si-Mochi is an implant intended to fill bony voids or gaps of the skeletal system (i.e.extremities, pelvis). These osseous defects may be surgically created or the result of traumatic injury to the bone and are not intrinsic to the stability of the bony structure. si-Mochi resorbs and is replaced with bone during the healing process.

Device Description

si-Mochi contains a multi porous bi-phase Calaium Phosphate ceramic granules, 12mm, suspended in an aqueous polymer carrier gel. The chemical composition of the multi-porous ceramic granules is trace silicate induced bi-phase calcium phosphate ceramic which has 80% hydroxylapatite Ca5(PO4)3(OH) and 20% beta -tricalcium phosphate Ca3(PO4)2 , similar levels to those identified in naturally-growing bone. Its porous structure comprising three types of porosities which are interconnected: macropores (100µm1mm), midipores (10~~100 µm) and microspaces (1~~10 µm). Calcium phosphate bone graft substitutes have been the topic of extensive clinical studies for several decades. Biocompatibility is addressed in the non-clinical testing section below. The interconnected macro-, midi- and micro- porous structure encourages the rapid formation of host bone and the growth of capillary blood vessels throughout the network of interconnecting pores. After implantation, si-Mochi undergoes physiologically- mediated resorption and is replaced by natural bone. The resorption of the Ca/P porous ceramic granules were controlled by the host nature bone remodelling process due to the proliferated osteocytes formation within the microporous structure of the ceramic granules. The resorption is not controlled by its chemical composition. si-Mochi is supplied in three different types of sterile applicator. si-Mochi does not set in-situ following implantation. si-Mochi does not contain antibiotics.

AI/ML Overview

The provided text is a 510(k) Premarket Notification from Biostone Limited for their device si-Mochi. This document details the device's description, intended use, and a comparison to predicate devices to establish substantial equivalence.

Based on the content of the provided document, the device in question, si-Mochi, is a resorbable calcium salt bone void filler, not an AI-powered image analysis device. Therefore, the information required to answer the questions about acceptance criteria for an AI/ML device, such as performance metrics (accuracy, sensitivity, specificity, AUC), sample size for test and training sets, expert ground truth establishment, MRMC studies, or standalone performance, are not present in this document.

The document focuses on non-clinical and animal studies to demonstrate substantial equivalence to legally marketed predicate devices (TriPore® K070132, Actifuse ABX™ K082575).

Here's an analysis based on the information available in the document, highlighting what is missing in relation to the prompt:

Missing Information (as per the prompt's requirements for AI/ML device study):

Acceptance Criteria for an AI device's performance: Not applicable; this is a medical implant, not an AI device.
Reported Device Performance against AI acceptance criteria: Not applicable.
Sample sized used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective): Not applicable for AI test sets. The document mentions an animal study (rabbit critical size defect in the distal femora model), but details on sample size within that study are not provided.
Number of experts used to establish the ground truth for the test set and the qualifications of those experts: Not applicable.
Adjudication method (e.g. 2+1, 3+1, none) for the test set: Not applicable.
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: Not applicable.
If a standalone (i.e. algorithm only without human-in-the-loop performance) was done: Not applicable.
The type of ground truth used (expert consensus, pathology, outcomes data, etc.): Not applicable for AI. For the animal study, the "ground truth" would be the observed new bone formation in the animal model.
The sample size for the training set: Not applicable.
How the ground truth for the training set was established: Not applicable.

Information Available (related to the device's clearance):

The only "study" mentioned in the document is an "animal study, rabbit critical size defect in the distal femora model, making direct comparison against the predicate device, Actifuse ABX."

Acceptance Criteria (for demonstrating substantial equivalence in this context): The implicit acceptance criterion for this type of device is "substantial equivalence" to predicate devices, meaning it performs as well as the predicate device regarding safety and effectiveness.
- The document states: "Biostone has determined that si-Mochi is substantially equivalent to the predicate devices on the basis of chemical composition tests on all three devices as prescribed in the 'Class II Special Controls Guidance Document' referenced above."
- And: "Secondly, si-Mochi itself complies with the requirements of the Special Controls Document referred to above."
- And: "Animal study, rabbit critical size defect in the distal femora model, making direct comparison against the predicate device, Actifuse ABX. However, the percentage of new bone formations were not statistically significant difference in animal model at all time points post-implantation between si-Mochi and the predicate device."
- Therefore, the "acceptance criteria" here are demonstrated comparability of chemical composition, compliance with special controls, and non-inferiority/statistical non-significance in new bone formation compared to the predicate in an animal model.
Reported Device Performance (against the above criteria):
- Chemical Composition: Stated to be comparable and comply with guidance.
- Animal Study: "the percentage of new bone formations were not statistically significant difference in animal model at all time points post-implantation between si-Mochi and the predicate device." This indicates the device performed comparably to the predicate.
Sample Size (for the animal study): Not explicitly stated in the provided text.
Data Provenance (Animal Study): Rabbit model. Country of origin not specified, but the submitter is in the UK.
Ground Truth (for Animal Study): The direct measurement of "percentage of new bone formations" in the animal model.

