Disposable cement spacer molds are indicated for use to mold a temporary total knee replacement (TKR) for skeletally mature patients undergoing a two-stage procedure due to a septic process. The molded temporary knee prosthesis is indicated for an implantation period of 180 days or less. Because of inherent mechanical limitations of the device material (gentamicin/polymethylmethacrylate) and mobility limitations, the molded temporary prosthesis is only indicated for patients who will consistently use traditional mobility assist devices (e.g. crutches, walkers) throughout the implant period.

Device Description

The femoral cement spacer molds are offered in four sizes (60mm, 65mm, 70mm & 75mm). The tibial cement spacer molds are offered in four sizes (65mm, 70mm, 75mm & 80mm). The disposable cement spacer molds are not implanted. The molds are filled with polymethylmethacrylate/gentamicin bone cement, or equivalent, either by injecting with a dispenser/gun, or by pouring the prepared cement into the mold. After the cement hardens, the temporary knee prosthesis components are removed from the mold and placed into the joint space. The temporary knee prosthesis remains in place until the second stage of the two-stage procedure is performed to implant a conventional knee joint prosthesis.

AI/ML Overview

The provided 510(k) summary for the "Disposable Cement Spacer Molds for Temporary Knee Prosthesis" does not describe a study that includes acceptance criteria and reported device performance in the typical sense of a diagnostic or AI-powered device.

This device is a Class II surgical tool (mold), not a diagnostic or AI-driven system, and therefore its regulatory submission focuses on demonstrating substantial equivalence to a predicate device through non-clinical testing, rather than clinical efficacy thresholds.

However, I can extract the relevant information concerning the non-clinical testing performed and how it demonstrates "performance" relative to its predicate.

Here's the breakdown based on the information provided:

1. Table of Acceptance Criteria and Reported Device Performance

Given that this is a surgical mold and not a diagnostic device, the "acceptance criteria" are implied by demonstrating equivalence to a predicate device's characteristics.

Acceptance Criterion (Implied)	Reported Device Performance
Equivalent Strength	Demonstrated equivalent strength to the predicate device in a knee joint simulator study.
Equivalent Wear Characteristics	Demonstrated equivalent wear characteristics to the predicate device in a knee joint simulator study.
Equivalent Gentamicin Release	Elution testing demonstrated equivalent gentamicin release compared to the predicate device.

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

Sample Size: Not explicitly stated as a number of devices tested. The "knee joint simulator" likely involved a set number of test articles (molded prostheses) from both the applicant's device and the predicate. The text states "knee joint simulator... utilizing both the temporary knee prosthesis made with the Biomet disposable cement spacer mold and the Exactech Spacer-K device."
Data Provenance: This was non-clinical testing (bench testing) performed under controlled laboratory conditions, not on patient data. Therefore, there's no country of origin or retrospective/prospective designation in the typical clinical sense.

3. Number of Experts Used to Establish Ground Truth and Qualifications

Not applicable. Ground truth for a surgical mold is not established by expert clinical consensus. Its effectiveness is based on its physical properties and performance in non-clinical settings, as well as its ability to produce a product (the temporary prosthesis) that mimics a legally marketed equivalent.

4. Adjudication Method for the Test Set

Not applicable, as this was not a clinical study involving human judgment or diagnostic outcomes.

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

Not applicable. This device is a mold for producing temporary prostheses, not a diagnostic tool requiring human interpretation or AI assistance.

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

Not applicable. This is a physical medical device (mold), not an algorithm or AI system.

7. Type of Ground Truth Used

The "ground truth" (or basis for comparison) was the performance of the legally marketed predicate device (Exactech Spacer-K temporary knee prosthesis) in a controlled non-clinical setting. The Biomet mold was deemed acceptable if the temporary prostheses it produced demonstrated equivalent strength, wear characteristics, and gentamicin release to those produced by the predicate device.

8. Sample Size for the Training Set

Not applicable. This is a physical medical device, not a machine learning model requiring a training set.

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

Not applicable, as there is no training set for this type of device.

Summary

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JUL 1 9 2005

510(k) Summary

Applicant/Sponsor: Biomet Manufacturing Corp. P.O. Box 587 Warsaw, Indiana 46581-0587

Contact Person: Lonnie Witham Telephone: (574) 267-6639 Fax: (574) 372-1683
Proprietary Name: Disposable Cement Spacer Molds for Temporary Knee Prosthesis

Common Name: Bone Cement Spacer Mold

Classification Name: Knee joint, patellofemorotibial, polymer/metal/polymer, semiconstrained, cemented prosthesis (21 CFR 888.3560)

Legally Marketed Devices To Which Substantial Equivalence Is Claimed: Eogany Marriousary Knee Prosthesis cleared by the FDA in K032522 and marketed by Exactech, Inc., Gainesville, FL.

