(163 days)
The bone density estimates from the Norland pDEXA™ Bone Densitometer can be used as an aid to the physician in determining fracture risk.
The Fracture Risk Option consists of updated software which adds the fracture risk features to the screens and printed reports for the pDEXA. It also includes a supplement to the pDEXA Operator's Guide which explains how to interpret the pDEXA bone density values to aid in the assessment of fracture risk and the diagnosis of osteoporosis.
The provided document for K973104, "Fracture Risk Assessment Option for the Norland pDEXA™ Bone Densitometer," is a 510(k) summary submitted to the FDA in 1997. This submission focuses on establishing substantial equivalence to a pre-amendment device (Norland-Cameron Model 178 Bone Mineral Analyzer) rather than presenting a performance study with detailed acceptance criteria and reported device performance. As such, many of the requested details about a specific study testing the device against performance criteria are not available in this document.
Here's a breakdown of what can be extracted and what is missing, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
Not available. The document does not describe specific numerical acceptance criteria or present data from a performance study of the "Fracture Risk Assessment Option." Its primary argument is substantial equivalence to an existing device's intended use and function.
2. Sample Size Used for the Test Set and Data Provenance
Not available. There is no mention of a test set, sample size, or data provenance (country of origin, retrospective/prospective) for evaluating the "Fracture Risk Assessment Option."
3. Number of Experts Used to Establish Ground Truth and Qualifications
Not available. Since no specific performance study is detailed, there's no information about experts establishing ground truth for a test set.
4. Adjudication Method for the Test Set
Not available. No test set or adjudication method is described.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No. The document does not describe an MRMC comparative effectiveness study, nor does it discuss human reader improvement with or without AI assistance. This device is a software option for a bone densitometer, and the focus is on its output's relationship to existing diagnostic guidelines, not its impact on human reader performance in an MRMC setting.
6. Standalone Performance Study (Algorithm Only)
Not performed or reported in this document. The submission is for a "Fracture Risk Assessment Option" which is an update to existing software. The focus is on the substantial equivalence of its output (T-Scores and fracture risk categorization based on WHO definitions) to a predicate device's method, not on new standalone performance metrics. The document states: "The Fracture Risk Option provides an assessment of relative fracture risk based on the T-Score value. It presents the World Health Organization's (WHO) definition of osteoporosis and osteopenia; and makes the same diagnostic recommendations originally made by the pre-amendment Model 178." This implies the performance is tied to the established science behind T-Scores and WHO definitions, not a new algorithm requiring a standalone study in this context.
7. Type of Ground Truth Used
The ground truth implicitly used for the "Fracture Risk Assessment Option" is based on:
- Expert Consensus and Established Medical Guidelines: Specifically, the World Health Organization's (WHO) definition of osteoporosis and osteopenia, which is based on T-scores (standard deviations below the young adult mean).
- Predicate Device's Methodology: The comparison to the "pre-amendment Model 178" implies that its established approach of assessing bone density relative to a reference population and assigning fracture risk based on deviations from the mean served as a form of "ground truth" for equivalence. The "Interpretation of Fracture Index Charts; E. Smith and J. R. Cameron" (Smith-Cameron charts) is referenced as proof for the predicate device's claims.
8. Sample Size for the Training Set
Not available. As a software update applying WHO definitions and T-scores to data from an existing bone densitometer, it is highly unlikely there was a "training set" in the modern machine learning sense. The device's "training" (establishment of reference populations) would have occurred during the development of the original pDEXA™ Bone Densitometer device and the predicate Model 178. The document mentions "reference population (device specific)" for comparison, but not sample sizes for this reference population.
9. How the Ground Truth for the Training Set Was Established
Not available for this specific submission. For the underlying bone densitometry, the "ground truth" for establishing reference populations would typically involve:
- Large Cohorts of Healthy Individuals: To establish normal bone mineral density (BMD) values across different age groups and genders.
- Clinical Studies and Epidemiological Data: To correlate BMD values with fracture incidence, leading to the establishment of thresholds like the WHO T-score criteria.
The document refers to the "reference population (device specific)" and states that the "Fracture Risk Option" and the Model 178 "both compare this bone density assessment to a reference population in terms of the number of standard deviations the value is below the mean." The ground truth for these reference populations was established through previous scientific and clinical work, much of which predates this 510(k) submission. The exact methods for the specific Norland devices' reference populations are not detailed here beyond mentioning the "Smith-Cameron charts."
§ 892.1170 Bone densitometer.
(a)
Identification. A bone densitometer is a device intended for medical purposes to measure bone density and mineral content by x-ray or gamma ray transmission measurements through the bone and adjacent tissues. This generic type of device may include signal analysis and display equipment, patient and equipment supports, component parts, and accessories.(b)
Classification. Class II.