HIGHLY CROSS-LINKED VITAMIN E UHMWPE TIBIAL INSERTS

K103223 · Encore Medical L.P. · OIY · Dec 21, 2010 · Orthopedic

Device Facts

• Record ID: K103223
• Device Name: HIGHLY CROSS-LINKED VITAMIN E UHMWPE TIBIAL INSERTS
• Applicant: Encore Medical L.P.
• Product Code: OIY · Orthopedic
• Decision Date: Dec 21, 2010
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 888.3560
• Device Class: Class 2
• Attributes: Therapeutic

Intended Use

DJO Surgical knee devices are intended for treatment of patients who are candidates for knee arthroplasty per the indications for use. While total knee replacements are not intended to withstand activity levels and loads of normal healthy bone, they are a means of restoring mobility and reducing pain for many patients.

Device Story

Highly Cross-Linked Vitamin E UHMWPE (HXL VEK) tibial insert; component of 3DKnee System. UHMWPE powder blended with alpha-tocopherol (Vitamin E), compression molded, machined, gamma-irradiated for cross-linking, and gas plasma sterilized. Used in total knee arthroplasty to restore joint mobility and reduce pain. Device provides improved wear resistance and oxidation stability compared to conventional compression molded (CM) UHMWPE. Implanted by orthopedic surgeons in clinical settings. Output is a mechanical bearing surface; clinical benefit is potential reduction in wear-related complications.

Clinical Evidence

No clinical data provided. Evidence consists of bench testing: accelerated aging (ASTM F2003), oxidation index (ASTM F2102), Izod impact (ASTM D256), tensile testing (ASTM D638), small punch testing (ASTM F2183), posterior peel-out testing, and knee simulator wear testing (ISO 14243-1). Biocompatibility evaluated via intramuscular rabbit implant study (ISO 10993).

Technological Characteristics

Material: UHMWPE blended with alpha-tocopherol (Vitamin E). Manufacturing: Compression molding, machining, gamma irradiation cross-linking, gas plasma sterilization. Mechanical properties evaluated per ASTM D638, D256, F2183, F2003, F2102. Device is a semi-constrained cemented/uncemented tibial insert.

Indications for Use

Indicated for patients with disability due to degenerative, post-traumatic, or rheumatoid arthritis; avascular necrosis of the femoral condyle; post-traumatic loss of joint configuration (patellofemoral erosion, dysfunction, or prior patellectomy); moderate valgus, varus, or flexion deformities; or fractures unmanageable by other techniques. Also indicated for salvage of failed surgical attempts. Used with 3DKnee System for cemented or uncemented applications.

Regulatory Classification

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).

Predicate Devices

• Highly Cross-Linked Vitamin E UHMWPE Tibial Insert (K091956)

Submission Summary (Full Text)

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# Summary of Safety and Effectiveness

| Preparation Date: | December 17, 2010 | DEC 21 2010 |
|----------------------|-------------------------------------------------------------------------------------------------------------------------|-------------|
| Applicant/Sponsor: | Encore Medical (d.b.a. DJO Surgical)<br>9800 Metric Blvd<br>Austin, TX 78758 | |
| Contact Person: | William Garzon<br>Regulatory Affairs Technician | |
| Device Name: | Highly Cross-Linked Vitamin E UHMWPE Tibial Insert | |
| Classification Name: | Knee joint patellofemorotibial polymer/metal/polymer semi-<br>constrained cemented prosthesis (888.3560), OIY, JWH, MBH | |

## Legally Marketed Devices to Which Substantial Equivalence is Claimed:

Encore Medical L.P. - Highly Cross-Linked Vitamin E UHMWPE Tibial Insert, K091956

## Device Description:

Subject of this Traditional 510(k) Premarket Notification is a request for labeling claims for the DJO Surgical 3DKnee HXL VE Tibial Insert. The in vitro wear claim will be made for the use of the 3DKnee femoral component coupled with a 3DKnee HXL VE Insert. It is important to note that there are no new total knee components being introduced as a result of this Traditional 510(k) premarket notification.

## Indications for Use:

Total joint replacement is indicated for patients suffering from disability due to:

- degenerative, post-traumatic or rheumatoid arthritis; .
- avascular necrosis of the femoral condyle; .
- post-traumatic loss of joint configuration, particularly when there is patellofemoral erosion, . dysfunction or prior patellectomy;
- . moderate valgus, varus or flexion deformities;
- Treatment of fractures that are unmanageable using other techniques .

