(33 days)
The Delta TT Acetabular System is indicated for use in total hip arthroplasty for reduction or relief of pain and/or improved hip function in skeletally mature patients with the following conditions:
- Non-inflammatory degenerative joint disease such as osteoarthritis, avascular necrosis and hip dysplasia;
- Rheumatoid arthritis;
- Post-traumatic arthritis,
- Correction of functional deformity;
- Fractures, dislocation of the hip and unsuccessful cup arthroplasty;
- Revisions in cases of good remaining bone stock.
The Delta TT cup is intended for cementless use.
The Delta TT Acetabular System consists of a Delta TT cup, a liner and a modular metal femoral head. Bone screws can also be used as additional fixation for the cup.
The Delta TT cup is manufactured using an EBM (Electron Beam Melting) process with titanium alloy powder (Ti6Al4V, ASTM F1472 - ISO 5832-3). The Delta TT cup consists of a non porous bulk interior surface and a Trabecular Titanium structure on the external surface.
The Delta TT cup has an external hemi-spherical shape. A polar threaded hole is used for introduction of the cup and mates with the polar peg of the liner when the two components are assembled. Three (3) threaded holes in lateral positions allow additional fixation of the cup using bone screws: polyethylene plugs are inserted into these holes when bone screws are not required. The Delta TT cup is designed to be coupled with ultra high molecular weight polyethylene (UHMWPE) liners by means of a taper coupling.
Delta TT cups are available with external diameters of 44, 46 and 48 mm (for Small liners), 50 and 52 mm (for Medium liners) and 54, 56, 58, 60, 62 and 64 mm (for Large liners). The new sizes of the Delta TT Cups, the Delta TT Jumbo Cups, are Delta TT Cups with external diameters of 66, 68, 70, 72, 74 and 76mm and they are all intended to be used with Large Delta TT cup liners that were cleared in K112898. The liners are manufactured from standard UHMWPE (ASTM F648 - ISO 5834-2) or from cross-linked UHMWPE (X-Lima).
Liners are coupled with the Delta TT cup by means of a taper coupling. Two features are intended to give stability to the coupling, a peripheral ring and a polar peg. The peripheral ring is manufactured from Ti6A14V (ASTM F1472 - ISO 5832-3) and surrounds the taper of the liner circumferentially, enhancing the rotational stability of the coupling. The polar peg fits into the polar hole of the cup, increasing the lever-out stability of the top of the peg is resurfaced by a Ti6Al4V (ASTM F1472 - ISO 5832-3) plug to avoid direct contact between polyethylene and bone.
The polyethylene liners are available in two (2) versions: neutral and protruded. The protruded design provides greater coverage of the femoral head and is intended to reduce the risk of dislocation. For both the designs, the following sizes are available:
- Cross-linked UHMWPE liners: Small (for femoral heads Ø 28 mm), Medium (for femoral heads Ø 28 and 32 mm) and Large (for femoral heads Ø 28, 32 and 36 mm).
- Standard UHMWPE liners: Small, Medium and Large liners for femoral heads Ø 28 mm.
Bone screws are manufactured from Ti6Al4V (ASTM F1472 -- ISO 5832-3) and can be used to provide additional initial stability to the cup. Bone screws have a diameter of 6.5 mm and are available in lengths of 20, 25, 30, 35, 40, 45, 50, 55 and 60 mm.
This document describes the regulatory submission for design modifications to a hip replacement system, specifically the Delta TT Acetabular System. As such, it does not contain information about software algorithms, AI, or clinical studies that gather performance metrics like sensitivity/specificity or human reader improvement.
The information provided focuses on demonstrating substantial equivalence to previously cleared devices through non-clinical mechanical testing.
