The Apex K2™ Hip Stem is intended for use as the femoral component of a primary or revision total hip replacement. This femoral hip stem is intended for uncemented fixation and single use implantation. This prosthesis may be used for the following conditions, as appropriate:

. Non-inflammatory degenerative joint disease, including osteoarthritis and avascular necrosis;
. Rheumatoid arthritis;
Correction of functional deformity: .
Congenital dislocation; .
Revision procedures where other treatments or devices have failed; .
. Femoral neck and trochanteric fractures of the proximal femur.

Device Description

The Apex K2™ Hip Stem consists of a rectangular tapered stem, modular necks that connect to the proximal end of the stem, and the modular heads that connect to the tapered trunion on the neck. This configuration allows the user to choose a combination of stem, neck, and head components to appropriately fit the anatomy of the patient. The various neck sizes allow for several length and lateral offset options for a given stem size. Several offset options are also available for the heads to allow further refinement of the lengths and offsets. The Apex K2 Hip Stem may be used in conjunction with the Apex Modular Acetabular Cup (K031110) for total hip arthroplasty.
The femoral stems (and modular necks) are manufactured from titanium alloy. The Apex K2 stems can be used with the cobalt chromium alloy heads and the alumina ceramic heads that are part of the Apex Modular hip system. The proximal metaphyseal region of each size femoral stem is circumferentially coated with unalloyed titanium applied by plasma spray, the same coating method used by the predicate Apex Modular hip stem. As in the predicate Apex Modular stem, the alignment pin in the stem is manufactured from wrought cobalt chromium alloy.

AI/ML Overview

The provided text describes a 510(k) premarket notification for the Apex K2™ Hip Stem, seeking to demonstrate substantial equivalence to predicate devices, rather than a study proving the device meets specific acceptance criteria with performance metrics. The information focuses on device description, intended use, and comparison to predicate devices. As such, the requested details regarding acceptance criteria, study design, sample sizes, expert ground truth, adjudication methods, MRMC studies, standalone performance, and training set information are not available in the provided text.

Specifically:

Acceptance Criteria and Reported Device Performance: This information is not explicitly stated in terms of quantitative performance metrics for the Apex K2™ Hip Stem. The document focuses on demonstrating substantial equivalence to predicate devices based on design, materials, and intended use.
Sample size used for the test set and data provenance: No test set is described. The document pertains to a 510(k) submission, not a clinical study on the Apex K2™ Hip Stem with a specific test set.
Number of experts used to establish the ground truth for the test set and the qualifications of those experts: Not applicable, as no clinical test set with corresponding ground truth is detailed.
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 document is for a hip stem, not an AI or diagnostic imaging device.
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.
The sample size for the training set: Not applicable.
How the ground truth for the training set was established: Not applicable.

The document indicates that "Performance testing of the modularity was completed as per the relevant FDA guidance documents" and "Performance testing of the plasma sprayed unalloyed (CP) titanium coating was completed as per the relevant FDA guidance documents." This suggests engineering and material testing were performed, but the specific acceptance criteria and results of these tests are not detailed in the provided text. The submission is primarily about establishing substantial equivalence through comparison of features and characteristics to existing predicate devices.

Summary

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DEC 21 2004

July 19, 2004

			Apex K2™ Hip Stem
--	--	--	-------------------

Apex Surgical, LLC

Lakeville, MA 02347

12 Harding Street

Suite 202

Contact: Edward J. Cheal, Ph.D. Managing Director (508) 947-6500 (voice) (208) 248-8227 (fax)

2. Device Name

Submitter:

Proprietary Name: Apex K2™ Hip Stem Common Name: Hip prosthesis, uncemented Classification Name: Hip joint metal/polymer/metal semi-constrained porouscoated uncemented prosthesis Requlatory Class: Class II per 21 CFR §888.3358

3. Intended Use

. Non-inflammatory degenerative joint disease, including osteoarthritis and avascular necrosis;
. Rheumatoid arthritis;
Correction of functional deformity: .
Congenital dislocation; .
Revision procedures where other treatments or devices have failed; .
. Femoral neck and trochanteric fractures of the proximal femur.

4. Device Description

The femoral stems (and modular necks) are manufactured from titanium alloy. The Apex K2 stems can be used with the cobalt chromium alloy heads and the alumina ceramic heads that are part of the Apex Modular hip system. The proximal metaphyseal region of each size femoral stem is circumferentially coated with unalloyed titanium applied by

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K041950 (pg 2 of 2)

plasma spray, the same coating method used by the predicate Apex Modular hip stem. As in the predicate Apex Modular stem, the alignment pin in the stem is manufactured from wrought cobalt chromium alloy.

