Fig. 9.1 Current plates are not designed to contain marginal fractures of the rim of the radius. Several authors have already shown that placing the plate in the theoretically correct spot carries a high risk of volar radiocarpal dislocation—an unsolvable problem if not detected early.
Fig. 9.2 To overcome this problem, decades ago, Diego Fernandez proposed inserting a K-wire from palmar to dorsal, which was left protruding dorsally. Alternatively, I have inserted a K-wire and left the tip exposed volarly. However, in both instances, the K-wire bothers the patient and may become infected. Obviously, such tenuous fixation of the fracture required immobilization for a number of weeks (m, volar margin).
Jorge Orbay has presented a hook plate extension to control the volar rim. However, the watershed line must be surpassed, a problem shared by other fixation devices.
Fig. 9.3 Management option one. Presently, I manage marginal fracture in three ways. The safest, although more difficult and exacting method, is to insert a cannulated screw through a mini-incision (red arrow). The K-wire has to hit the rim of the radius, where the bone is stronger, as otherwise fragmentation of the small volar rim fragment will occur (yellow arrow). This will be discussed in Chapter 22.
Fig. 9.4 Management option two. If the fragment is small and corresponds to the volar–ulnar corner of the radius, I add a volar ulnar approach to install a small buttress plate (see Fig. 2.51). The space between the ulnar bundle and the flexors is developed, and this gives direct access to this most inaccessible area of the radius when using the volar-radial approach. In this case it was detected several weeks after the surgery that the volar–ulnar corner of the radius had slipped from the ulnar screws. A 2-mm buttress plate applied ulnarly solved the problem.
Fig. 9.5 Management option three. As a general rule, however, my preferred method is to place the plate a bit distally, buttressing the rim. I warn the patient that the plate will most likely have to be removed, particularly if there is any sense of grating during finger flexion. It should be underscored that if the plate is to be placed slightly distal, only plates that allow insertion of variable-angle screws can be used. Otherwise, the screw will penetrate the joint (center). One trick I use when there is a risk of joint penetration is to set the drill in reverse, with minimal pushing of the power drill. In this way, the drill will slide on the harder subchondral bone rather than perforating it.
Fig. 9.6 This 27-year-old mountain biker sustained a fracture 14 days before presentation. No preoperative radiographs were available. The fracture had not been reduced, so even that early, one can expect healing in a compression fracture (the squeezed cancellous bone acts as a graft, boosting union). In the orthogonal cuts, it is clear that this is a complicated fracture.
Fig. 9.7 In the sagittal cuts two features are shown that complicate the management of this case. First, we are dealing with a rim fracture (marginal fracture), with metaphyseal comminution evident in S1 and S2. Second, in S3 and S4 a free osteochondral fragment (FOF) can be seen (arrows).
Fig. 9.8 More worrisome is the existence of comminution of the “keystone” volar ulnar fragment (yellow arrows). A red arrow points to the jammed FOF.
Fig. 9.9 In the articular view one can see that the fracture is composed of three main fragments, plus the FOF (outlined in red and red dotted line).
