Gamma Vacuum Foil (GVF) Versus Cross-linked Polyethylene in Total Knee Arthroplasty Study

Prospective, Comparative, Randomized Study of GVF Versus Cross-linked Polyethylene in Total Knee Arthroplasty

Status

Completed

Phases

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT00289133

Enrollment

938

Registered

2006-02-09

Start date

2005-02-01

Completion date

2013-05-01

Last updated

2017-04-24

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Arthritis, Rheumatoid, Osteoarthritis, Knee

Keywords

Arthroplasty, Replacement, Knee

Brief summary

The purpose of this study is to evaluate long-term clinical and radiographic data between geometrically identical GVF and cross-linked polyethylene-bearing inserts in total knee arthroplasty.

Detailed description

In 1996, Gamma Vacuum Foil (GVF) polyethylene was introduced as the first polyethylene to be gamma irradiated and packaged in an inert environment. This polyethylene, with its patented process and packaging, continues to be the only barrier-packaged process that is impermeable to both Hydrogen (H2) and Oxygen (O2), and allows the polyethylene to recombine and cross-link in the package. Though the new moderately cross-linked polyethylene being evaluated in this protocol is comparable to GVF geometrically and mechanically, the P.F.C.® Sigma™ cross-linked polyethylene also has the added benefit of being completely oxidatively stable both on the shelf and in-vivo. The P.F.C. Sigma tibial tray component being assessed in this study is made of Cobalt Chrome (CoCr). The new CoCr tibial tray has the same design geometrically as the original titanium (Ti) tray, however, it features a highly polished top surface where it is joined to the polyethylene. This polished surface is designed to decrease the coefficient of friction between the polyethylene and the tray, thus minimizing backside wear. A comparative clinical study will be conducted to evaluate long-term clinical and radiographic data between geometrically identical cemented implants using GVF and crosslinked polyethylene tibial tray bearing inserts in Total Knee Arthroplasty (TKA) using the P.F.C. Sigma Total Knee System. Patients will be assigned to study treatment groups at random if they meet specific demographic and pathophysiologic criteria for cemented total knee arthroplasty. The anticipated duration of this investigation is a minimum six years, which includes a one-year enrollment phase. The specific aims of this study are as follows: 1. Examine whether crosslinked polyethylene performs as well, if not better, than GVF polyethylene through standard clinical evaluations. 2. Evaluate long-term survivorship rates. 3. Report complications/adverse events. 4. Report radiographic findings of geometrically identical implants.

Interventions

DEVICEtotal knee arthroplasty

Gamma Vacuum Foil polyethylene tibial insert

Study design

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

TREATMENT

Masking

NONE

Eligibility

Sex/Gender

ALL

Age

No minimum to 80 Years

Healthy volunteers

Inclusion criteria

1. Osteoarthritis of the affected joint appropriate for Total Knee Arthroplasty. 2. Diagnosis of any of the following: rheumatoid or other inflammatory arthritis, post-traumatic arthritis, juvenile rheumatoid arthritis. 3. Radiographic evidence of sufficient sound bone stock to seat and support the prosthesis. 4. Subject requires a primary total knee replacement and is considered to be suitable for the specific knee prosthesis identified in protocol. 5. Subject has given consent to the transfer of his/her information to sponsor. 6. Subject will be compliant with requirements of protocol by returning for follow-up visits.

Exclusion criteria

1. History of recent/active joint sepsis. 2. Charcot neuropathy. 3. Psycho-social disorders that would limit rehabilitation. 4. Women who are pregnant or planning on being pregnant. 5. Greater than 80 years of age at the time of surgery. 6. Prior ipsilateral knee arthroplasty. 7. Metabolic disorders of calcified tissues, such as Paget's disease. 8. Severe diabetes mellitus that is not controlled by diet or oral agents. 9. Require joint replacement due to immunodeficiency syndromes. 10. Skeletal immaturity. 11. Avascular necrosis of the affected knee. 12. Chronic renal disease. 13. Subjects involved in medical-legal or worker's compensation claims.

Design outcomes

Primary

Measure	Time frame	Description
Survivorship (Revision of Any Component for Any Reason)	5 years	Survival was estimated by Kaplan-Meier method. Kaplan Meier survivorship analysis estimates the proportion of a population that will survive past a certain time avoiding a certain event. In this study, the event is removal of any component for any reason, also known as revision for any reason. Survival estimates are provided when 40 devices are left still being followed.

