(278 days)
KURZ middle ear prostheses are intended for the partial or total surgical replacement of the ossicular chain of the human middle ear. The objective is the restoration of the mechanical transfer of sound from the tympanic membrane to the oval window of the cochlear with the least impairment of hearing.
Specifically, the devices are designed for the treatment of
- Chronic middle ear inflammation (also following removal of a tumour, e.g. cholesteatoma) with functional impairment of the ossicular chain
- Otosclerosis (stapedial fixation) / congenital stapedial fixation
- Traumatic injury to the ossicular chain
- Malformation of the middle ear
- Revision surgery to correct inadequate hearing improvement, e.g. through dislocation of a prosthesis
Due to different preferences and different techniques of the surgeons various designs of stapes prosthesis are available. The objective of all stapedial prostheses is the restoration of the mechanical transfer of sound from the tympanic membrane to the oval window of the cochlear with the least impairment of hearing.
NiTiFLEX Stapes Prosthesis:
The NiTiFLEX is a stapes prosthesis for partial replacement of the ossicular chain. It consists of a Nitinol clip and the standard KURZ shaft (piston) made of pure titanium with a diameter of 0.4 and 0.6 mm (ASTM F67). The Nitinol clip is made of superelastic Nitinol. Due to the CliP Design, already available with the predicate device CliP® Piston àWengen, the NiTiFLEX can be fixed on the long process of the incus without manual crimping. With the superelastic characteristics of the loop the easier handling of the application of the CliP can be achieved.
Detroit Piston:
The Detroit Piston is a stapes prosthesis for partial replacement of the ossicular chain. It is made of pure titanium (ASTM F67). As shaft the standard KURZ piston is used with a diameter of 0.4 / 0.5 / 0.6 mm. The loop has got a width of 0.5 mm and is twisted (like the loop of the predicate device K-Piston) for easier application on the long process of the incus especially in cases were the incus diameter is very small. The attachment to the incus is done by manual crimping of the prosthesis loop.
Roberson Stapes Prosthesis:
The Roberson Stapes Prosthesis is a stapes prosthesis for partial replacement of the ossicular chain. It is made of pure titanium (ASTM F67). The long process of the incus is placed within the bucket. Two different diameters of the bucket are available - 0.9 and 1.0 mm - for different incus diameters. A piston diameter of 0.6 mm is used. Additional stability is provided by the wire that is placed over the incus. This design is comparable to the Roberson Stapes Prosthesis by Metronic (predicate device).
Skarzynski Piston:
The Skarzynski Piston is a stapes prosthesis for partial replacement of the ossicular chain. It is made of pure titanium (ASTM F67). As shaft the standard KURZ piston is used with a diameter of 0.4 and 0.6 mm. The loop has got a width of 0.25 mm and is twisted (like the loop of the predicate device K-Piston) for easier application on the long process of the incus especially in cases were the incus diameter is very small. The attachment to the incus is done by manual crimping of the prosthesis loop.
The provided document describes the 510(k) summary for several stapes prostheses manufactured by Heinz Kurz GmbH Medizintechnik. This is a premarket notification for medical devices, which typically focuses on demonstrating substantial equivalence to a predicate device rather than presenting new clinical study data to prove efficacy. Therefore, much of the requested information regarding "acceptance criteria" for performance metrics like sensitivity/specificity, or detailed clinical study designs with ground truth established by experts, will not be present in this type of submission. The "acceptance criteria" here refer more broadly to the regulatory requirements for showing safety and effectiveness through substantial equivalence and meeting specified non-clinical performance benchmarks.
Based on the provided document, here's an analysis of the acceptance criteria and the study that proves the device meets those criteria:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria Category | Specific Criteria/Test | Reported Device Performance | Comments |
|---|---|---|---|
| Intended Use | Restoring mechanical transfer of sound from tympanic membrane to oval window; treating specific ear conditions (chronic inflammation, otosclerosis, trauma, malformation, revision surgery). | Declared identical to predicate devices. | This is a key criterion for demonstrating substantial equivalence. |
| Design & Dimensions | Specific lengths, piston diameters, loop band widths, and bucket diameters as outlined in tables (Pages 4-6). | Adheres to specified dimensions and sizes for each device type. | Directly compared to predicate devices; design considered sufficiently similar. |
| Materials | NiTiFLEX: Nitinol clip, Titanium (ASTM F67) shaft. Detroit Piston, Skarzynski Piston, Roberson Piston: Titanium (ASTM F67). | Materials used as specified and are common in predicate devices. | ASTM F67 is a standard for unalloyed titanium. |
| Method of Attachment | NiTiFLEX: Manually, without crimping. Detroit Piston, Skarzynski Piston: Manually, with crimping. Roberson Stapes Prosthesis: Manually, without crimping. | Specific to each device type, consistent with predicate devices. | Important for surgical technique and device function. |
| Single Use & Sterility | Single Use, Sterile (SAL |
§ 874.3450 Partial ossicular replacement prosthesis.
(a)
Identification. A partial ossicular replacement prosthesis is a device intended to be implanted for the functional reconstruction of segments of the ossicular chain and facilitates the conduction of sound wave from the tympanic membrane to the inner ear. The device is made of materials such as stainless steel, tantalum, polytetrafluoroethylene, polyethylene, polytetrafluoroethylene with carbon fibers composite, absorbable gelatin material, porous polyethylene, or from a combination of these materials.(b)
Classification. Class II.