Here is the design of a clinical trial:

Official Title: Efficiency Assessment of the Methodology for the Follow-up of Patients With Knee Prostheses

Included conditions:
- Total Knee Arthroplasty

Study Armgroups:
- {'label': 'Total knee prosthesis 1', 'type': 'EXPERIMENTAL', 'description': 'prosthesis with medial condylar stabilization', 'interventionNames': ['Procedure: Total knee prosthesis with medial condylar stabilization']}
- {'label': 'Total knee prosthesis 2', 'type': 'ACTIVE_COMPARATOR', 'description': 'traditional prosthesis with central pivot stabilization', 'interventionNames': ['Procedure: Total knee prosthesis with central pivot stabilization']}

Interventions:
- {'type': 'PROCEDURE', 'name': 'Total knee prosthesis with medial condylar stabilization', 'description': 'Surgery will be done of Total knee prosthesis with medial condylar stabilization', 'armGroupLabels': ['Total knee prosthesis 1']}
- {'type': 'PROCEDURE', 'name': 'Total knee prosthesis with central pivot stabilization', 'description': 'Surgery will be done of Total knee prosthesis with central pivot stabilization', 'armGroupLabels': ['Total knee prosthesis 2']}

Primary Outcomes:
- {'measure': 'Maximum walking speed (MWS)', 'description': 'Maximum distance traveled by the body per unit of time (m·s-1). It will ask for participants to walk safely and as quickly as possible, without running, in a 10 m, straight and flat walkway. The two first and last stride will be discarded from the analysis in order to avoid the acceleration and deceleration of the star and end of the gait. The gait speed will be measured with the NedAMH/IBV v5.6 (Institute of Biomechanics of Valencia, Spain) software which uses two infrared or red light photocells to measured gait speed. This outcome will be measured in all the assessment times of the study.', 'timeFrame': '1 year'}

Please estimate the sample size based on the assumption: 
A statistical significance level of 5% (two-tailed) and a power of 90%, with an expected dropout rate of 20%.
Sample size and recruitment
        The sample size was determined using G*Power V.3.1. Due to the lack of previous studies with a similar methodology to that proposed in this protocol, the sample size estimation was based on the expected differences on gait between two participant groups who received two different prosthetic at 6-month follow-up post-TKA,32 in whose work the medial stabilisation model proposed in this protocol is used. A small-medium effect (f=0.15), a statistical significance of 5% at the two-tailed level and a power of 90% are set, which gives a total of 82 people to be recruited. If 20% of the possible dropouts are considered, the initial recruitment will be of 99 people. From the beginning of the study, the coordinating researcher and head of the Orthopedic Surgery and Traumatology Service has reviewed the scheduled surgeries and asks each patient with scheduled TKA if they are interested in participating. All patients who show interest are informed, and the criteria for participation in their usual pre-surgical trauma appointment are evaluated. The study recruitment period will remain open for 1 year.