When intended for pedicle screw fixation from T1 -S1, the indications include immobilization and stabilization of spinal segments in skeletally mature patients as an adjunct to fusion in the treatment of the following acute and chronic instabilities or deformities of the thoracic, lumbar and sacral spine: degenerative disc disease (defined as discogenic back pain with degeneration of the disc confirmed by history and radiographic studies), degenerative spondylolisthesis with objective evidence of neurologic impairment, fracture, dislocation, deformities or curvatures (i.e. scoliosis, and/or lordosis), tumor and failed previous fusion.

As pedicle screw system placed between L3 and S1, the indications include Grade 3 or Grade 4 spondylolisthesis, when utilizing autologous bone graft, when affixed to the posterior lumbosacral spine, and intended to be removed after the solid fusion is established.

Device Description

The existing, commercially available Zimmer Spine PathFinder NXT® system consists of various screws, rods and associated accessories and is intended to provide temporary stabilization following surgery to fuse the spine. PathFinder NXT screws are polyaxial cannulated designs with a range of spinal rod lengths. PathFinder NXT allows the surgeon to place polyaxial pedicle screws either through an open or mini-open procedure. PathFinder NXT is designed to aid in the surgical correction of several types of spinal conditions and intended only to provide stabilization during the development of a solid fusion with a bone graft. These implants are intended to be removed after the development of a solid fusion mass. Additionally, the PathFinder NXT MIS System includes instrumentation to facilitate the implantation of the PathFinder NXT implants. The prior 510(k) for the PathFinder NXT MIS System included both Class I 510(k) exempt instrumentation and those instruments considered to the implant. PathFinder NXT was cleared via 510(k) #K100845 on 21 September 2010.

The Fixed Percutaneous Rod Holder accessory that is the subject of this premarket notification instrument is intended for use with the PathFinder NXT® Pedicle Screw System. This instrument is designed specifically for use with the rod implant component of the PathFinder NXT® Pedicle Screw System and, is considered an accessory to the implant. The Fixed Percutaneous Rod Holder holds and inserts a rod percutaneously through the extender sleeves which are positioned on the implanted screw head.

AI/ML Overview

This 510(k) summary describes a modification to an existing medical device, the PathFinder NXT® Minimally Invasive Pedicle Screw System, specifically an accessory called the Fixed Percutaneous Rod Holder. The submission focuses on demonstrating substantial equivalence to the predicate device, not on proving de novo clinical effectiveness of the entire system.

Here's an analysis of the provided information regarding acceptance criteria and the study that proves the device meets them:

1. Table of Acceptance Criteria and Reported Device Performance

Acceptance Criterion	Reported Device Performance	Comments
Reliability under anticipated clinical loads	"Design Verification Testing conducted, (1) reliability testing under anticipated clinical loads, ... demonstrated that the proposed device is substantially equivalent to the predicate device."	No specific quantitative metrics or thresholds for "reliability" are provided beyond the statement of substantial equivalence.
Fatigue strength under aggressive use simulations (beyond foreseeable misuse)	"...and (2) aggressive use simulations to test the fatigue strength when subjected to excessive loading beyond foreseeable misuse to determine survivability and extent of impact on intended use (function), demonstrated that the proposed device is substantially equivalent to the predicate device."	No specific quantitative metrics or thresholds for "fatigue strength" or "survivability" are provided beyond the statement of substantial equivalence.
Material composition	"are both manufactured from the same material (-17-4PH Stainless Steel)" and "the steel utilized for the proposed and unmodified instrument meet the ASTM A-564 'Standard Specification for Hot-Rolled and Cold-Finished Age-Hardening Stainless Steel Bars and Shapes'."	This is a direct comparison to the predicate and a conformity to a recognized standard.
Cleaning and Sterilization	"are cleaned and sterilized in the same way with the same parameters"	This is a direct comparison to the predicate.
General form and design	"similar designs" and "similar to the predicate version of the instrument in general form"	This is a qualitative comparison to the predicate.
Intended Use	"have the same intended use"	This is a direct comparison to the predicate.

