Comparing Dual-mobility Cups Versus Unipolar Cups for Unselected Primary Total Hip Arthroplasty by Direct Anterior Approach

NCT07464665 | Recruiting

• 1 other identifier: 2025-A01817-42
• Study Type: interventional
• Target: 300
• Locations: 1 country
• Sites: 1

Brief Summary

THA comprises the replacement of the damaged bone and cartilage with prosthetic components. The proximal end of the femur is replaced with a stem and ball/head, while the acetabulum is most commonly replaced with a unipolar cup (UP) that consists of a liner inside of a metal shell. UP cups are associated with risks of dislocations, especially in elderly and female patients, as well as in patients with lumbar stiffness or operated for femoral neck fractures. In fact, one of the most common reasons for early revision of UP cups are dislocations. Dual-mobility (DM) cups were introduced in the 1970s by the French surgeon Gilles Bousquet, as an alternative to UP cups. They are made up of two articulations, a femoral head moving inside a mobile polyethylene liner, which in turn moves inside a metal shell. This design allows for a greater jump distance and range of motion (ROM) compared to UP cups, thus resulting in reduced rates of dislocation. A recent systematic review that evaluated 5 case-control studies (549 DM cups vs 649 UP cups) and 3 registry studies (5935 DM cups vs 217362 UP) found that in case-control studies, the dislocation rates were 0.2% for DM cups versus 7.1% for UP cups (p=0.009). Furthermore, in registry studies the revision rates due to dislocation were 0.2% for DM cups versus 0.5% for UP cups (p=0.050). Nonetheless, there have been some concerns associated with the use of DM cups, including intra-prosthetic dislocations (IPD), polyethylene wear, and iliopsoas impingement. Since the early 2000s, new improvements in the design of DM cups have nearly eliminated the risk of IPD, and the use of ultra-high molecular weight polyethylene (UHMWPE) has greatly reduced wear rates, even in young and active patients. Lastly, although some studies have reported iliopsoas impingement with DM cups, the impingement is usually against the optional fixations, and not against the mobile polyethylene insert. The hypothesis of the present interventional randomised controlled trial (RCT) is that THA using DM cups will not provide inferior outcomes compared to THA using UP cups, in terms of hip awareness measured using the forgotten joint score (FJS).

Conditions

Primary Total Hip Arthroplasty; Primary Total Hip Replacement

Keywords

total hip arthroplasty; THA; total hip replacement; THR; randomised controlled trial; RCT; unipolar cup; dual-mobility cup

Outcome Measures

Primary Outcomes (1)

• Forgotten Joint Score between DM cup group and UP cup group

  The primary outcome is defined as patient-reported hip awareness at 2 years postoperatively, measured using the Forgotten Joint Score (FJS). The FJS is a validated self-administered questionnaire that measures the patients' ability to forget about a joint as a result of successful treatment. The questionnaire comprises 12 items. Each item is scored using a 5-point Likert scale, ranging from "never" (0 points) to "mostly" (4 points). The final FJS score is calculated as the addition of all items, divided by the number of items answered. The mean score is then multiplied by 25, and that value is subtracted from 100. The FJS ranges from 0 to 100, with 100 corresponding to the best score: the patient has forgotten about their joint.

  2 years

Secondary Outcomes (9)

• Forgotten Joint Score between DM cup group and UP cup group

  3 months and 1 year

• To compare the patient's hip/groin pain between DM cups versus UP cups, as well as to compare the net change from baseline

  preoperatively, at 3 months, 1 year and 2 years

• To compare the patient's hip function between DM cups versus UP cups

  preoperatively, at 3 months, 1 year and 2 years

• To compare the patient's sports activity between DM cups versus UP cups

  1 year

• To compare the patient's sports activity between DM cups versus UP cups

  preoperatively, at 1 year and 2 years

Other Outcomes (8)

• To evaluate whether age is associated with the Forgotten Joint Score

  2 years

• To evaluate whether sex is associated with the Forgotten Joint Score

  2 years

• To evaluate whether body mass index is associated with the Forgotten Joint Score

  2 years

Study Arms (2)

THA with dual-mobility cup

ACTIVE COMPARATOR

The THA will be performed via the DAA. The liner will be made of highly-crosslinked vitamin-E infused polyethylene. The femoral head will be made of either metal or ceramic. The dual-mobility cup will always be cementless, while the stem will be cemented in female patients aged ≥75 years, as well as in any patient diagnosed with osteoporosis. A blunt dissection will be carried out through the tensor fasciae latae muscle (TFLM), between the sartorius and rectus femoris muscles. A femoral neck osteotomy will then be performed using an oscillating saw, and the femoral head will be removed with a corkscrew. The acetabular components and the selected liner according to the randomisation, will then be implanted.The femoral head will then be impacted onto the femoral stem, and the prosthesis will be reduced. Closure of the surgical site will be performed in layers.

