Operative Stabilization of Distal Radius Fractures Presenting with Ulnar Head Subluxation/ Dislocation Addresses DRUJ Instability without Further Stabilization Procedures.

OBJECTIVES To determine the prevalence of ulnar head subluxation/dislocation in distal radius fracture and to discuss management, surgical outcomes, and relevant anatomy. DESIGN Retrospective review of prospectively collected data. SETTING Urban tertiary care hospitalPatients/Participants: 271 patients with displaced distal radius fractures undergoing surgical management were reviewed to determine the incidence of ulnar head subluxation or dislocation using the criteria defined by Mino et al. MAIN OUTCOMES Post-operative CT and radiographs were assessed for sigmoid notch and DRUJ reduction and fracture healing. Range of motion, functional limitation, and pain were documented at final outcome. RESULTS Of the 271 cases, there were 8 cases of pre-reduction DRUJ subluxation/dislocation, including two frank dislocations and six subluxations (2.95%). All were treated with open reduction and internal fixation of the distal radius (ORIF) with a volar locked plate. Additionally, one patient underwent ORIF of an associated distal ulnar shaft fracture and another, who had a Grade 1 open fracture over the distal ulna, underwent open TFCC repair. The remaining six patients had closed reduction of the DRUJ without further stabilizing procedures. All had stable DRUJ joints following ORIF, both intra-operatively and at final follow-up. All ulnar heads were located within the DRUJ on post-op CT; using the more sensitive radioulnar ratio there was residual ulnar head subluxation in 5/8 patients. Range of motion and functional outcome were excellent at an average of 133 weeks post-operatively. The DRUJ was stable at long-term follow-up in all patients. CONCLUSIONS Ulnar head subluxation/dislocation is an uncommon injury in the setting of distal radius fracture. When present, it can usually be treated effectively with operative stabilization of the distal radius fracture without further stabilizing procedures. LEVEL OF EVIDENCE Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.