Device Description: The femoral cement spacer molds are offered in four sizes (60mm, 65mm, 70mm & 75mm). The tibial cement spacer molds are offered in four sizes (65mm, 70mm, 75mm & 80mm). The disposable cement spacer molds are not implanted. (Osmith, Tonin, Tonin Conethylmethacrylate /gentamicin bone cement, or equivalent, either by injecting with a dispenser/gun, or by pouring the prepared cement into the mold. enther by mjocant hardens, the temporary knee prosthesis components are removed from Aner the ochlent and placed into the joint space. The temporary knee prosthesis remains in place the mores and played the second stage of the two-stage procedure is performed to implant a conventional knee joint prosthesis.

Intended Use: The intended use of the Biomet disposable cement spacer molds is to provide the surgeon with a means to mold a temporary knee prosthesis at the point of care that is substantially equivalent to the Exactech Spacer-k temporary knee prosthesis cleared in K032522. The temporary knee prosthesis made with the Biomet disposable cleared in R0325221. The same indication for use as the Exactech Spacer-k.

Indication for Use: Disposable cement spacer molds are indicated for use to mold a temporary total knee replacement (TKR) for skeletally mature patients undergoing a twotemporary total the replaceting process. The molded temporary knee prosthesis is indicated for an implantation period of 180 days or less. Because of inherent mechanical limitations of the device material (polymethylmethacrylate/gentamicin), the molded temporary prosthesis is only indicated for patients who will consistently use traditional mobility assist devices (e.g. crutches, walkers) throughout the implant period.

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Contraindications:

The temporary knee prosthesis made with the disposable cement spacer molds is contraindicated for the following situations:

ndreated is to 's condition is such that a two-stage arthroplasty procedure is . I he patient's contrasted immune response or other relevant systemic clinical conditions.
Bone loss precluding adequate support of the prosthesis. .
Lack of adequate competence (anatomical and functional) of peripheral . ligamentous apparatus and extensor mechanism.
The procedure is unjustified due to deficiencies in the patient's muscular, nervous . or vascular systems.
or vasural by title . fracture host bone.
Infection of the TKR cannot be confirmed. .
The infected TKR devices cannot be removed. .
The infecting pathogens are resistant to gentamicin. .
The patient is sensitive (allergic) to gentamicin, aminoglycosides or PMMA bone . cement.
A systemic or secondary remote infection is expected or confirmed. .
The patient does not have a TKR and the infection is secondary to trauma, septic . arthritis or other surgical procedures.
The patient does not have sufficient bone stock to allow insertion and fixation of . the prosthesis.
The patient has neuromuscular disorders that do not allow control of the knee . ioint.
Joins.
The patient's age, weight, or activity level would cause the surgeon to expect . early failure of the system.

Summary of Technologies: The bone cement molds (femoral and tibial) are sterile disposables made of medical grade silicone. The disposable cement spacer molds produce temporary knee prosthesis components that are composed of similar bone cement in similar sizes as the predicate.

Non-Clinical Testing: Comparative testing was performed utilizing a knee joint Nor. Onlined. 16 both the temporary knee prosthesis made with the Biomet disposable cement sumulator of oour the Exactech Spacer-K device. The temporary knee prostheses were spacer mbe equivalent in strength and wear characteristics. Elution testing demonstrated equivalent gentamicin release.

Clinical Testing: No clinical testing was performed.

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Image /page/2/Picture/1 description: The image shows the seal of the Department of Health and Human Services (HHS) of the United States. The seal features a stylized eagle with three stripes forming its wing, symbolizing health, services, and people. The text "DEPARTMENT OF HEALTH AND HUMAN SERVICES - USA" is arranged in a circular pattern around the eagle.

JUL 1 9 2005

Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

Mr. Lonnie Witham Biomet, Inc. 56 East Bell Drive Warsaw, Indiana 46581

Re: K050210

K030210
Trade/Device Name: Disposable Spacer Molds for Temporary Knee Prosthesis Regulation Number: 21 CFR 888.3560 Regulation Name: Knee joint patellofemorotibial polymer semi-constrained cemented prosthesis Regulatory Class: II Product Code: JWH Dated: June 30, 2005 Received: July 1, 2005

Dear Mr. Witham:

