Nexus Evaluation Primary Trident II Uncemented Shell (NEPTUNE)

February 11, 2026 updated by: NHS Lothian

Nexus Evaluation Primary Trident II UNcemented shEll (NEPTUNE): A Longitudinal Cohort Study of the Hydroxyapatite Coated Trident II Acetabular System in Total Hip Arthroplasty

This is a prospective cohort study assessing the survival of a new acetabula component which is based on the original Trident acetabular system (cementless shell) which is used for Total Hip Arthroplasty. The manufacturer recently introduced the evolution of this product, the Trident® II acetabular shell which was launched in 2017. This implant is CE marked and is now widely available for the UK market, however has minimal clinical outcomes data to support its use. As part of a stepwise introduction of devices to orthopaedic practice. This study will report the 10 year implant survival and patient functional outcomes of this new implant.

Study Overview

Status

Active, not recruiting

Conditions

Intervention / Treatment

Detailed Description

125 patients will be recruited at a single-centre as part of a, phase-4 post-market surveillance, prospective cohort study

This is a 10-year study of the Trident II acetabular component as part of total hip replacement at the Royal Infirmary of Edinburgh, NHS Lothian.

Patients will receive a Trident® II acetabular component as part of primary total hip arthroplasty at the study centre. This component is CE marked and widely available for use by UK surgeons. The Trident® II shells are HA coated, cementless, press-fit acetabular shells composed of a Titanium (Ti-6Al-4V) substrate featuring a CpTi roughened surface with PureFix™ HA. The cup is available in a range of sizes and is indicated for primary and revision procedures.

A standard operative technique will be employed by all study surgeons, using the posterior approach. The routine post-operative patient care protocol of the study centre will be employed.

10 year implant survival is the primary aim, but in addition functional and radiographical outcome will be assessed a 1, 2, 5, 7 and 10 years.

Study Type

Interventional

Enrollment (Estimated)

125

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United Kingdom
    • Lothian
      • Edinburgh, Lothian, United Kingdom, EH16 4SA
        • NHS Lothian

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 75 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Patients undergoing planned primary total hip arthroplasty with standard implants, suitable for the use of the uncemented Trident® II acetabular component.
  2. Patients aged 18-75
  3. Patients willing and able to comply with the study protocol
  4. Patients that provide informed consent

Exclusion Criteria:

  1. Patients not meeting study inclusion criteria
  2. Bone stock that is inadequate for support or fixation of the prosthesis
  3. Patients with a body mass index (kg/m2) >40
  4. Procedures performed for pain relief in those with severely restricted mobility

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Trident® II HA coated shells
Patients will receive a Trident® II acetabular component as part of primary total hip arthroplasty at the study centre. This component is CE marked and widely available for use by UK surgeons. The Trident® II shells are HA coated, cementless, press-fit acetabular shells composed of a Titanium (Ti-6Al-4V) substrate featuring a CpTi roughened surface with PureFix™ HA.
Device: Stryker Trident® II HA coated cementless acetabula component
New acetabula component.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Implant survival
Time Frame: 10 years
All failures or revision of the Trident® II components as well as liner revisions will be documented.
10 years

