Traumatic Lunate Fracture Patterns and Outcomes of Treatment

Abstract The purpose of this study was to evaluate the incidence and outcomes of traumatic lunate fractures in a Level I trauma center over a 20-year period. Traumatic lunate fractures are rare, making it difficult to determine their frequency, outcomes, and patterns in clinical practice. A retrospective evaluation of 57 patients was conducted at a single institution from 2000 to 2022. Imaging studies, including radiographs, computed tomography, and magnetic resonance imaging, were reviewed to confirm traumatic etiology and fracture pattern. Fifty-seven lunate fractures met inclusion criteria: 11 were isolated and 46 had associated carpal fractures. Treatment included immobilization in 31 patients and surgery in 26. At a mean follow-up of 20.5 months (range, 2–186), average wrist flexion–extension range of motion was 90 degrees (range, 45–160), and grip strength averaged 26 kg (range, 6–48). Patient-reported outcomes were collected at a mean of 105 months (range, 12–226), with mean scores of 27 for the Disabilities of the Arm, Shoulder, and Hand, 19 for the Patient-Rated Wrist Evaluation, and 77 for the Mayo Wrist Score. Complications included 25 cases of posttraumatic arthritis, 2 cases each of avascular necrosis (AVN), nonunion, and complex regional pain syndrome, and 1 hardware infection. Posttraumatic arthritis was more frequently observed in patients with dorsal intercalated segment instability (DISI), age over 50 years, and displaced fractures. Lunate fractures occur in conjunction with greater arc injuries. Volar pole fractures were the most common fracture type observed. Predictors of long-term osteoarthritis included age over 50 years, DISI deformity, and displaced fractures at the time of diagnosis. Surgical fixation methods resulted in comparable outcomes. Two lunates progressed to AVN, both of which occurred following open operative fixation. Prognostic, Level IV