The use of a volar ulnar portal in wrist arthroscopy

Purpose: The purpose of this study was to quantitatively describe the neurovascular relationships of a volar ulnar (VU) wrist arthroscopy portal. A second purpose was to evaluate whether the use of a VU portal identified additional pathology of the lunotriquetral ligament and ulnar sling mechanism that was not seen through the dorsal portals. Type of Study: This study was an anatomic study and retrospective chart review. Methods: Cadaver dissections established the neurovascular anatomy of the VU portal. Measurements were taken from the portal to the ulnar nerve and artery, the palmar cutaneous branch of the ulnar nerve, and the pronator quadratus. A dorsal capsulotomy was performed to assess the ligamentous interval. A chart review was performed of 23 patients in whom a volar ulnar portal was used. Intraoperative pathology that was identified through the VU portal but was not visible through a dorsal portal was recorded. Postoperative neurovascular complications were noted. Results: The portal was generally > 5 mm radial to the ulnar neurovascular bundle, but no true internervous plane was seen. Tears of the palmar aspect of the lunotriquetral ligament were seen in 7 patients. One patient had a triangular fibrocartilage tear that extended into the dorsal radioulnar ligament. Conclusions: This study provides a safe, standardized approach to the volar ulnar aspects of the radiocarpal joint, which is useful for evaluation of the ulnar sling mechanism and the dorsal radioulnar ligament. The VU portal aids in the diagnosis and debridement of tears involving the palmar aspect of the lunotriquetral ligament. The VU portal should be considered for inclusion in the arthroscopic examination of any patient with ulnar sided wrist pain. Level of Evidence: Level IV.