Secondary

Measure	Time frame	Description
Western Ontario and McMaster Universities Arthritis Index (WOMAC) Osteoarthritis Total Score	2 year	WOMAC is a patient reported outcome (PRO) that evaluates the condition of subjects with knee osteoarthritis, and includes pain (score range 0-20), stiffness (score range 0-8), and physical function (score range 0-68) of the joint. The total score ranged from 0 to 96. The subscales are combined (summed) to compute a total score, where a lower score indicates a better outcome.
Radiographic Outcomes - Percentage of Knees With Femoral Radiolucencies (>2mm)	Minimum 5 years, up to 7.6 years	—
American Knee Society Evaluation - Total Score	2 year	American Knee Society (AKS) knee score is a 0-100 point score (where 100 indicates excellent knee condition) that evaluates the affected knee. The knee score is composed of Pain, Range of Motion, and Stability.
Radiographic Outcomes - Percentage of Knees With Femoral Osteolysis (>2mm)	Minimum 5 years, up to 7.6 years	—
Radiographic Outcomes - Percentage of Knees With Tibial Osteolysis (>2mm)	Minimum 5 years, up to 7.6 years	—
Radiographic Outcomes - Percentage of Knees With Tibial Radiolucencies (>2mm)	Minimum 5 years, up to 7.6 years	—

Countries

United States

Participant flow

Participants by arm

Arm	Count
GVF Poly Gamma Vacuum Foil polyethylene tibial insert total knee arthroplasty: Gamma Vacuum Foil polyethylene tibial insert	449
XLK Poly Cross-linked polyethylene tibial insert total knee arthroplasty: cross-linked polyethylene tibial insert	477
Total	926

Withdrawals & dropouts

Period	Reason	FG000	FG001
Overall Study	Death	5	10
Overall Study	Lost to Follow-up	92	115
Overall Study	Lost to Follow-up - Hurricane Katri	73	74
Overall Study	Non-study device implanted	12	0
Overall Study	Physician Decision	41	45
Overall Study	Protocol Violation	32	38
Overall Study	Revision	8	6
Overall Study	Withdrawal by Subject	9	10

Baseline characteristics

Characteristic	GVF Poly	XLK Poly	Total
Age, Continuous	66.3 years STANDARD_DEVIATION 8.5	66.4 years STANDARD_DEVIATION 8.5	66.3 years STANDARD_DEVIATION 8.5
Region of Enrollment United States	449 participants	477 participants	926 participants
Sex: Female, Male Female	290 Participants	308 Participants	598 Participants
Sex: Female, Male Male	159 Participants	169 Participants	328 Participants

Adverse events

Event type	EG000 affected / at risk	EG001 affected / at risk
deaths Total, all-cause mortality	— / —	— / —
other Total, other adverse events	146 / 461	164 / 477
serious Total, serious adverse events	16 / 461	15 / 477

Outcome results

Primary

Survivorship (Revision of Any Component for Any Reason)

Survival was estimated by Kaplan-Meier method. Kaplan Meier survivorship analysis estimates the proportion of a population that will survive past a certain time avoiding a certain event. In this study, the event is removal of any component for any reason, also known as revision for any reason. Survival estimates are provided when 40 devices are left still being followed.

Time frame: 5 years

Population: Survivorship can only be calculated on knees (not participants as some study subjects had bilateral knees in the study) with post-operative follow-up. 35 knees were excluded due to post-operative follow-up not being available. 67 knees were excluded due to protocol violations.

Arm	Measure	Value (NUMBER)
GVF Poly	Survivorship (Revision of Any Component for Any Reason)	96.8 percentage of knees
XLK Poly	Survivorship (Revision of Any Component for Any Reason)	98.1 percentage of knees

Secondary

American Knee Society Evaluation - Total Score

American Knee Society (AKS) knee score is a 0-100 point score (where 100 indicates excellent knee condition) that evaluates the affected knee. The knee score is composed of Pain, Range of Motion, and Stability.

Time frame: 2 year

Population: The number of knees analyzed was the number available for analysis at this post-operative timepoint.

Arm	Measure	Value (MEAN)	Dispersion
GVF Poly	American Knee Society Evaluation - Total Score	94.7 scores on a scale	Standard Deviation 7.9
XLK Poly	American Knee Society Evaluation - Total Score	93.5 scores on a scale	Standard Deviation 9.5

Secondary