Rockwood Adults CH64

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SECTION FOUR • Lower Extremity

Figure 64-12.  Maisonneuve frac- ture. A: An AP radiograph of the ankle and tibia and fibula shows a PER 3 Maisonneuve fracture (AO/OTA C3.1). B: External rota- tion shows lateral displacement of the talus and widening of the syndesmosis.

A

B

ankle rules 357 (Table 64-1) provide assistance in determining the need for x-ray. They offer a highly sensitive 22 and cost- effective 15,358,359 method of identifying those patients, presenting with ankle injuries, that are most likely to have sustained a frac- ture. While Stiell et al. 359 have demonstrated the effectiveness of these rules in a number of centers, other authors have reported difficulties in disseminating the rules, 54 and their applicability in certain patient groups such as diabetics has been questioned. 66

may reveal little due to the speed of the event, an apprecia- tion of the energy transfer involved is important as high-energy mechanisms indicate the likelihood of additional soft tissue complications, compartment syndrome, 30,303,428 the presence of the more complex pilon fracture, or other associated injuries. Certain comorbidities in particular are of importance: Diabetes will not only require preoperative work-up and perioperative blood sugar management, but also indicates an increased likeli- hood of wound complications owing to immunologic and vas- cular impairment. Poorly controlled diabetics in particular are at risk of peripheral neuropathy, which may influence postop- erative weight-bearing decisions. A history of smoking, alcohol abuse, and psychiatric illness similarly increases the likelihood of complications. Clinical examination begins with inspection for deformity, bruising, blistering, skin integrity, and color. A careful palpation of the limb then starts at the fibular head and progresses sequentially down the lateral aspect of the leg to the lateral malleolus and the soft tissues anterior and posterior to it before moving medially across the ankle joint to the medial malleolus and its adjacent soft tissue structures. Palpation of the skeleton of the foot will exclude commonly associated (or missed) injuries such as fractures of the metatarsals or lateral talar process, or disruption of the midtarsal (Lisfranc) articula- tion, which can occur following a similar mechanism. Palpation of the Achilles tendon and the Simmonds 347 or Thompson’s 376 test exclude rupture of this structure. A distal neurovascular assessment includes assessment of temperature and capillary refill. Skin marking of palpable dorsalis pedis and posterior tibial arterial pulsations at presentation will be helpful in later assessment if the condition of the limb deteriorates. The Ottawa

IMAGING AND OTHER DIAGNOSTIC STUDIES FOR ANKLE FRACTURES Radiography

The three standard radiographs are an anteroposterior (AP), a lateral, and a mortise projection of the ankle. Tenderness of the proximal fibula should be investigated with a full-length radio- graph of the leg. A mortise view of the ankle taken in 15 degrees of internal rotation is extremely helpful in assessing the lateral aspect of the ankle which is often poorly seen on the AP view because of the frustral shape of the talus and consequent over- lap of the tibia, fibula, and talus (Fig. 64-13).

TABLE 64-1. Ottawa Ankle Rules

Pain exists near one or both of the malleoli plus one or more of the following: • Age > 55 years old • Inability to bear weight • Bone tenderness over the posterior edge or the tip of either malleolus