Stabilization of Volar Ulnar Rim Fractures of the Distal Radius: Current Techniques and Review of the Literature

Abstract

Intra-articular distal radius fractures with involvement of the volar ulnar corner are particularly challenging to treat. Often deemed the " critical corner, " failure to stabilize this fragment can lead to volar subluxation of the carpus. 1–5 Harness et al reported on devastating complications when the volar facet was not adequately stabilized with standard volar plate fixation. 1 The difficulties encountered in securing the critical corner are due to its anatomy. The volar facet is the keystone of both the radiocarpal and the distal radioulnar joints and inade-quate reduction of this fragment result in altered mechanics of the radiocarpal and radioulnar articulations. 6 The distal radius is relatively flat and then curves volarly at the distal margin, ending in the volar ulnar corner from where the short radiolunate ligament originates. 7 Traumatic forces may cause the volar lunate facet to be rotated 180 degrees away from its anatomic position with only a small amount of subchondral bone and limited soft tissue attachments of the volar wrist capsule and intracapsular ligaments available for reduction and fixation. 8 An anatomical study of this facet found that the average dimensions are 19 mm by 3 mm resulting in diffi-culty with its fixation (►Fig. 1). 9 As it is distal to the water-shed line, standard volar plates are unable to safely capture and support this fragment. 1 Placing a standard plate distal to this line to capture this fragment can result in intra-articular penetration of pegs/screws as well as increasing risk for flexor tendon irritation/rupture. 10 Fixation options described for the volar corner include standard volar plate, fragment-specific fixation (wire form or hook plate) or the use of supplemental fixation methods such as suture, pinning, or external fixator. Many of the fixation constructs can be technically demanding and may not be Keywords ► distal radius fracture ► volar ulnar rim fracture ► volar hook plate Abstract Background Distal radius fractures involving the lunate facet can be challenging to manage. Reports have shown the volar carpal subluxation/dislocation that can occur if the facet is not appropriately stabilized. Literature Review Recent emphasis in the literature has underscored the difficulty in managing this fracture fragment, suggesting standard volar plates may not be able to adequately stabilize the fragment. This article reviews the current literature with a special emphasis on fixation with a specifically designed fragment-specific hook plate to secure the lunate facet. Case Description An extended flexor carpi radialis volar approach was made which allows access to the distal volar ulnar fracture fragment. Once provisionally stabilized with Kirschner wire fixation, a volar hook plate was applied to capture this fragment. Additional fracture stabilization was used as deemed necessary to stabilize the remain-ing distal radius fracture. Clinical Relevance The volar marginal rim fragment remains a challenge in distal radius fracture management. Use of a hook plate to address the volar ulnar corner allows for stable fixation without loss of reduction at intermediate-term follow-up.