The expected lifetime of a medical device should not be defined solely by its physical presence in the body, its material absorption time, or its theoretical mechanical durability. Instead, expected lifetime must be based on the period during which the device’s safety and performance are clinically relevant and have been adequately evaluated for the intended purpose and the specific indications, including different target body locations. In other words, expected lifetime is anchored in clinical follow-up requirements, as reflected in high-quality evidence and current medical practice, rather than in purely material or engineering properties. When determining the expected lifetime of a device or a device group, the manufacturer should base the definition primarily on the following sources:

→ Clinical practice guidelines and health authority recommendations (e.g. society guidelines, NICE, etc.).

→ National and international registries (e.g. arthroplasty registries, hernia/mesh registries).

→ Systematic reviews and meta-analyses.

Within this evidence base, aggregated and guideline-level evidence (systematic reviews, meta-analyses, registry analyses, society guidance) should take precedence over isolated case reports or small anecdotal series when defining expected lifetime.

For example: If systematic reviews, meta-analyses and society guidelines in a given field consistently report robust follow-up data and clinically relevant outcomes for up to 15 years for a particular device type, while a single case report documents 20-year follow-up in one patient, it is not necessary, nor appropriate, to extend the expected lifetime to 20 years solely on the basis of that isolated case. In such a situation, the expected lifetime should remain 15 years, aligned with the strongest and most generalizable evidence base.

Example 1 – Absorbable mesh For absorbable meshes, material properties alone (e.g. time to complete absorption) are not sufficient to define expected lifetime. The mesh material may be fully absorbed by around 3 months. However, if cumulative clinical evidence (studies, guidelines, registries, systematic reviews, meta-analyses) indicates that hernia recurrence, re-operation and late mesh-related complications must be evaluated with a follow-up of up to 5 years, then the clinically relevant observation window is 5 years. In such a case, the expected lifetime should be defined as: “

For this absorbable mesh, the expected lifetime is defined as 5 years. This period reflects the current clinical requirement for follow-up, as derived from published literature, clinical guidelines, registry data and systematic reviews/meta-analyses, which show that safety and performance outcomes such as recurrence and late mesh-related complications need to be assessed for up to 5 years. Although the material may be fully absorbed after approximately 3 months, the expected lifetime is aligned with the 5-year clinically relevant follow-up period, and the absorption time is treated as a subordinate parameter within this lifetime, not as the primary determinant.”

The expected lifetime of this orthopaedic implant is not determined solely by its theoretical mechanical or functional durability, but by the period over which its safety and performance have been demonstrated and are expected to be monitored for the relevant indication. For this device group, clinical studies, guidelines, registries and cumulative evidence currently provide reliable follow-up data up to 15 years, with no robust aggregated data beyond this time point. Although the device may remain functional beyond 15 years, current medical knowledge and clinical practice only support a follow-up period of 15 years. Therefore, the expected lifetime of the device is defined as 15 years; use beyond this period lies outside the currently evidenced lifetime and is considered an unevaluated long-term phase.

Example 2 – Orthopaedic implant with long-term follow-up (15 years) A similar philosophy applies to long-term orthopaedic implants (e.g. joint replacements). Suppose clinical studies, society guidelines and registry data provide robust follow-up and revision data for up to 15 years for a particular implant type and indication. Beyond 15 years, there is no sufficient cumulative evidence, even though the implant may mechanically continue to function. In this situation, the expected lifetime can be defined as:

Expected lifetime is not a fixed or immutable value; it should be periodically re-evaluated in light of new, high-quality evidence. Expected lifetime is defined according to the current state of the art and should be periodically reassessed. If, over time, comprehensive publications (such as updated systematic reviews, meta-analyses, registry reports or society guidelines) re-analyse accumulated data and demonstrate that clinically relevant follow-up for the same device group extends beyond the previously defined period (for example, from 15 to 20 or 25 years), then the expected lifetime should be updated accordingly. In such cases, the new expected lifetime should reflect the longest clinically justified follow-up period supported by robust aggregated evidence, while isolated case reports or anecdotal observations beyond this period are not, by themselves, sufficient to redefine expected lifetime.

For implantable devices,’’ expected’’lifetime is an indication-specific duration that reflects what is expected from the generic device group according to evidence-based medicine, not merely the follow-up length of the individual manufacturer’s own clinical studies. In other words, expected lifetime is defined by the evidence-based maximum clinical follow-up time established for that type of device in the literature, guidelines and registries, and cannot be shortened just because a particular product only has, for example, 1-year data. A hip implant with only 1 year of manufacturer data cannot legitimately claim an expected lifetime of 1 year if the state of the art for hip prostheses requires and demonstrates follow-up over 10–15 years.

The MDR does not require manufacturers to define a proven lifetime from the outset. Instead, it requires them to define an expected ( may be understood as ‘’necessary’’) lifetime and then to collect and evaluate data for that product over this expected lifetime through clinical evidence generation and post-market surveillance activities, in order to confirm that the device continues to meet its safety and performance claims throughout that period in line with evidence-based medicine. For implantable devices, this ‘expected’ aspect must be understood in the context of evidence-based medicine: it is the indication-specific, evidence-based clinical follow-up duration that medicine currently expects for that generic device group, as reflected in guidelines, registries and high-quality literature, not merely what the individual manufacturer has already generated as product-specific follow-up data.