Surgical Approaches to the Distal Radioulnar Joint Marc Garcia-Elias, MD, PhD a, *, Elisabet Hagert, MD, PhD b For the distal radioulnar joint (DRUJ) to be stable, not only do the articulating surfaces need to be congruent and well aligned but also the capsule and ligaments need to be mechanically and senso- rially competent. According to recent investiga- tions, ligaments should not be regarded as simple static structures maintaining articular align- ment but as complex arrangements of collagen fibers containing mechanoreceptors, which are able to generate neural reflexes aiming at a more efficient and a more definitive muscular stabiliza- tion. 1–4 It is certainly through a proper interaction of the 2 major DRUJ constraints, namely the trian- gular fibrocartilage (TFC) and the ulnocarpal liga- ments, and the 2 most effective DRUJ muscle stabilizers, the extensor carpi ulnaris (ECU) and the pronator quadratus (PQ) muscles, that joint stability is achieved. 5–7 Indeed, patients with substantial passive laxity of the DRUJ may remain asymptomatic if the destabilizing forces experi- enced by the joint are anticipated and quickly in- hibited by an adequate ECU and PQ muscle reaction. If the time between aggression and muscle reaction, the so-called latency time, is unusually prolonged, instability may worsen and result in further ligament injury. 1,2 The latency time, however, is directly dependent on the speed of afferent proprioceptive stimuli from the mecha- noreceptors in the joint to the spinal cord, and back to the muscles. If the DRUJ capsule and liga- ments have been denervated, muscle reactions may also appear, but the response may not be quick enough to provide stability, because this neuromuscular reaction will be a result of afferent stimuli from extra-articular receptors in adjacent tendons and skin. Joint denervation, a procedure often defended as an effective means to achieve pain relief, certainly may not be as benign a proce- dure as often suggested, and this is a factor worth considering in the planning of joint capsulotomies. One of the most notable, yet poorly recognized, advantages of arthroscopy is the ability to observe, manipulate, and correct problems within the joint without creating substantial damage to capsular innervation. This probably explains why procedures done arthroscopically tend to recover function faster than those performed through an open approach. If a condition can be solved ar- throscopically, open surgery is certainly not indi- cated. There are instances, however, where an open approach is mandatory. Depending on the location of the anatomic structure to be ad- dressed, one may choose from various surgical approaches. INNERVATION OF THE DISTAL RADIOULNAR JOINT According to Gupta and colleagues 8 and Shige- mitsu and colleagues, 9 the palmar capsule, ante- rior radioulnar, and ulnolunate ligaments are mostly innervated by branches of the ulnar nerve. Branches from the anterior interosseous nerve (AIN) are additionally found to innervate the volar DRUJ capsule, 10,11 but detailed microscopic studies have not disclosed AIN contributions to a Institut Kaplan, Passeig de la Bonanova, 9, 2on 2 a , 08022 Barcelona, Spain b Hand & Foot Reconstructive Surgery Center, Karolinska Institutet, Storangsv. 10, 115 42 Stockholm, Sweden * Corresponding author. E-mail address: garciaelias@institut-kaplan.com KEYWORDS  Distal radioulnar joint  Proprioception  Surgical approaches  Triangular fibrocartilage complex Hand Clin 26 (2010) 477–483 doi:10.1016/j.hcl.2010.05.001 0749-0712/10/$ – see front matter ª 2010 Elsevier Inc. All rights reserved. hand.theclinics.com