Sigma CR150 Versus Sigma CR Knee RCT

• Sponsor: DePuy International (Industry)
• Overall Status: Completed
• CT.gov ID: NCT01418378
• Collaborator: (none)
• Enrollment: 191
• Locations: 4
• Arms: 2
• Actual Duration (Months): 54.5
• Patients Per Site: 47.8
• Patients Per Site Per Month: 0.9

Study Details

Study Description

Brief Summary

This study will compare two very similar designs of knee replacement device. One device (Sigma CR150) is a slightly modified version of the original (Sigma CR) and has been modified to enhance/accommodate higher flexion. The original device has been in widespread clinical use with excellent results since 1996 and this study will determine whether the design modifications of the newer device add further value. The newer device has been in clinical use with good short-term(unpublished) outcomes since becoming commercially available in January 2009.

Achieving higher knee flexion may be required for cultural reasons or by the increasingly younger, more active patient population undergoing knee replacement today. In addition to promoting flexion, it is also possible that this design change may help the knee replacement to last longer than traditional implants in patients who achieve higher flexion. Therefore, the study will compare the two devices in terms of survivorship, flexion and other measures of the success of a total knee replacement (range of motion, knee-related quality of life, activity and generic quality of life) over the short-term.

A minimum of one hundred and forty subjects (minimum 70 per group) with osteoarthritis and aged 50-75 years will be included at UK/international hospitals.

Study duration is 2 years and patients will complete standard knee outcome scores plus radiological evaluation.

Subjects would receive one of the study devices regardless of their involvement in the study, and apart from (possible)additional visits, x-rays and/or questionnaires, treatment and follow-up care will be as per the care they would receive outside of the study.

Condition or Disease	Intervention/Treatment	Phase
Osteoarthritis	Device: Sigma CR150; Device: Sigma CR	Phase 4

Study Design

• Study Type: Interventional
• Actual Enrollment: 191 participants
• Allocation: Randomized
• Intervention Model: Parallel Assignment
• Masking: Double (Participant, Outcomes Assessor)
• Primary Purpose: Treatment
• Official Title: A Double-blinded Randomised Controlled Trial Comparing the Performance of the Sigma® CR150 and Sigma® CR Knee Systems, When Used in Fixed Bearing Primary Cruciate Retaining Total Knee Arthroplasty for the Treatment of Osteoarthritis
• Actual Study Start Date: Aug 3, 2011
• Actual Primary Completion Date: Feb 17, 2016
• Actual Study Completion Date: Feb 17, 2016

Arms and Interventions

Arm	Intervention/Treatment
Active Comparator: Sigma CR150 Sigma CR150 femoral component used in combination with the Highly Polished Cobalt Chrome fixed bearing tibial tray and the Curved (XLK) polyethylene bearing (cemented, no patellar resurfacing).	Device: Sigma CR150; Sigma CR150 femoral component used in combination with the Highly Polished Cobalt Chrome fixed bearing tibial tray and the Curved (XLK) polyethylene bearing (cemented, no patellar resurfacing).; Other Names: PFC Sigma CR150
Active Comparator: Sigma CR Sigma CR femoral component used in combination with the Highly Polished Cobalt Chrome fixed bearing tibial tray and the Curved (XLK) polyethylene bearing (cemented, no patellar resurfacing).	Device: Sigma CR; Sigma CR femoral component used in combination with the Highly Polished Cobalt Chrome fixed bearing tibial tray and the Curved (XLK) polyethylene bearing (cemented, no patellar resurfacing).; Other Names: PFC Sigma CR

Outcome Measures

Primary Outcome Measures

1. Percentage of Knees Who Survived at 2 Years Post-operative [2 Years]

   The Kaplan-Meier success rate at 24-months post-operatively was calculated with Kaplan-Meier time-to-event methodology, where the time variable for patients who were successful (no components revised for any reason) was censored at the time of last follow-up.

Secondary Outcome Measures

1. Change From Baseline in Goniometer Measured Maximum Passive Flexion at 2 Years [Pre-operative baseline to 2 years]

   Comparative evaluation of the change from baseline values in 2 year goniometer-measured passive flexion. A goniometer is an instrument used to measure angles in degrees and captures the change in angle between the upper and lower leg

2. Knee Injury and Osteoarthritis Outcome Pain Subscore - 1 Year [Pre-operative baseline to 1 year]

   Comparative evaluation of the change from baseline values at 1 years in Knee Injury and Osteoarthritis Outcome Pain Subscore The subscore ranges from 0 (no pain) to 36 (extreme pain). The subscore is then transformed into a 0 (extreme pain) to 100 (no pain) scale. 100 - (score x 100) / 36 = transformed score

3. Knee Injury and Osteoarthritis Outcome Pain Subscore - 2 Years [2 years]

   Comparative evaluation of the change from baseline values at 2 years in Knee Injury and Osteoarthritis Outcome Pain Subscore The subscore ranges from 0 (no pain) to 36 (extreme pain). The subscore is then transformed into a 0 (extreme pain) to 100 (no pain) scale. 100 - (score x 100) / 36 = transformed score

4. Knee Injury and Osteoarthritis Outcome Symptoms Subscore - 1 Years [1 years]

   Comparative evaluation of the change from baseline values at 1 year in Knee Injury and Osteoarthritis Outcome Symptom Subscore The subscore ranges from 0 (no symptoms) to 36 (always have symptoms). The subscore is then transformed into a 0 (always have symptoms) to 100 (never have symptoms) scale. 100 - (score x 100) / 36 = transformed score

5. Knee Injury and Osteoarthritis Outcome Symptom Subscore - 2 Years [2 years]

   Comparative evaluation of the change from baseline values at 2 years in Knee Injury and Osteoarthritis Outcome Symptom Subscore The subscore ranges from 0 (never have symptoms) to 28 (always have symptoms). The subscore is then transformed into a 0 (always have symptoms) to 100 (never have symptoms) scale. 100 - (score x 100) / 28 = transformed score

6. Knee Injury and Osteoarthritis Outcome - Activities of Daily Living Subscore - 1 Years [1 year]

   Comparative evaluation of the change from baseline values at 1 years in Knee Injury and Osteoarthritis Outcome Symptom Subscore The subscore ranges from 0 (no difficulty) to 68 (extreme difficulty). The subscore is then transformed into a 0 (extreme difficulty) to 100 (no difficulty) scale. 100 - (score x 100) / 68 = transformed score

