Denmark

Hospital of South West Jutland

Esbjerg, Region Of Southern Denmark, Denmark, 6700

Sponsors and Collaborators

University of Southern Denmark

More Information

• Responsible Party: Lars Lykke Hermansen, MD, Ph.d. Student, University of Southern Denmark
• ClinicalTrials.gov Identifier: NCT03859791
• Other Study ID Numbers: 3-3013-2128/1
• First Posted: March 1, 2019
• Last Update Posted: March 1, 2019
• Last Verified: February 2019

Individual Participant Data (IPD) Sharing Statement:

• Plan to Share IPD: No
• Plan Description: Data will not be shared.

• Studies a U.S. FDA-regulated Drug Product: No
• Studies a U.S. FDA-regulated Device Product: No

Additional relevant MeSH terms:

Joint Dislocations; Hip Dislocation; Joint Diseases; Musculoskeletal Diseases; Wounds and Injuries; Hip Injuries