Scorpio Posterior Stabilised (PS) vs Scorpio NRG ("Energize") PS - Total Knee Arthroplasty

Not Applicable

Completed

Conditions: Arthroplasty, Replacement, Knee

Interventions: Device: Scorpio PS (posterior stable)
Device: Scorpio NRG PS

Registration Number: NCT02520531

Lead Sponsor: Stryker Orthopaedics

Brief Summary: Single-centre, prospective, randomized comparative study to compare the maximum flexion and Chair Raise achievement ratios of the Scorpio PS and and the Scorpio NRG PS. Documentation of all complications.

Detailed Description: Surveillance design: Single-centre, prospective, randomized comparative study. Objectives: To compare the maximum flexion (active and passive) and Chair Raise achievement ratios. All complications will be documented.

Number of subjects to be enrolled: All consecutive Scorpio patients are included until a group size of 88 is reached.

Clinical evaluations: Chair raise test, Stair climb test, Western Ontario McMaster Osteoarthritis Index (WOMAC) patient self evaluation, EuroQuol - 5 dimension (EQ-5D) patient questionnaire. Standard clinical, functional and pain parameters (Knee Society Score), pre-operatively and post-operatively. All per- and post-op complications.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 84

Inclusion Criteria

Patients requiring a primary total knee arthroplasty (TKA)
Male and nonpregnant female patients
Between 18 and 80 years of age at time of surgery
Patients with a diagnosis of osteoarthritis (OA), avascular necrosis (AVN), and not severe posttraumatic arthritis
No previous osteosynthesis of the involved knee during the last 12 months
Patients who understand the conditions of the study and are wiling to participate for the length of the described follow up
Patients who are capable of, and have given, informed consent for participation in the study

Exclusion Criteria

Patients requiring revision surgery of a previous implanted total knee system
Patients with a diagnosis of severe posttraumatic arthritis (TA) and rheumatoid arthritis (RA)
Patients with active infection
Patients with malignancy
Patients with an immobile hip or ankle arthrodesis
Severe obese patients (BMI > 35)
Patients with a neurological deficit
Previous history of unicompartmental knee arthroplasty or patellar prosthesis
Patients with concurrent illnesses which are likely to affect their outcome

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Scorpio PS	Scorpio PS (posterior stable)	Patients on the waiting list for a total knee prosthesis who fulfil the inclusion and exclusion criteria will be asked to participate in this study and are randomized to receive the Scorpio PS Total Knee Replacement.
Scorpio NRG PS	Scorpio NRG PS	Patients on the waiting list for a total knee prosthesis who fulfil the inclusion and exclusion criteria will be asked to participate in this study and are randomized to receive the Scorpio NRG PS Total Knee Replacement.

Primary Outcome Measures

Name	Time	Method
Comparison of Maximum Passive and Active Flexion.	5 years follow-up	Comparison of maximum flexion, both passive and active between Scorpio NRG PS knee prosthesis and the Scorpio PS knee prosthesis. The active flexion-tolerated range is greater/equal 70 degree. The passive flexion-tolerated range is greater/equal 80 degree. The Hyperextension tolerated range is 0 to 10 degree. Higher scores mean a better outcome.

Secondary Outcome Measures

Name	Time	Method
WOMAC Patient Questionnaire	pre-operative, 12, 26 weeks and 1, 2 and 5 years follow-up	The WOMAC collects information specific to osteoarthritis outcomes. The patient response questionnaire uses a visual analog scale for pain, measuring factors of general pain, stiffness, and function. Each question is scored from 0 to 4 for each set of factors, with 0 indicating no pain, stiffness, or limited in function, and 4 indicating extreme pain stiffness, or limited in function. Total WOMAC scores range from 0 to 96 wit lower values representing better outcomes.
Knee Society Score (KSS)	pre-operative, 6, 12, 26 weeks and 1, 2 and 5 years follow-up	The Knee Society Clinical Rating System is comprised of two distinct sub-scores: one for pain, range of motion (ROM) and joint stability, and one for functional parameters. Sub-scores range from a potential minimum score of 0 to a maximum score of 100 points. Although the specific scores are not distinguished as "excellent," "good," "fair," or "poor," a higher value represents a better outcome.
Chair Raise Test	pre-operative, 6, 12, 26 weeks and 1, 2 and 5 years follow-up	A measurement to assess functional lower extremity strength. The participant is seated on a chair. Arms are crossed at the wrists and held against the chest. The participant is instructed to arise from an adjustable chair with the knees in a 90 degree angle (measurement with Goniometer) without using arms.
EQ-5D (Euro-Quol 5-Dimension) Patient Questionnaire	pre-operative, 12, 26 weeks and 1, 2 and 5 years follow-up	The EQ-5D is a subject-completed questionnaire designed to assess subject health state values. The EQ-5D descriptive system comprises the following five dimensions: mobility self care, usual activities, pain/comfort and anxiety/depression. Each dimension has 3 levels indicating no problems, some problems or extreme problems. The index values on a scale between -1 (low) and 1 (high) are showing the average health status according to the 5 dimensions: A low score shows worse health and a high score shows better health.