Chapter 10 Arthroscopically Assisted Foveal Reinsertion of the Triangular Fibrocartilage Complex

10.1055/b-0035-121120

Chapter 10 Arthroscopically Assisted Foveal Reinsertion of the Triangular Fibrocartilage Complex

Introduction

The triangular fibrocartilage complex (TFCC) is the primary stabilizer of the distal radioulnar joint (DRUJ). Recent histological and functional studies1 have elaborated on the three-dimensional structure of the TFCC and identified three components: (1) the proximal triangular ligament; (2) the distal ligament “hammock;” and (3) the ulnar collateral ligament (UCL), attached to the deep part of the sheath of the extensor carpi ulnaris (ECU) tendon. This distal hammock-like structure and the UCL form the “distal TFCC,” whereas the proximal ligament is considered the “proximal TFCC” ( Fig. 10.1 ). Within this structure lie both “arms” joining the anterior and posterior ulnar fovea and the edges of the distal radius—the real stabilizers of the DRUJ. These two main structures may be injured independently of each other, which can result in a specific clinical picture and DRUJ instability. Several arthroscopically assisted transosseous repair techniques have been described—either at the ulnar metaphyseal region, as described by Nakamura et al,2 or at the DRUJ itself, as described by Atzei et al.3 The only entirely arthroscopic technique, which has been described by Geissler,4 uses three portals and requires expensive disposable instrumentation. This chapter describes two simple, reliable, and reproducible techniques.

**Fig. 10.1** Schematic illustration of the two portions of the triangular ligament. Distal peripheral portion of the triangular fibrocartilage complex (D-TFCC) and the proximal portion that inserts into the fovea of the ulnar head (P-TFCC). UCL, ulnar collateral ligament.

Operative Technique 1 (Anchor)

Patient Preparation

The procedure is performed on an outpatient basis under local anesthesia. The patient is supine with the arm resting on a table with a pneumatic tourniquet. Vertical traction of 5 to 7 kg is applied to the hand.

Exploration

The arthroscope is introduced through the 3–4 radiocarpal portal, which allows visualization of the radiocarpal joint. In isolated foveal avulsion of the TFCC (stage 2 Atzei–European Wrist Arthroscopy Society [EWAS]), the appearance of the TFCC is usually normal. The hook test, which is performed by placing the probe at the styloid recess and applying a radial and distal pull, will raise the TFCC, indicating an avulsion of the TFCC from the fovea ( Fig. 10.2a–c ).

In patients where the foveal avulsion is associated with a peripheral tear (stage 3 Atzei–EWAS), there will also be a loss of the “trampoline” effect, considered a positive “trampoline test.”

Extending the Medial Incision

With the arthroscope inserted through the 3–4 radiocarpal portal, a needle is first inserted through the 6U portal medial to the ulnar styloid and distal to the TFCC ( Fig. 10.3a, b ). The arthroscope is then introduced through the DRUJ portal, located approximately 1 cm proximal to the 6R portal ( Fig. 10.4 ), underneath the TFCC. The view is often distorted at the zone of injury.

A hypodermic needle is inserted through the direct foveal (DF) portal to identify the avulsion of the TFCC at the fovea ( Fig. 10.5a, b ). This portal is located anterior to the ulnar styloid and on top of/distal to the ulnar head, with the forearm in supination.

**Fig. 10.2a–c** a Drawing showing a foveal avulsion associated with a peripheral tear. The probe at the styloid recess raises the triangular fibrocartilage complex (TFCC) (hook test). The red arrow shows the distal displacement of TFCC when the foveal attachment is disrupted. b Arthroscopic view showing the avulsion of the TFCC which seems peripheral. c Arthroscopic view showing a positive hook test, reflecting the foveal TFCC avulsion.

An incision of ~ 1 cm is then made joining the two needles while identifying and protecting the dorsal cutaneous branch of the ulnar nerve ( Figs. 10.6 and 10.7 ).

Exploration and Debridement of the Distal Radioulnar Joint

First, a blunt mosquito forceps is used to identify the DF portal ( Fig. 10.8 ). Then a full-radius shaver is introduced, and, under arthroscopic control, the area of the foveal insertion of the TFCC is cleaned and debrided ( Fig. 10.9a, b ). Scar tissue and ligament remnants often obscure visibility in this area until progressive cleaning creates better clarity ( Fig. 10.10 ).

**Fig. 10.3a, b** a Intraoperative view showing the passage of the needle through the 6U portal; the scope is in the 3–4 radiocarpal portal, and the probe is in the 6R portal. b Arthroscopic view showing the needle positioned through the 6U portal exiting above the triangular fibrocartilage complex.

**Fig. 10.4** View showing the needle used to find the correct position of the incision for creating the distal radioulnar joint (DRUJ) portal. The scope is in the 3–4 radiocarpal portal, and the other needle is in the 6U portal.

Insertion of the Anchor

With the arthroscope remaining in the same position for viewing the foveal insertion of the TFCC, a drill is used to create a hole in the ulnar head at the fovea ( Fig. 10.11a, b ). Sometimes a blunt forceps is introduced through the foveal portal, and its jaws are opened so the drill can be inserted between the forceps, allowing better visualization ( Fig. 10.12a–c ). An anchor is then inserted through the foveal portal, a direct path ( Fig. 10.13a–c ). We prefer to use a bioabsorbable anchor. With the anchor in place at the foveal insertion of the TFCC on the ulnar head, the sutures are left outside through the medial portal.