The STS screw is indicated for use in treatment of the hyperpronated foot and stabilization of the subtalar joint. It is designed to block the posterior and inferior displacement of the allowing normal subtalar joint motion while blocking excessive pronation and the resulting sequela.

Severely pronated foot;
Walking intemperance;
Calcaneal stance position greater than 50;
Manually correctable deformities;
Mid-tarsal breech (arch pain);
Forefoot varus greater than 10°.

Device Description

The Subtalar Spacer System (STS) a threaded implant designed to be inserted between the posterior and middle facets of the subtalar joint. It is manufactured from Ti-6A1-4V per ASTM F136 and is available in 6 sizes. STS has a center cannula design for use with a guide wire to facilitate proper placement.

AI/ML Overview

This FDA 510(k) summary (K150213) is for a medical device called the Subtalar Spacer System (STS). Here's an analysis of the acceptance criteria and study information provided:

1. Table of Acceptance Criteria and Reported Device Performance

This document does not present explicit acceptance criteria in the typical format of a table with quantitative metrics (e.g., sensitivity, specificity, accuracy, or specific mechanical performance thresholds).

Instead, the submission relies on demonstrating substantial equivalence to predicate devices. This means the primary "acceptance criterion" is that the new device is as safe and effective as a legally marketed predicate device. The performance is assessed by comparing the new device's technological characteristics and showing no new questions of safety or effectiveness are raised.

Acceptance Criterion (Implicit)	Reported Device Performance
Safety and Effectiveness (comparable to predicate device)	"The safety and effectiveness of the STS implant is adequately supported within this premarket notification." "The design characteristics of the subject devices do not raise any new types of questions of safety or effectiveness." "From the evidence submitted in this 510(k), the subject devices can be expected to perform at least as well as the predicate systems and are substantially equivalent."
Identical Indications for Use	The STS implant and the predicate Ortho-Pro STS Screw have "identical indications."
Same Overall Features	The STS implant and the predicate Ortho-Pro STS Screw have the "same overall features."
Identical Material	The STS implant and the predicate Ortho-Pro STS Screw are "identical in material" (Ti-6Al-4V per ASTM F136).
Technological Characteristics Comparison (Minor Differences)	The differences identified (Total length and Pitch) are presented as not impacting substantial equivalence. The document states, "Testing rationales were provided to support the substantial equivalence of the subject device and show that no new worst-case devices are introduced in this system." This implies that the differences in length and pitch were evaluated and deemed not to introduce new risks or affect performance adversely compared to the predicate.

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

Sample Size for Test Set: Not applicable in the context of this 510(k) submission. This submission does not detail a "test set" in the sense of a clinical trial or a performance study with a specific number of cases/patients. Instead, it relies on non-clinical (bench) testing and comparison to predicate devices.
Data Provenance: The data provenance is primarily from non-clinical evidence (bench testing and technical characteristic analysis) supporting the comparison to predicate devices. No human data (clinical or retrospective/prospective study) is described.

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

Not applicable. As no clinical "test set" with ground truth determination is described, there's no mention of experts for this purpose.

4. Adjudication Method for the Test Set

Not applicable. No "test set" requiring adjudication is described.

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done

No. This document explicitly states "N/A" under "Substantial Equivalence - Clinical Evidence," indicating that a clinical study, including an MRMC study, was not performed or deemed necessary for this 510(k) submission.

6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was done

Not applicable. This device is a physical implant (Subtalar Spacer System), not an algorithm or AI-driven system.

7. The Type of Ground Truth Used

Not applicable in the conventional sense of clinical ground truth (e.g., pathology, outcomes data). For a 510(k) based on substantial equivalence, the "ground truth" is established through:

Predicate Device Performance: The safety and effectiveness profile of the legally marketed predicate devices.
Engineering/Bench Test Data: Non-clinical testing data to ensure mechanical integrity and comparable performance to the predicate, often against established standards (e.g., ASTM F136 for material).

8. The Sample Size for the Training Set

Not applicable. This device is a physical implant, not an AI/ML model that requires a training set.

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

Not applicable. No training set is involved.

Summary

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Public Health Service

Food and Drug Administration 10903 New Hampshire Avenue Document Control Center - WO66-G609 Silver Spring, MD 20993-0002

Wright Medical Technology, Incorporated Ms. Tara Conrad Regulatory Affair Specialist II 1023 Cherry Road Memphis, Tennessee 38117

May 8, 2015

Re: K150213

Trade/Device Name: Subtalar Spacer System (STS) Regulation Number: 21 CFR 888.3040 Regulation Name: Smooth or threaded metallic bone fixation fastener Regulatory Class: Class II Product Code: HWC Dated: January 21, 2015 Received: January 30, 2015

Dear Ms. Conrad:

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. The general controls provisions of the Act include requirements for annual registration. Isting 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 801); medical device reporting of medical device-related adverse events) (21 CFR 803); good manufacturing practice requirements as set

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Page 2 - Ms. Tara Conrad

forth in the quality systems (QS) regulation (21 CFR Part 820); and if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

If you desire specific advice for your device on our labeling regulation (21 CFR Part 801), please contact the Division of Industry and Consumer Education at its toll-free number (800) 638-2041 or (301) 796-7100 or at its Internet address

http://www.fda.gov/MedicalDevices/ResourcesforYou/Industry/default.htm. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR Part 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to

http://www.fda.gov/MedicalDevices/Safety/ReportaProblem/default.htm for the CDRH's Office of Surveillance and Biometrics/Division of Postmarket Surveillance.

