Background: Scaphoid nonunion remains a challenging injury with no clear consensus on treatment. Surgical options, such as bone grafting procedures, are available for the treatment of scaphoid nonunions. While open grafting provides direct visualization, it is theoretically believed to lead to several problems due to the complex ligamentous structure responsible for wrist stability and challenges in the vascular supply of the scaphoid. On the other hand, despite its technical challenges, arthroscopic grafting is thought to avoid complications by preserving surrounding tissues., Questions/purposes: (1) Do patients undergoing bone grafting via arthroscopy for scaphoid nonunion report better function than patients undergoing an open procedure? (2) Do patients undergoing bone grafting via arthroscopy for scaphoid nonunion demonstrate better objective outcomes, such as ROM, extremity strength, and bony union?, Methods: Between January 2012 and January 2022, we operated on 141 patients with scaphoid nonunion. The following patients were excluded from this study: 33 patients with scaphoid nonunion advanced collapse and arthritis, 18 patients with proximal pole fractures, 5 patients with previous surgeries, 16 patients with avascular necrosis, and 8 patients with the radius used as a graft source. In total, 28 patients underwent open grafting, and 33 patients underwent arthroscopic grafting; for both groups, the iliac crest was used as the graft source. Two patients with nonunion were observed in each treatment group, and they were excluded from the study. Results from the remaining 26 patients treated with open grafting and 31 patients treated with arthroscopic grafting (totaling 57 patients) were analyzed. The decision to treat patients with open or arthroscopic methods was not based on a particular reason. In our clinic, we initially preferred open grafting for treating nonunion of the scaphoid. Subsequently, we began to prefer arthroscopic methods for the treatment of these injuries. Twenty patients in the arthroscopic group had additional ligamentous injuries, which were simultaneously treated arthroscopically. All patients in both groups had at least 1 year of follow-up, but 48% of patients treated arthroscopically and 42% of those treated with open approaches were lost before 2 years of follow-up. The remaining patients had follow-up periods longer than 24 months. Our primary analysis was performed at 1 year, and we did a secondary analysis at 2 years. We compared the Patient-Rated Wrist Evaluation (PRWE), QuickDASH, and VAS scores of the patients. We also compared ROM and grip and pinch strength in patients' contralateral wrists. We used predefined, evidence-based thresholds for the minimum clinically important differences for these outcome measures., Results: According to the 1-year functional analysis, we found no clinically important difference between the open surgery group and the arthroscopic surgery group in terms of PRWE score (median [IQR] 19 [25] versus 8 [9], difference of medians 11; p = 0.001), QuickDASH (median 14 [23] versus 7 [11], difference of medians 7; p = 0.004), and VAS scores (median 2 [2] versus 1 [1], difference of medians 1; p = 0.02). At 1 year, there were no differences in objective measurements, including grip strength (median 81 [16] versus 85 [14], difference of medians 4; p = 0.60), pinch strength (median 82 [18] versus 81 [15], difference of medians 1; p = 0.85), and ROM (flexion-extension median 83 [22] versus 85 [13], difference of medians 2; p = 0.74; radial deviation-ulnar deviation median 80 [36] versus 85 [14], difference of medians 5; p = 0.61). In the 2-year analysis, no clinically important difference was observed in terms of PRWE score, and no differences were found in terms of QuickDASH, VAS, strength tests, and ROM between the open and arthroscopic groups. No difference was observed in the union rates between the open group and the arthroscopic group (93% [26 of 28] versus 94% [31 of 33], OR 1.19 [95% CI 0.16 to 9.06]; p = 0.86)., Conclusion: In comparing open surgical procedures with arthroscopic techniques for the treatment of scaphoid nonunions, the present study revealed no differences in functional outcomes and objective measures such as ROM and strength tests at both the 1-year and 2-year follow-up visits. Although technically more challenging, arthroscopy provides a potential advantage, such as addressing concomitant ligament injuries simultaneously. However, patients did not perceive a difference between the two surgical methods. In future studies, investigating long-term outcomes in a larger population will contribute to better elucidating this issue., Level of Evidence: Level III, therapeutic study., Competing Interests: Each author certifies that there are no funding or commercial associations (consultancies, stock ownership, equity interest, patent/licensing arrangements, etc.) that might pose a conflict of interest in connection with the submitted article related to the author or any immediate family members. All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research® editors and board members are on file with the publication and can be viewed on request., (Copyright © 2024 by the Association of Bone and Joint Surgeons.)