Sigma CR150 Versus Sigma CR Knee RCT

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.

iii) 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.

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

v) Subjects with a primary diagnosis of osteoarthritis.

vi) Subjects who require a primary total knee arthroplasty.

vii) Subjects who can achieve active flexion of 90 degrees.

Exclusion Criteria:

i) 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.

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

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

iv) Subjects who are currently involved in any injury litigation claims.

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

vi) Subjects with a fixed flexion deformity of over 20 degrees.

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

viii) Subjects who cannot flex their hip to 90 degrees.

ix) Subjects with a BMI of 35 or above.

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

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

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

xiii) Subjects with primary or secondary diagnosis of inflammatory or traumatic arthritis.

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

xv) Subjects who in the opinion of the Investigator require patellar resurfacing.

Intra-operative exclusion criteria:

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

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

iii) Subjects who require patellar resurfacing