Nonunion is rare; almost all of these fractures heal. However, if the fracture is unstable the deformity at the fracture site will increase and cause limitation of wrist motion and forearm rotation, pronation and supination . If the joint surface is damaged and heals with more than 1–2 mm of unevenness, the wrist joint will be prone to post-traumatic osteoarthritis (Figures 4 and 5). Displaced fractures of the ulnar styloid base associated with a distal radius fracture result in instability of the distal radioulnar joint and resulting loss of forearm rotation (Figure 6).
Whichever approach is used, the actual injection site can be marked with a fingernail imprint or the barrel of a pen. Next, sterile preparation with a povidone iodine preparation (Betadine) and alcohol can be performed. A 22- to 25-gauge needle can be used for the injection. Local anesthesia with lidocaine before the injection can be used, but with a small gauge needle this is not always necessary. Alternatively, an ethyl chloride spray can be used for local anesthesia. Following puncture through the skin and into the joint space, the injection is accomplished. If resistance is encountered, redirection of the needle may be necessary.