PREVENTING COMPLICATIONS

Arthroscopy has justifiably been touted as a safe and effective method for examining the intra-articular components of the radiocarpal and midcarpal joints,²⁸ and it is considered a relatively low-risk procedure.^29–33 As with any surgical procedure, complications may be encountered, including tendon injury from inappropriately placed portals, skin slough from traction devices, nerve injury, complex regional pain syndrome,^34–36 and rare conditions such as one case involving fistula formation after wrist arthroscopy.³⁷ Associated with each portal are certain anatomic structures with which the surgeon must be familiar to prevent portal-specific complications from occurring.³⁸ This chapter seeks to familiarize the wrist surgeon with these structures and techniques for preventing injury to them. Portal anatomy and the risks associated with each portal based on surrounding anatomic structures are addressed, along with the general risks associated with wrist arthroscopy. The Pearls and Pitfalls section describes common errors made when learning wrist arthroscopy and the techniques employed to avoid those errors.

One commonly employed technique to facilitate wrist arthroscopy is to place the wrist into traction with slight flexion that distracts the joints, making the portal intervals more easily palpable and allowing easier and less traumatic trocar and cannula entry into the joint. One portal is established to allow visualization during placement of the other portals. Most commonly, it is the 3-4 portal. Insufflation of the joint using lactated Ringer’s solution through an 18-gauge needle placed in the 3-4 portal allows distention of wrist joint capsule. This portal is located just distal to Lister’s tubercle and radial to the extensor digitorum communis at the radiocarpal joint line.

For making portal skin incisions, we recommend using a no. 11 scalpel blade in the longitudinal orientation just into the skin with traction on the skin itself, thereby making a skin incision without the trauma of an in-and-out sawing motion, which places deeper structures at risk.

RISKS AND COMPLICATIONS BY PORTAL SITE

Wrist arthroscopy portals are based on the extensor compartments of the wrist. Figure 36-1 provides an overview of the dorsal arthroscopy portals with associated structures.

FIGURE 36-1 Dorsal arthroscopy portals 3-4, 4-5, and 6-R are safe to use because they are clear of the dorsal sensory nerves.

(Photograph courtesy of Pau Galano, MD, Barcelona, Spain.)

1-2 Portal

The structures most at risk by placement and use of the 1-2 portal (i.e., extensor pollicis brevis–extensor carpi radialis longus [EPB-ECRL] portal) are the radial artery and superficial radial nerve. The radial artery lies deep to the first dorsal compartment and therefore should be out of harm’s way if the portal is placed correctly. However, if the portal is placed too radially or too distally, this structure is at risk for injury. The easiest way to avoid damage to the radial artery as it passes deep to the tendons is to make a small portal incision, bluntly dissect down to capsule, and insert the trocar through the capsule after ensuring that the artery is not directly under the trocar.

The superficial radial nerve is also at risk because its dorsal branch lies over the 1-2 portal. The most effective way to avoid laceration or traction of this nerve as the medial branch of the superficial radial nerve arborizes ulnarly is to make the portal skin incision with a no. 11 blade knife inserted only through the skin layer and then by traction on the skin itself, rather than using the blade, to enlarge the portal. Blunt dissection down to the capsule is recommended to ensure preservation of this dorsal branch as it crosses the portal site (Fig. 36-2).

FIGURE 36-2 The 1-2 portal is near to the radial artery and superficial radial nerve.

(Photograph courtesy of Pau Galano, MD, Barcelona, Spain.)

3-4 Portal

The structures most at risk during placement of the 3-4 portal (i.e., extensor pollicis longus/extensor carpi radialis brevis–index extensor digitorum communis [EPL/ECRB-index EDC] portal) are the tendons of the EPL, ECRB, and EDC. This portal should be placed just distal to Lister’s tubercle, around which the EPL tendon passes.

The 3-4 portal is most commonly the first portal established and is most easily established by inserting an 18-gauge needle into the wrist joint just distal to Lister’s tubercle and insufflating the joint with as much solution as the joint can hold comfortably. At that point, the needle and syringe may be removed from the joint while maintaining the capsular distention. The information from needle insertion and palpation of the capsular distention guides placement of the 3-4 portal directly over the radiocarpal joint between the ECRB/EPL and the EDC. The skin is pulled over the tip of the blade to establish the portal, lessening the risk of inadvertently lacerating one of the tendons. After the skin incision is made, the blunt trocar and cannula are inserted, moving the tip in a medial and lateral direction to have tactile feedback and ensuring guidance into the joint without injury to the articular cartilage (Fig. 36-3).

FIGURE 36-3 The 3-4 portal provides excellent, safe access to the extensor pollicis longus, extensor carpi radialis brevis, and extensor digitorum communis tendons in the wrist.

(Photograph courtesy of Pau Galano, MD, Barcelona, Spain.)

4-5 Portal

The structures most at risk during placement of the 4-5 portal (i.e., extensor digitorum communis–extensor digiti quinti [EDC-EDQ] portal) are the terminal branch of the posterior interosseous nerve and the dorsal sensory branch of the ulnar nerve. The posterior interosseous nerve passes deep to the fourth dorsal compartment on the ulnar side dorsal to the wrist to provide sensation to the wrist joint. The risk of damage to this nerve during placement of the 4-5 portal is lessened by placement of the portal in a slightly ulnar position with relation to the EDC tendon. The portal should be placed just radial to the EDQ tendon. From a practical point of view, the loss of the function of this nerve causes no functional deficit, and some think that it diminishes pain in the wrist joint.

The transverse branch of the ulnar dorsal sensory nerve is also at risk during placement of this portal. The transverse branch of this nerve passes distal to the portal, and risk of injury may be lessened by placing the portal as proximal as possible in the wrist joint. We recommend longitudinal portal placement followed by blunt insertion into the joint to ensure preservation of the nerve (Fig. 36-4).

FIGURE 36-4

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