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Oxford hip score
Time Frame: Preoperative, 1, 2, 5, 7 and 10 years
The Oxford Hip Score is a patient reported outcome measure that was developed specifically to measure the impact of pain and functional disability in patients undergoing hip replacement. It consists of 12-questions and is scored using a 5-item Likert response format, reported on a 0 (worst) to 48 (best) scale with higher scores representing better outcomes. It is an extensively validated and widely adopted outcome measure in patients undergoing hip replacement surgery.
Preoperative, 1, 2, 5, 7 and 10 years
Forgotten Joint Score
Time Frame: Preoperative, 1, 2, 5, 7 and 10 years
The Forgotten Joint Score-12 is a patient-reported outcome scale to assess joint awareness in hips during various activities of daily living. It uses a 5-point Likert response format, consists of 12-questions and the raw score is transformed to range from 0 (worst) to 100 (best) points. High scores indicate good outcome, i.e. a high degree of being able to forget about the affected joint in daily life. The FJS has a low ceiling effect and especially discriminates between good, very good and excellent outcome after THA and TKA. In its validation study it showed high internal consistency and discriminated well between patient groups known to show different outcome.
Preoperative, 1, 2, 5, 7 and 10 years
Short Form 12
Time Frame: Preoperative, 1, 2, 5, 7 and 10 years
The Short Form 12 is a 12-item questionnaire used to assess generic health outcomes from the patient's perspective. The SF-12 results in two summary scores: the physical and mental components summary (PCS and MCS) scores. This score is calculated using norm-based methodology and population mean scores. Both PCS and MCS have a population mean score of 50 with an standard deviation of 10.
Preoperative, 1, 2, 5, 7 and 10 years
EuroQol 5-dimension
Time Frame: Preoperative, 1, 2, 5, 7 and 10 years
The EuroQol 5-dimension is a standardised instrument with five items for use as a measure of self-reported general health. Applicable to a wide range of health conditions and treatments, it provides a simple descriptive profile and a single index value for health status. This index for the UK population is on a scale of -0.594 to 1, where 1 represents perfect health and 0 represents death, with a utility of less than 0 being worse than death. It is one of the most frequently used measures to gain quality of life scores for analysis in health economy as utility weights for calculating quality of life adjusted life years (QALYs) can be obtained
Preoperative, 1, 2, 5, 7 and 10 years
Hip pain
Time Frame: Preoperative, 1, 2, 5, 7 and 10 years
Global hip pain severity will be assessed using an 11 point (0-10) numerical rating scale (NRS), where 0 represents no pain and 10 the worst possible pain. The validity and sensitivity of the NRS has been well documented. As it has been suggested that using multiple measurements of pain status as opposed to a single value of 'current pain' may provide more realistic and meaningful measurements of pain intensity, separate assessments will be made of 'worst pain' and 'perceived mean daily pain' as has been specifically recommended for use in OA clinical trials.
Preoperative, 1, 2, 5, 7 and 10 years
Patient satisfaction
Time Frame: Preoperative, 1, 2, 5, 7 and 10 years

Satisfaction questions are reported using a 5-point Likert response format hip (very satisfied, satisfied, unsure, dissatisfied or very dissatisfied). Specifically, questions will ask patients as to their

  1. overall satisfaction with their operated hip
  2. how well the surgery relieves pain in the operated joint
  3. how well surgery increases the ability to perform regular activities of daily living and to perform heavy work or sport activities
Preoperative, 1, 2, 5, 7 and 10 years
Radiographic (x-ray) assessment
Time Frame: Preoperatively, 1, 5 and 10 years
Plain radiographs will be obtained for assessment of fixation of the device evaluating radiolucent lines (mm), cup abduction angle (degrees), anteversion (degrees) and cup-centre-edge angle (degrees). Plain radiographs will be divided into the three acetabular zones according to those defined by DeLee and Charnley. Radiolucent lines will be defined as less then 2mm, more than this will be defined a lysis. Lysis in all three acetabular zone will define a loose cup. Acetabular component inclination and version will be calculated from anteroposterior radiographs of the hip and/or hip and pelvis using established and validated techniques. The safe zones for acetabular component positioning were assessed using the commonly adopted parameters defined by Lewinnek et al. (inclination of 30° to 50° and anteversion of 5° to 25°) and Callanan et al. (inclination of 30° to 45° and anteversion of 5° to 25°).
Preoperatively, 1, 5 and 10 years

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

NHS Lothian

Collaborators

University of Edinburgh

Investigators

  • Principal Investigator: Paul Gaston, MBChB, FRCS, NHS Lothian

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 1, 2022

Primary Completion (Actual)

November 25, 2024

Study Completion (Estimated)

November 25, 2034

Study Registration Dates

First Submitted

May 4, 2022

First Submitted That Met QC Criteria

May 4, 2022

First Posted (Actual)

May 9, 2022

Study Record Updates

Last Update Posted (Actual)

February 13, 2026

Last Update Submitted That Met QC Criteria

February 11, 2026

Last Verified

February 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • AC20120

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Due to patient confidentiality there is no plans to share patient level data.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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