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

Not Applicable

Completed

Interventions: Device: NexGen LPS-Flex Fixed Bearing Knee
Device: NexGen Legacy Posterior Stabilized Knee

Brief Summary: The purpose of this study is to test for significant differences in functional outcomes obtained by using a NexGen LPS versus a NexGen LPS-Flex knee implant. Specifically, it is predicted that an increase in postoperative range of motion will be experienced by patients treated with the NexGen LPS-Flex knee implant.

Detailed Description: This study will compare the clinical results of the NexGen LPS femoral component with the higher flexion potential of the NexGen LPS-Flex femoral component in all patients with degenerative joint disease that require total knee arthroplasty. The primary variable of interest is postoperative 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 & Eligibility

Inclusion Criteria

Age, 21-80 years
Sex, Males and females will be included
BMI less than or equal to 39 and calf-thigh less than or equal to 90 degrees
Stable health, the patient would be able to undergo surgery and participate in the follow-up program based on physical examination and medical history.
Patient is willing and able to cooperate in follow-up therapy.
Patient exhibits preoperative radiographic evidence of joint degeneration consistent with TKA that cannot be treated in non-operative fashion.
Patient has stable and functional 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 90 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.

Arm && Interventions

Group	Intervention	Description
1	NexGen LPS-Flex Fixed Bearing Knee	Study arm will consist of patients that are treated with the NexGen LPS-Flex Fixed Bearing Knee.
2	NexGen Legacy Posterior Stabilized Knee	Study arm will consist of patients that are treated with the NexGen Legacy Posterior Stabilized Knee.

Primary Outcome Measures

Name	Time	Method
Postoperative Range of Motion (ROM)	6 Weeks to 2 Years Post-op, based on on the intervals listed	Postoperative ROM was calculated by taking the measurement of patient flexion minus the measurement of patients' extension.

Secondary Outcome Measures

Name	Time	Method
Return to Function (RtF) Via Knee Society Score (Modified)	6 Weeks to 2 Years Post-op, based on on the intervals listed	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 established follows: 80-100 =Excellent; 70-79 = Good; 60-69 = Fair; and Below 60 = Poor.

Locations (15): VA Medical Center
🇺🇸
Decatur, Georgia, United States
Albert Einstein Healthcare Network
🇺🇸
Philadelphia, Pennsylvania, United States
Orthopaedic Specialists of Spartanburg
🇺🇸
Spartanburg, South Carolina, United States
Southern Illinois University School of Medicine
🇺🇸
Springfield, Illinois, United States
Joint Replacement Surgeons of Indiana
🇺🇸
Indianapolis, Indiana, United States
OrthoCarolina Research Institute
🇺🇸
Charlotte, North Carolina, United States
VSAS Orthopaedics
🇺🇸
Allentown, Pennsylvania, United States
Piedmont Orthopaedic Associates
🇺🇸
Greenville, South Carolina, United States
Rebecca Sealy Hospital
🇺🇸
Galveston, Texas, United States
The Rectors and Visitors of the University of Virginia
🇺🇸
Charlottesville, Virginia, United States
Hopital du Sacre-Coeur de Montreal
🇨🇦
Montreal, Quebec, Canada
Duke University Medical Center
🇺🇸
Durham, North Carolina, United States
University of Alabama at Birmingham
🇺🇸
Birmingham, Alabama, United States
Vanderbilt Orthopaedic Institute
🇺🇸
Nashville, Tennessee, United States
The Center for Hip and Knee Surgery
🇺🇸
Mooresville, Indiana, United States