Procedure: Primary total hip arthroplasty using dual-mobility cup

THA with unipolar cup

ACTIVE COMPARATOR

The THA will be performed via the DAA. The liner will be made of highly-crosslinked vitamin-E infused polyethylene. The femoral head will be made of either metal or ceramic. The unipolar cup will always be cementless, while the stem will be cemented in female patients aged ≥75 years, as well as in any patient diagnosed with osteoporosis. A blunt dissection will be carried out through the tensor fasciae latae muscle (TFLM), between the sartorius and rectus femoris muscles. A femoral neck osteotomy will then be performed using an oscillating saw, and the femoral head will be removed with a corkscrew. The acetabular components and the selected liner according to the randomisation, will then be implanted.The femoral head will then be impacted onto the femoral stem, and the prosthesis will be reduced. Closure of the surgical site will be performed in layers.

Procedure: Primary total hip arthroplasty using unipolar cup

Interventions

Primary total hip arthroplasty using dual-mobility cup PROCEDURE

Replacement of hip articulating surface.

Also known as: Primary total hip replacement, THA, THR

THA with dual-mobility cup

Primary total hip arthroplasty using unipolar cup PROCEDURE

Replacement of hip articulating surface.

Also known as: Primary total hip replacement, THA, THR

THA with unipolar cup

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• men and women aged ≥18 years old
• set to undergo elective primary THA via direct anterior approach (DAA)
• affiliated with a social security scheme
• able to answer questionnaires and to communicate freely in French

You may not qualify if:

• with prior ipsilateral hip surgery
• with prior contralateral hip surgery
• that require acetabular cup diameters ≤50mm (because DM cups are not available from the same manufacturer for diameters ≤50mm, and UP cups require head diameters of 36mm and thus minimum cup diameters of 52mm)
• undergoing emergency or trauma surgery (e.g. femoral neck fractures)
• with any concomitant disease or disorder which, in the opinion of the surgeon, may put the patient at risk, notably of hip instability or dislocation (hip dysplasia, neuromuscular deficit, fracture sequelae…) or may influence the result of the study
• that are pregnant or breastfeeding
• under legal protection (guardianship or curatorship or deprived of liberty).

Sponsors & Collaborators

• Elsan: lead

Study Sites (1)

Polyclinique Jean Villar

Bruges, 33520, France

RECRUITING

Related Publications (4)

• Jones HB, Hinkle AJ, Liu Y, Sambandam SN. Multivariate Analysis of Risk Factors for In-Hospital Dislocation Following Primary Total Hip Arthroplasty. J Clin Med. 2024 Jun 13;13(12):3456. doi: 10.3390/jcm13123456.

  PMID: 38929981 BACKGROUND

• Fessy MH, Viste A, Philippot R, Belzile EL. Recent progress in dual mobility total hip arthroplasty: an irresistible French icon. Orthop Traumatol Surg Res. 2024 Oct;110(6):103993. doi: 10.1016/j.otsr.2024.103993. Epub 2024 Sep 10. No abstract available.

  PMID: 39265929 BACKGROUND

• Jonker RC, van Beers LWAH, van der Wal BCH, Vogely HC, Parratte S, Castelein RM, Poolman RW. Can dual mobility cups prevent dislocation without increasing revision rates in primary total hip arthroplasty? A systematic review. Orthop Traumatol Surg Res. 2020 May;106(3):509-517. doi: 10.1016/j.otsr.2019.12.019. Epub 2020 Apr 8.

  PMID: 32278733 BACKGROUND

• Varacallo MA, Luo TD, Johanson NA. Total Hip Arthroplasty Techniques. 2023 Aug 4. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2026 Jan-. Available from http://www.ncbi.nlm.nih.gov/books/NBK507864/

  PMID: 29939641 BACKGROUND

MeSH Terms

Interventions

Tacrine

Intervention Hierarchy (Ancestors)

Aminoacridines; Acridines; Heterocyclic Compounds, 3-Ring; Heterocyclic Compounds, Fused-Ring; Heterocyclic Compounds

Central Study Contacts

Nicolas Verdier

CONTACT

+33(0)535549569; dr.nicolas.verdier@gmail.com

Charlène Py

CONTACT

+33(0)556003048; charlene.py@elsan.care

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: This study is a patient-blinded prospective monocentric interventional comparative randomised trial in parallel groups, to evaluate the non-inferiority of DM cups compared to unipolar cups for THA.

Study Record Dates

• First Submitted: March 2, 2026
• First Posted: March 11, 2026
• Study Start: July 7, 2026
• Primary Completion (Estimated): July 1, 2030
• Study Completion (Estimated): July 1, 2030
• Last Updated: July 16, 2026

Record last verified: 2026-07

Data Sharing

• IPD Sharing: Will not share

Locations

FR (1)