EU Expert Panel Identifies Clinical Evidence Limitations for Bioabsorbable Orthopaedic Screws under MDR CECP

The European Commission has published an expert panel decision and scientific opinion במסגרת the Clinical Evaluation Consultation Procedure (CECP) for a Class III implantable bioabsorbable orthopaedic screw intended for fracture fixation and osteotomies.

Scientific Opinion Requested by Screening Experts

The screening experts decided that a scientific opinion should be provided, based on:

• Medium level of novelty

• Moderate potential clinical/health impact

• Presence of open issues regarding safety and performance

The device, based on magnesium (Mg), calcium (Ca), and zinc (Zn) alloy, may offer benefits such as avoiding removal surgery and potentially improving recovery. However, safety and performance aspects require systematic appraisal.

Key Findings from the Expert Panel

Limited Clinical Evidence

The expert panel concluded that:

• The notified body’s clinical evaluation assessment report (CEAR) includes important issues that are not sufficiently addressed

• Clinical data is mainly based on:

  • Literature including non-equivalent devices

  • A single prospective non-randomized feasibility study conducted in one center

• There is no sufficient clinical data demonstrating the degradation duration and implant stability in humans

Concerns Related to Mg-Alloy Degradation

The panel highlighted that:

• Degradation of the magnesium alloy starts upon implantation

• The process may be accelerated due to device design (e.g. cannulated screws)

• There are uncertainties regarding degradation behaviour and mechanical stability over time

In addition, identified risks associated with Mg-alloy screws include:

• Inflammatory reactions and osteolysis

• Lower load-bearing capacity compared to metallic implants

• Rapid degradation leading to premature loss of mechanical integrity

• Hydrogen gas formation

• Accumulation of degradation products

• Potential toxicity concerns from alloying elements

• Challenges in controlling degradation rate

Benefit-Risk Determination Not Adequately Supported

According to the expert panel:

• The benefit-risk determination relies mainly on non-clinical data and literature

• Some referenced studies involve devices with different alloy compositions

• Certain conclusions (e.g. bone regeneration and implant replacement) are not supported by sufficient clinical evidence

The panel states that additional clinical data is required to properly assess the benefit-risk profile.

Insufficient Evidence Across Indications

The device is intended for multiple fracture types and anatomical locations. However:

• Clinical evidence is provided only for medial malleolar fractures

• Different indications involve different biomechanical requirements

The panel concluded that each indication should be supported by appropriate clinical data.

PMCF Plan Lacks Detail

The expert panel noted that the PMCF plan:

• Provides limited detail on clinical follow-up

• Does not clearly define:

  • Monitoring of degradation

  • Assessment of bone healing

  • Timepoints and imaging methods

Further clarification is required, including use of radiographs and CT scans at defined intervals.

Expert Panel Recommendations

The panel recommends that the notified body request the manufacturer to:

1. Conduct a literature review on Mg-alloy degradable screws

2. Perform a pre-authorisation clinical study comparing with standard fixation methods

3. Conduct a post-authorisation clinical study, including:

   • Radiographs at defined timepoints (e.g. 6 weeks, 3 months, 1 year)

   • CT scans (e.g. 6 months and 1 year)

Conclusion

The expert panel concludes that:

• Additional clinical evidence is required

• Current data is insufficient to support key claims and the benefit-risk determination

• Further studies are needed to address uncertainties related to degradation, stability, and clinical performance.

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