After a supination trauma, it is important to distinguish a simple distortion from an acute ankle ligament rupture since adequate treatment is associated with a better prognosis (Van Dijk et al. 1996a). Because of the poor reliability of physical examination after inversion trauma of the ankle, stress radiography, arthrography, MRI, and ultrasonography are often performed simultaneously (Friedrich et al. 1993). However, these methods are expensive and their reliability is debated. The reliability of physical examination can be enhanced when the investigation is repeated a few days after the trauma. The accuracy of physical examination has been determined in a series of 160 patients, who underwent arthrography, comparing physical examination within 48 h of the injury and 5 days after the injury. The specificity and sensitivity of delayed physical examination for the presence or absence of a lateral ankle ligament rupture were 84 and 96 %, respectively. The most important features of physical examination are swelling, hematoma discoloration, pain on palpation, and the anterior drawer test (Figs. 9.8 and 9.9). Physical examination is unreliable in the acute situation, since the anterior drawer test cannot be performed due to pain. A few days after the trauma, the swelling and pain have diminished and it becomes clear that the cause of swelling is edema or hematoma (Fig. 9.10). The pain on palpation has become more localized and the anterior drawer test can now be performed. If there is no pain on palpation over the anterior talofibular ligament, there is no acute lateral ligament rupture. Pain on palpation over the anterior talofibular ligament itself cannot distinguish between a rupture and a distortion. Pain on palpation in combination with a hematoma discoloration has a 90 % chance of acute lateral ligament rupture. A positive anterior drawer test has a sensitivity of 73 % and a specificity of 97 % (Figs. 9.9, 9.11, and 9.12). A positive anterior drawer test in combination with pain on palpation over the anterior talofibular ligament and hematoma discoloration has a sensitivity of 100 % and a specificity of 77 %. Delayed physical examination provides a diagnostic modality with a high sensitivity and specificity (Van Dijk 1994; Boytim et al. 1991; Taylor et al. 1992; Van Dijk et al. 1996b). It has been reported by the ISAKOS consensus meeting to be the method of choice (Van Dijk 2005).

Repeated studies and recent systematic reviews have shown that simple sprains can safely be treated conservatively using functional treatment with a short period of rest, cooling (ice), compression, and elevation to reduce the edema (the RICE principle) during the first 1–3 days. Early weight bearing is encouraged. Active range of motion training is started after the acute phase treatment is completed, followed by neuromuscular coordination training using balance boards and peroneal strengthening exercises (Hamilton 1994; Kerkhoffs et al. 2003, 2005).

The ankle must be protected from new injuries during the healing phase by using an external support to control the range of motion. Both ankle tape and ankle braces, e.g., the air-stirrup, are easy to apply, versatile, and effective in stimulating the proprioceptive system. The results of functional treatment are satisfactory in the majority of cases, and most athletes are able to return to sporting activities within a few weeks (Kerkhoffs et al. 2003). It has been shown that costs are significantly lower and ankle function is significantly better following early functional brace treatment than after immobilization in a plaster cast (Karlsson and Andreasson 1992; Karlsson et al. 1991a; Kerkhoffs et al. 2002, 2001).

There is still a controversy as to whether ligament ruptures should be treated nonsurgically either by active functional treatment and early mobilization or by primary surgical. There are only a few prospective, randomized, and controlled studies in literature (Munk et al. 1995; Povacz et al. 1998). A recent meta-analysis concluded that surgical treatment leads to superior results in the short- and mid-term follow-up, in terms of giving-way and residual pain. Also, a large randomized prospective trial of surgical and functional treatment of lateral ankle ligament ruptures with 6–11 years of follow-up revealed that operative treatment leads to less residual pain and giving-way than functional treatment (Pijnenburg et al. 2000). Most studies show that the medium- and long-term results are satisfactory in the majority of these patients regardless of the primary choice of treatment, i.e., surgical repair, cast immobilization alone for 3–6 weeks, or functional treatment based on the principle of early immobilization (Kemler et al. 2011). In a prospective, randomized trial, comparing early mobilization with plaster cast immobilization, it was shown that these treatment modalities prevented late residual symptoms and persistent ankle instability equally well, but patients treated with early mobilization had significantly less pain at 3 weeks and were more likely to be back at work after 1 week (Karlsson et al. 1991a). Taken together, at least 80–90 % of patients with lateral ankle ligament ruptures will regain satisfactory functional stability after nonsurgical treatment.

Still, an unsolved problem is how the approximately 30–40 % of patients who will develop chronic instability in spite of adequate primary treatment and may need surgical reconstruction at a later stage can be identified. Neither the degree of ligament injury nor the degree of radiographic laxity as measured by stress radiographs is reliable predictors (Karlsson 1989). Therefore, this question still remains unanswered.