Diagnosis of a high ankle sprain requires an accurate history, physical image, and imaging studies. The history provides information on the mechanism of current injury and prior ankle instability issues. The location of injury, tenderness, and clinical examination assist in evaluating for possible syndesmotic injury. Four view radiographs are the initial radiologic workup (AP, lateral, mortise views of the ankle, and orthogonal view of entire tibia-fibula). Weight-bearing films are preferred if the patient can tolerate the exam; otherwise bilateral non-weight-bearing films can be obtained (Smith and Bach 2004). The medial clear space, tibiofibular overlap, and tibiofibular clear space are the three critical areas to evaluate (Zalavras and Thordarson 2007) (Fig. 6.6). The medial clear space is the distance between the medial talus and the lateral aspect of the medial malleolus at the level of the talar dome. In neutral positioning, this space should be less than or equal to the distance between the talar dome and tibial plafond. Associated deltoid ligament injury is suspected when the medial clear space is widened (Ebraheim et al. 2006). On the AP view, tibiofibular overlap should be at least 6 mm and on the mortise view greater than 1 mm, measured 1 cm above the tibial plafond (Zalavras and Thordarson 2007). Tibiofibular clear space is measured 1 cm proximal to the tibial plafond. The distance between the medial border of the fibula and the lateral aspect of the tibia should be less than 6 mm on both the mortise and AP views. Radiographs are the initial workup although anatomical differences and borderline measurements may lead to further cross-sectional imaging. CT scan is more sensitive in detecting subtle tibiofibular diastasis (Doughtie 1999). MRI is useful for the confirmation of the diagnosis as the syndesmotic complex is directly visualized (Fig. 6.7). A secondary sign frequently associated with syndesmotic injury is fluid extending greater than 12 mm into the tibiofibular recess on coronal sequences (Morris et al. 1996). At the professional level, MRI is increasingly used to confirm which structures are injured and evaluate for concomitant injuries (Sikka et al. 2012). Even though MRI provides this advanced level of detail, the exact role of MRI in prognosis and treatment management is still unclear (Jones and Amendola 2007).

In athletes, syndesmotic ankle sprains are typically graded accorded to the West Point Ankle Grading System (Smith and Bach 2004). Grade 1 is no evidence of instability with minimal edema and tenderness. On MRI, grade I injuries are isolated to anterior inferior tibiofibular ligament (AITFL). Grade 2 is a decreased range of motion, moderate edema and tenderness, and possible instability. The difficulty in determining instability in grade 2 injuries has the potential to lead to underdiagnosis and inadequate treatment with devastating consequences. MRI grade II is injury to the AITFL and interosseous ligament. Grade 3 injuries demonstrate definite instability and significant edema and tenderness. MRI grade III is injury to the AITFL, interosseous, and posterior inferior tibiofibular ligaments. MRI grade IV is a grade III and injury to the deltoid ligament.

The treatment goal is to restore anatomical alignment between the tibia and fibula to allow ligament healing. Compared to lateral ankle sprains, syndesmotic sprains can lead to persistent pain and disability with a significantly longer mean lost time from participation in the NFL at 15.4 days (Osbahr et al. 2013). A higher-grade injury on MRI has been correlated to a longer time on the disability list for players (Sikka et al. 2012). Unlike lateral ankle sprains, syndesmotic injury is not always treated conservatively. A majority of NFL syndesmotic injuries do not demonstrate diastasis, and a survey of NFL athletic trainers showed that most syndesmotic sprains are treated nonoperatively with immobilization, corticosteroid injection, rest, and ice being the most frequent treatments (Gerber et al. 1998). However, with frank diastasis, surgical correction is recommended; time away from play ranges from 9 to 16 weeks (Osbahr et al. 2013).

