**6. Structures which can be identified via dorsal radiocarpal portals**

The images below (**Figures 7**–**18**) illustrate the anatomical structures of the wrist that can be identified from different standard portals.

#### **Figure 7.**

*Standard dorsal portals of the wrist. MCR – midcarpal radial portal, MCU – midcarpal ulnar portal, STT scapho-trapezio-trapezoidal portal, DDRU – dorsal distal radioulnar joint portal, PDRU – proximal distal radioulnar joint portal, ECU –* m. extensor carpi ulnaris, *EDC –* m. extensor digitorum communis*, EDM –* m. extensor digiti minimi*, EPL –* m. extensor pollicis longus*, 1/2;, 3/4;, 4/5;, 6R;, 6 U – radiocarpal portals.*

#### **Figure 9.**

*Straight/radial view from 3 to 4 portal. SC – scaphoid, RSC – radioscaphocapitate ligament, LRL – long radiolunate ligament.*

#### **Figure 10.**

*Straight view from 3 to 4 portal. SC – scaphoid, RLT – radiolunotriquetral ligament, Lu – lunate, LRL – long radiolunat ligament, SLIL – scapholunate interosseous ligament.*

#### **Figure 11.**

*Straight/ulnar view from 3 to 4 portal - Lu – lunate, SC – scaphoid, UL – ulnolunate ligament, UT – ulnotriquetral ligament, SLIL - scapholunate interosseous ligament.*

#### **Figure 13.**

*Ulnar view from 3 to 4 portal – TFCC, proximal part of Triquetrum and ulnar recess. 6 U – possible location of 6 U portal.*

**Figure 14.** *Degenerative central tear of TFCC in "ulna +" variation.*

**Figure 15.** *Rupture of the dorsal SLIL. View from 6R portal. SLIL - scapholunate interosseous ligament.*

**Figure 16.** *View of STT joint from MCR portal. STT – Scaphotrapeziotrapezoidal joint, MCR – midcarpal radial portal.*

**Figure 17.** *View of scapholunate joint from MCR portal.*

**Figure 18.** *View of lunotriquetral joint from MCR portal.*

#### *Arthroscopy*

There are four described arthroscopy portals in the distal radio-ulnar joint. The anatomy of the DRUJ is complex because ulna articulates with both radius and proximal carpal row. Stability of the DRUJ is provided by TFCC with its volar and dorsal distal radioulnar ligaments, connecting at the fovea of the ulnar head. Even in normal wrists DRUJ is a quite narrow place for visualization and instrumentation, therefore it's suggested to use 1.9 mm scope, reduce the traction of the arm and introduce the scope in the DRUJ when the wrist is fully supinated [16–18]. Localization of the DRUJ portals, their functions and structures of the risk are described in **Table 3**.


*ECU –* m. extensor carpi ulnaris*, EDC –* m. extensor digitorum communis*, EDM –* m. extensor digiti minimi*, FCU –* m. flexor carpi ulnaris*, DF – dorsal foveal portal, D-DRUJ – dorsal distal radioulnar portal, P-DRUJ – proximal distal radioulnar portal, V-DRUJ – volar distal radioulnar portal,TFCC – triangular fibrocartilage complex, VU – volar ulnar portal.*

**Table 3.** *DRUJ portals.*

#### **7. Small joint arthroscopy portals**

There mostly are two standard portals for STT, first carpometacarpal joint (CMC), metacarpophalangeal (MCP), proximal interphalangeal joint (PIP) and distal interphalangeal joint (DIP). Arthroscopical access to pisotriquetral (PT) [19, 20] and fourth or fifth CMC joints also are described while usefulness of these procedures is limited or not yet established [10].

First CMC portals are localized approximately 1 cm distally from STT portals on both sides of the first dorsal compartment. Accessory dorsal portal (the dorsal ulnar portal) can be used as necessary for better viewing the radial side of the joint by placing a trocar into the volar portal, across the CMC or the STT joint and out the dorsum of the hand (**Figure 19**) [21].

**Figure 19.** *CMC and STT portals. a – localization on the skin, b – verification with fluoroscope.*

There are two portals – radial and ulnar for MCP, PIP and DIP joint arthroscopies, the naming of them is related to relationship with extensor tendons and they were established by Chen [2]. MCP joint arthroscopies can be successfully used in the rheumatoid conditions when synovectomy and thermal shrinkage can be performed [22–24], or in traumatic cases such as gamekeepers injury [10, 25], collateral ligament ruptures and reduction of the intraarticular metacarpal head fractures as well as in cases of complex MCP joint dislocations [26, 27]. Indications of the MCP joint arthroscopy include also chronic cases of instability, removal of the loose bodies as well as in cases of joint stiffness caused by intraarticular fibrosis or even cases of septic arthritis [18, 28].

Arthroscopy of the PIP and DIP joints has not been widely accepted because of the limited indications and technical limitations. The main indications are inflammatory or septic arthritis as well as removal of foreign bodies. Several authors suggest horizontal placement of the hand instead of using a traction tower, as it is important to be able to flex the joint freely [29, 30]. Cobb reported several cases of the DIP arthroscopic arthrodesis [10]. Since authors have no personal experience in finger joint arthroscopy, further discussion on this topic will not be continued in this chapter.

Many years the use of intra-articular fluid for wrist arthroscopy was considered essential. Francisco del Piñal *et al*. described a technique for dry arthroscopy in 2007 [5].
