(241 days)
The X-PSI Knee System is indicated as an orthopedic instrument system to assist in the positioning of knee replacement components. It involves surgical planning software used pre-operatively to plan the surgical placement of the components on the basis of provided patient radiological images and 3-D reconstructed bones with identifiable placement anatomical landmarks, and surgical instrument components that include patient specific or customized guides fabricated on the basis of the surgical plan to precisely reference the placement of the implant components intra-operatively per the surgical plan. The X-PSI Knee system is indicated for patients without severe bone deformities, such as a HKA greater than 15° or deformities due to prior fracture of the distal femur or proximal tibia.
The X-PSI Knee System is to be used with the following fixed bearing knee replacement systems in accordance with their indications and contraindications: NexGen® CR, NexGen CR-Flex Gender, NexGen LPS, NexGen LPS-Flex, NexGen LPS-Flex Gender, Persona® CR, Persona PS, Vanguard® CR and Vanguard PS.
The patient specific guide components are intended for single-use only.
The present Zimmer Biomet® X-PSI Knee System is an instrumentation system that includes customized surgical guides to mate each patient's bony and articular surface topographies to reference the location and orientation of the implant system's instruments which in turns sets the position and alignment of the femoral and tibial implant components.
It involves the following:
- A CAS X-PSI Knee Software Suite used in preparation for the surgery to sequentially construct 3-D surface models of each patient's knee joint bony structures and articular surfaces from the patient's X-Ray images, plan the location and orientation of the knee replacement implant components upon the patient's model, and create the corresponding specification models for the patient specific surgical guides (PSI Guides) with surfaces and elements to uniquely fit each patient topographical features and set or reference the placement of the implant system components per the plan,
- . The Zimmer Biomet ® X-PSI Guides (also called jigs) that are manufactured per the above models and plan, for intra-operative and single use, which include one to set the placement of the distal femoral cut guides which set the resection depth, the varus/valgus and the flexion of the distal cut and one to set the placement of the tibial cut guides which set the resection depth, the varus/valgus, and the posterior slope of the proximal cut.
- . Each patient's Zimmer Biomet ®3-D Bone Models (femur and tibia components) that are fabricated and provided along with the PSI Guides for use intra-operatively to provide the surgeon with an intra-operative visual reference of the planned location of the PSI Guides in order to help guide their locations on the patient's actual joint,
- Zimmer Biomet X-PSI Reusable Surgical Instrumentations are provided both sterile . and non-sterile and are reusable for intra-operative use, which include femoral stylus, and femoral and tibial cut block instrumentations to allow setting the resection level and performing the bone cuts as defined by the PSI Guides.
- Fixation Pins are accessories for use of the guides, these accessories are Class I devices under the classification "Orthopedic manual surgical instrument (21 CFR § 888.4540)".
The Zimmer Biomet® X-PSI Knee System is compatible for use with the following class II Zimmer Biomet Nexgen, Persona and Vanguard total knee replacement implant systems:
- . NexGen®family: NexGen CR, NexGen CR-Flex, NexGen CR-Flex Gender, NexGen LPS, NexGen LPS-Flex, NexGen LPS-Flex Gender
- . Persona® family: Persona CR, Persona PS
- Vanguard® family: Vanguard CR, Vanguard PS
Finally, the following accessories are used for the acquisition of the x-ray images:
- X-Ray Marker 3D Zimmer Biomet ® X-PSI (re-usable) ●
- X-Ray Calibration Straps, Short and Long (single-use)
The provided document is a 510(k) premarket notification for the Zimmer Biomet X-PSI Knee System. It details the device, its indications for use, and a summary of performance data used to establish substantial equivalence to predicate devices.
Here's a breakdown of the requested information based on the provided text:
1. A table of acceptance criteria and the reported device performance
The document states that a non-significant risk clinical study was performed to evaluate the proper positioning of the Zimmer Biomet X-PSI Knee guides. The primary metric measured was the resulting frontal Hip-Knee-Ankle (HKA) alignment angle versus the surgically planned HKA alignment angle.
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Satisfactory performance per the intended use regarding the resulting frontal Hip-Knee-Ankle (HKA) alignment angle versus the surgically planned HKA alignment angle. | The results demonstrated satisfactory performance per the intended use. |
Note: The document states "satisfactory performance" but does not provide specific numerical thresholds or a statistical comparison for the HKA alignment angle, which would typically be included in detailed acceptance criteria. It also mentions "substantial equivalence in cut accuracy with regards to femoral and tibial frontal and sagittal angles, as well as femoral rotation and resection depth" based on full system validation tests, but no specific acceptance criteria for these were detailed.
2. Sample size used for the test set and the data provenance (e.g., country of origin of the data, retrospective or prospective)
The document does not explicitly state the sample size for the clinical study (test set) or the data provenance (country of origin, retrospective/prospective). It only refers to it as a "Non-Significant Risk Clinical Study."
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g., radiologist with 10 years of experience)
The document does not provide details on the number of experts or their qualifications for establishing the ground truth in the clinical study.
4. Adjudication method (e.g., 2+1, 3+1, none) for the test set
The document does not describe any adjudication method used for the clinical study's test set.
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
The document does not mention a multi-reader multi-case (MRMC) comparative effectiveness study or any assessment of human reader improvement with AI assistance. The device is an orthopedic instrument system that assists in surgical planning and guiding, not a diagnostic AI tool that human readers would interpret.
6. If a standalone (i.e., algorithm only without human-in-the-loop performance) was done
The document describes "Software System Tests" which were performed to "ensure that no hazardous anomalies were present in the system software components" and "consisted of testing software features and functionalities in correspondence to software design requirements." This implies a standalone evaluation of the software's functional performance, but not in terms of diagnostic accuracy or clinical outcomes in isolation. The "Full System Validation Tests" using cadaver specimens and bone models involved "multiple surgeons," indicating a human-in-the-loop component for these tests, rather than purely standalone algorithm performance on clinical metrics.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
For the clinical study, the ground truth was implied by surgically planned HKA alignment angle against which the "resulting frontal Hip-Knee-Ankle (HKA) alignment angle" was compared. This implies the surgical plan served as the reference for evaluating positioning accuracy. For the "Full System Validation Tests," the ground truth for "cut accuracy" (femoral/tibial angles, rotation, resection depth) would typically be established by precise measurements from the bone models or cadaver specimens, likely compared against the planned surgical cuts.
8. The sample size for the training set
The document does not specify a sample size for the training set for the software or any AI/ML components. It mentions that the software "sequentially construct[s] 3-D surface models of each patient's knee joint bony structures and articular surfaces from the patient's X-Ray images," but it doesn't detail how this software was trained or validated in terms of data volume.
9. How the ground truth for the training set was established
The document does not provide information on how the ground truth for any potential training set was established.
§ 888.3560 Knee joint patellofemorotibial polymer/metal/polymer semi-constrained cemented prosthesis.
(a)
Identification. A knee joint patellofemorotibial polymer/metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace a knee 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 a tibial component or components and a retropatellar resurfacing component made of ultra-high molecular weight polyethylene. This generic type of device is limited to those prostheses intended for use with bone cement (§ 888.3027).(b)
Classification. Class II.