Trial Outcomes & Findings for A Study to Compare the NexGen CR and CR-Flex Knee Implants (NCT NCT00761956)

Results Overview

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.

Recruitment status

COMPLETED

Study phase

NA

Target enrollment

189 participants

Primary outcome timeframe

24 Months

Results posted on

2012-07-16

Participant Flow

Patients were enrolled between 2004 and 2008 at a total of 15 sites throughout the USA

Participant milestones

Participant milestones
Measure	CR Flex Fixed Bearing Knee Study arm will consist of patients that are treated with the NexGen CR-Flex Fixed Bearing Knee.	CR Standard Knee Study arm will consist of patients that are treated with the NexGen CR Knee.
Overall Study STARTED	87	102
Overall Study COMPLETED	52	48
Overall Study NOT COMPLETED	35	54

Reasons for withdrawal

Reasons for withdrawal
Measure	CR Flex Fixed Bearing Knee Study arm will consist of patients that are treated with the NexGen CR-Flex Fixed Bearing Knee.	CR Standard Knee Study arm will consist of patients that are treated with the NexGen CR Knee.
Overall Study Lost to Follow-up	6	11
Overall Study Withdrawal by Subject	3	8
Overall Study Death	0	1
Overall Study Adverse Event	26	34

Baseline Characteristics

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

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	CR Flex Fixed Bearing Knee n=87 Participants Study arm will consist of patients that are treated with the NexGen CR-Flex Fixed Bearing Knee.	CR Standard Knee n=102 Participants Study arm will consist of patients that are treated with the NexGen CR Knee.	Total n=189 Participants Total of all reporting groups
Age, Categorical <=18 years	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Age, Categorical Between 18 and 65 years	37 Participants n=5 Participants	48 Participants n=7 Participants	85 Participants n=5 Participants
Age, Categorical >=65 years	50 Participants n=5 Participants	54 Participants n=7 Participants	104 Participants n=5 Participants
Age Continuous	66.8 years STANDARD_DEVIATION 8.5 • n=5 Participants	65.7 years STANDARD_DEVIATION 8.5 • n=7 Participants	66.2 years STANDARD_DEVIATION 189 • n=5 Participants
Sex: Female, Male Female	53 Participants n=5 Participants	48 Participants n=7 Participants	101 Participants n=5 Participants
Sex: Female, Male Male	34 Participants n=5 Participants	54 Participants n=7 Participants	88 Participants n=5 Participants
Region of Enrollment United States	87 participants n=5 Participants	102 participants n=7 Participants	189 participants n=5 Participants

PRIMARY outcome

Timeframe: 24 Months

Population: There was one case in the CR Standard Knee cohort where the Range of Motion was not complete. Therefore, the total number analyzed is 47 and not 48.

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.

Outcome measures

Outcome measures
Measure	CR Flex Fixed Bearing Knee n=52 Participants Study arm will consist of patients that are treated with the NexGen CR-Flex Fixed Bearing Knee.	CR Standard Knee n=47 Participants Study arm will consist of patients that are treated with the NexGen CR Knee.
Postoperative Range of Motion (ROM)	119.1 degrees Standard Deviation 16.5	120.7 degrees Standard Deviation 11.1

SECONDARY outcome

Timeframe: 24 Months

Population: There was one case in the CR Flex Fixed cohort and 3 in the CR Standard Knee cohort where the Return to Function was not complete. Therefore, the total number analyzed is 51 instead of 52 and 45 instead of 48 respectfully.

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.

Outcome measures

Outcome measures
Measure	CR Flex Fixed Bearing Knee n=51 Participants Study arm will consist of patients that are treated with the NexGen CR-Flex Fixed Bearing Knee.	CR Standard Knee n=45 Participants Study arm will consist of patients that are treated with the NexGen CR Knee.
Return to Function (RtF) Via Knee Scoiety Score (Modified)	80.9 units on a scale Standard Deviation 18.8	85.1 units on a scale Standard Deviation 16.9

Adverse Events

CR Flex Fixed Bearing Knee

Serious events: 1 serious events

Other events: 2 other events

Deaths: 0 deaths

CR Standard Knee

Serious events: 2 serious events

Other events: 6 other events

Deaths: 0 deaths

Serious adverse events

Serious adverse events
Measure	CR Flex Fixed Bearing Knee n=87 participants at risk Study arm will consist of patients that are treated with the NexGen CR-Flex Fixed Bearing Knee.	CR Standard Knee n=102 participants at risk Study arm will consist of patients that are treated with the NexGen CR Knee.
General disorders Death	0.00% 0/87	0.98% 1/102 • Number of events 1
Skin and subcutaneous tissue disorders Wound Dehiscence	0.00% 0/87	0.98% 1/102 • Number of events 1
Musculoskeletal and connective tissue disorders Articular Polyethylene Excessive Wear	1.1% 1/87 • Number of events 1	0.00% 0/102

Other adverse events

Other adverse events
Measure	CR Flex Fixed Bearing Knee n=87 participants at risk Study arm will consist of patients that are treated with the NexGen CR-Flex Fixed Bearing Knee.	CR Standard Knee n=102 participants at risk Study arm will consist of patients that are treated with the NexGen CR Knee.
Musculoskeletal and connective tissue disorders Other Knee Related Complication	2.3% 2/87 • Number of events 2	0.00% 0/102
Musculoskeletal and connective tissue disorders Stiff Knee Resulting in Manipulation	0.00% 0/87	5.9% 6/102 • Number of events 6

Additional Information

Kacy Arnold, Associate Director, Clinical Affairs

Zimmer, Inc

Phone: 574-371-8336

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place