The MOST System is intended to replace the proximal, distal and/or total femur, especially in cases that require extensive resection and restoration. The Hex I/M Stem is intended for cemented use only in these situations. Specific diagnostic indications for use of the MOST System include:

metastatic diseases (e.g., osteosarcomas, chondrosarcomas, giant cell tumors, bone tumors) . requiring extensive resection(s) and replacement(s) of the proximal and/or distal femur;
patient conditions of noninflammatory degenerative joint disease (NIDJD), e.g., avascular . necrosis, osteoarthritis, and inflammatory joint disease (IJD), e.g., rheumatoid arthritis, requiring extensive resection and replacement of the proximal and/or distal femur;
patients suffering from severe arthropathy of the hip and/or knee that does not respond to . any conservative therapy or better alternative surgical treatment;
. revision cases requiring extensive resection(s) and replacement(s) of the proximal, distal, or total femur.

Device Description

The MOST System is used for the replacement of the proximal, distal and/or total femur. Unlike primary hip and knee systems, this system is used where the amount of femoral resection and restoration required is extreme (e.g., in oncology cases). A total replacement is possible in those cases where no part of the femur can be salvaged.

The Hex I/M stems are hex shaped and designed to serve as the modular stem portion of either the proximal or distal femoral replacement. A taper feature at the end of the stem allows for connection to the mating modular component. The hex shape allows for rotational stability within the femoral canal once the stem is cemented into place. A ring of CSTi coating around the neck of the CoCr stem (ASTM F1537) allows for tissue attachment.

AI/ML Overview

This 510(k) summary (K973087) submitted by Sulzer Orthopedics Inc. for the MOST Hex Intramedullary (I/M) Stem does not contain information about acceptance criteria or a study proving that the device meets acceptance criteria.

The document is a premarket notification (510(k)) which is primarily focused on demonstrating substantial equivalence to existing legally marketed predicate devices, rather than establishing specific performance criteria through new studies.

Therefore, I cannot provide the requested information from the provided text.

Here's why the information is missing:

510(k) Premarket Notification: This regulatory pathway is typically used for lower-risk devices and relies on showing that a new device is "substantially equivalent" to a legally marketed predicate device. This often means demonstrating similar technological characteristics and indications for use, without necessarily requiring extensive new clinical or performance studies to define and meet specific acceptance criteria for a novel performance claim.
Focus on Substantial Equivalence: The document explicitly lists predicate devices and states "Substantial equivalence determination is based on comparison of the MOST Hex I/M Stem to the following legally marketed predicate competitive devices." This comparison is the core of the submission, not a new performance study against defined acceptance criteria.
Nature of the Device: The MOST Hex I/M Stem is a cemented stem for modular trauma or oncology applications in hip and knee joint replacement. For orthopedic implants like this, substantial equivalence often relies on material biocompatibility, mechanical testing (which might be referenced but isn't detailed as a 'study proving acceptance criteria' in this summary), and design similarity to already approved devices.

To answer your specific questions:

A table of acceptance criteria and the reported device performance: Not provided.
Sample sized used for the test set and the data provenance: Not provided.
Number of experts used to establish the ground truth for the test set and the qualifications of those experts: Not applicable, as there's no "test set" in the context of a performance study to establish ground truth.
Adjudication method 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. This device is a physical implant, not an AI-assisted diagnostic tool.
If a standalone (i.e. algorithm only without human-in-the-loop performance) was done: Not applicable. This is a physical implant.
The type of ground truth used: Not applicable.
The sample size for the training set: Not applicable.
How the ground truth for the training set was established: Not applicable.

Summary

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August 13, 1997

NOV 1 4 1997
K973087

In accordance with the Food and Drug Administration Interim Rule to implement provisions of the Safe Medical Devices Act of 1990 and in conformance with 21 CFR 807, this is to serve as a 510(k) summary for the Sulzer Orthopedics Inc. MOST (Modular Options for Severe Bone Loss and Trauma) System Hex I/M Stem.

Submitter:	Sulzer Orthopedics Inc.9900 Spectrum DriveAustin, TX 78717(512)432-9900
Contact Person:	Jacquelyn HughesManager, Regulatory Affairs
Classification Name:	21CFR 888.3353 - Hip joint metal/ceramic/polymer semi-constrained cemented or nonporous uncemented prosthesis21CFR 888.3510 - Knee joint femorotibial metal/polymerconstrained cemented prosthesis
Common/Usual Name:	Cemented stem for modular trauma or oncology applications
Trade/Proprietary Name:	MOST Hex Intramedullary (I/M) Stem

PRODUCT DESCRIPTION:

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SPECIFIC DIAGNOSTIC INDICATIONS:

metastatic diseases (e.g., osteosarcomas, chondrosarcomas, giant cell tumors, bone tumors) . requiring extensive resection(s) and replacement(s) of the proximal and/or distal femur;
patient conditions of noninflammatory degenerative joint disease (NIDJD), e.g., avascular . necrosis, osteoarthritis, and inflammatory joint disease (IJD), e.g., rheumatoid arthritis, requiring extensive resection and replacement of the proximal and/or distal femur;
patients suffering from severe arthropathy of the hip and/or knee that does not respond to . any conservative therapy or better alternative surgical treatment;
. revision cases requiring extensive resection(s) and replacement(s) of the proximal, distal, or total femur.

