Valid from 9 July 2025

Click here to download the current ODEP Trapeziometacarpal Joint Criteria (PDF)

ODEP welcomes submissions for Total Trapeziometacarpal Arthroplasty (total base of thumb replacement at the first carpometacarpal joint). The ODEP rating applies to the construct as a whole rather than to individual components. A construct represents a unique combination of components (or catalogue numbers) that together form the implanted device.

What constitutes a construct?

A Total Trapeziometacarpal Arthroplasty construct is defined by the specific combination of trapezial (cup) component and metacarpal (stem) component, together with any associated bearing or head where applicable. Each unique combination of these elements is treated as a separate construct for the purposes of ODEP rating.

What must be identical across a construct?

For components to be grouped within a single construct, the following characteristics must be identical:

Trapezial (Cup) Component

• Material composition (e.g. polyethylene, pyrocarbon, metal-backed)
• Surface finish and coating
• Fixation philosophy (e.g. press-fit, cemented, screw-augmented)
• Method of fixation (cemented vs. uncemented)

Metacarpal (Stem) Component

• Material composition (e.g. cobalt chrome, titanium alloy, pyrocarbon)
• Surface finish and coating (e.g. hydroxyapatite, porous, polished)
• Stem geometry and fixation philosophy (e.g. straight stem, curved stem, press-fit, cemented)
• Head type and articulation (e.g. modular head, monoblock)
• Method of fixation (cemented vs. uncemented)

Bearing / Articulating Surface

• Bearing couple (e.g. metal-on-polyethylene, pyrocarbon-on-pyrocarbon, ceramic-on-polyethylene)
• Polyethylene type where applicable (e.g. conventional UHMWPE, highly cross-linked polyethylene)

Bearing surface distinctions

Where an implant system offers more than one type of bearing couple, each configuration must be assessed separately and will receive its own ODEP rating based on survival data that relates specifically to that bearing surface. If a bearing type lacks sufficient data, it will not be awarded an ODEP rating.

Constrained vs. unconstrained designs

Implant systems that are available in both constrained (ball-and-socket) and unconstrained configurations represent different design philosophies and shall be treated as separate constructs.

Size variations

Different sizes within the same component design family do not constitute separate constructs, provided all other characteristics listed above remain identical.

The benchmark criteria for trapeziometacarpal constructs follow the standard ODEP rating framework. The assessment criteria have been adapted from the methodologies used for other joints, informed by a literature review of the best available evidence specific to base of thumb arthroplasty.

The ODEP rating for a trapeziometacarpal construct is determined by the rating achievable by the most recently introduced component within that construct.

The methodology described above will be reviewed periodically in line with standard ODEP practice. There are regular opportunities for manufacturers to submit data for assessment by the Panel and dates are advertised through the ODEP website – Events