(78 days)
Total hip components are indicated for individuals undergoing primary and revision surgery where other treatments or devices have failed in rehabilitating hips damaged as a result of trauma, inflammatory joint disease such as rheumatoid arthritis, or noninflammatory degenerative joint disease (NIDJD) or any of its composite diagnoses such as osteoarthritis; avascular necrosis; traumatic arthritis; slipped capital epiphysis; fused hip; fracture of the pelvis; diastrophic variant; old, remote osteomyelitis with an extended drainage-free period; nonunion, femoral neck fracture and trochanteric fractures of the proximal femur with head involvement that are unmanageable using other techniques; femoral osteotomy, or Girdlestone resection; fracture dislocation of the hip; and correction of deformity. Smith & Nephew Oxinium DH femoral heads are for single use only.
The Oxinium DH femoral heads are designed for use with existing Smith & Nephew hip stems featuring a 12/14 taper and will articulate against existing acetabular shell and liner constructs. A complete list of hip stems and acetabular components intended for use with the Oxinium DH heads is provided in Tables 1 and 2, respectively. The overall design of the Oxinium DH femoral heads is based upon the existing Total Hip 12/14 Taper Femoral Heads cleared via K021673 and the Oxinium femoral heads cleared as part of K022958 for Total Hip Femoral Heads & Liners.
Here's an analysis of the provided text regarding the acceptance criteria and study for the Smith & Nephew Oxinium DH Femoral Heads:
The provided document (K081566) is a 510(k) Summary of Safety and Effectiveness for a medical device. It's important to understand that 510(k) clearances are based on demonstrating "substantial equivalence" to a predicate device, rather than proving stand-alone clinical efficacy through randomized controlled trials. Therefore, the information you're requesting regarding "acceptance criteria" and a "study that proves the device meets the acceptance criteria" in the context of performance metrics like sensitivity, specificity, human reader improvement with AI, etc., will likely not be present in this type of regulatory submission.
Instead, the "acceptance criteria" for a 510(k) device like this are typically related to:
- Mechanical performance: Ensuring the device meets strength, durability, and biocompatibility standards.
- Indications for Use: Confirming the device is intended for the same or similar purposes as the predicate device.
- Design and Materials: Demonstrating similarity in overall design and materials to a legally marketed predicate.
The "study" proving these criteria are met is often a combination of mechanical testing and a comparison to predicate devices.
Given this context, here's the information extracted from the provided text, addressing your questions where possible:
1. Table of Acceptance Criteria and Reported Device Performance
Note: As explained above, "acceptance criteria" for a 510(k) submission are generally not expressed in clinical performance metrics (like sensitivity/specificity) but rather in engineering and design equivalence.
| Acceptance Criteria Category | Reported Device Performance (from text) |
|---|---|
| Mechanical Performance | "A review of the mechanical testing results indicated that the Smith & Nephew Oxinium DH femoral heads are equivalent to devices currently used clinically and are capable of withstanding expected in vivo loading without failure." |
| Indications for Use | The stated Indications for Use are identical to the predicate devices, covering rehabilitation of hips damaged by trauma, inflammatory/degenerative joint disease, avascular necrosis, fractures, etc. |
| Design & Materials | "The Smith & Nephew Oxinium DH femoral heads are similar in overall design, indications, and materials to the Total Hip 12/14 Taper Femoral Heads cleared via K021673 and the Oxinium femoral heads cleared as part of K022958 for Total Hip Femoral Heads & Liners." |
| Biocompatibility | (Not explicitly detailed in the provided text, but implied through substantial equivalence to predicate devices likely already deemed biocompatible.) |
2. Sample Size Used for the Test Set and Data Provenance
- Test Set Sample Size: Not applicable in the context of clinical performance evaluation (like for diagnostic AI). The "test set" here refers to the samples used in mechanical testing. The document states "A review of the mechanical testing results," implying tests were conducted, but does not specify the sample size (e.g., number of heads tested for fatigue, static strength, etc.).
