Minimally Invasive Total Knee Replacement - Navigated Versus Non-navigated Study

The primary objective of this investigation is to compare the precision of long leg alignment achieved by the two types of procedure. The secondary objectives of this investigation are to:

Compare the accuracy of long leg alignment achieved by the two types of procedure.

Compare the number of optimal implantations achieved by the two types of procedure.

Compare the clinical performance of the knee replacement in subjects who have undergone one of the two types of procedure.

Compare the functional outcome achieved by subjects who have undergone one of the two types of procedure.

Compare the interface radiographic appearance 5 years post-operatively between the two types of procedure.

Compare the accuracy and precision of long leg alignment achieved by the two types of procedure 5 years post-operatively, i.e., at final follow-up and also the change in accuracy and precision between the final follow-up and baseline.

Compare the Adverse Events experienced by the subjects who have undergone the two types of procedure.

Primary endpoint: to compare the precision of the long leg alignment of the Ci MiTKA vs. the non navigated conventional TKA, specifically 3 months to demonstrate the variability of the mechanical axis.

Secondary endpoints: to compare the precision of the long leg alignment of the Ci MiTKA vs. the non navigated conventional TKA specifically to demonstrate the proportion of procedures that fall within a satisfactory alignment window in either group.

Eligibility Criteria:
Inclusion Criteria:

* Male or female subjects aged between 18 and 80 years inclusive.
* Subjects who require a primary total knee replacement and are considered by the Investigator to be suitable for the specific knee prosthesis identified in the protocol.
* Subjects who are able to give and have given voluntary, written informed consent to participate in this clinical investigation.
* Subjects who have given consent to the transfer of his/her information to DePuy.
* 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.

Exclusion Criteria:

* Subjects who have a pre-operative limb deformity of equal to or greater than 10° varus or 15° valgus as defined using the anatomical axis.
* Subjects who have a fixed flexion contracture of greater than 10º.
* Subjects who are clinically obese i.e. BMI ≥30.
* Subjects who have, in the opinion of the Investigator, an existing condition that would compromise their participation and follow-up in this study.
* Female subjects who are pregnant or lactating.
* Subjects who are known drug or alcohol abusers or have a psychological disorder that could affect follow-up care or treatment outcomes.
* Subjects who have participated in a clinical investigation with an investigational product in the last 3 months.
* Subjects currently involved in any personal injury litigation, medical-legal or worker's compensations claims.
* Subjects who have previously had a prosthetic knee replacement device (any type) of the affected knee.
* Subjects who present with ankylosis of the hip joint on the side to be treated or previous ipsilateral Upper Tibial Osteotomy/High Tibial Osteotomy.
* Subjects who require simultaneous bilateral total knee replacements.
* Subjects who have had a contralateral TKA performed less than six months before the proposed TKA.
* Subjects who have had a contralateral TKA and that knee was previously entered in the study.
* Subjects who, in the opinion of the surgeon, will require a contralateral TKA within 6 months of the index procedure.
* Subjects in whom the surgeon intends to implant a knee component that is not one of those listed in Table 1.
* Subjects who have inflammatory arthritis.