Rockwood Adults CH64

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SECTION FOUR • Lower Extremity

predictive value for deep deltoid injury and instability. The inad- equacy of stress testing was further confirmed by a subsequent study by the COTS group 330 who found that when patients with an isolated lateral malleolar fracture, but a 5 mm medial clear space on stress testing, were randomized to surgery or no surgery, there was no difference in function at 1 year. None of the nonop- erative patients were permitted to weight-bear during treatment. One operative and six nonoperative patients were found to have displacement of the talus (with 5 or, in one case, 6 mm MCS) at 1 year; however, the displacement may have occurred early during the initial treatment period which would have allowed a simple corrective intervention. Six operated patients had wound complications requiring further treatment, and these patients with complications had a worse outcome. It therefore seems that functional instability cannot be gauged simply from clinical or radiographic measurements and that the integrity of the deep ligament may not be the crucial fac- tor determining functional stability previously thought. This is entirely consistent with our progressive understanding of ankle biomechanics and the concept of dynamic stability. Because the stress examination is “truly insufficient in determining ankle instability,” 389 many centers use a pragmatic walking test to dif- ferentiate stable from unstable fractures. The patient is provided with a removable boot orthosis in the emergency department and is allowed to bear full weight through the ankle. They are reviewed after a week with further radiographs. If there is dis- placement of the mortise, patients are offered surgery. If there is no displacement despite weightbearing, the ankle is considered to be stable and the patient is then reviewed at 6 weeks after injury for final assessment and radiographs. Further research is required to define the natural history of these injuries and to determine which patients require surgery, and which will ulti- mately prove to have adequate functional stability and a benign outcome without surgery. Isolated Medial Malleolar Fractures Pankovitch described injuries to the medial osteoligamentous complex of the ankle based on anatomic and clinical investi- gation. These included fractures of the anterior colliculus with or without deep deltoid ligament rupture, fractures of the pos- terior colliculus, supracollicular fractures (further subdivided into vertical, oblique, and transverse), and avulsion chip frac- tures. 294,295 Herscovici et al. 150 suggested a simpler classification based upon the level of the medial malleolar fracture. Although in 1945 Muller recommended screw fixation of all medial malleolar fractures, 265 isolated medial malleolar fractures can generally be managed nonoperatively. Herscovici et al. 150 reviewed the functional and radiographic outcomes of 57 patients with isolated medial malleolar fractures treated nonoperatively, 3 years after injury. Immobilization consisted of a below-knee non–weight-bearing cast for 6 weeks followed by progressive weightbearing and physiotherapy. In this cohort, despite many of the fractures showing initial displacement of up to 6 mm, only two fractures (3.5%) went on to nonunion. Despite several cases of medial malleolar malunion, no patient showed any evidence of displacement of the ankle mortise or osteoarthritis. Pankovitch et al. 295 also reported good outcomes

with isolated anterior colliculus fractures associated with a deep deltoid ligament tear when managed nonoperatively, although this injury only represented a small number of the patients in their cohort.

Bimalleolar Fractures Conservative Treatment

For all ankle fractures in which the talus can be reduced anatom- ically under the mortise and held there until fracture healing, a good result can be anticipated. Accordingly, Lloyd in 1939 220 opined that fixation of ankle fractures in general was unneces- sary and in 1952 Cox and Laxson 77 concurred that only “in a rare instance it may be necessary to attack the fibular fracture operatively”: Indeed several authors then 201,416 and since 108,324 have reported acceptable results with conservative treatment. Wei et al. 410 published their results of 19 conservatively man- aged unstable bimalleolar and trimalleolar ankle fractures at an average of 20 years post injury. Their patients had been 17 to 79 years of age at the time of injury, and were placed in an above-knee cast for 6 weeks followed by a below-knee cast for a further 6 weeks, and subjected to close surveillance. After 20 years only two of their patients were “mildly symptomatic,” and they reported AOFAS score between 87 to 100, with a mean of 98 points. These findings were substantiated by Joy et al. 176 who studied 118 unstable fractures up to 7 years after injury. Most of these had been treated nonoperatively, and the 40% treated operatively had only undergone isolated medial-sided screw fixation or deltoid repair. Despite the heterogeneity of their patient group, by careful study of their postoperative radio- graphs they were able to show that anatomical reduction of the talus under the plafond resulted in a good clinical result in 85% of cases. Conversely, where reduction was poor, the clin- ical result was also poor in two-thirds of cases. More recently, Willett et al. 414 reported the results of a multicenter RCT com- paring fracture fixation with the application of a close-contact plaster cast under general anesthesia for patients > 65 years. Patient-related outcome in the two groups was no different at 6 months, despite a 10% rate of wound problems in the surgi- cal group. However, 25% of nonsurgical patients experienced a treatment failure, either requiring remanipulation or conversion to ORIF, and a further 15% went on to malunion. Longer-term follow-up is awaited. The principal drawback of a nonoperative strategy is therefore practical: Several authors have shown that maintaining reduction is difficult 43,164,232,414,416 and a prolonged casting regime with nonweightbearing might now be consid- ered burdensome. However, the principle demonstrated here is clear: With accurate reduction and vigilant monitoring a good anatomical and clinical result can be obtained with nonopera- tive management. 89,324 Fixation of Medial Malleolus Only If isolated fractures of the lateral malleolus are stable, it might be assumed that fixation of a medial malleolar fracture would restore the same mechanical environment and be sufficient treatment for bimalleolar fractures; indeed fixation of the medial malleolus alone was considered adequate for many years. 244,265