This device may also be indicated in the salvage of previously failed surgical attempts. This device is intended to be used with the 3DKnee System for cemented or uncemented applications.

## Intended Use:

DJO Surgical knee devices are intended for treatment of patients who are candidates for knee arthroplasty per the indications for use. While total knee replacements are not intended to withstand activity levels and loads of normal healthy bone, they are a means of restoring mobility and reducing pain for many patients.

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. .

## Comparable Features to Predicate Device(s):

- . similar product claims
- have the same indicated use, .
- incorporate the same design, .
- . incorporate the same materials.
- . have the same shelf life, and
- . packaged and sterilized using the same materials and processes

## Claims:

The following is a summary of the claims submitted for clearance:

#### Claim 1:

DJO Surgical HXL VEK showed no measurable oxidation during accelerated age testing per ASTM-2003

FTIR analysis was performed on samples of HXL VEK tibial inserts at three different time points: non- aged, two weeks aged, and four weeks aged. Accelerated aging was performed per ASTM F2003 (oxygen environment at 5 atmospheres at 70℃ for 14 and 28 days). The oxidation index was calculated using the method described in ASTM F2102. All three time points showed no detectable oxidation indices < 0.1). Oxidation indices were 0.0440.02, 0.04±0.00, and 0.03±0.02 respectively. As a comparison, oxidation index for Compression Molded UHMWPE (CM) at two weeks aged is 0.73±0.12.

Izod Impact testing was performed on HXL VEK test specimens per ASTM D256 in both pre and post aged material. Impact testing can indicate the relative brittleness of a material; a consequence of oxidation. Accelerated aging was performed per ASTM F2003 (oxygen environment at 5 atmospheres at 70°C for 14 days). CM was used as a control group for comparative purposes. The average impact resistance for CM before and after accelerated aging was 93.5±7.2 KJ/m² and 25.1±7.0 KJ/m² respectively while the average impact resistance for HXL VEK before and after accelerated aging was 96.2±12.3 KJ/m2 and 102.3±13.3 KJ/m2 respectively.

HXL VEK showed no reduction in impact resistance after accelerated aging whereas CM showed marked degradation in impact resistance after accelerated aging.

CM bar stock is machined into a final part and then inspected, cleaned, packaged with nitrogen flush, and sterilized via gamma irradiation.

HXL VEK is UHMWPE powder that is blended with pure liquid pharmaceutical grade alpha-tocopheral (Vitamin E), compression molded, and machined into bar stock. HXL VEK bar stock is then gamma irradiated to cross link the material. The HXL VEK bar stock is then machined into a final part and then inspected, cleaned, pre-packaged, sterilized via gas plasma, and final packaged.

Bench testing is not necessarily indicative of clinical performance.

#### Claim 2:

DJO Surgical HXL VEK maintains the mechanical strength of conventional compression molded UHMWPE (CM) during mechanical testing.

Tensile testing was performed per ASTM D638 on CM, Highly Cross-Linked (HXL), and HXL VEK material. All test specimens were accelerated aged per ASTM F2003 (oxygen environment at 5 atmospheres at 70°C for 14 days). Average yield strength for each material was 24.98±0.76 MPa, and 25.09±0.72 MPa, and 25.09±0.72 MPa respectively. There was approximately a 12% drop off in yield strength for HXL as compared to CM. However, there was no drop off in yield strength for HXL VEK as compared to CM. Maintaining yield strength is a critical parameter for knee tibial insert performance.

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Tibial insert posterior peel-out testing was performed to determine the mechanical integrity of the tibial inserts relative to the metal baseplate. A snap feature is utilized to secure the metal baseplates. Tibial insert test parts that employ identical snap features were manufactured at nominal conditions for both CM and HXL VEK material. Testing was performed to simulate a worst case peel-out phenomenon in which the thickest tibial insert is forced out of the baseplate by applying a load to the insert in the anterior direction. An acceptance criterion was that the HXL VEK inserts should exhibit at least the same amount of resistance to posterior peel-out force as CM inserts. The average resistance load to posterior peel-out for CM and HXL VEK were 169.67±18.18 lbs and 182.43±2.23 bs respectively.

CM bar stock is machined into a final part and then inspected, cleaned, packaged with nitrogen flush, and sterilized via gamma irradiation.

HXL bar stock is CM bar stock that is gamma irradiated to cross link the material. The HXL bar stock is then machined into a final part and then inspected, cleaned, sterilized via gas plasma, and final packaged.