7. Knee Injury and Osteoarthritis Outcome - Activities of Daily Living Subscore - 2 Years [2 year]

   Comparative evaluation of the change from baseline values at 2 years in Knee Injury and Osteoarthritis Outcome Activities of Daily Living Subscore The subscore ranges from 0 (no difficulty) to 68 (extreme difficulty). The subscore is then transformed into a 0 (extreme difficulty) to 100 (no difficulty) scale. 100 - (score x 100) / 68 = transformed score

8. Knee Injury and Osteoarthritis Outcome - Sport and Recreation Subscore - 1 Years [1 year]

   Comparative evaluation of the change from baseline values at 1 years in Knee Injury and Osteoarthritis Outcome Activities of Daily Living Subscore The subscore ranges from 0 (no difficulty) to 20 (extreme difficulty). The subscore is then transformed into a 0 (extreme difficulty) to 100 (no difficulty) scale. 100 - (score x 100) / 20 = transformed score

9. Knee Injury and Osteoarthritis Outcome Sport and Recreation Subscore - 2 Years [2 year]

   Comparative evaluation of the change from baseline values at 2 years in Knee Injury and Osteoarthritis Outcome Activities of Daily Living Subscore The subscore ranges from 0 (no difficulty) to 20 (extreme difficulty). The subscore is then transformed into a 0 (extreme difficulty) to 100 (no difficulty) scale. 100 - (score x 100) / 20 = transformed score

10. Knee Injury and Osteoarthritis Outcome - Quality of Life Subscore - 1 Years [1 year]

    Comparative evaluation of the change from baseline values at 1 years in Knee Injury and Osteoarthritis Outcome Activities of Quality of life Subscore The subscore ranges from 0 (no difficulty) to 16 (extreme difficulty). The subscore is then transformed into a 0 (extreme difficulty) to 100 (no difficulty) scale. 100 - (score x 100) / 16 = transformed score

11. Knee Injury and Osteoarthritis Outcome - Quality of Life Subscore - 2 Years [2 years]

    Comparative evaluation of the change from baseline values at 2 years in Knee Injury and Osteoarthritis Outcome Quality of Life Subscore The subscore ranges from 0 (no difficulty) to 16 (extreme difficulty). The subscore is then transformed into a 0 (extreme difficulty) to 100 (no difficulty) scale. 100 - (score x 100) / 16 = transformed score

12. Change From Baseline in Goniometer Measured Maximum Passive Flexion at 1 Year. [1 year]

    Comparative evaluation of the change from baseline values in 1 year goniometer-measured passive Flexion. A goniometer is an instrument used to measure angles in degrees and captures the change in angle between the upper and lower leg. Passive flexion involves moving the leg through range of motion without active muscle contraction

13. Change From Baseline in Goniometer Measured Maximum Passive Extension at 1 Year [1 year]

    Comparative evaluation of the change from baseline values in 1 year goniometer-measured passive extension. A goniometer is an instrument used to measure angles in degrees and captures the change in angle between the upper and lower leg. Passive extension involves the leg being moved without active muscle contraction

14. Change From Baseline in Goniometer Measured Maximum Passive Extension at 2 Years [2 year]

    Comparative evaluation of the change from baseline values in 2 year goniometer-measured passive extension. A goniometer is an instrument used to measure angles in degrees and captures the change in angle between the upper and lower leg. Passive extension involves moving the leg without active muscle contraction

15. Change From Baseline in Goniometer Measured Maximum Total Range of Motion at 1 Year [1 year]

    Comparative evaluation of the change from baseline values in 1 year goniometer-measured total range of motion. A goniometer is an instrument used to measure angles in degrees and captures the change in angle between the upper and lower leg. Total range of motion is the full distance the lower leg travels in relation to the upper leg.

16. Change From Baseline in Goniometer Measured Maximum Total Range of Motion at 2 Years. [2 years]

    Comparative evaluation of the change from baseline values in 2 year goniometer-measured total range of motion. A goniometer is an instrument used to measure angles in degrees and captures the change in angle between the upper and lower leg. Total range of motion is the full distance the lower leg travels in relation to the upper leg.

17. Number of Participants With Flexion Contracture at 1 Year [1 years]

    Summary of flexion contracture at 1 year time point. Flexion contracture is a shortening of the muscles that prevents the leg from fully extending

18. Number of Participants With Flexion Contracture at 2 Years [2 years]

    Summary of flexion contracture at 2 year time point.Flexion contracture is a shortening of the muscles that prevents the leg from fully extending

19. Total Knee Society Score at 1 Year [1 year]

    Total Knee Society Knee Score change from baseline at 1 year The Total Knee Society Score is comprised of two scores: the Knee Score and the Function Score. Both have a 0-100 range. Sub-scales are combined to compute a total score of 100 The Total Knee Society Score is made up of pain, range of motion, alignment and stability subscores. An Excellent score is 80-100, a good score is 70-79, a fair score is 60-69 and a poor score is anything below 60.

20. Total Knee Society Knee Score at 2 Years [2 years]

    Total Knee Society Knee Score change from baseline at 2 years The Total Knee Society Score is comprised of two scores: the Knee Score and the Function Score. Both have a 0-100 range. Sub-scales are combined to compute a total score of 100 The Total Knee Society Score is made up of pain, range of motion, alignment and stability subscores. An Excellent score is 80-100, a good score is 70-79, a fair score is 60-69 and a poor score is anything below 60.

21. Anatomic Alignment Angle [1 year time point]

    Anatomic angle measured at 1 year time point. If one draws a line from the center of the hip joint to the center of the ankle joint this is considered to be the mechanical axis of the femur. A line drawn through the center of the femoral shaft is the anatomic axis. The angle created at the intersection of these lines is referred to as the anatomic alignment angle. A normal angle is approximately 7-9 degrees "valgus" or slightly "knock-kneed". "Varus" angles are less common and are also referred to as "bow-legged".