SUBSTANTIAL EQUIVALENCE:

Substantial equivalence determination is based on comparison of the MOST Hex I/M Stem to the following legally marketed predicate competitive devices:

파 Sulzer Orthopedics MOST System
트 Wright Medical Segmented Oncology System (S.O.S.)
비 Waldermar Link MP Reconstruction Prosthesis
체 Johnson & Johnson/Joint Medical Products Noiles Knee System
동 Howmedica Kinematic II Rotating Hinge Knee System

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Image /page/2/Picture/1 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo consists of a stylized image of an eagle with its wings spread, facing to the right. The words "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" are arranged in a circular pattern around the eagle image.

Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

Mitchell A. Dhority, RAC Senior Requlatory Affairs Specialist Sulzer Orthopedics, Inc. 9900 Spectrum Drive Austin, Texas 78717

NOV 1 4 1997

K973087 Re: MOST System Hex Intramedullary (I/M) Stem Trade Name: Requlatory Class: II Product Codes: JDI, LZO, and KRO Dated: August 14, 1997 Received: August 18, 1997

Dear Mr. Dhority:

We have reviewed your Section 510(k) notification of intent to market the device referenced above and we have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to 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). 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.

If your device is classified (see above) into either class II (Special Controls) or class III (Premarket Approval), it may be subject to such additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 895. ਸੇ substantially equivalent determination assumes compliance with the current Good Manufacturing Practice requirement, as set forth in the Quality System Requlation (QS) for Medical Devices: General regulation (21 CFR Part 820) and that, through periodic (QS) inspections, the Food and Drug Administration (FDA) will verify such assumptions. Failure to comply with the GMP requlation may result in requlatory action. In addition, FDA may publish further announcements concerning your device in the Federal Register. Please note: this response to your premarket notification submission does not affect any obligation you might have under sections 531 through 542 of the Act for devices under the Electronic Product Radiation Control provisions, or other Federal laws or requlations.

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Page 2 - Mitchell A. Dhority, RAC

This letter will allow you to begin marketing your device as described in your 510(k) premarket notification. The FDA finding of substantial equivalence of your device to a legally marketed predicate device results in a classification for your device and thus, permits your device to proceed to the market.

If you desire specific advice for your device on our labeling regulation (21 CFR Part 801 and additionally 809.10 for in vitro diagnostic devices), please contact the Office of Compliance at (301) 594-4659. Additionally, for questions on the promotion and advertising of your device, please contact the Office of Compliance at (301) 594-4639. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). Other general information on your responsibilities under the Act may be obtained from the Division of Small Manufacturers Assistance at its toll-free number (800) 638-2041 or (301) 443-6597 or at its internet address "http://www.fda.gov/cdrh/dsmamain.html".

Sincerely yours,

a M. Witten, Ph.D., M.D. Director Division of General and Restorative Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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K973087

510(k) Number (if known):

Device Name: Modular Options for Severe Bone Loss or Trauma (MOST) - Hex I/M Stem

Indications for Use:

metastatic diseases (e.g., osteosarcomas, chondrosarcomas, giant cell tumors, bose . tumors) requiring extensive resection(s) and replacement(s) of the proximal and/or distal femur;
patient conditions of noninflammatory degenerative joint disease (NIDJD), e.g., . avascular necrosis, osteoarthritis, and inflammatory joint disease (IID), e.g., rheumatoid arthritis, requiring extensive resection and replacement of the proximal and/or distal femur;
patients suffering from severe arthropathy of the hip and/or knee that does not respond . to any conservative therapy or better alternative surgical treatment;
revision cases requiring extensive resection(s) and replacement(s) of the proximal, . distal, or total femur.

(PLEASE DO NOT WRITE BELOW THIS LINE - CONTINUE ON ANOTHER PAGE IF NEEDED)

Concurrence of CDRH, Office of Device Evaluation (ODE)
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(Division Sign-Off)
Division of General Restorative Devices
510(k) Number	K973087

Prescription Use	X
OR
Over-the Counter Use

(Optional Format 1-2-96)

Regulation Number and Section

§ 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.