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Indications for use include:

• Elbow joint destruction which significantly compromises the activities of daily living
• Post-traumatic lesions or bone loss contributing to elbow instability
• Ankylosed joints, especially in cases of bilateral ankylosis from causes other than active sepsis
• Advanced rheumatoid, post-traumatic, or degenerative arthritis with incapacitating pain
• Instability or loss of motion when the degree of joint or soft tissue damage precludes reliable osteosynthesis
• Acute comminuted articular fracture of the elbow joint surfaces that precludes less radical procedures, including 13-C3 fractures of the distal humerus
• Revision arthroplasty
  CAUTION: This device is intended for cemented use only.

The Zimmer Nexel Total Elbow system includes a cemented total elbow prosthesis and instrumentation. No changes are being made to the implants, but two changes to the instrumentation are being proposed in this submission.
• The Zimmer Nexel Total Elbow surgical technique is being modified to include a back table utilization of the Ulnar Bearing Assembly Tool (UBAT).
• As a result of the surgical technique change, the subject Zimmer Nexel Total Elbow Ulnar Cement Diverter is being added as an accessory instrument to the existing Zimmer Nexel Total Elbow system. The proposed cement diverter is a sterile, single-use manual orthopedic instrument manufactured from Ultra High Molecular Weight Polyethylene in conformance with ASTM F648-14. The subject component diverts excess bone cement from the articular surfaces of the existing ulnar implant component during implantation.

This document describes the Zimmer® Nexel® Total Elbow Ulnar Cement Diverter. Based on the provided text, the device is an accessory instrument to an existing total elbow replacement system, designed to divert excess bone cement during implantation. The document does not describe a clinical study in the typical sense (e.g., no patient data, no comparison of outcomes with and without the diverter). Instead, it relies on non-clinical performance data to demonstrate substantial equivalence to a predicate device.

Here's an analysis of the acceptance criteria and the "study" (non-clinical) that proves the device meets them:

1. A table of acceptance criteria and the reported device performance

The document does not explicitly state numerical acceptance criteria in the typical format of a clinical trial (e.g., "sensitivity must be > X%", "accuracy must be > Y%"). Instead, the acceptance is based on demonstrating the safety and effectiveness of the cement diverter and the updated surgical technique through non-clinical evaluations.

2. Sample size used for the test set and the data provenance (e.g., country of origin of the data, retrospective or prospective)

• Test Set Sample Size: The document mentions a "Cadaveric Evaluation." While the specific number of cadavers or test instances is not explicitly stated in this summary, cadaveric studies typically involve a small number of specimens.
• Data Provenance: The study is non-clinical, involving cadavers. The country of origin for the cadavers is not specified. It is inherently a prospective evaluation in the context of the device's development and regulatory submission, even though it uses post-mortem tissue.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g., radiologist with 10 years of experience)

The document does not specify the number or qualifications of experts involved in the cadaveric evaluation. While such studies would ideally involve orthopedic surgeons or biomechanical engineers, this information is not provided in the 510(k) summary. The "ground truth" for these tests would likely be the direct, observable performance of the device during simulated implantation on the cadaveric specimens, assessed by the researchers and potentially expert surgeons.

4. Adjudication method (e.g., 2+1, 3+1, none) for the test set

The document does not describe an adjudication method for the non-clinical test set. Methods like 2+1 or 3+1 are typically used in imaging studies where interpretations are subjective and require expert consensus. In a cadaveric mechanical/functional test, the assessment of "safety and effectiveness" would likely be based on direct observation and measurement, rather than a subjective interpretation requiring adjudication among multiple readers.

5. If a multi reader multi case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance

There was no MRMC comparative effectiveness study done. This device is an orthopedic instrument, not an AI or imaging diagnostic tool. Therefore, the concept of "human readers improving with AI assistance" is not applicable here.

6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done

There was no standalone (algorithm-only) performance study done. This device is a manual orthopedic instrument, not an algorithm.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)

The ground truth for the non-clinical evaluations was primarily direct observation and functional assessment during the cadaveric evaluation and mechanical testing (Functional Relationship Analysis). For the cadaveric study, the "ground truth" was whether the cement diverter effectively diverted cement and allowed for proper implantation without compromising the ulnar component. For the FRA, the ground truth was whether the diverter physically fit and functioned correctly with the existing components.

8. The sample size for the training set

There is no training set sample size because this is a mechanical device, not a machine learning algorithm.

9. How the ground truth for the training set was established

Not applicable, as there is no training set.

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