22. Anatomic Alignment Angle [2 year time point]

    Anatomic angle measured at 2 year time point. If one draws a line from the center of the hip joint to the center of the ankle joint this is considered to be the mechanical axis of the femur. A line drawn through the center of the femoral shaft is the anatomic axis. The angle created at the intersection of these lines is referred to as the anatomic alignment angle. A normal angle is approximately 7-9 degrees "valgus" or slightly "knock-kneed". "Varus" angles are less common and are also referred to as "bow-legged".

23. Alignment - Femoral Component to Anatomic Angle. [1 year time point]

    Femoral component angle measured at 1 year time point. This angle is measured between a line drawn from the center of the femoral head and a line across the bottom of the femoral implant (condyles).

24. Alignment - Femoral Component to Anatomic Angle [2 year time point]

    Femoral component angle measured at 2 year time point. This angle is measured between a line drawn from the center of the femoral head and a line across the bottom of the femoral implant (condyles).

25. Alignment - Tibial Component to Anatomic Angle [1 year time point]

    Tibial component angle measured at 1 year time point. This angle is measured between a line drawn from the center of the femoral head tibial implant.

26. Alignment - Tibial Component to Anatomic Angle [2 year time point]

    Tibial component angle measured at 2 year time point. This angle is measured between a line drawn from the center of the femoral head tibial implant.

27. Alignment - Femoral Component Flexion [1 year time point]

    Femoral Component Flexion measured at 1 year time point. This measures the angle between a line drawn though the center of the side of the femur and a line drawn across the top of the flat inner surface of the femoral component.

28. Alignment - Femoral Component Flexion [2 year time point]

    Alignment - Femoral Component Flexion measured at 2 year time point. This measures the angle between a line drawn though the center of the side of the femur and a line drawn across the top of the flat inner surface of the femoral component.

29. Alignment - Tibial Posterior Slope [1 year time point]

    Tibial Posterior Slope measured at 1 year time point. This angle is measured between a line through the center of the side of the tibia and the top flat surface of the tibial implant

30. Alignment - Tibial Posterior Slope [2 year time point]

    Alignment - Tibial Posterior Slope measured at 2 year time point. This angle is measured between a line through the center of the side of the tibia and the top flat surface of the tibial implant

31. Number of Subjects With Radiolucencies - Femoral Component [6 to 12 week and 24 month intervals]

    The bone-implant interface at the femoral components were examined radiographically and radiolucencies were measured in millimeters. Radiolucent lines (RLLs) greater than 2mm are considered to be clinically significant.

32. Number of Subjects With Radiolucencies - Tibial Component [6 weeks to 24 months]

    The bone-implant interface at the tibial components were examined radiographically and radiolucencies were measured in millimeters. Radiolucent lines (RLLs) greater than 2mm are considered to be clinically significant. Radiolucent lines greater than 2mm are considered to be clinically significant.

33. Radiographic Evaluation of Maximum Flexion [1 year time point]

    Maximum knee flexion measured radiographically at 1 year time point

Eligibility Criteria

Criteria

• Ages Eligible for Study: 50 Years to 75 Years
• Sexes Eligible for Study: All
• Accepts Healthy Volunteers: No

Inclusion Criteria:

i)Male or female subjects, aged between 50 and 75 years inclusive.

ii)Subjects who are able to give voluntary, written informed consent to participate in this clinical investigation and from whom consent has been obtained.

1. Subjects who, in the opinion of the Clinical Investigator, are able to understand this clinical investigation, co-operate with the investigational procedures and are willing to return to the hospital for all the required post-operative follow-ups.

2. Subjects defined by the Investigator as ASA Grade I or II.

3. Subjects with a primary diagnosis of osteoarthritis.

4. Subjects who require a primary total knee arthroplasty.

5. Subjects who can achieve active flexion of 90 degrees.

Exclusion Criteria:

1. Subjects who, in the opinion of the Clinical Investigator, have an existing condition that would compromise their participation and follow-up in this clinical investigation.

2. Subjects who are known drug or alcohol abusers or with psychological disorders that could affect follow-up care or treatment outcomes.

3. Subjects who have participated in a clinical investigation with an investigational product in the last month.

4. Subjects who are currently involved in any injury litigation claims.

5. Subjects with an anatomical limb alignment of above 20 degrees varus or valgus.

6. Subjects with a fixed flexion deformity of over 20 degrees.

7. Subjects with recurvatum (definition: hyperextension ≥ 5 degrees).

8. Subjects who cannot flex their hip to 90 degrees.

9. Subjects with a BMI of 35 or above.

10. Subjects defined by the Investigator as ASA Grade III-V.

11. Subjects who are identified pre-operatively as having bone defects which require augmentation.

12. Subjects who have previously undergone total or unicondylar knee arthroplasty, high tibial osteotomy, ligament reconstruction, ORIF or with previous fracture in the knee joint.

13. Subjects with primary or secondary diagnosis of inflammatory or traumatic arthritis.

14. Subjects who have undergone contralateral total knee arthroplasty during the previous 6 months.

15. Subjects who in the opinion of the Investigator require patellar resurfacing.

Intra-operative exclusion criteria:

1. Subjects who have uncontained bone defects or defects bigger than 8 mm3 and/or require augmentation.

2. Subjects who are not suitable to receive both the study and comparator devices.

3. Subjects who require patellar resurfacing

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	Sunshine Hospitals	Secunderabad	Andhra Pradesh	India	500003
2	Singapore General Hospital	Singapore		Singapore	169608
3	Victoria Hospital	Kirkcaldy	Fife	United Kingdom	KY2 5AH
4	Calderdale Royal Hospital	Halifax	West Yorkshire	United Kingdom	HX3 0PW

Sponsors and Collaborators

• DePuy International

Investigators

• Principal Investigator: Gautam Chakrabarty, FRCS Orth., Calderdale and Huddersfield Foundation NHS Trust

Study Documents (Full-Text)

None provided.

More Information

Publications

None provided.