You may obtain other general information on your responsibilities under the Act from the Division of Industry and Consumer Education at its toll-free number (800) 638-2041 or (301) 796-7100 or at its Internet address

http://www.fda.gov/MedicalDevices/ResourcesforYou/Industry/default.htm.

Sincerely yours,

Mark N. Melkerson -S

Mark N. Melkerson Director Division of Orthopedic Devices Office of Device Evaluation 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) K150213

Device Name

Subtalar Spacer System (STS)

Indications for Use (Describe)

· Severely pronated foot;
· Walking intemperance;
· Calcaneal stance position greater than 50;
· Manually correctable deformities;
· Mid-tarsal breech (arch pain);
· Forefoot varus greater than 10°.

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

X] Prescription Use (Part 21 CFR 801 Subpart D)

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

PLEASE DO NOT WRITE BELOW THIS LINE -- CONTINUE ON A SEPARATE PAGE IF NEEDED.

FOR FDA USE ONLY

Concurrence of Center for Devices and Radiological Health (CDRH) (Signature)

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K150213 (page 1/2)

Headquarters Whant Monical TA

023 Cherry Road mohis TN 3811

901867 997 wmt.com

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510(K) SUMMARY OF SAFETY AND EFFECTIVENESS

In accordance with the Food and Drug Administration Rule to implement provisions of the Safe Medical Devices Act of 1990 and in conformance with 21 CFR 807.92, this information serves as a Summary of Safety and Effectiveness for the use of the Subtalar Spacer System (STS).

	Submitted By:	Wright Medical Technology, Inc.1023 Cherry RoadMemphis, TN 38117
	Date:	May 13, 2015
	Contact Person:	Tara ConradRegulatory Affairs Specialist IIPhone: 901-867-4367 Fax: 901-867-4190
2.	Proprietary Name:	Subtalar Spacer System (STS)
	Common Name:	Smooth or threaded metallic bone fixation fastener
	Classification Name and Reference:	21 CFR 888.3040- Class II
	Device Product Code, Device Panel:	HWC- Orthopedic
3.	Predicate Device:	K032682-Ortho-Pro STS ScrewK070441-Metasurg Subtalar Implant

4. Device Description

Intended Use

ડ.

Indications for Use:

The STS implant is indicated for use in treatment of the hyperpronated foot and stabilization of the subtalar joint. It is designed to block the posterior and inferior displacement of the talus, thus allowing normal subtalar joint motion while blocking excessive pronation and the resulting sequela.

Severely pronated foot; .
. Walking intemperance;
o Calcaneal stance position greater than 50;
o Manually correctable deformities;

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Mid-tarsal breech (arch pain); .
Forefoot varus greater than 10°. .

6. Technological Characteristics Comparison

The STS implant and the legally marketed predicate Ortho-Pro STS Screw have identical indications, have the same overall features, and are identical in material. The two differences are:

1. Total length
1. Pitch

7. Substantial Equivalence- Non-Clinical Evidence

Testing rationales were provided to support the substantial equivalence of the subject device and show that no new worst-case devices are introduced in this system. The safety and effectiveness of the STS implant is adequately supported within this premarket notification. Through the analysis of technical characteristics the new devices are substantially equivalent to the predicate devices.

8. Substantial Equivalence- Clinical Evidence

N/A

9. Substantial Equivalence- Conclusions

The design characteristics of the subject devices do not raise any new types of questions of safety or effectiveness. From the evidence submitted in this 510(k), the subject devices can be expected to perform at least as well as the predicate systems and are substantially equivalent.

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Regulation Number and Section

§ 888.3040 Smooth or threaded metallic bone fixation fastener.

(a)
Identification. A smooth or threaded metallic bone fixation fastener is a device intended to be implanted that consists of a stiff wire segment or rod made of alloys, such as cobalt-chromium-molybdenum and stainless steel, and that may be smooth on the outside, fully or partially threaded, straight or U-shaped; and may be either blunt pointed, sharp pointed, or have a formed, slotted head on the end. It may be used for fixation of bone fractures, for bone reconstructions, as a guide pin for insertion of other implants, or it may be implanted through the skin so that a pulling force (traction) may be applied to the skeletal system.(b)
Classification. Class II.