The Impact of Scapholunate Angle Correction on Radiographic Union in Adult Scaphoid Nonunion Surgery: An Institutional Retrospective Cohort Study

Background: The objective of the study is to characterize factors associated with radiographic union and pain at final follow-up in surgical repair of scaphoid nonunion. Methods: Patients who underwent scaphoid nonunion repair at our institution between 2005 and 2024 were retrospectively reviewed. Demographic and surgical factors were abstracted. Preoperative, immediate postoperative, and final follow-up scapholunate (SL) angles were measured. Radiographic union (>75% healing) and patient-reported pain at final follow-up were assessed. Associations between SL angle measurements, patient characteristics, and surgical variables with union and pain were evaluated using unpaired t tests and χ 2 tests. Results: Fifty-five patients met inclusion criteria with persistent nonunion occurring in 17 patients (30.1%). Patient sex was significantly associated with union ( P = .045) but not pain at final follow-up ( P = .399). All other demographic factors (smoking status, diabetes, prior surgery) and surgical factors (fracture location, surgical approach, implant type, graft type, and use of adjunct Kirschner-wire) were not significantly associated with union or pain at final follow-up (all P > .05). Among SL angle measurements, only a lower final follow-up SL angle was significantly associated with higher union rates ( P = .038). No SL angle measurement was associated with pain at follow-up (all P > .05). Conclusions: Patient sex was associated with union. No other demographic or surgical variables were associated with union or pain at final follow-up. A lower SL angle at final follow-up was independently associated with successful union, suggesting that correction of carpal alignment may contribute to improved healing in scaphoid nonunion repair.