• Responsible Party: DePuy International
• ClinicalTrials.gov Identifier: NCT01418378
• Other Study ID Numbers: CT07/04
• First Posted: Aug 17, 2011
• Last Update Posted: Aug 28, 2019
• Last Verified: Jul 1, 2019

• Keywords provided by DePuy International: Sigma; cruciate; retaining; fixed; primary; total; knee; arthroplasty; cemented; osteoarthritis
• Additional relevant MeSH terms: Osteoarthritis

Study Results

Participant Flow

Recruitment Details	191 subjects were recruited at sites in the UK, India and Singapore. Enrollment took place between 3 August 2011 and 21 January 2014
Pre-assignment Detail	After written informed consent was obtained from subjects, eligibility was confirmed and subjects were allocated a subject identification number

Arm/Group Title	Sigma CR 150	Sigma CR
Arm/Group Description	Subjects who received a Sigma CR 150 implant	Subjects who received a Sigma CR implant
Period Title: Overall Study
STARTED	90	88
Subjects Who Received Study Implant	90	88
COMPLETED	89	83
NOT COMPLETED	1	5

Baseline Characteristics

Arm/Group Title	Sigma CR 150	Sigma CR	Total
Arm/Group Description	Subjects who received a Sigma CR 150 implant	Subjects who received a Sigma CR implant	Total of all reporting groups
Overall Participants	90	88	178
Age (Years) [Mean (Standard Deviation) ]
Mean (Standard Deviation) [Years]	63.2 (6.9)	64.4 (6.2)	63.8 (6.6)
Sex: Female, Male (Count of Participants)
Female	61 67.8%	50 56.8%	111 62.4%
Male	29 32.2%	38 43.2%	67 37.6%
Pre-operative flexion angle (Degrees) [Mean (Standard Deviation) ]
Mean (Standard Deviation) [Degrees]	110.8 (21.4)	110.4 (19.4)	110.6 (20.4)
BMI (kg/m^2) [Mean (Standard Deviation) ]
Mean (Standard Deviation) [kg/m^2]	27.1 (3.6)	27.7 (3.9)	27.4 (3.8)
Primary Diagnosis (Count of Participants)
Count of Participants [Participants]	90 100%	88 100%	178 100%

Outcome Measures

1. Primary Outcome

Title	Percentage of Knees Who Survived at 2 Years Post-operative
Description	The Kaplan-Meier success rate at 24-months post-operatively was calculated with Kaplan-Meier time-to-event methodology, where the time variable for patients who were successful (no components revised for any reason) was censored at the time of last follow-up.
Time Frame	2 Years

Outcome Measure Data

Analysis Population Description

Safety population

Arm/Group Title	Sigma CR 150	Sigma CR
Arm/Group Description	Subjects who received a Sigma CR 150 implant	Subjects who received a Sigma CR implant
Measure Participants	90	88
Number (95% Confidence Interval) [Percentage of Knees remaining]	100	100

2. Secondary Outcome

Title	Change From Baseline in Goniometer Measured Maximum Passive Flexion at 2 Years
Description	Comparative evaluation of the change from baseline values in 2 year goniometer-measured passive flexion. A goniometer is an instrument used to measure angles in degrees and captures the change in angle between the upper and lower leg
Time Frame	Pre-operative baseline to 2 years

Outcome Measure Data

Analysis Population Description

Per protocol population

Arm/Group Title	Sigma CR 150	Sigma CR
Arm/Group Description	Subjects who received a Sigma CR 150 implant	Subjects who received a Sigma CR implant
Measure Participants	73	63
Mean (Standard Deviation) [degrees]	-3.37 (12.97)	-0.67 (11.81)

3. Secondary Outcome

Title	Knee Injury and Osteoarthritis Outcome Pain Subscore - 1 Year
Description	Comparative evaluation of the change from baseline values at 1 years in Knee Injury and Osteoarthritis Outcome Pain Subscore The subscore ranges from 0 (no pain) to 36 (extreme pain). The subscore is then transformed into a 0 (extreme pain) to 100 (no pain) scale. 100 - (score x 100) / 36 = transformed score
Time Frame	Pre-operative baseline to 1 year

Outcome Measure Data

Analysis Population Description

Subjects within per protocol population with complete, available data

Arm/Group Title	Sigma CR 150	Sigma CR
Arm/Group Description	Subjects who received a Sigma CR 150 implant	Subjects who received a Sigma CR implant
Measure Participants	75	61
Mean (Standard Deviation) [Scores on a scale]	46.59 (16.68)	48.54 (16.69)

4. Secondary Outcome

Title	Knee Injury and Osteoarthritis Outcome Pain Subscore - 2 Years
Description	Comparative evaluation of the change from baseline values at 2 years in Knee Injury and Osteoarthritis Outcome Pain Subscore The subscore ranges from 0 (no pain) to 36 (extreme pain). The subscore is then transformed into a 0 (extreme pain) to 100 (no pain) scale. 100 - (score x 100) / 36 = transformed score
Time Frame	2 years

Outcome Measure Data

Analysis Population Description

Study subjects at 2 years - Subjects within per protocol population with complete, available data

Arm/Group Title	Sigma CR 150	Sigma CR
Arm/Group Description	Subjects who received a Sigma CR 150 implant	Subjects who received a Sigma CR implant
Measure Participants	72	62
Mean (Standard Deviation) [Scores on a scale]	51.50 (17.71)	55.38 (15.40)

5. Secondary Outcome

Title	Knee Injury and Osteoarthritis Outcome Symptoms Subscore - 1 Years
Description	Comparative evaluation of the change from baseline values at 1 year in Knee Injury and Osteoarthritis Outcome Symptom Subscore The subscore ranges from 0 (no symptoms) to 36 (always have symptoms). The subscore is then transformed into a 0 (always have symptoms) to 100 (never have symptoms) scale. 100 - (score x 100) / 36 = transformed score
Time Frame	1 years

Outcome Measure Data

Analysis Population Description

Study subjects at 1 year - Subjects within per protocol population with complete, available data

Arm/Group Title	Sigma CR 150	Sigma CR
Arm/Group Description	Subjects who received a Sigma CR 150 implant	Subjects who received a Sigma CR implant
Measure Participants	75	61
Mean (Standard Deviation) [Scores on a scale]	44.00 (20.95)	39.99 (20.86)

6. Secondary Outcome

Title	Knee Injury and Osteoarthritis Outcome Symptom Subscore - 2 Years
Description	Comparative evaluation of the change from baseline values at 2 years in Knee Injury and Osteoarthritis Outcome Symptom Subscore The subscore ranges from 0 (never have symptoms) to 28 (always have symptoms). The subscore is then transformed into a 0 (always have symptoms) to 100 (never have symptoms) scale. 100 - (score x 100) / 28 = transformed score
Time Frame	2 years

