The CastleLoc-S Posterior Cervical Fixation System is intended to provide immobilization and stabilization of spinal segments as an adjunct to fosion for the following acute and chronic instabilities of the cervical spine (C1 to C7) and the thoracic spine (TI-T3): traumatic spinal fractures and/or traumatic dislocations; instability or deformity; failed previous fusions (e.g., pseudoarthrosis); tumors involving the cervical spine; and degenerative disease, including intractable radiculopathy and/or myelopathy, neck and/or arm pain of discogenic origin as confirmed by radiographic studies, and degenerative disease of the facets with instability. The CastleLoc-S Posterior Cervical Fixation System is also intended to restore the integrity of the spinal column even in the absence of fusion for a limited time period in patients with advanced stage tumors involving the cervical spine in whom life expectancy is of insufficient duration to permit achievement of fusion. The CastleLoc-S Posterior Cervical Fixation System can be linked to the LnK Spinal Fixation System, OpenLoc-L Spinal Fixation System and AccelFix Spinal Fixation System via rod to rod connector and transitional rod.

Device Description

The CastleLoc-S Posterior Cervical Fixation System is a top-loading, multiple components, posterior (cervical-thoracic) spinal fixation system which consists of poly screw, Reduction poly screw, partially screw, semi-reduction partially screw, straight rod, set screw, hooks and accessories that can be used via an open surgical approach. The devices are manufactured from titanium alloy per ASTM F136 and cobalt chromium per ASTM F1537.

AI/ML Overview

This document is a 510(k) Premarket Notification from L&K Biomed Co., Ltd. for their CastleLoc-S Posterior Cervical Fixation System. It asserts substantial equivalence to previously cleared predicate devices.

1. Table of Acceptance Criteria and Reported Device Performance:

The document does not specify quantitative acceptance criteria or provide new device performance data. Instead, it relies on the assertion of identicality and substantial equivalence to predicate devices. The "performance" is implicitly deemed acceptable because the device is stated to be identical to already cleared devices that met the necessary performance standards.

Acceptance Criteria (Explicitly Stated)	Reported Device Performance
Not explicitly stated (relies on substantial equivalence to predicates)	"The CastleLoc-S Posterior Cervical Fixation System is identical to the predicates; mechanical testing is not required to establish substantial equivalence."

2. Sample Size Used for the Test Set and Data Provenance:

No new test set was used for this submission to establish substantial equivalence based on performance. The document states: "The CastleLoc-S Posterior Cervical Fixation System is identical to the predicates; mechanical testing is not required to establish substantial equivalence."

A risk assessment, including ASTM F1717 testing for static compression bending and static torsion mechanical testing, was conducted "to confirm that the additional components do not introduce new issues of safety or effectiveness." However, this testing was performed on predicate devices, and the data from those previous clearances (K103414, K120879, K143278, K162136, K200793) was leveraged.

Therefore, there is no distinct "test set" and no new data provenance for the CastleLoc-S system's performance.

3. Number of Experts Used to Establish Ground Truth for the Test Set and Their Qualifications:

Not applicable. No new studies requiring expert-established ground truth were performed for this submission, as the device's performance is asserted through substantial equivalence to predicate devices.

4. Adjudication Method for the Test Set:

Not applicable. No new studies requiring adjudication were performed.

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study:

No MRMC comparative effectiveness study was done. This type of study is typically associated with AI/software devices and would measure the improvement of human readers with AI assistance. The CastleLoc-S system is a physical medical device (spinal fixation system), not an AI diagnostic tool.

6. Standalone (Algorithm Only Without Human-in-the-loop Performance) Study:

Not applicable. The CastleLoc-S system is a physical medical device, not an algorithm or software.

7. Type of Ground Truth Used:

Not applicable, as no new performance studies for the CastleLoc-S system were conducted for this submission. The "ground truth" for the predicate devices' performance would have been established through mechanical testing standards (e.g., ASTM F1717 for static compression bending and static torsion) which define acceptable physical properties and performance characteristics for spinal fixation systems.

8. Sample Size for the Training Set:

Not applicable. The CastleLoc-S system is a physical medical device. It does not employ a "training set" in the context of machine learning or AI models.

9. How the Ground Truth for the Training Set Was Established:

Not applicable. As above, there is no "training set" for this physical device.

Summary

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July 20, 2023

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.

