Comparison of Alignment Achieved Using the VELYS Robotic-Assisted Solution Versus Manual Instrumentation in Total Knee Arthroplasty

The primary objective of this clinical investigation is to evaluate whether the accuracy to plan of the long leg alignment achieved with VELYS Robotic-Assisted Solution is non-inferior to the accuracy to plan of the long leg alignment achieved with the manual ATTUNE Intuition instrumentation. This will be assessed by measuring the Hip-Knee-Ankle angle (HKA) on long-leg X-rays taken at 12 weeks and comparing to the planned HKA. A smaller number represents improved accuracy and a better outcome.

The accuracy of the distal femoral varus-valgus angle was assessed by comparing the angle measured on an X-ray 12 weeks post operatively to the angle that the surgeon was targeting or planning intra operatively. A smaller number represents improved accuracy and a better outcome.

The accuracy of the proximal tibial varus-valgus angle was assessed by comparing the angle measured on an X-ray 12 weeks post operatively to the angle that the surgeon was targeting or planning intra operatively. A smaller number represents improved accuracy and a better outcome.

The accuracy of the femoral component flexion angle was assessed by comparing the angle measured on a lateral X-ray 12 weeks post operatively to the angle that the surgeon was targeting or planning intra operatively. A smaller number represents improved accuracy and a better outcome.

The accuracy of the Tibial slope angle was assessed by comparing the angle measured on a lateral X-ray 12 weeks post operatively to the angle that the surgeon was targeting or planning intra operatively. A smaller number represents improved accuracy and a better outcome.

Rate of local Adverse events and local serious adverse events reported within the first 90 days and the first year post surgery. Local means at the site of the procedure (i.e. the operated Knee). Serious adverse events are events that required medical or surgical intervention to prevent a serious impairment to health.

Investigators conducted an intra-operative assessment of the condition and function of key soft tissue structures in both Manual and Robotic-assisted cohorts.

The descriptive system comprises five dimensions: mobility, self-care, usual activities, pain/discomfort and anxiety/depression. Each dimension has 5 levels: no problems, slight problems, moderate problems, severe problems and extreme problems. The patient is asked to indicate his/her health state by ticking the box next to the most appropriate statement in each of the five dimensions. Scores are derived by a 5 digit code. The higher the number, the better the overall health status of the patient with 1 (meaning full health) and 0 (meaning a state as bad as being dead).

The Forgotten Joint Scores comprise measures for the assessment of joint-specific patient-reported outcome (PRO). These PRO questionnaires focus on patients' awareness of a specific joint in everyday life. Joint awareness can be simply defined as any unintended perception of a joint. This may include strong sensations like pain, but also includes more subtle feelings like mild stiffness, subjective dysfunction, or any discomfort. The FJS-12 score ranges from 0 to 100, with 0 being the worst score and 100 being the best. A higher score means the patient is better able to forget about the artificial joint in daily life. So, the higher the score, the better the outcome is.

A knee-specific instrument that derives a score developed to assess the patients' opinion about their knee and associated problems. The maximum total score is 100 indicating no symptoms and the minimum is 0 indicating extreme symptoms.

A knee-specific instrument that derives a score developed to assess the patients' opinion about their knee and associated problems. The maximum total score is 100 indicating no symptoms and the minimum is 0 indicating extreme symptoms.

A knee-specific instrument that derives a score developed to assess the patients' opinion about their knee and associated problems. The maximum total score is 100 indicating no symptoms and the minimum is 0 indicating extreme symptoms.

A knee-specific instrument that derives a score developed to assess the patients' opinion about their knee and associated problems. The maximum total score is 100 indicating no symptoms and the minimum is 0 indicating extreme symptoms.

A knee-specific instrument that derives a score developed to assess the patients' opinion about their knee and associated problems. The maximum total score is 100 indicating no symptoms and the minimum is 0 indicating extreme symptoms.

A single patient reported question that asks the patient to score their level of satisfaction with their knee from 0-10, with 0 being fully satisfied and 10 being fully unsatisfied

Subjects are asked how much knee pain they have had in the last week while resting (0-10) and during activity (0-10) with 0 being no pain and 10 being worst pain, therefore lower score is a better outcome.

The effect of learning curve on the accuracy was assessed by comparing the accuracy between the first 10 cases each surgeon completed and the subsequent cases. The accuracy was assessed by measuring the Hip-Knee-Ankle angle (HKA) on long-leg X-rays taken at 12 weeks and comparing to the planned HKA. A smaller number represents improved accuracy and a better outcome.