HXL VEK is UHMWPE powder that is blended with pure liquid pharmaceutical grade alpha-tocopheral (Vitamin E), compression molded, and machined into bar stock. HXL VEK bar stock is then gamma irradiated to cross link the material. The HXL VEK bar stock is then machined into a final part and then inspected, cleaned, pre-packaged, sterilized via gas plasma, and final packaged.

Bench testing is not necessarily indicative of clinical performance.

#### Claim 3:

DJO Surgical HXL VEK maintains mechanical strength after accelerated aging.

Tensile, small punch, and Izod Impact testing were performed on HXL VEK before and after accelerated aging. There was no significant decrease in yield strength, ultimate load, or impact resistance after accelerated aging was performed per ASTM F2003 (oxygen environment at 5 atmospheres at 70°C for 14 days). Tensile testing was performed per ASTM D638. The average yield strength for HXL VEK before and after accelerated aging was 26.76+0.96 MPa and 25.09+0.72 MPa respectively. Small punch testing was performed per ASTM F2183. The average ultimate load for HXL VEK before and after accelerated aging was 80.80±4.56 N and 81.31±4.22 N respectively. Izod impact testing was performed per ASTM D256. The average impact resistance for HXL VEK before and after accelerated aging was 96.2±12.3 KJ/m² and 102.3±13.3 KJ/m² respectively.

HXL VEK is UHMWPE powder that is blended with pure liquid pharmaceutical grade alpha-tocopheral (Vitamin E), compression molded, and machined into bar stock. HXL VEK bar stock is then gamma irradiated to cross link the material. The HXL VEK bar stock is then machined into a final part and then inspected, cleaned, pre-packaged, sterilized via gas plasma, and final packaged.

Bench testing is not necessarily indicative of clinical performance.

#### Claim 4:

DJO Surgical HXL VEK tibial bearings had an average wear rate that was 57% less than that of a conventional direct compression molded UHMWPE (DCM) bearing of the same geometry in knee simulator wear testing.

Wear testing was performed on the 3D™ Knee system comparing DCM tibial inserts and machined HXL VEK tibial inserts. Each test was performed on a multi-axis, force driven knee simulator (Instron/Stanmore 4-Station Knee Simulator) per ISO 14243-1 for 5 million cycles in a 25% concentration of defined bovine caff serum. Both inserts were articulated against a 3D™ Knee CoCr femoral component of matching size. The HXL VEK inserts were aged for two weeks per ASTM F2003 (oxygen environment at 5 atmospheres at 70°C for 14 days) while the DCM inserts were not aged. Both sets of inserts employed soak controls (loaded and unloaded) to correct for fluid absorption of the polyethylene during wear testing. The test specimens were Size 6 Left Femoral Components, Size 6 Left 11mm Inserts, and Size 6 Left Tibial Baseplates. The average wear rate for the DCM and HXL VEK tibial inserts were 4.4±3.0

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mg/million cycles and 1.9±1.9 mg/million cycles respectively significant (p<0.01). Even though the HXL VEK inserts were machined and aged (vs. not aged for the DCM inserts), the HXL VEK inserts still showed superior wear properties over the DCM inserts.

Note, reduction in total polyethylene wear volume or wear rate alone may not result in an improved clinical outcome as wear particle size and morphology are also critical factors in the potential for wear mediated osteolysis and associated aseptic implant loosening. Particle size and morphology were not evaluated as part of this wear claim.

DCM parts are inspected, cleaned with nitrogen flush, and sterilized via gamma irradiation,

HXL VEK is UHMWPE powder that is blended with pure liquid pharmaceutical grade alpha-tocopheral (Vitamin E). compression molded, and machined into bar stock. HXL VEK bar stock is then gamma irradiated to cross link the material. The HXL VEK bar stock is then machined into a final part and then inspected, cleaned, pre-packaged, sterilized via gas plasma, and final packaged.

Bench testing is not necessarily indicative of clinical performance.

#### Claim 5:

DJO Surgical HXL VEK material was classified as a non-irritant as compared to the control under the conditions of the muscle implantation study.

