What makes a successful acetabular system? Trinity™ Acetabular System: The story so far

Trinity acetabular shells have been a flagship implant system for Corin for over a decade. First implanted in 2009, over 160,000 total hip arthroplasty (THA) procedures have been performed in 25 countries1. With an increasing bank of global clinical data and integration with Corin’s growing suite of orthopaedic technologies, Trinity is proving itself as a worldleading acetabular shell system.


In 2020, Trinity was the third most implanted primary acetabular shell in Australia (AOANJRR 2020)2. We asked our customers across the globe to identify the reasons why our flagship shell is their preferred choice and how it adds value in practice, and this is how they’ve responded:


What are the key pillars of Trinity’s global success?


Advanced design


Boasting a wealth of advanced and optimised features, one third of global surgeons identified this as the main reason for first choosing Trinity.

PRIME (psoas rim enhancement) - the round, polished outer edge of the Trinity shell, was developed to reduce psoas irritation during impingement. In a recent survey our surgeons identified PRIME as a highly beneficial feature, with an Australian surgeon finding “less psoas symptoms” when implanting Trinity.


The 18° optimised taper has been designed to provide repeatable, accurate liner insertion without instrumental aids, even with historically at risk ‘hard’ liners or minimally invasive approaches. This is supported by a surgeon who explained that the taper design was “great for seating ceramics in DAA”.


Another beneficial design feature is the Trinity-i variant, which a US surgeon says provides them with “extra joint stability in smaller cups”. These shells are available in 46mm, 50mm or 54mm and offer ‘upsized’ heads compared to the equivalent standard shell. This enables a 50mm Trinity-i shell to accommodate a 36mm head.


Fixation and stability

Primary stability is first targeted by a porous titanium coating, which not only provides a consistent 1mm press fit, but also gives excellent grip on impaction thanks to its high surface roughness. There is also the option to use supplementary fixation, in the form of three strategically positioned screw holes.


“In my experience, Trinity provides a superior ‘scratch fit’. Trinity has a high primary stability and is often achieved with minimal auxiliary screwing.”

Dr M Kim. Osaka, Japan.


Secondary stability (or biological stability) is promoted by a fine, biomimetic coating of calcium phosphate. At just 20um thick and chemically tailored for rapid resorption, it aims to target bony ongrowth, stabilising the shell long-term. A UK-based surgeon sees excellent long-term stability with Trinity, reporting they “haven’t seen shell loosening much at all”.




Trinity provides versatility and agility to surgeons, allowing them to select a patient-matched solution. As a modular system, Trinity offers a wide range of shell designs and liner materials. These liner options include common polyethylene and ceramic options, as well as ECiMa and dual mobility. ECiMa is a vitamin E polyethylene which is an ultra-low wear, mechanically stable and oxidation-resistant alternative to hard bearings. Trinity Dual Mobility is a modular construct, aimed at protecting against dislocation by increasing joint stability and targeting protection in at risk areas.

Trinity is integrated in our OPSInsight™ hip planning platform, part of Corin’s growing suite of orthopaedic technologies. When recently asked, OPS™ integration was identified by nearly half of surgeons as their key driver for using Trinity, because it can provide dynamic information relating to a patient’s individual biomechanics critical to optimising the implant selection and guiding the implantation.





 “I can deliver an optimal solution for each of my patients using OPS technology. The range of bearing options is critical in optimising patient outcomes.”

Dr Michael Solomon, Sydney, Australia


Powerful insights. Proven clinical performance.


These pillars combine and form the basis for Trinity’s success. National registries and independent reviewers show that Trinity provides excellent clinical performance globally.


  • Third most used shell in Australia2
  • Trinity-MetaFix ninth most used shell-stem combination in NJR3
  • 7A* ODEP rating4
  • 1.44% revision rate at 5 yrs3
  • 2.8% CPR at 8 yrs2
  • 0.4 yearly cumulative incidence revision for dislocation at 5 yrs, compared to all other hips at 0.85


For a more detailed look at how Trinity is performing, see the latest see the latest Trinity Evidence Base.


The next chapter


At Corin, we are committed to advancing the orthopaedic landscape with a growing suite of implants and technologies. Trinity will continue to be a fundamental implant system for Corin, heavily integrated with OPSInsight and we expect its proven, superior clinical performance to continue.


For now, Trinity provides the surgeon with the freedom to match a solution to their patient, the opportunity to use advanced technology to plan and personalise each implantation, and confidence that the implant will perform thanks to proven, impartial data.


To learn more about our advanced acetabular system and how it can benefit you and your patients, contact us or visit our solutions page.


Corin Hip Team





  1. Data on file (Internal sales data). Corin Group Ltd. Accessed Nov 2020.
  2. Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR). Hip, Knee & Shoulder Arthroplasty: 2020 Annual Report, Adelaide; AOA, 2020: 1-474. [Accessed from: https://aoanjrr.sahmri.com/annual-reports-2020].
  3. National Joint Registry (NJR). 17th Annual Report 2020: Surgical data to 31 December 2019, NJR, 2020: 1-312. [Accessed from: https://reports.njrcentre.org.uk].
  4. Orthopaedic Data Evaluation Panel (ODEP) product ratings. [Accessed from: odep.org.uk; November 2020].
  5. Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR), Automated Industry Report System (AIRS), ID No.1514 for Corin Australia, Trinity Total Conventional Hip (Procedures from 1 September 1999-19 August 2019). Generated 20 August 2019. AOA, Adelaide: 1-18. Disclaimer: The AOANJRR has taken every care to ensure that the data supplied are accurate but does not warrant that the data are error free and does not accept any liability for errors or omissions in the data.