Rockwood Adults CH64

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CHAPTER 64 • Ankle Fractures

complications. Both of these studies were limited by the inability to place a screw across the syndesmosis with this nail, resulting in some failure of fixation with lateral talar subluxation. The Acumed fibular nail does allow for the placement of a screw across the syndesmosis, controlling fibular length, angu- lation, and rotation. Appleton and McQueen 17 described their results in patients with significant comorbidities that had sus- tained unstable ankle fractures. They obtained good clinical and radiographic results in their cohort of 37 patients with a mean Olerud and Molander score of 87, and few complications. Thevendran and Younger 374 have also reported good results with arthroscopy as an aid to reduction and Bugler et al. 52 reported good clinical and radiographic outcomes in a larger cohort of 105 patients. White et al. 411 have recently presented the results of a randomized trial comparing this nail with standard plate fixation in patients aged over 65, and has shown good radio- graphic and functional results and a significant advantage in favor of the nail in terms of wound-related complications.

The patient set-up is as for fibular plating but a tourniquet is required only if a subsequent open medial malleolar fracture fixation is contemplated. The ankle mortise is reduced with ligamentotaxis. A small cortical step of 2 to 3 mm at the frac- ture is acceptable provided the mortise reduction is anatomi- cal. Modest angular and translational deformities can usually be reduced with the nail as described below. Very occasionally more substantial deformity may need to be addressed by plac- ing a reduction clamp across the fracture via a minimal access incision. To place the nail, a 10-mm longitudinal incision is made beginning 10 mm distal to the tip of the fibula and pro- ceeding distally. A 1.6-mm guidewire is delivered to the very tip of the fibula and driven into the center of the metaphysis of the distal fragment (Fig. 64-23A,B). Correct placement of the guidewire along the longitudinal axis of the distal fragment is critical, especially where there is residual angular displacement, as this allows subsequent fracture realignment. In particular, a medial start point will tend to displace the lateral malleolus laterally resulting in talar subluxation. The cannulated drill is passed over the guidewire to prepare the distal segment, and then exchanged for a hand reamer to prepare the diaphyseal segment. The nail is then implanted in 20 degrees of external rotation (Fig. 64-23C). This is essential to allow later placement of the syndesmosis screw into the center of the tibia, if one is required (Fig. 64-23D). Using the jig, an AP distal locking screw is now predrilled and placed with the screw tip at, but not penetrating, the dorsal cortex (Fig. 64-23E). The jig can now be manipulated to finalize the reduction of the distal fragment. Most commonly light back-taps on the jig are required to regain normal fibular length, and occasionally additional internal rota- tion will complete the reduction. Finally, the (lateral to medial) proximal locking screw is implanted to maintain fibular length and rotation, and to secure the crucial lateral buttress against talar subluxation (Fig. 64-23D). In weak, osteoporotic bone, two proximal locking screws are recommended. The wounds are closed with sutures or steristrips. The patient is allowed full weightbearing the following day. The syndesmosis screw does not usually require removal. Other Fixation Techniques In carefully selected younger patients with good bone stock and simple oblique fracture patterns, two to four lag screws can be used in isolation without a neutralization plate (see Fig. 64-21D), thus minimizing potentially irritating metal- work: Good clinical outcomes have been reported by several authors. 185,243,386 Inevitably, poor surgical execution will affect results, and peroneal tendon irritation from the tip of exces- sively long lag screws has been reported. 134 More importantly, cautious patient selection is crucial and the specific patient and fracture types that are appropriate for this biomechanically less robust construct remain to be defined. An alternative technique of cerclage wiring with a syndes- motic staple involves a minimal degree of dissection and very little prominent metalwork, and was popularized by Cedell in the 1960s, 56 with subsequent variations reported by other aut hors. 7,24,284 It remains popular in Scandinavia although little recent work has been published. Olerud et al. 282 reported the

Preoperative Planning

✔ ✔ Fibular Intramedullary Nailing of Ankle Fractures: PREOPERATIVE PLANNING CHECKLIST

❑ Radiolucent

OR table

❑ Supine with a bolster under the ipsilateral buttock. ❑ Radiolucent block under injured ankle

Position/positioning aids

❑ C -arm from contralateral side

Fluoroscopy location

❑ S mall fragment plate

Equipment

❑ If open reduction is panned—250 mm Hg, otherwise no tourniquet required

Tourniquet

Other

Technique

✔ ✔ Fibular Intramedullary Nailing of Ankle Fractures: KEY SURGICAL STEPS ❑ Careful fluoroscopic assessment of reduction with traction and rotation. Consider percutaneous or open reduction (and reduction clamp) if the fracture widely displaced ❑ 10-mm longitudinal incision, beginning 10 mm distal to the tip of the fibula and proceeding distally ❑ 1.6-mm guidewire placed at the very tip of the fibula and driven into the center of the metaphysis of the distal fragment as seen on both AP and lateral screening ❑ Cannulated drill is passed over the guidewire to prepare distal segment ❑ Hand reamer to prepare the diaphyseal segment ❑ Implant nail in 20 degrees of external rotation ❑ Drill and insert distal locking screw to, but not through, posterior cortex ❑ Backslap nail to ensure fully out to length. Minor alteration of rotation occasionally helps. Assess lateral joint space on mortise view fluoroscopically ❑ Insert proximal locking screw(s)