(86 days)
The PMMA Distal Centralizers are intended 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, ankylosis, protrusio acetabuli, and painful hip dysplasia;
- inflammatory degenerative joint disease such as rheumatoid arthritis;
- correction of functional deformity; and,
- revision procedures where other treatments or devices have failed
The PMMA Distal Centralizers are single use components, intended for use as part of a cemented total hip arthroplasty.
The PROFEMUR® X™ Distal Centralizers are molded PMMA centralizers placed within the femoral canal before the hip stem implant, providing a guide for the implant and allowing the surgeon to easily center the hip stem implant within a uniformly thick cement mantle. The centralizer bears no body weight, since the cured bone cement transfers all loading forces from the stem to the bone. The material used for the Distal Centralizers identically conforms to the same material standard as the predicate devices (molded PMMA), but will use a new material resin. Like the predicate, the replacement resin will contain 2 copolymers, designed to contribute to material properties.
This document describes a 510(k) summary for the PROFEMUR® X™ Distal Centralizers, a medical device used in total hip arthroplasty. The submission claims substantial equivalence to predicate devices based on nonclinical testing.
Here's an analysis of the provided text with respect to acceptance criteria and supporting studies:
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Table of Acceptance Criteria and Reported Device Performance:
The document does not explicitly state quantitative acceptance criteria for device performance in the traditional sense (e.g., statistical thresholds for accuracy, sensitivity, specificity). Instead, the acceptance is based on demonstrating "equivalence" to predicate devices through functional and biocompatibility testing, and chemical analysis.
Acceptance Criteria (Implied) Reported Device Performance Equivalence in material properties to predicate devices "The material used for the Distal Centralizers identically conforms to the same material standard as the predicate devices (molded PMMA), but will use a new material resin. Like the predicate, the replacement resin will contain 2 copolymers, designed to contribute to material properties." "The material used for the Distal Centralizers identically conforms to ASTM F451 as does the material used for the predicate devices (molded PMMA)." Ability to withstand expected in vivo conditions without failure "The worst case design of the subject material for the PROFEMUR® X™ Centralizers was evaluated via functional testing, chemical analysis and biocompatibility. A review of these that the PROFEMUR® X" Centralizers are equivalent to predicate devices and are capable of withstanding expected in vivo conditions without failure." Identical indications for use as predicate devices "The indications for use of the PROFEMUR® X™ Distal Centralizers are identical to the previously cleared predicate devices." Unchanged design features and processing "The design features and processing of the devices are unchanged." Unchanged fundamental scientific technology "The fundamental scientific technology of the modified devices has not changed relative to the predicate devices." -
Sample size used for the test set and the data provenance:
- Test Set Sample Size: The document does not specify a "test set" in the context of clinical or performance data from human subjects. The evaluation was based on nonclinical (laboratory) testing. Therefore, sample sizes for functional testing, chemical analysis, and biocompatibility would be relevant here, but they are not provided in the document.
- Data Provenance: The data provenance is from nonclinical testing conducted by Wright Medical Technology, Inc. There is no mention of country of origin for any data, nor if it was retrospective or prospective, as it's not a clinical study.
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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 this submission. The ground truth was established through engineering and scientific testing standards (e.g., ASTM F451 for material conformity, biocompatibility testing standards). There is no mention of human experts establishing ground truth for performance in the way experts would for medical image review or diagnostic accuracy.
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Adjudication method for the test set:
- This is not applicable. There was no "test set" requiring adjudication by human experts. The evaluation focused on material and functional equivalence demonstrated through nonclinical tests.
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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:
- No, an MRMC comparative effectiveness study was not done. This device is a physical medical implant (a centralizer for hip surgery), not an AI-powered diagnostic or assistive technology. Therefore, the concept of "human readers improve with AI" is not relevant here.
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If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- No, a standalone algorithm performance study was not done. This is a physical medical device, not an algorithm.
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The type of ground truth used (expert consensus, pathology, outcomes data, etc):
- The "ground truth" for the nonclinical evaluation was based on established engineering and material standards, and the performance characteristics of the predicate devices. For example, conformity to ASTM F451 for PMMA is a form of ground truth for material properties, and the ability to withstand in vivo conditions without failure is a ground truth established through functional testing simulating those conditions.
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The sample size for the training set:
- This is not applicable. There was no "training set" as this is not an AI/machine learning device. The material properties and design were likely developed through standard engineering design processes, possibly involving iterative testing and refinement, but not in the context of a "training set" for an algorithm.
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How the ground truth for the training set was established:
- This is not applicable as there was no training set for an algorithm.
§ 888.3353 Hip joint metal/ceramic/polymer semi-constrained cemented or nonporous uncemented prosthesis.
(a)
Identification. A hip joint metal/ceramic/polymer semi-constrained cemented or nonporous uncemented prosthesis is a device intended to be implanted to replace a hip joint. This device limits translation and rotation in one or more planes via the geometry of its articulating surfaces. It has no linkage across-the-joint. The two-part femoral component consists of a femoral stem made of alloys to be fixed in the intramedullary canal of the femur by impaction with or without use of bone cement. The proximal end of the femoral stem is tapered with a surface that ensures positive locking with the spherical ceramic (aluminium oxide, A12 03 ) head of the femoral component. The acetabular component is made of ultra-high molecular weight polyethylene or ultra-high molecular weight polyethylene reinforced with nonporous metal alloys, and used with or without bone cement.(b)
Classification. Class II.