Clinical outcome of scaphoid malunion as a result of scaphoid fracture nonunion surgical treatment: A 5-year minimum follow-up study

Abstract

Although scaphoid fractures are the most common carpal bone fractures, as many as one fourth of them may be missed during the acute stage of fracture because of their anatomical complexity. Nondisplacement and simple fracture of the scaphoid is often invisible on plain radiographs [1]. Moreover, because of the scaphoid's complex and insufficient blood supply, nonunion or malunion commonly occurs unless appropriate treatment is administered [2]. Therefore, it is most important that the initial diagnosis is made precisely, and adequate surgical remedies should be available to resolve nonunion or malunion if early diagnosis or treatment is delayed. Among the various reconstruction techniques for scaphoid nonunion reported, curettage and internal fixation with bone graft and vascularized bone graft are known to be effective [3], [4], [5], [6], [7] and [8]. However, if severe humpback deformity or preoperative shortening of the scaphoid are present, malunion may occur despite effective surgical treatments [9] and [10]. Malunion resulting from surgery for scaphoid fracture nonunion is a typical complication; however, there has been little consideration regarding the clinical outcomes. Some previous studies had reported the poor clinical outcome of scaphoid malunion [11] and [12]. However, the validity of findings of those studies on malunion has been questioned because of concerns regarding the use of the lateral intrascaphoid angle to assess malunion, as this has poor reproducibility [13] and [14]. Thus, in this study, we used the height/length ratio as a more reliable measure of scaphoid malunion and evaluated the midterm clinical outcomes of scaphoid malunions that occurred after reconstruction for scaphoid fracture nonunions in comparison with those of well-united scaphoids, and analyzed the correlation between the degree of scaphoid malunion and clinical outcomes.