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NCT Number: NCT04685239

Dual Mobility Cup Versus Unipolar Cup

The general purpose of this study is to examine whether the dual mobility cup (Novae® Serf) reduces the number of hip dislocations after total hip replacement, both early dislocation (≤1 year) and late dislocation (>1 year) after primary THR compared with a conventional cup design (Trabecular MetalTM Modular Acetabular System).

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Key information

Conditions

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

Age range

65 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

About this study

Surgery with THR for arthritis and other hip disorders has long been one of the most successful orthopedic surgical treatments. The majority of the patients gain pain relief and experience improved hip function. In 2017, a total of 10,691 THRs were implanted in Denmark (annual report 2018).

Hip dislocation is a known complication after THR. It is a painful condition which may have far-reaching consequences for the patient, who may experience both physical and mental discomfort. Ultimately, multiple hip dislocations may result in reoperation.

In the literature, the incidence of hip dislocation is reported at 2-6 %, and a more recent review reports a risk of 0.5-10 %.

In Denmark, recurrent hip dislocation is the cause of 21 % of the reoperations per year according to The Danish Hip Arthroplasty Register. According to the British National Joint Registry (NJR) and the Australian register (AOANJRR), hip dislocation is the cause of 15.5 % and 21 %, respectively, of the reoperations.

The best method to avoid reoperation due to instability is to choose the correct implant for the individual patient and thereby spare the patient of having to endure a painful complication and yet another procedure. There are multiple risk factors for instability after THR, and increased use of dual mobility cups (DMC) is already documented.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Patients with hip arthritis who are amenable to surgery with THR and age ≥ 65 years referred to the Department of Orthopedic Surgery at either Section Farsø, Frederikshavn Hospital or Aalborg University Hospital. Patients who are willing to participate in the trial and who give their written, informed consent after receiving oral and written information.

Exclusion criteria

  • Patients who do not wish to participate.
  • Sequelae of Calvé-Legg-Perthes' disease, caput necrosis, epiphysiolysis.
  • Proximal femoral or acetabular fracture.
  • Hip dysplasia with subluxation Crowe types III and IV.
  • Earlier hip bone surgery (excluding arthroscopic surgery).
  • Elective bilateral surgery.
  • If the patient's bone morphology is unsuitable for a cemented Exeter® femoral stem.
  • Patients with no e-mail.

Treatment and study plan

Dual Mobility Cup

Device

The use of a Sunfit dual mobility cup

unipolar cup

Device

The use of a TMT cup

Primary outcomes

  1. Early dislocation, Difference in dislocation within 1 year.

    Time frame: 1 year after surgery

    The primary outcome is the difference in cumulative incidence proportion of dislocation between the 2 randomized groups within the first year after total hip replacement. The information will be collected from both the patient through questionnaires and from the Danish Hip Arthroplasty Register and the Danish National Patient Register.

Secondary outcomes

  1. Difference in dislocation within 5 years

    Time frame: 5 years after surgery

    The difference in cumulative incidence proportion of dislocation between the 2 randomized groups within 5 years after total hip replacement. The information will be collected from both the patient through questionnaires and from the Danish Hip Arthroplasty Register and the Danish National Patient Register.

  2. Dislocation 10 year

    Time frame: 10 years after surgery

    The difference in cumulative incidence proportion of dislocation between the 2 randomized groups within 10 years after total hip replacement. The information will be collected from both the patient through questionnaires and from the Danish Hip Arthroplasty Register and the Danish National Patient Register.

  3. Prosthesis survival.

    Time frame: 1, 5 and 10 year

    Evaluated by the cumulative incidence of THR's reoperated within 1, 5 and 10 years after total hip replacement. The information will be collected from both the patient through questionnaires and from the Danish Hip Arthroplasty Register and the Danish National Patient Register.

  4. Patient reported outcome measure: European quality of life 5 dimensions (EQ-5D 5L)

    Time frame: 1, 5 and 10 years

    Patients will be scored with EQ-5D 5L preoperatively and at 1,5 and 10 years. It consists of 5 dimensions ranging from 1-5, with 1 being the best in each dimension. It also consist of a visual analog scale ranging from 0-100, 100 being the best imaginable health, The EQ VAS describes the respondents current overall health. Data will be showed as changes in health over time showing responses at baseline and at follow up or as frequencies and proportions reported by dimension and level.

  5. Patient reported outcome measure: Oxford Hip Score (OHS)

    Time frame: 1, 5 and 10 years

    Patients will be scored with OHS at baseline and at 1, 5 and 10 years. OHS is a patient-recorded outcome measure designed to assess the outcome of hip replacements. Its a score between 0-48 with 48 being the best.

  6. Patient reported outcome measures: The Copenhagen Hip and Groin Outcome Score (HAGOS)

    Time frame: 1, 5 and 10 years

    HAGOS pain subscale will be used to report pain pre and postoperatively. The score in the pain subscale ranges from 0 (extreme hip/groin problems) -100 (no hip/groin problems).

Study contacts

Contact information is provided by the study sponsor or research team.

Anders Diernæs, MD

CONTACT

[email protected]

+4597662503

Thomas Jakobsen, MD, PhD

CONTACT

[email protected]

Sponsors and collaborators

Lead sponsor

Northern Orthopaedic Division, Denmark

Other

Registry information

Official study title

Risk of Dislocation After Total Hip Replacement: Dual Mobility Cup vs. Unipolar Cup. A Randomized Controlled Trial With Patients ≥65 Years Operated for Hip Osteoarthritis With Primary Total Hip Replacement (THR).

Important dates

Study start
2023
Primary completion
2025
Study completion
2035
First posted
Dec 28, 2020
Registry last updated
Mar 27, 2023

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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