Distal Radioulnar Joint Arthroscopy and the Volar Ulnar Portal

Abstract

Pain on the ulnar side of the wrist remains poorly understood. As attention has shifted toward the myriad causes of ulnar-sided wrist pain, the utility of viewing the wrist from a volar ulnar (VU) perspective has emerged. Lunotriquetral ligament tears have been implicated in the pathogenesis of volar intercalated segmental instabilities. They often originate in the palmar subregion, which is most important for maintaining stability. These tears are difficult to visualize through the 4, 5, or 6R portals. They are well seen through a VU portal, and the direct line of sight facilitates debridement. The VU portal has potential use in the arthroscopic diagnosis and treatment of patients with injuries to the ulnar sling mechanism. It aids in triangular fibrocartilage repairs especially those involving the dorsal aspect between the ulnar styloid and the radial insertion, because the proximity of the 4, 5, and 6R portals makes triangulation of the instruments difficult. Although arthroscopy of the dorsal aspect of the distal radioulnar joint has been well described, it has largely remained a curiosity, with few clinical indications. Recent biomechanical studies have highlighted the importance of the deep attachment of the triangular fibrocartilage complex in maintaining distal radioulnar joint stability. The volar distal radioulnar portal is useful for assessing the foveal attachment. It may be used where there is the suspicion of a peripheral triangular fibrocartilage detachment due to a loss of its normal tension despite the lack of a visible tear during radiocarpal arthroscopy. The judicious use of these portals deserves consideration for inclusion as part of a thorough arthroscopic examination of selected patients with ulnar-sided wrist pain.