Outcome Measure Data

Analysis Population Description

Study subjects at 2 year -Subjects within per protocol population with complete, available data

Arm/Group Title	Sigma CR 150	Sigma CR
Arm/Group Description	Subjects who received a Sigma CR 150 implant	Subjects who received a Sigma CR implant
Measure Participants	72	63
Mean (Standard Deviation) [Scores on a scale]	38.59 (20.33)	40.65 (18.17)

7. Secondary Outcome

Title	Knee Injury and Osteoarthritis Outcome - Activities of Daily Living Subscore - 1 Years
Description	Comparative evaluation of the change from baseline values at 1 years in Knee Injury and Osteoarthritis Outcome Symptom Subscore The subscore ranges from 0 (no difficulty) to 68 (extreme difficulty). The subscore is then transformed into a 0 (extreme difficulty) to 100 (no difficulty) scale. 100 - (score x 100) / 68 = transformed score
Time Frame	1 year

Outcome Measure Data

Analysis Population Description

Study subjects at 1 year - Subjects within per protocol population with complete, available data

Arm/Group Title	Sigma CR 150	Sigma CR
Arm/Group Description	Subjects who received a Sigma CR 150 implant	Subjects who received a Sigma CR implant
Measure Participants	75	61
Mean (Standard Deviation) [Scores on a scale]	44.00 (20.95)	39.99 (20.86)

8. Secondary Outcome

Title	Knee Injury and Osteoarthritis Outcome - Activities of Daily Living Subscore - 2 Years
Description	Comparative evaluation of the change from baseline values at 2 years in Knee Injury and Osteoarthritis Outcome Activities of Daily Living Subscore The subscore ranges from 0 (no difficulty) to 68 (extreme difficulty). The subscore is then transformed into a 0 (extreme difficulty) to 100 (no difficulty) scale. 100 - (score x 100) / 68 = transformed score
Time Frame	2 year

Outcome Measure Data

Analysis Population Description

Study subjects at 2 years - Subjects within per protocol population with complete, available data

Arm/Group Title	Sigma CR 150	Sigma CR
Arm/Group Description	Subjects who received a Sigma CR 150 implant	Subjects who received a Sigma CR implant
Measure Participants	72	63
Mean (Standard Deviation) [Scores on a scale]	38.59 (20.33)	40.65 (18.17)

9. Secondary Outcome

Title	Knee Injury and Osteoarthritis Outcome - Sport and Recreation Subscore - 1 Years
Description	Comparative evaluation of the change from baseline values at 1 years in Knee Injury and Osteoarthritis Outcome Activities of Daily Living Subscore The subscore ranges from 0 (no difficulty) to 20 (extreme difficulty). The subscore is then transformed into a 0 (extreme difficulty) to 100 (no difficulty) scale. 100 - (score x 100) / 20 = transformed score
Time Frame	1 year

Outcome Measure Data

Analysis Population Description

Study subjects at 1 years - Subjects within per protocol population with complete, available data

Arm/Group Title	Sigma CR 150	Sigma CR
Arm/Group Description	Subjects who received a Sigma CR 150 implant	Subjects who received a Sigma CR implant
Measure Participants	73	60
Mean (Standard Deviation) [Scores on a scale]	46.99 (32.82)	46.42 (28.91)

10. Secondary Outcome

Title	Knee Injury and Osteoarthritis Outcome Sport and Recreation Subscore - 2 Years
Description	Comparative evaluation of the change from baseline values at 2 years in Knee Injury and Osteoarthritis Outcome Activities of Daily Living Subscore The subscore ranges from 0 (no difficulty) to 20 (extreme difficulty). The subscore is then transformed into a 0 (extreme difficulty) to 100 (no difficulty) scale. 100 - (score x 100) / 20 = transformed score
Time Frame	2 year

Outcome Measure Data

Analysis Population Description

Study subjects at 2 years - Subjects within per protocol population with complete, available data

Arm/Group Title	Sigma CR 150	Sigma CR
Arm/Group Description	Subjects who received a Sigma CR 150 implant	Subjects who received a Sigma CR implant
Measure Participants	70	63
Mean (Standard Deviation) [Scores on a scale]	61.29 (35.60)	60.40 (32.75)

11. Secondary Outcome

Title	Knee Injury and Osteoarthritis Outcome - Quality of Life Subscore - 1 Years
Description	Comparative evaluation of the change from baseline values at 1 years in Knee Injury and Osteoarthritis Outcome Activities of Quality of life Subscore The subscore ranges from 0 (no difficulty) to 16 (extreme difficulty). The subscore is then transformed into a 0 (extreme difficulty) to 100 (no difficulty) scale. 100 - (score x 100) / 16 = transformed score
Time Frame	1 year

Outcome Measure Data

Analysis Population Description

Study subjects at 1 years - Subjects within per protocol population with complete, available data

Arm/Group Title	Sigma CR 150	Sigma CR
Arm/Group Description	Subjects who received a Sigma CR 150 implant	Subjects who received a Sigma CR implant
Measure Participants	75	61
Mean (Standard Deviation) [Scores on a scale]	50.75 (24.83)	49.59 (18.71)

12. Secondary Outcome

Title	Knee Injury and Osteoarthritis Outcome - Quality of Life Subscore - 2 Years
Description	Comparative evaluation of the change from baseline values at 2 years in Knee Injury and Osteoarthritis Outcome Quality of Life Subscore The subscore ranges from 0 (no difficulty) to 16 (extreme difficulty). The subscore is then transformed into a 0 (extreme difficulty) to 100 (no difficulty) scale. 100 - (score x 100) / 16 = transformed score
Time Frame	2 years

Outcome Measure Data

Analysis Population Description

Study subjects at 2 years - Subjects within per protocol population with complete, available data

Arm/Group Title	Sigma CR 150	Sigma CR
Arm/Group Description	Subjects who received a Sigma CR 150 implant	Subjects who received a Sigma CR implant
Measure Participants	72	63
Mean (Standard Deviation) [Scores on a scale]	60.33 (23.90)	59.92 (21.23)

13. Secondary Outcome

Title	Change From Baseline in Goniometer Measured Maximum Passive Flexion at 1 Year.
Description	Comparative evaluation of the change from baseline values in 1 year goniometer-measured passive Flexion. A goniometer is an instrument used to measure angles in degrees and captures the change in angle between the upper and lower leg. Passive flexion involves moving the leg through range of motion without active muscle contraction
Time Frame	1 year

