NexGen Gender Fixed Bearing Knee Versus NexGen Legacy Knee Posterior Stabilized (LPS) - Flex Fixed Bearing Knee: A Study Comparing Two Different Knee Prostheses

NEXGEN Gender Fixed Bearing Knee Versus NEXGEN LPS-Flex Fixed Bearing Knee - a Prospective Randomized Study Comparing Two Different Knee Prostheses

The purpose of this trial is to study potential differences between two prostheses, including: "feel of prosthesis" (i.e., how natural does the prosthesis feel), range of motion (ROM), pain perception for each prosthesis, satisfaction, patella tracking and quantification of the removed bone anterior on the femur (weight).

Study Overview

• Status: Unknown
• Conditions: Total Knee Arthroplasty
• Intervention / Treatment: Device: NexGen Gender Fixed Bearing Knee prosthesis; Device: NexGen LPS-Flex Fixed Bearing Knee prosthesis

Detailed Description

The present study compares the Gender prosthesis against the LPS-flex in a bilateral study, where patients are given two different prostheses: Gender on one side and LPS-flex on the other side. Patients are blinded to which prosthesis is selected for which side. The potential advantages of the Gender prosthesis include: less post-op pain due to better sizing (less overhang), less post-op patellofemoral pain and less compromised extensor mechanism and better patella tracking (due to less overstuffing of the patellofemoral joint).

Design:

The study is prospective, randomized, comparative and blinded. 24 female patients scheduled for simultaneous bilateral total knee arthroplasty are included (48 knees).

Power calculations cannot be performed as to how many patients are needed since no previous studies have been conducted.

All patients are included and operated by consultant Henrik Husted.

Methods:

Patients are randomized to which side is operated with which prosthesis (LPS-flex or Gender); the operations are performed using standard instrumentation and standard approaches.

At the operation the weight of the cut bone from the anterior femur is noted for each side. Before discharge radiographs including skyline views are performed to evaluate patella tracking (and are repeated at the final out-patient check 1 year post-op).

Gait analyses are performed before operation and 1 year post-op. All other procedures are standard procedures already implemented in the department.

Patients follow an accelerated track (ANORAK, 1,2) with an intended LOS of 4 days for bilaterally operated knee-arthroplasties, all patients are discharged directly to their homes.

• Study Type: Interventional
• Enrollment (Actual): 24
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Denmark
  • Copenhagen
    • Hvidovre, Copenhagen, Denmark, 2650
      • Hvidovre University Hospital
  • Hvidovre
    • Copenhagen, Hvidovre, Denmark, 2650
      • orthopedic department, section of arthroplasty, Hvidovre University Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Female

Description

Inclusion Criteria:

• female patients scheduled for simultaneous bilateral total knee arthroplasty (TKA) are included
• bilateral knee disease necessitating bilateral TKA

Exclusion Criteria:

• male sex

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: 1: Gender prosthesis	Device: NexGen Gender Fixed Bearing Knee prosthesis; new female prosthesis
Active Comparator: 2: LPS flex prosthesis	Device: NexGen LPS-Flex Fixed Bearing Knee prosthesis; standard knee prosthesis

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
follow-up at 6 weeks, 3 months, 6 months and one year. - knee-score and function score - feel of prosthesis (VAS 0-10) - ROM (max passive and active ROM is measured using a goniometer) - pain (VAS 0-10) - satisfaction (VAS 0-10)	1 year

Collaborators and Investigators

• Sponsor: Hvidovre University Hospital
• Collaborators: Zimmer Biomet

Study record dates

Study Major Dates

• Study Start: May 1, 2007
• Primary Completion (Anticipated): December 1, 2009
• Study Completion (Anticipated): December 1, 2010

Study Registration Dates

• First Submitted: May 12, 2009
• First Submitted That Met QC Criteria: May 12, 2009
• First Posted (Estimate): May 13, 2009

Study Record Updates

• Last Update Posted (Estimate): May 13, 2009
• Last Update Submitted That Met QC Criteria: May 12, 2009
• Last Verified: May 1, 2009

More Information

Terms related to this study

• Keywords: pain; gait; functional outcome; ROM; TKA
• Other Study ID Numbers: HD2007-0123