Postoperative Dorsal Proximal Interphalangeal Joint Subluxation in Volar Base Middle Phalanx Fractures

Introduction  This study was designed to assess factors associated with postoperative dorsal proximal interphalangeal (PIP) joint subluxation after operative treatment of volar base middle phalanx fractures. Our second purpose was to study the association between postoperative dorsal subluxation with postoperative arthritis. Materials and Methods  We identified 44 surgically treated volar base PIP joint fractures with available pre- and postoperative radiographs between 2002 and 2015 at two academic medical systems with a median follow-up of 3.5 months. Demographic, injury, radiographic, and treatment data that might be associated with postoperative dorsal subluxation were collected. Three hand surgeons independently assessed subluxation and arthritis on radiographs. Bivariate analysis was performed to analyze our two study purposes. Results  Six of 44 (14%) had postoperative dorsal subluxation after initial surgery. Bivariate analysis showed no factors with statistically significant association with postoperative subluxation, assessed independently by three hand surgeons on radiographs. Fifty per cent of the joints with postoperative arthritis had postoperative subluxation compared with 21% of joints without postoperative subluxation. No significant association was found between postoperative dorsal subluxation with postoperative arthritis. Conclusion  The association of persistent subluxation and early arthrosis in dorsal PIP joint fracture dislocations needs further study. At this time, it is unclear in what ways persistent subluxation or arthrosis affects the rate of reoperation. Level of Evidence  This is a therapeutic level IV study.