In summary, this document is for a medical implant, not an AI/ML diagnostic tool, and as such, the specific metrics and study designs outlined in your prompt for AI applications are not relevant or present.

Summary

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April 21, 2021

Image /page/0/Picture/1 description: The image contains the logo of the U.S. Food and Drug Administration (FDA). On the left is the Department of Health & Human Services logo. To the right of that is the FDA logo, which is a blue square with the letters "FDA" in white. To the right of the blue square is the text "U.S. FOOD & DRUG ADMINISTRATION" in blue.

Biostone Limited Wei-Jen Lo, Ph.D. Chief Scientific Officer BioCity, Pennyfoot Street Nottingham, Notts NG1 1GF United Kingdom

Re: K202639

Trade/Device Name: si-Mochi Regulation Number: 21 CFR 888.3045 Regulation Name: Resorbable Calcium Salt Bone Void Filler Device Regulatory Class: Class II Product Code: MQV Dated: March 16, 2021 Received: March 29, 2021

Dear Dr. Lo:

We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. Although this letter refers to your product as a device, please be aware that some cleared products may instead be combination products. The 510(k) Premarket Notification Database located at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm identifies combination product submissions. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.

If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.

Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part

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801); medical device reporting of medical device-related adverse events) (21 CFR 803) for devices or postmarketing safety reporting (21 CFR 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safety-reportingcombination-products); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR 4. Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR Part 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to https://www.fda.gov/medical-device-safety/medical-device-reportingmdr-how-report-medical-device-problems.

For comprehensive regulatory information about mediation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medicaldevices/device-advice-comprehensive-regulatory-assistance) and CDRH Learn (https://www.fda.gov/training-and-continuing-education/cdrh-learn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See the DICE website (https://www.fda.gov/medical-device-advice-comprehensive-regulatoryassistance/contact-us-division-industry-and-consumer-education-dice) for more information or contact DICE by email (DICE@fda.hhs.gov) or phone (1-800-638-2041 or 301-796-7100).

Sincerely,

for

Laura C. Rose, Ph.D. Assistant Director DHT6C: Division of Restorative, Repair and Trauma Devices OHT6: Office of Orthopedic Devices Office of Product Evaluation and Quality Center for Devices and Radiological Health

Enclosure

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Indications for Use

Form Approved: OMB No. 0910-0120 Expiration Date: 06/30/2023 See PRA Statement below.

510(k) Number (if known) K202639

Device Name

si-Mochi

Indications for Use (Describe)

Type of Use (Select one or both, as applicable)

Prescription Use (Part 21 CFR 801 Subpart D)

Over-The-Counter Use (21 CFR 801 Subpart C)

