Here is the design of a clinical trial:

Official Title: A Multi-center Randomized Controlled Trial of Acupuncture Treatment for Knee Osteoarthritis With Sensitive Acupoints and Tender Points

Included conditions:
- Acupuncture
- Knee Osteoarthritis
- Sensitive Acupoints
- Tender Points

Study Armgroups:
- {'label': 'acupuncture at highly sensitive points', 'type': 'EXPERIMENTAL', 'description': 'Sterile, single-use filiform acupuncture needles (Hwato Needles, Sino-foreign Joint Venture Suzhou Hwato Medical Instruments Co., China) with a length of 40 mm and a diameter of 0.30 mm will be inserted to a depth of 15-30mm in five highly sensitive points.', 'interventionNames': ['Other: acupuncture']}
- {'label': 'acupuncture at lowly/non-sensitive points', 'type': 'ACTIVE_COMPARATOR', 'description': 'Sterile, single-use filiform acupuncture needles (Hwato Needles, Sino-foreign Joint Venture Suzhou Hwato Medical Instruments Co., China) with a length of 40 mm and a diameter of 0.30 mm will be inserted to a depth of 15-30mm in five low/non-sensitive points.', 'interventionNames': ['Other: acupuncture']}
- {'label': 'no acupuncture (waiting-list)', 'type': 'NO_INTERVENTION', 'description': 'Patients in the waiting-list group will not receive any acupuncture intervention during the study.'}

Interventions:
- {'type': 'OTHER', 'name': 'acupuncture', 'description': 'a stimulation of the body or auricular points', 'armGroupLabels': ['acupuncture at highly sensitive points', 'acupuncture at lowly/non-sensitive points']}

Primary Outcomes:
- {'measure': 'The change of Western Ontario and McMaster Universities Osteoarthritis index total score from baseline to 16 weeks', 'description': 'It consists of 24 items assessing the knee osteoarthritis patients pain, stiffness, and physical function. Each of the 24 items will be graded on a visual analog scale ranging from 0 to 10, with higher scores reflecting more pain, stiffness and poorer physical function.', 'timeFrame': 'Assessments will be conducted at baseline and 16 weeks after randomization'}

Please estimate the sample size based on the assumption: 
SD of total score of 33, a two-sided significance level of 0.025, a power of 0.9, and a loss to follow-up rate of 10%.
Sample size
        Our primary study hypothesis is that acupuncture on high-sensitive points (ie, experimental group) would achieve more reduction in the total WOMAC score than acupuncture on low/non-sensitive points (ie, active control group) or waiting-list group (ie, no treatment group).
        The sample size estimation was based on the mean difference in the change of total WOMAC score from baseline given the estimates obtained from our pilot trial. The following assumptions were made to calculate the sample size: a mean difference of 12 between the high and low/non-sensitisation groups, SD of total score of 33, a two-sided significance level of 0.025 (adjusted for multiple testing) and a power of 0.9. With these assumptions, a sample size 189 patients per arm is required to provide a power of 90% at the alpha level of 0.025 to detect a difference of 12 points between the high and low/non-sensitisation groups. This sample size would provide adequate power to detect the difference between high-sensitisation group versus waiting-list group, on the ground that the treatment effect between high-sensitisation group and low/non-sensitisation group would be smaller than that between high-sensitisation group and waiting-list group.
        To allow for a loss to follow-up of 10%, a minimum sample size of 666 patients (222 patients per arm) at baseline was required.