Intramuscular implant testing was performed per ISO 10993 on three healthy adult New Zealand White rabbits. Compression molded UHMWPE (CM) material was used as the control article to compare to HXL VEK. Five HXL VEK sites and five CM sites were implanted for each rabbit. The surgical sites were closed, and the animals were observed daily for 13 weeks, After 13 weeks, the rabbits were euthanized and the HXL VEK and CM specimens were explanted at necropsy. All tissues were fixed in 10% neutral buffered formalin. Hematoxyiin and eosin (H&E) stained sections of the test and control implant sites were prepared from all animals. A veterinary pathologist microscopically evaluated the H&E stained tissue sections of each implant site. There were no gross abnormalities. The average imitant scores for CM and HXL VEK were 5.7 and 5.1 respectively. The Irritant Ranking Score is defined as: Test Group Average - Control Group Average. In this case, 5.1 - 5.7 = - 0.6. According to the interpretation of the Irritant Ranking Score, a non-irritant is classified as having a range of 0.0 - 2.9. Therefore, with an Irritant Ranking Score of -0.6. HXL VEK is classified as a non-irritant. Note, inflammatory response to device wear particles has not been evaluated.

CM bar stock is machined into a final part and then inspected, cleaned, packaged with nitrogen flush, and sterilized via gamma irradiation.

HXL VEK is UHMWPE powder that is blended with pure liquid pharmaceutical grade alpha-tocopheral (Vitamin E), compression molded, and machined into bar stock. HXL VEK bar stock is then gamma irradiated to cross link the material. The HXL VEK bar stock is then machined into a final part and then inspected, cleaned, pre-packaged, sterilized via gas plasma, and final packaged.

Per the ISO 10993-1 standard, all permanently implanted medical devices should be evaluated for irritation potential as part of the biocompatibility assessment.

Animal testing is not necessarily indicative of clinical performance.

### Non-Clinical Testing:

The following non-clinical laboratory testing was performed to determine substantial equivalence: mechanical material characterization (Tensile, Small Punch, Izod Impact, and crack propagation), physical and chemical characterization ( Oxidation Index, Compressive Modulus, Poisson's Ratio, Surface Roughness, Density, Onset Melting Temperature, Peak Melting Temperature, Delta H, Degree of Crystallinity, Crosslink Density, Swell Ratio, Molecular Weight, Polydispersity Index,

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Lamallae Thickness, Free Radical Concentration, Vitamin E Concentration, Vitamin E Consolidation, Vitamin E Elution/Extraction, Trans-vinylene Index), tibial insert peel-out strength, wear testing, and biocompatibility. All testing has demonstrated the device is substantially equivalent to the predicate devices.

# Clinical Testing:

None provided as a basis for substantial equivalence.

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Image /page/5/Picture/1 description: The image shows the logo for the Department of Health & Human Services USA. The logo consists of a stylized eagle or bird-like symbol with three curved lines forming its body and wings. The text "DEPARTMENT OF HEALTH & HUMAN SERVICES USA" is arranged in a circular fashion around the symbol.

Food and Drug Administration 10903 New Hampshire Avenue Document Mail Center - WO66-0609 Silver Spring, MD 20993-0002

Encore Medical, L.P. % Mr. William Garzon Regulatory Affairs Technician 9800 Metric Boulevard Austin, Texas 78758

DEC 2 1 2010

Re: K103223

Trade/Device Name: Highly Cross-Linked Vitamin E UHMWPE Tibial Insert Regulation Number: 21 CFR 888.3560 Regulation Name: Knee joint patellofemorotibial polymer/metal/polymer semi-constrained cemented prosthesis Regulatory Class: Class II Product Code: OIY, JWH, MBH Dated: October 29, 2010 Received: November 4. 2010

Dear Mr. Garzon:

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 CFR Part 807); labeling (21 CFR Part 801); medical device reporting (reporting of medical

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## Page 2 - Mr. William Garzon

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/McdicalDevices/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 [phone] or [phone] or at its Internet address http://www.fda.gov/MedicalDevices/Resourcesfor You/Industry/default.htm.

Sincerely yours,

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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DEC 2 1

510(k) Number (if known):

Device Name: Highly Cross-Linked Vitamin E UHMWPE Tibial Insert

GEC 2 1 2010

# Indications for Use:

Joint replacement is indicated for patients suffering from disability due to:

- degenerative, post-traumatic or rheumatoid arthritis; .
- . avascular necrosis of the femoral condyle;
- post-traumatic loss of joint configuration, particularly when there is patellofemoral . erosion, dysfunction or prior patellectomy;
- . moderate valgus, varus or flexion deformities;
- Treatment of fractures that are unmanageable using other techniques .

This device may also be indicated in the salvage of previously failed surgical attempts. This device is intended to be used with the 3DKnee System for cemented or uncemented applications.

Prescription Use X (Part 21 CFR 801 Subpart D)

AND/OR

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

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

Concurrence of CDRH, Office of Device Evaluation (ODE)

for m. Melkeron

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

510(k) Number K103223