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SubmitterTelephoneFacsimileContact Person	Biostone LimitedBioCityPennyfoot StreetNottinghamNG1 1GFUnited Kingdom011 44 7906 001281Wei-Jen Lo PhD
Date PreparedTrade Name	21/ July/ 2019si-Mochi
Common Name	Resorbable calcium salt bone void filler device
Classification	Resorbable calcium salt bone void filler devices havebeen classified by the Orthopedics Device Panel asClass II Special Controls per 21 CFR 888.3045.Product code: MQV
Predicate Devices	TriPore® K070132, Actifuse ABX™ K082575
Device Description	si-Mochi contains a multi porous bi-phase CalaiumPhosphate ceramic granules, 12mm, suspended in anaqueous polymer carrier gel. The chemical composition ofthe multi-porous ceramic granules is trace silicate inducedbi-phase calcium phosphate ceramic which has 80%hydroxylapatite $Ca_5(PO_4)_3(OH)$ and 20% $β$ -tricalciumphosphate $Ca_3(PO_4)_2$ , similar levels to those identified innaturally-growing bone.Its porous structure comprising three types of porositieswhich are interconnected: macropores (100µm1mm),midipores (10~~100 µm) and microspaces (1~~10 µm).Calcium phosphate bone graft substitutes have beenthe topic of extensive clinical studies for several decades.Biocompatibility is addressed in the non-clinical testingsection below. The interconnected macro-, midi- andmicro- porous structure encourages the rapid formation ofhost bone and the growth of capillary blood vesselsthroughout the network of interconnecting pores. Afterimplantation, si-Mochi undergoes physiologically-mediated resorption and is replaced by natural bone.
	The resorption of the Ca/P porous ceramic granuleswere controlled by the host nature bone remodellingprocess due to the proliferated osteocytes formationwithin the microporous structure of the ceramicgranules. The resorption is not controlled by its chemicalcomposition. si-Mochi is supplied in three different typesof sterile applicator. si-Mochi does not set in-situfollowing implantation. si-Mochi does not containantibiotics.
Intended Use	si-Mochi is an implant intended to fill bony voids orgaps of the skeletal system (i.e. extremities, pelvis).These osseous defects may be surgically created orthe result of traumatic injury to the bone and are notintrinsic to the stability of the bony structure. si-Mochiresorbs and is replaced with bone during the healingprocess.
Technical Characteristicsand SubstantialEquivalence	si-Mochi and the predicate device, Actifuse ABX sharesimilar characteristics in that they are all calcium saltbone void fillers covered by 'Class II Special ControlsGuidance Document: Resorbable Calcium Salt BoneVoid Filler Device" (FDA Guidance Document 855,dated June 2, 2003).Both si-Mochi and Actifuse ABX are packed in differenttype of applicator for different clinic application. Bothhave the multi-porous Ca/P ceramic granules withadded trace silicate, 1~2mm, suspended in the samechemical composition of synthetic aqueous binding gel.The multi-porous ceramic granules in si-Mochi are nearidentical to TriPore SBG. They share the same chemicalcomposition but the multiparous Ca/P ceramic granuleshad added additional trace silicate. They have the samemulti-porous structure and their manufacturing processand annealing profile are exactly the same.
Determination ofsubstantial equivalence	Biostone has determined that si-Mochi is substantiallyequivalent to the predicate devices on the basis of
(non-clinical data)	chemical composition tests on all three devices as prescribed in the'Class II Special Controls Guidance Document' referenced above.Secondly, si-Mochi itself complies with the requirements of the SpecialControls Document referred to above. The non-clinical data also includedbiocompatibility, pyrogenicity testing and endotoxin monitoring, shelf-life apackaging validation.
Determination ofsubstantialequivalence(animal studies)	Animal study, rabbit critical size defect in the distal femora model,making direct comparison against the predicate device, Actifuse ABX.However, the percentage of new bone formations were not statisticallysignificant difference in animal model at all time points post-implantationbetween si-Mochi and the predicate device.
TechnicalCharacteristicsDifference	si-Mochi and Actifuse ABX1) The first is the chemical composition, where the calcium phosphategranules in Actifuse ABX is pure hydroxylapatite with 0.8% Silicate. Tcalcium phosphate granules in si-Mochi comes as bi-phase calciumphosphate comprised of 20% beta tri-calcium phosphate and 80%hydroxylapatite with 0.8% silicate. The differences in the chemicalcomposition of the porous calcium phosphate ceramic granules do notaffect the safety or effectiveness of si-Mochi, since all materials areresorbable and provide the same function.2) The second is the viscosity of the Kolliphor gel in both si-Mochi andActifuse ABX. The composition of Kolliphor gel in the Actifuse ABX is a20%, and the viscosity will increase when the temperature raised tohuman body temperature at 37°C. However, it was found that the lowviscosity gel is not sufficient to hold the granules together during thelower operation theater temperature. Therefore, the composition of theKolliphor gel was increased to 33% to construct si-Mochi, for si-Mochifunction normally in operation theater condition. The Kolliphor gel isbioinert and will not impede the function of the porous calciumphosphate ceramic granules as the bone ingrowth scaffold.si-Mochi and TriporeThe only difference is that the porous Ca/P ceramic granules containadditional 0.8% of Silica in its chemical composition, the same as the othepredicate device Actifuse ABX. However, the added Silica shall not affectclinical performance. Since the osteointegration thesis of the porous cerargranules and TriPore® are precisely the same.These differences do not raise new issues of safety.
Conclusions	Therefore, Biostone concludes that the non clinical and animal studios

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Conclusions	Therefore, Biostone concludes that the non-clinical and animal studiesdiscussed above demonstrate that si-Mochi performs as well the predicatedevice.
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Regulation Number and Section

§ 888.3045 Resorbable calcium salt bone void filler device.

(a)
Identification. A resorbable calcium salt bone void filler device is a resorbable implant intended to fill bony voids or gaps of the extremities, spine, and pelvis that are caused by trauma or surgery and are not intrinsic to the stability of the bony structure.(b)
Classification. Class II (special controls). The special control for this device is the FDA guidance document entitled “Class II Special Controls Guidance: Resorbable Calcium Salt Bone Void Filler Device; Guidance for Industry and FDA.” See § 888.1(e) of this chapter for the availability of this guidance.