Here is the design of a clinical trial:

Official Title: The European Robotic Spinal Instrumentation (EUROSPIN) Study: A European Prospective Multicenter Multinational Pragmatic Trial on Robot-guided Versus Navigated Versus Freehand Pedicle Screw Fixation

Included conditions:
- Degenerative Disc Disease
- Spondylolisthesis
- Spinal Stenosis
- Recurrent Disc Herniation
- Spondylodiskitis
- Spinal Tumor
- Spinal Metastases

Study Armgroups:
- {'label': 'Robot-Guided Transpedicular Instrumentation', 'description': 'This arm will comprise all patients that receive transpedicular instrumentation by use of a robotic guidance system (SpineAssist or Renaissance, Mazor Robotics, Ltd., Caesarea, Israel or ROSA Spine, Medtech, Montpellier, France).', 'interventionNames': ['Procedure: Transpedicular Instrumentation']}
- {'label': 'Navigated Transpedicular Instrumentation', 'description': 'This arm will comprise all patients that receive transpedicular instrumentation by use of navigation (computer assistance using CT, O-arm or 3D-fluoroscopic imaging).', 'interventionNames': ['Procedure: Transpedicular Instrumentation']}
- {'label': 'Freehand Transpedicular Instrumentation', 'description': 'This arm will comprise all patients that receive transpedicular instrumentation by use of the conventional freehand technique.', 'interventionNames': ['Procedure: Transpedicular Instrumentation']}

Interventions:
- {'type': 'PROCEDURE', 'name': 'Transpedicular Instrumentation', 'description': 'Transpedicular screw placement and instrumentation', 'armGroupLabels': ['Freehand Transpedicular Instrumentation', 'Navigated Transpedicular Instrumentation', 'Robot-Guided Transpedicular Instrumentation']}

Primary Outcomes:
- {'measure': 'Revision surgery for a malpositioned pedicle screw', 'description': 'We defined the primary endpoint as required revision surgery for a malpositioned or loosened pedicle screw within the first postoperative year.', 'timeFrame': '12 months'}

Please estimate the sample size based on the assumption: 
Power of 0.8, significance level of 0.05, and a low dropout rate.
Sample size calculation
        It was determined that, to detect an absolute intergroup difference of 5% in the primary endpoint, 205 patients are required per group to achieve a power of 1 - Î²=0.8 at Î±=0.05.47 Recruitment for a specific arm is stopped once the 205 patients have been included. The incidence rates are based on the published literature, with an approximated incidence rate of the primary endpoint of ~0% for the intervention and 5% for the control group.5 6 Because the study protocol is in line with the normal clinical follow-up protocol of most centres, a low dropout rate is expected. This leads to a minimum total sample size of 615 patients.