An interventional study of Stryker Trident® II HA coated cementless acetabula component in Arthritis of Hip, Hip Dysplasia and Hip Arthropathy, sponsored by NHS Lothian. Active, not recruiting at 1 site in United Kingdom. Open to participants aged 18 Years to 75 Years. Per ClinicalTrials.gov, last updated 2026-02-13.
Sponsored by NHS Lothian · Not applicable, Interventional, and Treatment
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.
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.
107 studies on the registry are indexed under Hip Dislocation; 36 are open to participants now.
This study's planned enrollment of 125 is above the median of 86 across 64 interventional studies indexed under Hip Dislocation.
Browse Hip Dislocation studies →NHS Lothian is the lead sponsor of 53 studies on the registry; 6 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
Implant survival
All failures or revision of the Trident® II components as well as liner revisions will be documented.
Time frame: 10 years
Oxford hip score
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.
Time frame: Preoperative, 1, 2, 5, 7 and 10 years
Forgotten Joint Score
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.
Time frame: Preoperative, 1, 2, 5, 7 and 10 years
Short Form 12
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.
Time frame: Preoperative, 1, 2, 5, 7 and 10 years
EuroQol 5-dimension
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
Time frame: Preoperative, 1, 2, 5, 7 and 10 years
Hip pain
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.
Time frame: Preoperative, 1, 2, 5, 7 and 10 years
Patient satisfaction
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
Time frame: Preoperative, 1, 2, 5, 7 and 10 years
Radiographic (x-ray) assessment
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°).
Time frame: Preoperatively, 1, 5 and 10 years
Plan to share: No — Due to patient confidentiality there is no plans to share patient level data.
Ran from Jun 2022 to primary completion in Nov 2024, 29 months.
Of 32 interventional studies with no phase under Hip Dislocation, half reached primary completion within 45 months of starting (the median), counting those still running; a quarter within 18. This study's 29 months is below that.
How these figures are worked out, and which studies are left out of them.
This study is active, not recruiting, as verified in Feb 2026. You cannot join it, but the record below documents what was studied.
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NHS Lothian