Volar Lunate Facet Rim Fractures: K-I Classification and Technique.

 It is difficult to capture and safely support a small volar lunate facet (VLF) fragment and obtain sufficient initial fixation. The challenge in treating VLF rim fractures has resulted in various management options. The purpose of this study was to evaluate the clinical and radiological outcomes of a consecutive series of VLF rim fractures of the distal radius treated surgically and to report the Kondo-Imatani (K-I) classification of these fractures, using computed tomography (CT) images and surgical technique, which is termed the Plate buttress and Double tiered subchondral support (PD) technique.  A retrospective review was conducted on 35 patients with VLF rim fractures that included postoperative clinical evaluations, CT images, and radiographs.  The PD technique to stabilize the VLF fragment with an anatomical and low-profile volar locking plate (VLP).  All fractures healed at the final follow-up; Mayo wrist performance score average was 81.7 points (45-100), and the quick disabilities of the arm, shoulder, and hand (quick-DASH) score average was 9.5 points (0-31.8), showing relatively good clinical results.  VLF rim fragments are not amenable to standard VLP fixation. Unstable fixation may result in postoperative correction loss, aseptic necrosis, malunion, radiocarpal subluxation, and wrist dysfunction. This report described the K-I classification for VLF rim fractures of the distal radius and surgical technique, termed the PD technique, to stabilize the VLF rim fragment with an anatomical and low-profile VLP.  This is a Level IV, case series study.