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

This submission does not describe a clinical study with a "test set" in the traditional sense of patient data. The "tests" performed were engineering design verification tests on the device itself. Therefore, the concepts of "sample size for the test set" and "data provenance (e.g., country of origin of the data, retrospective or prospective)" are not applicable to this type of submission.

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

There were no human experts used to establish ground truth for a test set of patient data, as this was a device modification and engineering verification testing. The "ground truth" for the performance was established by the physical testing against engineering specifications and comparison to the predicate device. Therefore, this information is not applicable.

4. Adjudication Method for the Test Set

As there was no clinical test set requiring human interpretation or labeling, an adjudication method is not applicable. The "adjudication" in this context would be the internal engineering and regulatory review process by Zimmer Spine, Inc. and ultimately the FDA.

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

This submission does not involve Artificial Intelligence (AI) or reader interpretation of images. It is for a physical medical device (pedicle screw system accessory). Therefore, an MRMC comparative effectiveness study is not applicable.

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

This is a physical medical device, not an algorithm or AI system. Therefore, a standalone algorithm performance study is not applicable.

7. The Type of Ground Truth Used

For this device modification, the "ground truth" was established by:

Engineering Specifications: The design verification tests measured physical properties and performance against defined engineering requirements and tolerances.
Predicate Device Performance: The primary ground truth for substantial equivalence was the established performance and safety profile of the legally marketed predicate device (PathFinder NXT® Minimally Invasive Pedicle Screw System, #K100845). The modified accessory was deemed equivalent if it performed at least as well as the predicate under specified conditions and did not introduce new safety or effectiveness concerns.
Industry Standards: Compliance with ASTM A-564 for material specification.

8. The Sample Size for the Training Set

There was no "training set" in the context of machine learning or AI. The design and manufacturing process for a physical device doesn't involve a training set. If interpreted in a broader sense as development and testing, the "samples" would be the prototype devices and test articles subjected to the design verification tests. The exact number of units tested is not specified in the summary but would be detailed in the full design verification report.

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

As there was no "training set" in the AI sense, this question is not applicable. If referring to the development process of the device itself, the design "ground truth" was established through engineering design processes, material selection based on established standards, and performance goals derived from clinical needs and the performance of the predicate device.

Summary

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K121671
page 1 of 3

JUL 1 8 2012

Image /page/0/Picture/2 description: The image shows the logo for Zimmer Spine. The logo consists of a circle with a stylized "Z" inside it, above the word "zimmer" in a bold, sans-serif font. Below "zimmer" is the word "spine" in a smaller, sans-serif font.

510(K) SUMMARY OF SAFETY AND EFFECTIVENESS

SUBMITTER:

Zimmer Spine, Inc.

ESTABLISHMENT REGISTRATION NUMBER:

CONTACT PERSON:

DATE:

TRADE NAME:

COMMON NAME:

Classification Name and Reference:

1649384

David Padgett, RAC (US) Project Manager Regulatory Affairs Telephone: (512) 533-1998 Fax: (512) 219-5463

10 July 2012

PathFinder NXT ® Minimally Invasive Pedicle Screw System

Pedicle Screw Spinal System

Pedicle Screw Spinal System 21 CFR & 888.3070, NKB

DEVICE DESCRIPTION:

Zimmer Spine, Inc. PathFinder NXT Pedicle Screw System 510(k) Summary pg. 1

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specifically for use with the rod implant component of the PathFinder NXT® Pedicle Screw System and, is considered an accessory to the implant. The Fixed Percutaneous Rod Holder holds and inserts a rod percutaneously through the extender sleeves which are positioned on the implanted screw head.

INDICATIONS for Use:

Predicate Device:

Zimmer Spine, Inc. PathFinder NXT® Minimally Invasive Pedicle Screw System, #K100845

Device Technological Characteristics and Comparison to Predicate Device(s):

Zimmer Spine Inc. has submitted documentation demonstrating the substantial equivalence of the modified PathFinder NXT instrument to the original version of the device.