Outcome Measure Data

Analysis Population Description

Subjects at 1-year within per protocol population with complete, available data

Arm/Group Title	Sigma CR 150	Sigma CR
Arm/Group Description	Subjects who received a Sigma CR 150 implant	Subjects who received a Sigma CR implant
Measure Participants	74	62
Mean (Standard Deviation) [degrees]	-1.03 (12.65)	-0.23 (12.21)

14. Secondary Outcome

Title	Change From Baseline in Goniometer Measured Maximum Passive Extension at 1 Year
Description	Comparative evaluation of the change from baseline values in 1 year goniometer-measured passive extension. A goniometer is an instrument used to measure angles in degrees and captures the change in angle between the upper and lower leg. Passive extension involves the leg being moved without active muscle contraction
Time Frame	1 year

Outcome Measure Data

Analysis Population Description

Subjects at one year within per protocol population with complete, available data

Arm/Group Title	Sigma CR 150	Sigma CR
Arm/Group Description	Subjects who received a Sigma CR 150 implant	Subjects who received a Sigma CR implant
Measure Participants	74	62
Mean (Standard Deviation) [degrees]	-2.34 (4.84)	-3.15 (6.89)

15. Secondary Outcome

Title	Change From Baseline in Goniometer Measured Maximum Passive Extension at 2 Years
Description	Comparative evaluation of the change from baseline values in 2 year goniometer-measured passive extension. A goniometer is an instrument used to measure angles in degrees and captures the change in angle between the upper and lower leg. Passive extension involves moving the leg without active muscle contraction
Time Frame	2 year

Outcome Measure Data

Analysis Population Description

Subjects at 2 years within per protocol population with complete, available data

Arm/Group Title	Sigma CR 150	Sigma CR
Arm/Group Description	Subjects who received a Sigma CR 150 implant	Subjects who received a Sigma CR implant
Measure Participants	73	63
Mean (Standard Deviation) [degrees]	-2.63 (5.14)	-3.44 (7.78)

16. Secondary Outcome

Title	Change From Baseline in Goniometer Measured Maximum Total Range of Motion at 1 Year
Description	Comparative evaluation of the change from baseline values in 1 year goniometer-measured total range of motion. A goniometer is an instrument used to measure angles in degrees and captures the change in angle between the upper and lower leg. Total range of motion is the full distance the lower leg travels in relation to the upper leg.
Time Frame	1 year

Outcome Measure Data

Analysis Population Description

Subjects at 1 year within per protocol population with complete, available data

Arm/Group Title	Sigma CR 150	Sigma CR
Arm/Group Description	Subjects who received a Sigma CR 150 implant	Subjects who received a Sigma CR implant
Measure Participants	74	62
Mean (Standard Deviation) [degrees]	1.31 (13.83)	2.92 (14.59)

17. Secondary Outcome

Title	Change From Baseline in Goniometer Measured Maximum Total Range of Motion at 2 Years.
Description	Comparative evaluation of the change from baseline values in 2 year goniometer-measured total range of motion. A goniometer is an instrument used to measure angles in degrees and captures the change in angle between the upper and lower leg. Total range of motion is the full distance the lower leg travels in relation to the upper leg.
Time Frame	2 years

Outcome Measure Data

Analysis Population Description

Subjects at 2 years within per protocol population with complete, available data

Arm/Group Title	Sigma CR 150	Sigma CR
Arm/Group Description	Subjects who received a Sigma CR 150 implant	Subjects who received a Sigma CR implant
Measure Participants	73	63
Mean (Standard Deviation) [degrees]	-0.74 (14.42)	2.78 (15.99)

18. Secondary Outcome

Title	Number of Participants With Flexion Contracture at 1 Year
Description	Summary of flexion contracture at 1 year time point. Flexion contracture is a shortening of the muscles that prevents the leg from fully extending
Time Frame	1 years

Outcome Measure Data

Analysis Population Description

Subjects at 1 year within per protocol population with complete, available data

Arm/Group Title	Sigma CR 150	Sigma CR
Arm/Group Description	Subjects who received a Sigma CR 150 implant	Subjects who received a Sigma CR implant
Measure Participants	75	62
5-10 degrees	7 7.8%	5 5.7%
11-15 degrees	1 1.1%	0 0%

19. Secondary Outcome

Title	Number of Participants With Flexion Contracture at 2 Years
Description	Summary of flexion contracture at 2 year time point.Flexion contracture is a shortening of the muscles that prevents the leg from fully extending
Time Frame	2 years

Outcome Measure Data

Analysis Population Description

Subjects at 2 years within per protocol population with complete, available data

Arm/Group Title	Sigma CR 150	Sigma CR
Arm/Group Description	Subjects who received a Sigma CR 150 implant	Subjects who received a Sigma CR implant
Measure Participants	77	65
5-10 degrees	4 4.4%	2 2.3%
11-15 degrees	0 0%	0 0%

20. Secondary Outcome

Title	Total Knee Society Score at 1 Year
Description	Total Knee Society Knee Score change from baseline at 1 year The Total Knee Society Score is comprised of two scores: the Knee Score and the Function Score. Both have a 0-100 range. Sub-scales are combined to compute a total score of 100 The Total Knee Society Score is made up of pain, range of motion, alignment and stability subscores. An Excellent score is 80-100, a good score is 70-79, a fair score is 60-69 and a poor score is anything below 60.
Time Frame	1 year

Outcome Measure Data

Analysis Population Description

Subjects at 1 year within per protocol population with complete, available data

Arm/Group Title	Sigma CR 150	Sigma CR
Arm/Group Description	Subjects who received a Sigma CR 150 implant	Subjects who received a Sigma CR implant
Measure Participants	74	62
Mean (Standard Deviation) [Scores on a scale]	45.07 (17.99)	52.50 (14.76)

21. Secondary Outcome

Title	Total Knee Society Knee Score at 2 Years
Description	Total Knee Society Knee Score change from baseline at 2 years The Total Knee Society Score is comprised of two scores: the Knee Score and the Function Score. Both have a 0-100 range. Sub-scales are combined to compute a total score of 100 The Total Knee Society Score is made up of pain, range of motion, alignment and stability subscores. An Excellent score is 80-100, a good score is 70-79, a fair score is 60-69 and a poor score is anything below 60.
Time Frame	2 years

