By Michael R. Boland, MBChB, FRCS, FRACS

For the patient with ulna wrist pain, my favorite tool is to arthroscope the distal radioulnar joint (DRUJ). I started doing radiocarpal and mid-carpal arthroscopy in 1997. I then started doing DRUJ arthroscopy in 2004, after realizing there was a way to visualize the structures and pathology proximal to the articular disc and these pathologies are not visible on radiocarpal arthroscopy. The proximal TFC and deep dorsal and palmar radioulnar ligaments, the fovea and ligamentum subcruetum, as well as the sigmoid notch and ulnar head, are not visible on TFCC intact radiocarpal arthroscopy. They are only visible using DRUJ arthroscopy or artificially created perforations in the TFCC. [1,2]

Distal radioulnar joint (DRUJ) arthroscopy was described by Whipple [3]. I use two dorsal portals. The proximal portal is located at the axilla of the DRUJ, at the flare of the ulna and proximal to the sigmoid notch. This flare is palpable, and the portal is in a direct proximal line with the 4/5 (radiocarpal) portal. This portal is an excellent first portal for visualisation. Reduction of traction, supination of the forearm facilitates access by relaxing the dorsal capsule and the TFC, plus translating the ulna head anteriorly. The joint is identified using a 22-gauge needle and insufflated with about 2 cc of saline. A small incision at the level of the portal entry is made and an artery clip is used to carefully open the capsule, allowing insertion of the trocar, followed by the 30 degree 2.7 mm scope (a 1.9 mm scope can also be used). The second portal is located just proximal to the 6R portal. A 22-gauge need is used and directly visualised under the TFC and over the ulnar head.

There have been recent reports highlighting the incidence of proximal TFCC tears in the presence of a normal radiocarpal arthroscopy [4,5]. Foveal attachment tears have been described in the presence of normal TFC on the radiocarpal portals but with a positive hook test [4,6]. I also find DRUJ arthroscopy helps in diagnosing instability and chondral lesions of the ulna head and sigmoid notch.

Further reading:
1. Yamamoto M, Koh S, Tatebe M, et al. Arthroscopic visualization of the distal radioulnar joint. Hand Surg. 2008; 13:133-8.
2. Seo JB, Kim JP, Yi HS, Park KH. The outcomes of arthroscopic repair versus debridement for chronic unstable triangular fibrocartilage complex tears in patient undergoing ulnar-shortening osteotomy. J Hand Surg Am. 2016; 41.
3. Whipple TL. Arthroscopy of the distal radioulnar joint. Indications, portals, and anatomy. Hand Clin. 1994; 10:589-92.
4. Atzei A, Luchetti R. Foveal TFCC tear classification and treatment. Hand Clin. 2011; 27:263-272.
5. Yamamoto M, Koh S, Tatebe M, et al. Importance of distal radioulnar joint arthroscopy for evaluating the triangular fibrocartilage complex. J Orthop Sci. 2010; 15:210-215.
6. Slutsky D. Arthroscopic evaluation of the foveal attachment of the triangular fibrocartilage. Hand Clin. 2011; 27:255-26.