The unmodified and modified versions of the Zimmer Spine PathFinder NXT® System differ only in the design of the Fixed Percutaneous Rod Holder accessorv. The unmodified versions of the instrument and the proposed version have the same intended use, operate on the same technological principles, are both manufactured from the same material (-17-4PH Stainless Steel), are cleaned and sterilized in the same way with the same parameters, and have similar designs. In addition, the steel utilized for the proposed and unmodified instrument meet the ASTM A-564 "Standard Specification for Hot-Rolled and Cold-Finished Age-Hardening Stainless Steel Bars and Shapes".

PERFORMANCE DATA:

Design Verification Testing conducted, (1) reliability testing under anticipated clinical loads, and (2) aggressive use simulations to test the fatigue strength when subjected to excessive loading beyond foreseeable misuse to determine survivability and extent of impact on intended use (function), demonstrated that the proposed device is substantially equivalent to the predicate device.

Zimmer Spine, Inc. PathFinder NXT Pedicle Screw System 510(k) Summary pg. 2

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Substantial Equivalence:

Zimmer Spine Inc. has submitted documentation demonstrating the substantial equivalence of the modified and unmodified versions of the PathFinder NXT® System. The proposed Fixed Percutaneous Rod Holder instrument is similar to the predicate version of the instrument in general form, materials, sterilization and cleaning, and intended use. As demonstrated by supporting tests and descriptions, this design modification does not present new issues of safety or effectiveness.

Zimmer Spine, Inc. PathFinder NXT Pedicle Screw System 510(k) Summary pg. 3

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DEPARTMENT OF HEALTH & HUMAN SERVICES

Public Health Service

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

Zimmer Spine, Incorporated % Mr. David Padgett Project Manager, Regulatory Affairs 5301 Riata Park Court, Building F Austin, Texas 78727

JUL 18 2012

Re: K121671

Trade/Device Name: Pathfinder NXT ® Minimally Invasive Pedicle Screw System Regulation Number: 21 CFR 888.3070 Regulation Name: Pedicle screw spinal system Regulatory Class: Class III Product Code: NKB, MNH, MNI Dated: June 05, 2012 Received: June 06, 2012

Dear Mr. Padgett:

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, 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

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Page 2 - Mr. David Padgett

CFR Part 807); labeling (21 CFR Part 801); medical device reporting (reporting of medical device-related adverse events) (21 CFR 803); good manufacturing practice requirements as set 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 go to http://www.fda.gov/AboutFDA/CentersOffices/CDRH/CDRHOffices/ucm115809.htm for the Center for Devices and Radiological Health's (CDRH's) Office of Compliance. 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 Small Manufacturers, International and Consumer Assistance at its toll-free number (800) 638-2041 or (301) 796-7100 or at its Internet address

http://www.fda.gov/MedicalDevices/Resourcesfor You/Industry/default.htm.

Sincerely yours,

Erine L. Keith

-Mark N. Melkerson Director Division of Surgical, Orthopedic and Restorative Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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Indications for Use

510(k) Number (if known):

Device Name: PathFinder NXT ® Minimally Invasive Pedicle Screw System

Indications for Use:

Prescription Use X (Part 21 CFR 801 Subpart D) AND/OR

Over-The-Counter Use (21 CFR 807 Subpart C).

(Please do not write below this line - Continue on another page if needed)

Concurrence of CDRH, Office of Device Evaluation (ODE)

(Diysion Sign-Off) Diffision of Surgical, Orthopedic, and Restorative Devices

K121671

510(k) Number.

Regulation Number and Section

§ 888.3070 Thoracolumbosacral pedicle screw system.