Outcome Measure Data

Analysis Population Description

Subjects at 2 years within per protocol population with complete, available data

Arm/Group Title	Sigma CR 150	Sigma CR
Arm/Group Description	Subjects who received a Sigma CR 150 implant	Subjects who received a Sigma CR implant
Measure Participants	73	63
Mean (Standard Deviation) [Scores on a scale]	46.44 (17.74)	54.51 (15.71)

22. Secondary Outcome

Title	Anatomic Alignment Angle
Description	Anatomic angle measured at 1 year time point. If one draws a line from the center of the hip joint to the center of the ankle joint this is considered to be the mechanical axis of the femur. A line drawn through the center of the femoral shaft is the anatomic axis. The angle created at the intersection of these lines is referred to as the anatomic alignment angle. A normal angle is approximately 7-9 degrees "valgus" or slightly "knock-kneed". "Varus" angles are less common and are also referred to as "bow-legged".
Time Frame	1 year time point

Outcome Measure Data

Analysis Population Description

Subjects at 1 year within safety population with complete, available data

Arm/Group Title	Sigma CR 150	Sigma CR
Arm/Group Description	Subjects who received a Sigma CR 150 implant	Subjects who received a Sigma CR implant
Measure Participants	67	67
Varus	1 1.1%	0 0%
valgus	66 73.3%	67 76.1%

23. Secondary Outcome

Title	Anatomic Alignment Angle
Description	Anatomic angle measured at 2 year time point. If one draws a line from the center of the hip joint to the center of the ankle joint this is considered to be the mechanical axis of the femur. A line drawn through the center of the femoral shaft is the anatomic axis. The angle created at the intersection of these lines is referred to as the anatomic alignment angle. A normal angle is approximately 7-9 degrees "valgus" or slightly "knock-kneed". "Varus" angles are less common and are also referred to as "bow-legged".
Time Frame	2 year time point

Outcome Measure Data

Analysis Population Description

Subjects at 2 years within safety population with complete, available data

Arm/Group Title	Sigma CR 150	Sigma CR
Arm/Group Description	Subjects who received a Sigma CR 150 implant	Subjects who received a Sigma CR implant
Measure Participants	69	65
Varus	3 3.3%	0 0%
Valgus	66 73.3%	65 73.9%

24. Secondary Outcome

Title	Alignment - Femoral Component to Anatomic Angle.
Description	Femoral component angle measured at 1 year time point. This angle is measured between a line drawn from the center of the femoral head and a line across the bottom of the femoral implant (condyles).
Time Frame	1 year time point

Outcome Measure Data

Analysis Population Description

Subjects at 1 year within safety population with complete, available data

Arm/Group Title	Sigma CR 150	Sigma CR
Arm/Group Description	Subjects who received a Sigma CR 150 implant	Subjects who received a Sigma CR implant
Measure Participants	82	79
Mean (Standard Deviation) [Degrees]	94.37 (1.95)	94.21 (2.64)

25. Secondary Outcome

Title	Alignment - Femoral Component to Anatomic Angle
Description	Femoral component angle measured at 2 year time point. This angle is measured between a line drawn from the center of the femoral head and a line across the bottom of the femoral implant (condyles).
Time Frame	2 year time point

Outcome Measure Data

Analysis Population Description

Subjects at 2 year within safety population with complete, available data

Arm/Group Title	Sigma CR 150	Sigma CR
Arm/Group Description	Subjects who received a Sigma CR 150 implant	Subjects who received a Sigma CR implant
Measure Participants	80	77
Mean (Standard Deviation) [Degrees]	93.94 (2.11)	94.48 (2.2)

26. Secondary Outcome

Title	Alignment - Tibial Component to Anatomic Angle
Description	Tibial component angle measured at 1 year time point. This angle is measured between a line drawn from the center of the femoral head tibial implant.
Time Frame	1 year time point

Outcome Measure Data

Analysis Population Description

Subjects at 1 year within safety population with complete, available data

Arm/Group Title	Sigma CR 150	Sigma CR
Arm/Group Description	Subjects who received a Sigma CR 150 implant	Subjects who received a Sigma CR implant
Measure Participants	82	80
Mean (Standard Deviation) [Degrees]	89.96 (1.39)	90.06 (1.83)

27. Secondary Outcome

Title	Alignment - Tibial Component to Anatomic Angle
Description	Tibial component angle measured at 2 year time point. This angle is measured between a line drawn from the center of the femoral head tibial implant.
Time Frame	2 year time point

Outcome Measure Data

Analysis Population Description

Subjects at 2 year within safety population with complete, available data

Arm/Group Title	Sigma CR 150	Sigma CR
Arm/Group Description	Subjects who received a Sigma CR 150 implant	Subjects who received a Sigma CR implant
Measure Participants	80	77
Mean (Standard Deviation) [Degrees]	89.69 (1.60)	90.19 (1.98)

28. Secondary Outcome

Title	Alignment - Femoral Component Flexion
Description	Femoral Component Flexion measured at 1 year time point. This measures the angle between a line drawn though the center of the side of the femur and a line drawn across the top of the flat inner surface of the femoral component.
Time Frame	1 year time point

Outcome Measure Data

Analysis Population Description

Subjects at 1 year within safety population with complete, available data

Arm/Group Title	Sigma CR 150	Sigma CR
Arm/Group Description	Subjects who received a Sigma CR 150 implant	Subjects who received a Sigma CR implant
Measure Participants	82	80
Mean (Standard Deviation) [Degrees]	89.74 (2.44)	90.10 (2.12)

29. Secondary Outcome

Title	Alignment - Femoral Component Flexion
Description	Alignment - Femoral Component Flexion measured at 2 year time point. This measures the angle between a line drawn though the center of the side of the femur and a line drawn across the top of the flat inner surface of the femoral component.
Time Frame	2 year time point

Outcome Measure Data

Analysis Population Description

Subjects at 2 years within safety population with complete, available data

Arm/Group Title	Sigma CR 150	Sigma CR
Arm/Group Description	Subjects who received a Sigma CR 150 implant	Subjects who received a Sigma CR implant
Measure Participants	80	77
Mean (Standard Deviation) [Degrees]	89.93 (2.35)	89.80 (2.99)