The ACL’s major role is to limit anterior translation of the tibia and secondary restraint to valgus/varus angulation when the knee is extended. Of note, given the increased awareness of head injuries with substantial penalties and fines for hits to the helmet, theories are arising that players are committing more low tackles resulting in an increase in ACL tears. However, a recent unofficial survey (Vrentas 2013) and a review of ACL tears showed that noncontact tears were more common than contact-related injury (Boden et al. 2000). Players’ strength and intensity during play are thought to contribute to these injuries. Planting the foot and cutting movements (decelerating prior to a change in direction) occur often, and this motion exerts a valgus load to a nearly fully extended knee with resulting overloading of the ACL (Olsen et al. 2004; Yu and Garrett 2007) (Fig. 6.8). Other proposed risk factors for noncontact ACL injuries include female gender, landing on the hindfoot, knee abduction, and hip flexion (Boden et al. 2009). Contact ACL tears in football are usually also a valgus injury and occur when a player takes a direct blow to the anterior thigh or lateral knee on a planted foot (Boden et al. 2000).

When a player has a sports hernia, the media may use the words “abdominal strain” to describe the injury. “Sports hernia” is a misnomer because this injury is not a hernia by the traditional medical classification. Sports hernia (also known as athletic pubalgia) is a spectrum of musculotendinous strain involving the rectus abdominis, adductor longus, and pubis. The rectus abdominis and adductor longus share a common aponeurosis with the attachment on the pubis (Omar et al. 2008). Although the exact mechanical cause of injury is poorly understood, a leading theory is that an imbalance develops between the downward and lateral pull of the adductor muscles opposing the upward and oblique torque of the abdominal muscles (Fig. 6.13). In football, this may stem from cutting and explosive twisting movements where the hip is abducted and extended with rotation (hyperextension) at the waist. This disequilibrium results in tearing of the rectus abdominis, adductor longus aponeurosis, and reactive bone marrow edema in the pubis. An initial minor injury may result in instability at the pubis predisposing to further damage and instability with even minor activity (Omar et al. 2008). A majority of sports hernias are the result of repetitive trauma rather than acute injury (Preskitt 2011), and a common symptom is recurrent pain with activity that decreases at rest. The injuries can have a slow onset over weeks to months and recur with inadequate treatment.

Hip pointer is a general term used to describe a variety of injuries to the anterior iliac crest, greater trochanter, and surrounding soft tissues. Confusion arises because in the strictest sense, “hip pointer” injury only includes a contusion to the iliac crest (Blazina 1967) as opposed to a broader use of the term referring to osseous and soft tissue injuries encompassing the entire region of the iliac crest. These injuries are most frequent in contact sports because of the direct hits to the pelvis (Hall and Anderson 2013). Also, players frequently fall to the ground landing on the anterior pelvis resulting in injury. While players wear padding to protect themselves, the degree of padding over the anterior iliac crest is usually minimal to limit the amount of restriction to a player’s range of motion and quickness. The result is relatively superficial bone and soft tissue that can readily be injured. Bone contusion and hematoma at the anterior iliac crest are the “classic” hip pointer injury, although fractures and tendon avulsions around the iliac crest and iliac spines are of utmost concern and the main reason for obtaining radiologic imaging (Figs. 6.17, 6.18, and 6.19). Muscle attachments on the pelvis that are frequently injured include internal/external obliques, transverse abdominis, gluteus medius, sartorius, rectus femoris, and tensor fascia lata.

Acromioclavicular joint separation, referred to as a shoulder separation, occurs frequently in football. Quarterbacks have been shown to have the highest incidence rate of these injuries which usually occur during passing plays of a game (Kelly et al. 2004). The intense collisions either with another player or the ground result in a majority of these injuries. When a player falls to the ground with arm adducted or is contacted on the point of the shoulder, the shoulder girdle and scapula are driven downward, while the clavicle maintains anatomical positioning by restraint at the sternoclavicular joint (Fig. 6.20). The result is either ligamentous injury or clavicular fracture (Beim 2000). The supporting ligaments at the AC joint are the acromioclavicular and coracoclavicular. The acromioclavicular ligament is comprised of four areas of capsular thickening at the AC joint and maintains anterior-posterior stability. The coracoclavicular ligament is actually two ligaments (conoid and trapezoid) and prevents superior-inferior instability (Beim 2000).