Tehran University of Medical Sciences Journal of Orthopedic and Spine Trauma 2538-2330 12 1 2026 03 06 15 18 Ruchit Vyas Senior Resident, GMERS Medical College Gotri, Vadodara, India Meet Patel Junior Resident, GMERS Medical College Gotri, Vadodara, India Tarun Desai Associate Professor, GMERS Medical College Gotri, Vadodara, India Dhaval Tailor Assistant Professor, GMERS Medical College Gotri, Vadodara, India Dhaval Pandya Assistant Professor, GMERS Medical College Gotri, Vadodara, India Chirag Thakkar Professor, GMERS Medical College Gotri, Vadodara, India 2025 05 19 2026 01 26 Background: First metacarpal base fractures, comprising 4% of hand fractures, pose treatment challenges due to the thumb’s functional importance. This study evaluates the functional and radiological outcomes of the Minimally Invasive Reduction and Osteosynthesis System (MIROS) for these fractures. Methods: A prospective study was conducted on 30 patients with first metacarpal base fractures treated with MIROS at a single institute from June 2022 to October 2024, with a 6-month follow-up. Patients aged ≥≥18 years with closed fractures were included; open fractures were excluded. Results: Functional outcomes, assessed by the Kapandji score, showed 80% of patients achieving a perfect score of 10 (mean: 9.85 ± 0.46). Radiographic union occurred at a mean of 5.13 ± 1.30 weeks. Extra-articular fractures had the best outcomes, while Rolando fractures showed reduced function. Conclusion: MIROS demonstrated excellent results, with high functional scores, early mobilization, minimal complications, and faster union compared to traditional fixation techniques. It is a reliable, minimally invasive option for managing first metacarpal base fractures, particularly for extra-articular and Bennett types, although Rolando fractures may require more rigid fixation strategies. https://jost.tums.ac.ir/index.php/jost/article/view/683 https://jost.tums.ac.ir/index.php/jost/article/download/683/457