N Johnson, Roshni Francis, Surabhi Choudhary, Kanagaratnam Jeyapalan, Joseph Dias
Aims: The association between scaphoid fractures and ligament injuries is uncertain, and the clinical relevance is not well established. The aim of this study was to undertake a secondary analysis of data from the Scaphoid Waist Internal Fixation for Fractures Trial (SWIFFT) to evaluate the incidence of concurrent ligament injuries in patients with a scaphoid waist fracture displaced by ≤ 2 mm, explore the radiological changes between one and five years after the injury, and assess whether there is an association between the characteristics of the fracture and ligament injury. Methods: All 439 patients from the SWIFFT had baseline measurements available from plain radiographs and CT scans. Further follow-up measurements were undertaken from CT scans in 292 patients at 52 weeks and 239 patients at five years. A total of 345 patients had radiographs suitable for assessment of the scapholunate (SL) and lunotriquetral (LT) intervals at 52 weeks and/or five years. Results: Only 12 patients (2.8%) had widening of the SL gap by > 3 mm on initial imaging. There was no progression of these gaps at five years, and no patient had widening of the LT gap. Conclusion: Injury to the interosseous intercarpal ligaments causing diastasis of carpal bones is rare in patients with a scaphoid waist fracture displaced by ≤ 2 mm. Treatment of the fracture with a cast or surgical fixation, without additional imaging or intervention for a potential ligament injury, appears adequate for most fractures. If there are ligament injuries not identified with standard imaging, they do not seem to progress.