Distal Radioulnar Joint Instability: Diagnosis and Treatment

Abstract

Distal radioulnar joint (DRUJ) instability and triangular fibrocartilage complex (TFCC) tears are more usual than estimated and are frequently overlooked. Diagnosis is often clinical, which can be confirmed using computed tomography (CT) scan and magnetic resonance imaging (MRI). In doubtful cases, bilateral computed tomography in neutral forearm rotation, supination, and pronation should also be performed. Wrist arthroscopy can be diagnostic and therapeutic for ulnar-sided wrist pain. Two systematic reviews showed equivalent outcomes between open and arthroscopic repair of the TFCC. There is scant proof to advise one technique over the other in clinical practice. TFCC repair and reconstruction are contraindicated when there is a bony deformation of the radius or ulna or osteoarthritis of the DRUJ. With the advancement of implant arthroplasty, salvage procedures are less desirable. Constrained distal radioulnar arthroplasty is stable, and the longevity is encouraging.

Keywords: Distal radioulnar joint; Instability; Treatment; Triangular fibrocartilage complex.

Figure 1

DRUJ is subluxated following a displaced distal radius fracture

Figure 2

ECU subsheath (left) and a part of the ulnocarpal ligaments (upper) are exposed during an open TFCC refixation procedure

Figure 3

It shows the anatomy of the interosseous ligament and the distal oblique ligament, which plays a role in distal radioulnar stability and has to be avoided during the Darrach procedure

Figure 4

Dorsal lunate facet malunion causing instability, pain, and limited wrist motion

Figure 5

Bone reduction forceps for reduction of the dorsal fragment through the volar approach

Figure 6

Injury occurs to the DRUJ during a Galeazzi fracture-dislocation (a), which is restored after surgical intervention (b, c).

Figure 7

Coronal view of the wrist CT scan shows distal radius fracture with instability and incongruence in the sigmoid notch

Figure 8

In the Mino technique, we draw two lines, with the first through the dorsal ulnar and radial borders of the radius. The other line passes through the volar ulnar and radial borders of the radius

Figure 9

In the congruency method, we assess the arc of the ulnar head relative to the arch of the sigmoid notch

Figure 10

In the epicenter method, we draw a line from the center of the head to the ulnar styloid center to determine the center of rotation of the DRUJ. We then draw a line perpendicular to the chord of the sigmoid notch to the center of the rotation of the DRUJ. The DRUJ is considered normal if this line falls in the middle half of the sigmoid notch

Figure 11

In the ratio method, we use the concentric circles to find the ulnar head center. A line is drawn from the volar to the dorsal edge of the sigmoid notch. A perpendicular line to this line is drawn toward the ulnar head center. The ratio is then measured. The typical ratio is equal to $\frac{\mathbf{AD}}{\mathbf{AB}}\pm 2\mathbf{SD}$

Figure 12

MRI coronal and axial views show ECU tendinitis in distal radioulnar joint instability by caput ulnar syndrome (a, b, c), and intra-op (d)

Figure 13

The shaver is under the TFCC through the ulnar-sided tear from the foveal attachment

Figure 14

Arthroscopic repair of the TFCC with cross sutures passing through the TFCC and the bone tunnel existing at the fovea

Figure 15

TFCC tear type IB, the transosseous suture refixation provide reasonable fixation

Figure 16

Triangular fibrocartilage complex repair through bone tunnels (Palmer type 1D).

Figure 17

Ulnar shortening osteotomy improves the osseous stability at the DRUJ in the ulnar impaction syndrome

Figure 18

A tendon graft is passed through a bone tunnel in the radius in the anteroposterior direction just proximal to the TFCC insertion. The tendon is passed around the ulnar neck extra-articularly to secure the ulnar head against the sigmoid notch

Figure 19

Sauvé-Kapandji arthrodesis is a salvage procedure for post-traumatic instability and arthritis at the DRUJ

Figure 20

Aptis DRUJ prostheses, Aptis Medical, USA DRUJ prosthesis: This prosthesis is a constrained ball and socket joint composed of a radial and an ulnar component that functions the sigmoid notch and ulnar head. The radial component is fixed to the radius by the distal peg and cortical screws

Figure 21

Intraosseous distal radioulnar joint prosthesis is a new design based on the Sauvé-Kapadji procedure to help stabilize the DRUJ (a, b, c, d). (Reproduced with permission from the Archives of Bone and Joint Surgery Journal)