(292 days)
Indications for the Arcos™ Interlocking Distal Stem include:
- Noninflammatory degenerative joint disease including osteoarthritis and avascular necrosis.
- Rheumatoid arthritis.
- Correction of functional deformity.
- Treatment of non-union, femoral neck fracture and trochanteric fractures of the proximal femur with head involvement, unmanageable using other techniques.
- Revision of previously failed total hip arthroplasty.
The Arcos™ Interlocking Distal Stems are single-use implants, intended for uncemented applications.
The Arcos™ Interlocking Distal Stem was designed to be a part of the Arcos™ Modular Femoral Revision System, a modular system using interchangeable stems and proximal bodies commonly seen in femoral revision surgery. The proximal bodies consist of broached, calcar-replacing, and cone-style implants, made from Ti-6Al-4V (ASTM F-136) and featuring a roller hardened taper, is fully porous coated (Ti-6AL-4V, ASTM F-1580) with a fine buffed finish on the bullet-tip. The distal stems will be offered in a range of diameters from 15-26mm and lengths of 200mm, 250mm, and 300mm. The stems are offered in porous cylindrical with proximal taper and splined tapered designs. The stem provides holes for interlocking screws to provide temporary rotational stability. The system also includes auxiliary implants to aid in fixation. The system is intended for uncemented applications
Here's an analysis of the provided 510(k) summary regarding the acceptance criteria and the study that proves the device meets them:
1. A table of acceptance criteria and the reported device performance
| Acceptance Criteria (Stated) | Reported Device Performance |
|---|---|
| Distal Pot Fatigue Test: Surgical implants must have sufficient strength to survive distal pot fatigue testing to 5 million cycles, as required by ISO 7206-8. | Six stems were shown to have sufficient strength to survive distal pot fatigue testing to 5 million cycles. The smallest design (15mm bullet-tipped stem) in the product line was confirmed to meet this requirement based on previous testing of the worst-case scenario. |
| Kaessmann Transverse Screws Torsional Fatigue Test: Screws must demonstrate the ability to provide temporary rotational stability, as stated in the package insert. | The test performed was a torsional fatigue test to determine the ability of the screws to provide temporary rotational stability. The results indicated that the device was functional within its intended use. |
Important Note: The acceptance criteria for the "Kaessmann Transverse Screws Torsional Fatigue Test" are less quantitatively defined in the provided document. It states "determine the ability... as stated in the package insert" and that "the device was functional within its intended use." This suggests the criteria might be qualitative or specified in detail within the package insert, which is not included here.
2. Sample sized used for the test set and the data provenance
- Distal Pot Fatigue Test: Six stems were used for this test.
- Kaessmann Transverse Screws Torsional Fatigue Test: The sample size for this test is not explicitly stated in the provided document. It mentions the screws were "tested... two separate times," but not the number of screws per test.
- Data Provenance: The document does not specify the country of origin of the data or whether the studies were retrospective or prospective. Given that this is a pre-market submission for a physical medical device, these would be laboratory-based mechanical tests, not clinical studies involving human patients.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
This information is not applicable to the type of testing performed. The studies described are mechanical engineering tests (fatigue and torsional strength) of physical components, not clinical diagnostic studies requiring expert human interpretation of data for ground truth establishment.
4. Adjudication method for the test set
This information is not applicable for the reasons stated above. Adjudication methods like 2+1 or 3+1 are used in clinical studies to establish a consensus ground truth among human readers/experts, which isn't relevant to mechanical bench testing.
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
An MRMC comparative effectiveness study was not done. This type of study relates to the performance of AI algorithms, often in diagnostic imaging, and is not relevant to the mechanical testing of orthopedic implants.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
This is not applicable. The device described is a physical orthopedic implant system, not a software or AI algorithm.
7. The type of ground truth used
For both tests, the "ground truth" is established by engineering standards and direct physical measurement/testing against a predefined threshold (e.g., surviving 5 million cycles, demonstrating rotational stability). It is not expert consensus, pathology, or outcomes data.
8. The sample size for the training set
This is not applicable. There is no "training set" in the context of mechanical bench testing for a physical implant. Training sets are used in machine learning for AI algorithms.
9. How the ground truth for the training set was established
This is not applicable for the reasons stated above.
§ 888.3330 Hip joint metal/metal semi-constrained, with an uncemented acetabular component, prosthesis.
(a)
Identification. A hip joint metal/metal semi-constrained, with an uncemented acetabular component, prosthesis is a two-part 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 consist of a femoral and an acetabular component, both made of alloys, such as cobalt-chromium-molybdenum. The femoral component is intended to be fixed with bone cement. The acetabular component is intended for use without bone cement (§ 888.3027).(b)
Classification. Class III.(c)
Date PMA or notice of completion of PDP is required. A PMA or a notice of completion of a PDP is required to be filed with the Food and Drug Administration on or before May 18, 2016, for any hip joint metal/metal semi-constrained prosthesis with an uncemented acetabular component that was in commercial distribution before May 28, 1976, or that has, on or before May 18, 2016, been found to be substantially equivalent to a hip joint metal/metal semi-constrained prosthesis with an uncemented acetabular component that was in commercial distribution before May 28, 1976. Any other hip joint metal/metal semi-constrained prosthesis with an uncemented acetabular component shall have an approved PMA or a declared completed PDP in effect before being placed in commercial distribution.