(a)
Identification. (1) Rigid pedicle screw systems are comprised of multiple components, made from a variety of materials that allow the surgeon to build an implant system to fit the patient's anatomical and physiological requirements. Such a spinal implant assembly consists of a combination of screws, longitudinal members (e.g., plates, rods including dual diameter rods, plate/rod combinations), transverse or cross connectors, and interconnection mechanisms (e.g., rod-to-rod connectors, offset connectors).(2) Semi-rigid systems are defined as systems that contain one or more of the following features (including but not limited to): Non-uniform longitudinal elements, or features that allow more motion or flexibility compared to rigid systems.
(b)
Classification. (1) Class II (special controls), when intended to provide immobilization and stabilization of spinal segments in skeletally mature patients as an adjunct to fusion in the treatment of the following acute and chronic instabilities or deformities of the thoracic, lumbar, and sacral spine: severe spondylolisthesis (grades 3 and 4) of the L5-S1 vertebra; degenerative spondylolisthesis with objective evidence of neurologic impairment; fracture; dislocation; scoliosis; kyphosis; spinal tumor; and failed previous fusion (pseudarthrosis). These pedicle screw spinal systems must comply with the following special controls:(i) Compliance with material standards;
(ii) Compliance with mechanical testing standards;
(iii) Compliance with biocompatibility standards; and
(iv) Labeling that contains these two statements in addition to other appropriate labeling information:
“Warning: The safety and effectiveness of pedicle screw spinal systems have been established only for spinal conditions with significant mechanical instability or deformity requiring fusion with instrumentation. These conditions are significant mechanical instability or deformity of the thoracic, lumbar, and sacral spine secondary to severe spondylolisthesis (grades 3 and 4) of the L5-S1 vertebra, degenerative spondylolisthesis with objective evidence of neurologic impairment, fracture, dislocation, scoliosis, kyphosis, spinal tumor, and failed previous fusion (pseudarthrosis). The safety and effectiveness of these devices for any other conditions are unknown.”
“Precaution: The implantation of pedicle screw spinal systems should be performed only by experienced spinal surgeons with specific training in the use of this pedicle screw spinal system because this is a technically demanding procedure presenting a risk of serious injury to the patient.”
(2) Class II (special controls), when a rigid pedicle screw system is intended to provide immobilization and stabilization of spinal segments in the thoracic, lumbar, and sacral spine as an adjunct to fusion in the treatment of degenerative disc disease and spondylolisthesis other than either severe spondylolisthesis (grades 3 and 4) at L5-S1 or degenerative spondylolisthesis with objective evidence of neurologic impairment. These pedicle screw systems must comply with the following special controls:
(i) The design characteristics of the device, including engineering schematics, must ensure that the geometry and material composition are consistent with the intended use.
(ii) Non-clinical performance testing must demonstrate the mechanical function and durability of the implant.
(iii) Device components must be demonstrated to be biocompatible.
(iv) Validation testing must demonstrate the cleanliness and sterility of, or the ability to clean and sterilize, the device components and device-specific instruments.
(v) Labeling must include the following:
(A) A clear description of the technological features of the device including identification of device materials and the principles of device operation;
(B) Intended use and indications for use, including levels of fixation;
(C) Identification of magnetic resonance (MR) compatibility status;
(D) Cleaning and sterilization instructions for devices and instruments that are provided non-sterile to the end user; and
(E) Detailed instructions of each surgical step, including device removal.
(3) Class II (special controls), when a semi-rigid system is intended to provide immobilization and stabilization of spinal segments in the thoracic, lumbar, and sacral spine as an adjunct to fusion for any indication. In addition to complying with the special controls in paragraphs (b)(2)(i) through (v) of this section, these pedicle screw systems must comply with the following special controls:
(i) Demonstration that clinical performance characteristics of the device support the intended use of the product, including assessment of fusion compared to a clinically acceptable fusion rate.
(ii) Semi-rigid systems marketed prior to the effective date of this reclassification must submit an amendment to their previously cleared premarket notification (510(k)) demonstrating compliance with the special controls in paragraphs (b)(2)(i) through (v) and paragraph (b)(3)(i) of this section.