(43 days)
The Implex Cobrex Hip Stem is intended for use where severe degeneration, trauma, or other pathology of the hip joint indicates cemented or hybrid total hip arthroplasty.
The Implex Cobrex Hip Stem, cemented, is a modular femoral hip stem manufactured from forged cobalt chromium alloy conforming to ASTM F-799. The Cobrex hip stem has a 12/14 taper and is available in five stem sizes (10, 11, 12, 13, and 14) with proportionally increasing neck offsets (24 mm, 30 mm, and 36 mm). Also, the Cobrex hip stem is collared with a cobra type flange on the proximal section.
The provided text is a 510(k) summary for the Implex Cobrex Hip System, Femoral Component. It describes the device, its indications for use, and a conclusion of substantial equivalence to predicate devices based on technological characteristics and performance data.
Here's an analysis of the acceptance criteria and the study that proves the device meets them, based only on the provided text:
1. A table of acceptance criteria and the reported device performance
The document does not explicitly state quantitative acceptance criteria in terms of specific performance metrics (e.g., maximum stress, minimum cycles to failure) or reported numerical performance data. Instead, it refers to a type of test and a conclusion.
| Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|
| Mechanical Fatigue Performance | "Fatigue testing has been provided to demonstrate that the Cobrex hip stem will perform as intended." |
2. Sample size used for the test set and the data provenance
The document does not specify the sample size used for the fatigue testing, nor does it provide information on the data provenance (e.g., country of origin, retrospective or prospective).
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
This is not applicable as the study described is physical fatigue testing of a mechanical device, not a study requiring expert interpretation of clinical data or images.
4. Adjudication method (e.g., 2+1, 3+1, none) for the test set
This is not applicable as the study described is physical fatigue testing of a mechanical device.
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
This is not applicable as the device is a hip implant, not an AI-based diagnostic or imaging device.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
This is not applicable as the device is a hip implant, not an algorithm. The "standalone" performance here refers to the device's mechanical integrity under fatigue loading.
7. The type of ground truth used
The "ground truth" for this type of device is its ability to withstand mechanical stresses and cyclic loading over its intended lifespan without failure. This is established through mechanical fatigue testing which simulates in-vivo conditions to demonstrate expected performance and durability. Specific failure points or acceptable deformation levels would be predefined based on engineering standards (like ASTM F-799 mentioned in the device description).
8. The sample size for the training set
This is not applicable as the device is a mechanical implant, not an AI model requiring a training set.
9. How the ground truth for the training set was established
This is not applicable as the device is a mechanical implant, not an AI model.
Summary of what is known from the document:
- Acceptance Criteria/Performance: The device underwent "fatigue testing" to demonstrate it "will perform as intended." The specific criteria for "perform as intended" are not detailed but are implied to be sufficient for substantial equivalence.
- Study Type: Mechanical fatigue testing.
- Device Type: Femoral component of a hip prosthesis.
- Material: Forged cobalt chromium alloy conforming to ASTM F-799.
§ 888.3350 Hip joint metal/polymer semi-constrained cemented prosthesis.
(a)
Identification. A hip joint metal/polymer semi-constrained cemented 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 includes prostheses that have a femoral component made of alloys, such as cobalt-chromium-molybdenum, and an acetabular resurfacing component made of ultra-high molecular weight polyethylene and is limited to those prostheses intended for use with bone cement (§ 888.3027).(b)
Classification. Class II.