- Data Provenance: Not applicable in the context of clinical data. The "data" primarily comes from mechanical laboratory testing performed on the device prototypes or production samples. The country of origin for such testing is not specified. It is a prospective test in the sense that the device was manufactured and then tested to confirm its properties.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications
- Number of Experts: Not applicable. For mechanical testing, "ground truth" is established by engineering standards, specifications, and physical measurements, not by expert consensus in a clinical sense. The review of these results would be done by internal engineers, potentially external consultants, and ultimately FDA reviewers.
- Qualifications of Experts: Not specified. If "experts" refers to those who designed or evaluated the mechanical tests, they would typically be biomechanical engineers, materials scientists, or other relevant technical professionals.
4. Adjudication Method for the Test Set
- Adjudication Method: Not applicable. Adjudication methods like 2+1 or 3+1 are used for establishing clinical ground truth (e.g., diagnosis from imaging). For mechanical testing, the "adjudication" is typically a direct comparison of measured values against established engineering specifications or performance of predicate devices. There isn't a "consensus" process for adjudicating if a material broke at a certain load.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
- No, an MRMC comparative effectiveness study was not done. This type of study is relevant for evaluating diagnostic tools or AI systems where human readers interpret results. This submission is for a physical implantable device (femoral head) and focuses on mechanical and material equivalence.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
- No. This question is irrelevant to the device described. This is a physical orthopedic implant, not an algorithm or AI system.
7. The Type of Ground Truth Used
- Ground Truth Type:
- For mechanical performance: Engineering specifications, material properties, and performance data from predicate devices. The "ground truth" is that the device must withstand "expected in vivo loading without failure," which is assessed via standardized biomechanical testing (e.g., fatigue testing, static load testing to ISO or ASTM standards, though specific standards aren't cited in this summary).
- For design, materials, and indications: The characteristics and performance of the legally marketed predicate devices (K021673 and K022958).
8. The Sample Size for the Training Set
- Sample Size for Training Set: Not applicable. This document is not describing an AI/machine learning model, so there is no "training set" in that context. If interpreted very broadly as the historical data used to design the device, it would be the cumulative knowledge and clinical experience with previous hip prostheses, but specific numbers are not given.
9. How the Ground Truth for the Training Set Was Established
- How Ground Truth for Training Set Was Established: Not applicable, as there is no "training set" in the common understanding for an AI/ML device. The "ground truth" for the design of the device is based on established biomechanical principles, historical clinical performance of similar devices, and regulatory standards for orthopedic implants.
In summary: The K081566 document is a regulatory submission for substantial equivalence for a physical medical device. It relies on a comparison to existing, legally marketed predicate devices and demonstrates equivalence through mechanical testing and design/material similarity, rather than clinical performance studies (like those used for diagnostic AI or new drug approvals). The terms "acceptance criteria" and "study" in this context are interpreted differently than they would be for software-as-a-medical-device (SaMD) or AI medical devices.
§ 888.3358 Hip joint metal/polymer/metal semi-constrained porous-coated uncemented prosthesis.
(a)
Identification. A hip joint metal/polymer/metal semi-constrained porous-coated uncemented prosthesis is a device intended to be implanted to replace a hip joint. The device limits translation and rotation in one or more planes via the geometry of its articulating surfaces. It has no linkage across the joint. This generic type of device has a femoral component made of a cobalt-chromium-molybdenum (Co-Cr-Mo) alloy or a titanium-aluminum-vanadium (Ti-6Al-4V) alloy and an acetabular component composed of an ultra-high molecular weight polyethylene articulating bearing surface fixed in a metal shell made of Co-Cr-Mo or Ti-6Al-4V. The femoral stem and acetabular shell have a porous coating made of, in the case of Co-Cr-Mo substrates, beads of the same alloy, and in the case of Ti-6Al-4V substrates, fibers of commercially pure titanium or Ti-6Al-4V alloy. The porous coating has a volume porosity between 30 and 70 percent, an average pore size between 100 and 1,000 microns, interconnecting porosity, and a porous coating thickness between 500 and 1,500 microns. The generic type of device has a design to achieve biological fixation to bone without the use of bone cement.(b)
Classification. Class II.