5. Predicate Device Comparison

Substantial equivalence is claimed to the SL-Plus® and SLR-Plus® hip stems distributed by Plus Orthopedics (K001942 and K021178), and the Apex Modular ™ Hip System (K000788). The table below compares the features and characteristics of the Apex Modular™ Hip Stem to these predicate devices:

	Apex K2™ HipStem	ApexModular™(K000788)	SL-Plus® andSLR-Plus®(K001942, K021178)
INTENDED USE
Primary and revision hipreplacement, non-cemented use	Yes	Yes	Yes
DESIGN
Porous coated	Yes - plasmaspray	Yes - plasmaspray	No
Proximal coating (only)	Yes	Yes	NA
Modular head	Yes	Yes	Yes
Surface finish	Al-oxide grit blast	Ti grit blast	Al-oxide grit blast
Modular neck	Yes	Yes	No
Tapered stem	Yes	No	Yes
Distal Cross-sectionalshape	Rectangular	Round	Rectangular
Distal slot(s)	No	Yes	No
Distal flutes	No	Yes - ridges	No
Proximal steps	No	Yes	No
MATERIALS
Titanium alloy (Ti6Al4V)stem and neck	Yes	Yes	Yes
Cobalt chromium oralumina ceramic heads	Yes (both)	Yes (both)	Yes (both)
Titanium porous coating	Yes - unalloyed	Yes - unalloyed	No

The Apex K2 stem geometry is similar to the SL-Plus® and SLR-Plus® distributed by Plus Orthopedics. The most significant difference between these devices is that the Apex K2 stem employs modular necks (and heads) similar to the Apex Modular™ hip system, whereas the SL-Plus and SLR-Plus stems have modular heads (only). Performance testing of the modularity was completed as per the relevant FDA guidance documents. Performance testing of the plasma sprayed unalloyed (CP) titanium coating was completed as per the relevant FDA guidance documents by APS Materials, Inc. and Bio-Coat, Inc.

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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 circular seal with the text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" arranged around the perimeter. Inside the circle is a stylized symbol resembling an abstract bird or human figure, composed of three curved lines.

Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

DEC 2 1 2004

Edward J. Cheal, Ph.D. Managing Director Apex Surgical, LLC 12 Harding Street. Suite 202 Lakeville, Massachusetts 02347

Re: K041950 Trade Name: Apex K2"Hip Stem Regulation Number: 21 CFR 888.3358 Regulation Name: Hip joint metal/polymer/metal semi-constrained porous-coated uncemented prosthesis. Regulatory Class: II Product Code: LPH Dated: July 19, 2004 Received: July 20, 2004

Dear Dr. Cheal:

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. Iisting 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 (PMA), 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 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); 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.

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Page 2 - Edward J. Cheal, Ph.D.

This letter will allow you to begin marketing your device as described in your Section 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), please contact the Office of Compliance at (240) 276-0120. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR Part 807.97). 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) 443-6597 or at its Internet address http://www.fda.gov/cdrh/dsma/dsmamain.html

Sincerely yours,

Wlankoth

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

Enclosure

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Koria50

Indications for Use

510(k) Number (if known): K041950

Device Name: Apex K2™ Hip Stem

Indications For Use:

The Apex K2™ Hip Stem is intended for use as the femoral component of a primary total hip replacement. This femoral hip stem is intended for uncemented fixation and single use implantation. This prosthesis may be used for the following conditions, as appropriate:

Non-inflammatory degenerative joint disease, including osteoarthritis and . avascular necrosis;
Rheumatoid arthritis; .
Correction of functional deformity; .
Congenital dislocation; .
Revision procedures where other treatments or devices have failed; .
Femoral neck and trochanteric fractures of the proximal femur. .

Prescription Use	X
------------------	---

AND/OR

(Per 21 CFR 801 Subpart D)

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

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

Concur ce of CDRH, Office of Device Evaluation (ODE)

ing with
ford to

Division

1949 22 22 22 47 24

Neurological Devices

510(k) Number K041950

Page 1 of ____________________________________________________________________________________________________________________________________________________________________

Regulation Number and Section

§ 888.3358 Hip joint metal/polymer/metal semi-constrained porous-coated uncemented prosthesis.

(a)
Identification. A hip joint metal/polymer/metal semi-constrained porous-coated uncemented prosthesis is a device intended to be implanted to replace a hip joint. The device limits translation and rotation in one or more planes via the geometry of its articulating surfaces. It has no linkage across the joint. This generic type of device has a femoral component made of a cobalt-chromium-molybdenum (Co-Cr-Mo) alloy or a titanium-aluminum-vanadium (Ti-6Al-4V) alloy and an acetabular component composed of an ultra-high molecular weight polyethylene articulating bearing surface fixed in a metal shell made of Co-Cr-Mo or Ti-6Al-4V. The femoral stem and acetabular shell have a porous coating made of, in the case of Co-Cr-Mo substrates, beads of the same alloy, and in the case of Ti-6Al-4V substrates, fibers of commercially pure titanium or Ti-6Al-4V alloy. The porous coating has a volume porosity between 30 and 70 percent, an average pore size between 100 and 1,000 microns, interconnecting porosity, and a porous coating thickness between 500 and 1,500 microns. The generic type of device has a design to achieve biological fixation to bone without the use of bone cement.(b)
Classification. Class II.