L & K Biomed Co., Ltd. Katherine Kim RA #101, 201, 202 16-25, Dongbaekjungang-ro 16 beon-gil. Giheung-gu Yongin-si, Gyeonggi-do 17015 South Korea

Re: K231840

Trade/Device Name: CastleLoc-S Posterior Cervical Fixation System Regulation Number: 21 CFR 888.3075 Regulation Name: Posterior Cervical Screw System Regulatory Class: Class II Product Code: NKG, KWP Dated: June 20, 2023 Received: June 22, 2023

Dear Katherine Kim:

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

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requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 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 (OS) 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,

Colin
O'neill -S

Colin O'Neill, M.B.E. Assistant Director DHT6B: Division of Spinal Devices OHT6: Office of Orthopedic Devices Office of Product Evaluation and Quality Center for Devices and Radiological Health

Enclosure

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DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration

Indications for Use

510(k) Number (if known) K231840

Device Name

CastleLoc-S Posterior Cervical Fixation System

Indications for Use (Describe)

Prescription Use (Part 21 CFR 801 Subpart D)	X
Over-The-Counter Use (21 CFR 801 Subpart C)

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510(k) SUMMARY

The following 510(k) summary is being submitted as required by 21 CFR 807.92(a):

1. Manufacturer

Submitter's Name:	L&K Biomed Co., Ltd.
Submitter's Address:	#101, 201, 202 16-25, Dongbaekjungang-ro 16 beon-gilGiheung-gu, Yongin-si, Gyeonggi-do, 17015, Korea.
Submitter's Telephone:	82-2-6717-1983
Contact Person:	Katherine Kim/82-2-6717-1983khkim@lnkbiomed.com
Prepared Date:	June 20, 2023

Device Identification 2.

Device Trade Name	CastleLoc-S Posterior Cervical Fixation System
Common/Usual Name	Spinal Fixation System
Regulation Class /Number	Class II / 21 CFR 888.3075 / 21 CFR 888.3050
Regulation Name	Posterior cervical screw system
Product Code	NKG, KWP
Classification Panel	Spinal Devices (DHT6B)

Predicate or legally marketed devices which are substantially equivalent. 3.

The subject devices are identical to the predicate devices in all characteristics.

510k Number	Trade or Proprietary or Model Name	Predicate Type
K 143278	LnK Posterior Cervical Fixation System	Primary
K 120879	LnK Posterior Cervical Fixation System
K 103414	LnK Posterior Cervical Fixation System	Additional
K 162136	LnK Posterior Cervical Fixation System and CastleLoc-S
K 200793	Posterior Cervical Fixation System
K 210035	MegaCerfix(Former name) Posterior Cervical Fixation System	Additional
K 221050	Paeon Posterior Cervical Fixation System

The design feature, indications for use and manufacturing process for the subject devices are substantially equivalent to the predicate devices.

Materials 4.

CastleLoc-S Posterior CervicalFixation System	Ti-6Al-4V ELI titanium alloy (ASTM F136) and Cobalt-28Chromium-6Molybdenum-4Vanadium ELI (ASTM F1537)
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5. Description of the Device

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Image /page/4/Picture/0 description: The image shows the logo for L&K Biomed, along with the text "K231840 Page 2 of 2". The logo consists of the text "L&K Biomed" in a sans-serif font, with a circular graphic to the left of the text. The text "K231840" and "Page 2 of 2" are located to the right of the logo.

6. INDICATION FOR USE

The CastleLoc-S Posterior Cervical Fixation System is intended to provide immobilization and stabilization of spinal segments as an adjunct to fusion for the following acute and chronic instabilities of the cervical spine (C1 to C7) and the thoracic spine (T1-T3): traumatic spinal fractures and/or traumatic dislocations; instability or deformity; failed previous fusions (e.g., pseudoarthrosis); tumors involving the cervical spine; and degenerative disease, including intractable radiculopathy and/or myelopathy, neck and/or arm pain of discogenic origin as confirmed by radiographic studies, and degenerative disease of the facets with instability. The CastleLoc-S Posterior Cervical Fixation System is also intended to restore the integrity of the spinal column even in the absence of fusion for a limited time period in patients with advanced stage tumors involving the cervical spine in whom life expectancy is of insufficient duration to permit achievement of fusion. The CastleLoc-S Posterior Cervical Fixation System can be linked to the LnK Spinal Fixation System, OpenLoc-L Spinal Fixation System and AccelFix Spinal Fixation System via rod connector and transitional rod.

7. Performance Testing

The CastleLoc-S Posterior Cervical Fixation System is identical to the predicates; mechanical testing is not required to establish substantial equivalence.

A risk assessment, including ASTM F1717 testing for static compression bending and static torsion mechanical testing, was conducted to confirm that the additional components do not introduce new issues of safety or effectiveness. The additional components to be added through this submission do not require additional mechanical testing. None of the additional sizes is the worst case of the CastleLoc-S Posterior Cervical Fixation System. Therefore, we substitute mechanical test data of additional components of CastleLoc-S Posterior Cervical Fixation System with the predicate device (K103414, K120879, K143278, K162136, K200793).