Here's a breakdown based on the categories requested, with explanations for why certain information is not present in the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
| Test | Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|---|
| Wear test | "Applicable" to previously cleared device (K112898) | Results of tests performed on Delta TT Cups cleared via K112898 are applicable. |
| Push-out, Lever-out, Axial torque | "Applicable" to previously cleared device (K112898) | Results of tests performed on Delta TT Cups cleared via K112898 are applicable. |
| Cup deformation | "Applicable" to previously cleared device (K112898) | Results of tests performed on Delta TT Cups cleared via K112898 are applicable. |
| Fatigue/Fretting test | "Applicable" to previously cleared device (K112898) | Results of tests performed on Delta TT Cups cleared via K112898 are applicable. |
Explanation: The acceptance criteria are not explicitly stated as numerical values. Instead, the document relies on the concept of "substantial equivalence" to predicate devices. The performance of the new components (Delta TT Jumbo Cups) is deemed acceptable because they do not represent a "worst case for mechanical testing" compared to the previously cleared Delta TT Cups (K112898). Therefore, the existing test results from K112898 are considered sufficient to demonstrate acceptable performance for the new sizes, implying they meet the same criteria as the original device.
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: Not specified for the mechanical tests. For mechanical testing of medical devices, sample sizes are typically determined by engineering and statistical standards for the specific test (e.g., ISO or ASTM standards) and depend on the variability of the material and design. However, the document does not disclose the exact number of units tested.
- Data Provenance: Not explicitly stated (e.g., country of origin, retrospective/prospective). The tests were conducted to support a regulatory submission for a device manufactured by Limacorporate S.p.A. in Italy, so it's likely the testing was conducted either internally by the manufacturer or by a contracted laboratory. The testing described is non-clinical (i.e., not involving human patients or clinical data).
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications
- Not applicable. This document describes mechanical testing of a physical medical device, not a diagnostic or prognostic algorithm that requires expert "ground truth" for interpretation of data.
4. Adjudication Method for the Test Set
- Not applicable. Adjudication methods like 2+1 or 3+1 are used in studies where human interpretation of data (e.g., medical images) needs consensus. This document pertains to mechanical engineering tests.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
- No. This is not a study involving human readers or AI assistance.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
- No. This is not a study involving an algorithm.
7. The Type of Ground Truth Used
- Not applicable. For mechanical testing, the "ground truth" is defined by the physical behavior of the device under specific load conditions, measured by instruments, and compared against engineering specifications or results from predicate devices. There is no subjective human interpretation involved in establishing ground truth for these types of tests.
8. The Sample Size for the Training Set
- Not applicable. This document describes a physical medical device, not a machine learning model that requires a training set.
9. How the Ground Truth for the Training Set Was Established
- Not applicable. As above, no training set or ground truth in the context of machine learning.
Summary of the Study Proving Device Meets Acceptance Criteria:
The "study" in this context is a series of non-clinical mechanical tests detailed in the K112898 submission for the original Delta TT Acetabular System. The current submission (K141395) argues that because the new "Jumbo" cup sizes (66-76mm) do not represent a "worst case for mechanical testing" compared to the existing cleared sizes (44-64mm), the results from the K112898 tests are directly applicable and demonstrate substantial equivalence.
The tests conducted for K112898 (and deemed applicable for K141395) include:
- Wear test
- Push-out test
- Lever-out test
- Axial torque test
- Cup deformation test
- Fatigue/Fretting test
The underlying premise is that if the smaller, original cups performed acceptably under these mechanical tests, and the larger "Jumbo" cups are structurally similar and not more highly stressed, then they will also perform acceptably. The acceptance criteria for these tests would have been established based on recognized industry standards (e.g., ASTM, ISO) for hip prostheses at the time of the K112898 submission. The document relies on the previous clearance to establish that these criteria were met.
Clinical Testing: The document explicitly states, "Clinical testing was not necessary to demonstrate substantial equivalence of the Delta TT Jumbo Cups to the Delta TT Acetabular System." This further emphasizes that the basis for clearance was non-clinical mechanical performance.
§ 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.