30. Secondary Outcome

Title	Alignment - Tibial Posterior Slope
Description	Tibial Posterior Slope measured at 1 year time point. This angle is measured between a line through the center of the side of the tibia and the top flat surface of the tibial implant
Time Frame	1 year time point

Outcome Measure Data

Analysis Population Description

Subjects at 1 year within safety population with complete, available data

Arm/Group Title	Sigma CR 150	Sigma CR
Arm/Group Description	Subjects who received a Sigma CR 150 implant	Subjects who received a Sigma CR implant
Measure Participants	82	80
Mean (Standard Deviation) [Degrees]	85.95 (2.25)	85.47 (2.62)

31. Secondary Outcome

Title	Alignment - Tibial Posterior Slope
Description	Alignment - Tibial Posterior Slope measured at 2 year time point. This angle is measured between a line through the center of the side of the tibia and the top flat surface of the tibial implant
Time Frame	2 year time point

Outcome Measure Data

Analysis Population Description

Subjects at 2 years within safety population with complete, available data

Arm/Group Title	Sigma CR 150	Sigma CR
Arm/Group Description	Subjects who received a Sigma CR 150 implant	Subjects who received a Sigma CR implant
Measure Participants	80	76
Mean (Standard Deviation) [Degrees]	85.99 (2.29)	85.15 (3.24)

32. Secondary Outcome

Title	Number of Subjects With Radiolucencies - Femoral Component
Description	The bone-implant interface at the femoral components were examined radiographically and radiolucencies were measured in millimeters. Radiolucent lines (RLLs) greater than 2mm are considered to be clinically significant.
Time Frame	6 to 12 week and 24 month intervals

Outcome Measure Data

Analysis Population Description

Subjects within safety population with complete, available data

Arm/Group Title	Sigma CR 150	Sigma CR
Arm/Group Description	Subjects who received a Sigma CR 150 implant	Subjects who received a Sigma CR implant
Measure Participants	90	88
6 Weeks to 12 Weeks	0 0%	2 2.3%
24 months	2 2.2%	1 1.1%

33. Secondary Outcome

Title	Number of Subjects With Radiolucencies - Tibial Component
Description	The bone-implant interface at the tibial components were examined radiographically and radiolucencies were measured in millimeters. Radiolucent lines (RLLs) greater than 2mm are considered to be clinically significant. Radiolucent lines greater than 2mm are considered to be clinically significant.
Time Frame	6 weeks to 24 months

Outcome Measure Data

Analysis Population Description

Subjects within safety population with complete, available data

Arm/Group Title	Sigma CR 150	Sigma CR
Arm/Group Description	Subjects who received a Sigma CR 150 implant	Subjects who received a Sigma CR implant
Measure Participants	90	88
6 Weeks to 12 Weeks	0 0%	1 1.1%
12 months	0 0%	1 1.1%

34. Secondary Outcome

Title	Radiographic Evaluation of Maximum Flexion
Description	Maximum knee flexion measured radiographically at 1 year time point
Time Frame	1 year time point

Outcome Measure Data

Analysis Population Description

Subjects at 1 year within safety population with complete, available data

Arm/Group Title	Sigma CR 150	Sigma CR
Arm/Group Description	Subjects who received a Sigma CR 150 implant	Subjects who received a Sigma CR implant
Measure Participants	74	70
Mean (Standard Deviation) [Degrees]	108.51 (18.90)	107.11 (17.41)

Adverse Events

Time Frame	2 years
Adverse Event Reporting Description	Adverse events were evaluated during clinic visits at protocol-defined post-operative intervals
Arm/Group Title	CR 150		C-RET
Arm/Group Description	Subjects who received a Sigma CR150 implant		Subjects who received a Sigma CR implant
All Cause Mortality
	CR 150		C-RET
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	/ (NaN)		/ (NaN)
Serious Adverse Events
	CR 150		C-RET
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	9/90 (10%)		8/88 (9.1%)
Gastrointestinal disorders
Colitis ulcerative	1/90 (1.1%)	1	0/88 (0%)	0
Rectal haemorrhage	0/90 (0%)	0	1/88 (1.1%)	1
Infections and infestations
Localised infection	0/90 (0%)	0	1/88 (1.1%)	1
Bacterial sepsis	1/90 (1.1%)	1	0/88 (0%)	0
Wound infection	1/90 (1.1%)	1	0/88 (0%)	0
Injury, poisoning and procedural complications
Lumbar vertebral fracture	1/90 (1.1%)	1	0/88 (0%)	0
Musculoskeletal and connective tissue disorders
Osteoarthritis	1/90 (1.1%)	1	1/88 (1.1%)	1
Arthralgia	1/90 (1.1%)	1	0/88 (0%)	0
Foot deformity	1/90 (1.1%)	1	0/88 (0%)	0
Neoplasms benign, malignant and unspecified (incl cysts and polyps)
Lung adenocarcinoma	0/90 (0%)	0	1/88 (1.1%)	1
Lung neoplasm malignant	0/90 (0%)	0	1/88 (1.1%)	1
Gastrointestinal carcinoma	0/90 (0%)	0	1/88 (1.1%)	2
Nervous system disorders
Cerebrovascular accident	1/90 (1.1%)	1	2/88 (2.3%)	2
Vascular disorders
Deep vein thrombosis	1/90 (1.1%)	1	0/88 (0%)	0
Other (Not Including Serious) Adverse Events
	CR 150		C-RET
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	14/90 (15.6%)		14/88 (15.9%)
Musculoskeletal and connective tissue disorders
Osteoarthritis	14/90 (15.6%)	14	14/88 (15.9%)	14

Limitations/Caveats

Many subjects had last visit before 2yrs from date of surgery-KM survivorship estimate calculated at 1.8 years when 40 knees left in study. Subject data not available for every outcome- numbers analyzed vary between outcomes and Participant Flow.

More Information

Certain Agreements

Principal Investigators are NOT employed by the organization sponsoring the study.

The only disclosure restriction on the PI is that the sponsor can review results communications prior to public release and can embargo communications regarding trial results for a period that is less than or equal to 60 days. The sponsor cannot require changes to the communication and cannot extend the embargo.