We have reviewed your Section 510(k) premarket notification of intent to market the device We have reviewed your Section 3 rots) premained is substantially equivalent (for the indications ferenced and nave decembined the are are are are are are and see marketed in interstate for use stated in the encrosule for tegally manaties provice Americal Device Ameral Read, Drug commerce prior to May 20, 1970, the encordance with the provisions of the Federal Food, Drug, devices that have been reciassince in accordance was a premarket approval application (PMA).
and Cosmetic Act (Act) that do not require approval of a premarket approval appli and Cosment Act (Act) that do not require special controls provisions of the Act. The You may, therefore, market the devices, boyer to the ments for annual registration, listing of general controls provisions of the rise, 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 if your device is classified (see above) into exist in the subs are of the device can
may be subject to such additional controls. Existing major regulations FDA may may be subject to such additional controller in the 21, Parts 800 to 898. In addition, FDA may be found in the Code of Pouchal Ing.
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 Please be advised that FDA 3 issualled of a backers of a backer requirements of the Act
that FDA has made a determination that your device complies with other requirements of that FDA has made a delorimiation administered by other Federal agencies. You must of any Federal statutes and regulations and admited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); good manufacturing practice requirements as set CPR Part 807), labening (21 CFR Part 820); and if applicable, the electronic forth in the quality systems (Sections 531-542 of the Act); 21 CFR 1000-1050.

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Page 2 - Mr. Lonnie Witham

This letter will allow you to begin marketing your device as described in your Section 510(k) I his letter will anow you to begin manieting your and equivalence of your device to a legally prematicate 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 If you desire specific advice for your aconce to the 0.000. Also, please mote the regulation entitled, a Colliact the Office of Compuner of the (21CFR Part 807.97). You may obtain Misolalling by reference to premail.com bilities under the Act from the Division of Small other general information on your response Assistance at its toll-free number (800) 638-2041 or Manufacturers, International and Ochess http://www.fda.gov/cdrh/dsma/dsmamain.html

Sincerely yours,

Muriam C. Provost

Miriam C. Provost, Ph.D Acting Director Division of General, Restorative and Neurological 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: Disposable Cement Spacer Molds for Temporary Knee Prosthesis

Indications For Use:

Indications For Use:
Disposable cement spacer mold a temporary total kneereduced van a sentic process. The molded Disposable cement spacer molds are nutleated to as wonedure due to a septic process. The molded for skeletally mature patients undergolity a two-stage prodot of 180 days of inherent
temporary knee prosthesis is indicated for an implantation period of 180 days of inheren temporary knee prosthesis is mulce material (gentamicin/polyombility), the molded
mechanical limitations of the device material (gentamicin/polyments), is a si mechanical limitations of the device material (gentainensportions) and mobility assist devices (e.g. crutches, walkers) throughout the implant period.

Contraindications:

Contraindications:
The temporary knee prosthesis made with the disposable cement spacer molds is contraindicated for the following situations:

ng situations:
The patient's condition is such that a two-stage arthroplasty procedure is contraindicated due to . I he patient's condition is sack and systemic clinical conditions.
Bone loss precluding adequate support of the prosthesis.
. Bone loss preciuding adequate support of the problemal) of peripheral ligamentous apparatus �
and extensor mechanism. The procedure is unjustified due to deficiencies in the patient's muscular, nervous or vascular . systems.
systems.
Poor bone quality (as in osteoporosis) could cause the prosthesis to migrate or to fracture host . bone.
Infection of the TKR cannot be confirmed. ●
The infected TKR devices cannot be removed. .
The infecting pathogens are resistant to gentamicin. .
The intecting patiogens are resiblant to grain.
The patient is sensitive (allergic) to gentamicin, aminoglycosides or PMMA bone cement. .
I he pation is sensitere (remote infection is expected or confirmed.
. A systemic of secondary renote infection is oxposited or collary to trauma, septic arthritis or other . surgical procedures.
surgical procedures.
The patient does not have sufficient bone stock to allow insertion and fixation of the prosthesis.
. The patient has neuromuscular disorders that do not allow control of the knee joint.
. I he patient's age, weight, or activity level would cause the surgeon to expect early failure of the . system.

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

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

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

Concurrence of CDRH, Office of Device Evaluation (ODE)

8050210

iriam C. Provost

(Division Sign-Off) Division of General, Restorative and Neurological Devices

Page 1 of 1

510(k) Number --

Regulation Number and Section

§ 888.3560 Knee joint patellofemorotibial polymer/metal/polymer semi-constrained cemented prosthesis.

(a)
Identification. A knee joint patellofemorotibial polymer/metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace a knee 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 includes prostheses that have a femoral component made of alloys, such as cobalt-chromium-molybdenum, and a tibial component or components and a retropatellar resurfacing component made of ultra-high molecular weight polyethylene. This generic type of device is limited to those prostheses intended for use with bone cement (§ 888.3027).(b)
Classification. Class II.