Summary of Technology Characteristics 8.

Subject devices are identical to the predicate devices, material, design, mechanism, indication for use and manufacturing process in all characteristics.

Substantial Equivalence 9.

Subject devices are shown to be substantially equivalent to the predicate devices in indications for use, design, same manufacturing process, function and materials used.

	510K no.	Indication for use	Material	Design	Sterilization Method
Subject CastleLoc-SCastleLoc-S PosteriorCervical Fixation System		Similar	Same	Identicaldevice	Same
LnK Posterior CervicalFixation System andCastleLoc-S PosteriorCervical Fixation System	K103414 K120879 K143278 K162136 K200793	Similar	Same	Identicaldevice	Same
Paeon Posterior CervicalFixation System	K 210035K 221050	Similar	Same	Identicaldevice	Same

10. Conclusion

The overall technology characteristics lead to the conclusion that the CastleLoc-S Posterior Cervical Fixation System is substantially equivalent to the predicate devices (K103414, K120879, K143278, K162136, K200793).

Regulation Number and Section

§ 888.3075 Posterior cervical screw system.

(a)
Identification. Posterior cervical screw systems are comprised of multiple, interconnecting components, made from a variety of materials that allow an implant system to be built from the occiput to the upper thoracic spine to fit the patient's anatomical and physiological requirements, as determined by preoperative cross-sectional imaging. Such a spinal assembly consists of a combination of bone anchors via screws (i.e., occipital screws, cervical lateral mass screws, cervical pedicle screws, C2 pars screws, C2 translaminar screws, C2 transarticular screws), longitudinal members (e.g., plates, rods, including dual diameter rods, plate/rod combinations), transverse or cross connectors, interconnection mechanisms (e.g., rod-to-rod connectors, offset connectors), and closure mechanisms (e.g., set screws, nuts). Posterior cervical screw systems are rigidly fixed devices that do not contain dynamic features, including but not limited to: non-uniform longitudinal elements or features that allow more motion or flexibility compared to rigid systems.Posterior cervical screw systems are intended to provide immobilization and stabilization of spinal segments in patients as an adjunct to fusion for acute and chronic instabilities of the cervical spine and/or craniocervical junction and/or cervicothoracic junction such as: (1) Traumatic spinal fractures and/or traumatic dislocations; (2) deformities; (3) instabilities; (4) failed previous fusions (
e.g., pseudarthrosis); (5) tumors; (6) inflammatory disorders; (7) spinal degeneration, including neck and/or arm pain of discogenic origin as confirmed by imaging studies (radiographs, CT, MRI); (8) degeneration of the facets with instability; and (9) reconstruction following decompression to treat radiculopathy and/or myelopathy. These systems are also intended to restore the integrity of the spinal column even in the absence of fusion for a limited time period in patients with advanced stage tumors involving the cervical spine in whom life expectancy is of insufficient duration to permit achievement of fusion.(b)
Classification. Class II (special controls). The special controls for posterior cervical screw systems are:(1) The design characteristics of the device, including engineering schematics, must ensure that the geometry and material composition are consistent with the intended use.
(2) Nonclinical performance testing must demonstrate the mechanical function and durability of the implant.
(3) Device components must be demonstrated to be biocompatible.
(4) Validation testing must demonstrate the cleanliness and sterility of, or the ability to clean and sterilize, the device components and device-specific instruments.
(5) Labeling must include the following:
(i) A clear description of the technological features of the device including identification of device materials and the principles of device operation;
(ii) Intended use and indications for use including levels of fixation;
(iii) Device specific warnings, precautions, and contraindications that include the following statements:
(A) “Precaution: Preoperative planning prior to implantation of posterior cervical screw systems should include review of cross-sectional imaging studies (
e.g., CT and/or MRI) to evaluate the patient's cervical anatomy including the transverse foramen, neurologic structures, and the course of the vertebral arteries. If any findings would compromise the placement of these screws, other surgical methods should be considered. In addition, use of intraoperative imaging should be considered to guide and/or verify device placement, as necessary.”(B) “Precaution: Use of posterior cervical pedicle screw fixation at the C3 through C6 spinal levels requires careful consideration and planning beyond that required for lateral mass screws placed at these spinal levels, given the proximity of the vertebral arteries and neurologic structures in relation to the cervical pedicles at these levels.”
(iv) Identification of magnetic resonance (MR) compatibility status;
(v) Cleaning and sterilization instructions for devices and instruments that are provided non-sterile to the end user, and;
(vi) Detailed instructions of each surgical step, including device removal.