Robot-Assisted Partial Knee Replacement Versus Standard Total Knee Replacement

We will use the 5-item Return To Function (RTF) questionnaire to determine when a trial participant returns to work, leisure, and activities around the home after an injury or surgery (measured as time to return to unrestricted activities).

We will measure knee function using the Oxford Knee Score (OKS), which is a validated and well-used 12 item questionnaire used to measure knee function when performing daily activities after total knee replacement surgery. The OKS is scored on a 0-48 scale with higher scores representing a better outcome.

We will use the Forgotten Joint Score (FJS-Knee) to measure how natural the replaced knee feels. The FJS-Knee is a 12 item questionnaire that aims to assess both function and feeling by asking about patients' awareness of their artificial knee while doing various daily activities. The FJS is scored on a 0-100 scale with higher scores representing a better outcome.

Overground walking kinematic gait analysis will be performed in the clinic environment using a ten-camera optoelectronic motion capture system. Primary gait outcomes will include the knee joint flexion and adduction angle magnitudes and range during the stance phase of gait. Secondary gait outcomes will include stride characteristics as defined above, knee transverse rotation during stance, knee flexion during swing, hip and ankle range of motion and peak magnitudes during stance.

We will use the Euro-Qol 5 Dimensions (EQ-5D) questionnaire, a widely used and well-validated quality of life tool, to measure participant quality of life. The EQ-5D is a comprehensive, 5-item compact health status classification and health state preference questionnaire.

We will use a modified version of the WHO's definition of PPSP, to include a minimum threshold of pain severity:

1. Pain that began after surgery or a tissue trauma;
2. Pain is in an area of preceding surgery or tissue trauma;
3. Pain has persisted for at least three months after surgery; and
4. The pain is not better explained by an infection, malignancy, a pre-existing pain condition or any other alternative cause.
5. ≥4 out of 10 on the numeric rating scale (NRS) from the Brief Pain Inventory (BPI-SF) for "average pain over the last week". The scale ranges from 0 (no pain) to 10 (pain as bad as you can imagine)

We will use The Patient Global Impression of Change (PGIC) scale to assess patients' beliefs about the efficacy of treatment. The PGIC is one item and asks patients to rate the effectiveness of the treatment of interest on a 7-point ordinal scale ranging from "very much improved" to "very much worse

We will collect healthcare resource utilization information (e.g. hospitalization, physician visits) and information on productivity (e.g. time missed from work) to assist with health economic analyses.

We will measure knee ROM using a goniometer at in-clinic visits according to standard practice

We will measure mechanical alignment on pre-operative and post-operative weightbearing x-rays

We will collect all serious adverse events and surgery-related non-serious adverse events throughout the trial for safety monitoring purposes

We will report the number of revision surgeries within the study period including cases of periprosthetic joint infection, aseptic loosening, instability, poly wear, intractable pain, periprosthetic fracture etc.