A Study to Compare the NexGen CR and CR-Flex Knee Implants

Osteoarthritis Clinical Trial

Official title:

Prospective Randomized Multicenter Study of NexGen CR-Flex Knee

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00761956
• Other study ID #: 04-300
• Status: Completed
• Phase: N/A
• First received: September 26, 2008
• Last updated: June 12, 2012
• Start date: September 2004
• Est. completion date: December 2010

Study information

• Verified date: June 2012
• Source: Zimmer, Inc.
• Contact: n/a
• Is FDA regulated: No
• Health authority: United States: Institutional Review Board
• Study type: Interventional

Clinical Trial Summary

The purpose of this study is to test for significant differences in functional outcomes, specifically pre-operative ROM and post-operative ROM obtained by using a NexGen CR versus a NexGen CR-Flex knee implant. Specifically, it is predicted that an increase in post-operative range of motion will be experienced by patients treated with the NexGen CR-Flex knee implant.

Description:

This study will compare the clinical results of the NexGen CR femoral component with the higher flexion potential of the NexGen CR-Flex femoral component in all patients with degenerative joint disease that require total knee arthroplasty. The primary variable of interest is post-operative range of motion achieved with the two devices, which are implanted with slightly different surgical techniques in patients who may also be subjected to different rehabilitation programs depending on the device they are assigned.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 189
• Est. completion date: December 2010
• Est. primary completion date: December 2010
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 21 Years to 80 Years

Eligibility

Inclusion Criteria:

• Age, 21-80 years

• Sex, Male and Females will be included

• BMI less than or equal to 39

• Stable Health, the patient would be able to undergo surgery and participate in a follow-up program based on physical examination and medical history.

• Patient is willing and able to cooperate in follow-up therapy.

• Patient exhibits pre-operative radiographic evidenced of joint degeneration consistent with TKA that cannot be treated in non-operative fashion.

• Patient has stable and functional posterior cruciate and collateral ligaments.

• Patient has potential to perform higher than average range of motion activities.

• Operative side range of motion flexion greater than or equal to 120 degrees.

• Severe knee pain and disability due to degenerative joint disease.

• Patient or patient's legal representative has signed the Informed Consent form.

Exclusion Criteria:

• Previous history of infection in the affected joint.

• Previously failed knee endoprosthesis of any kind.

• Charcot joint disease or other severe neurosensory deficits.

• Previous patellectomy

• Patient is skeletally immature.

• Grossly insufficient femoral or tibial bone stock.

• Patient is pregnant.

• Varus or valgus deformity greater than 20 degrees.

• Fixed flexion deformity greater than 15 degrees.

• Previous high tibial osteotomy.

• Previous femoral osteotomy.

• Patient is a poor compliance risk, currently treated for ethanol or drug abuse, physical or mental handicap, etc.

• Loss of musculature or absence of musculoligamentous supporting structures required for adequate soft tissue balance.

Study Design

Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Parallel Assignment, Masking: Single Blind (Subject), Primary Purpose: Treatment

Related Conditions & MeSH terms

• Osteoarthritis
• Total Knee Arthroplasty

Intervention

Device:
• NexGen CR-Flex Fixed Bearing Knee
NexGen CR-Flex Fixed Bearing femoral component
• NexGen CR Knee
NexGen Complete Knee Solution Cruciate Retaining femoral component

Locations

Country	Name	City	State
United States	University of Chicago Hospital	Chicago	Illinois
United States	The Orthopedic Group	Clairton	Pennsylvania
United States	Slocum Orthopedics, PC	Eugene	Oregon
United States	Orthopaedic Associates of Grand Rapids, PC	Grand Rapids	Michigan
United States	Dickinson Medical Group, LLC	Milford	Delaware
United States	Pinehurst Surgical Center	Pinehurst	North Carolina
United States	Rockford Orthopedic Associates	Rockford	Illinois
United States	University of Massachusetts Memorial Medical Center	Worcester	Massachusetts

Sponsors (1)

Lead Sponsor	Collaborator
Zimmer, Inc.

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Postoperative Range of Motion (ROM)	The subject will have the operative joint's range of motion/movement assessed through a series of exercises and bends. The assessor will measure how far the joint bends/moves in each direction by degrees. The measurements are taken at each visit interval and recorded.	24 Months	No
Secondary	Return to Function (RtF) Via Knee Scoiety Score (Modified)	Scores were calculated from responses on a modified Knee Society Score by the enrolled subjects for the stated visit intervals.; Grading for the Knee Society Score is based on a scale from 0-100 and results are estabalished follows: 80-100 = Excellent; 70-79 = Good; 60-69 = Fair; and Below 60 = Poor.	24 Months	No