Intra-articular fractures of the head are uncommon, due to its inherent anatomy. Nestled snuggly within the acetabular pedis, it is protected by the navicular and the strong surrounding capsular and ligamentous structures [11]. However, ankle sprains and shearing injuries can result in periarticular avulsions by these same ligaments and strong capsular insertions. These avulsion injuries respond well to immobilization and protected weight bearing and rarely require radiographic follow-up. When intra-articular, direct reduction via open means is important to reduce disability from late posttraumatic arthrosis. As seen with most midfoot and hindfoot fractures because of the complex architecture, computed tomography can yield significant information in fracture geography facilitating decision making [12].

Articular realignment is the goal, so displaced fractures should be anatomically reduced because these missed injuries and subtle malalignments can result in accelerated posttraumatic arthritis [13]. If discovered prior to symptomatic arthritis, realignment osteotomies are recommended. A misaligned and healed head fracture, which usually is malaligned in varus and adduction, may be approached through a medial incision extending toward the naviculocuneiform joint between the tibialis anterior and tibialis posterior tendons (Fig. 18.3). A sagittal saw is then used to osteotomize the head just proximal to the cartilage [14]. A lamina spreader is inserted into the osteotomy site and opened until the first metatarsal talar head angle is parallel on the dorsoplantar fluoroscopic projection. The defect can be filled with autogenous corticocancellous structural graft. The iliac crest serves as an excellent donor site, but typically the defects are small, and in lieu of the iliac crest, proximal or distal tibia, or even a calcaneal graft, can be harvested. The length of the bone graft should match the maximum length of the defect. The remaining defect can be filled with autogenous cancellous bone from the donor site. The lamina spreader is removed, and the osteotomy site is fixated with a small minifragment buttress plate with positional screw fixation within the plate on either side of the osteotomy site. Care must be employed to confirm that the distal screw orientation is not within the talonavicular joint . Acute or missed compression fractures of the head should be disimpacted and backfilled with bone graft as described above. Temporary augmented external fixation helps to allow consolidation of the head by neutralizing compressive forces to the site. A delta frame construct can be placed with Schanz pins within the distal tibia metaphysis, the calcaneus, and the cuneiforms (Fig. 18.4).

Hindfoot stiffness can be debilitating, and as a result early mobilization with passive range of motion exercises postoperatively may reduce the incidence of postoperative arthrofibrosis and are initiated immediately after suture removal. The duration of non-weight bearing nonetheless remains 12 weeks or until clinical and radiographic union is confirmed. These reconstructions are last ditch efforts, and as such early weight bearing can potentially compromise the reconstruction leading to delayed or nonunion.

Primary talonavicular arthrodesis should be reserved for severe fractures of the head that are not reconstructible and are approached with standard arthrodesis techniques [15, 16] (Fig. 18.5).

Fractures of the talar neck have been the subject of extensive discussion and scientific publications. The mechanism has historically been described as a hyperdorsiflexion injury where the hard talar neck is cleaved on impact by the distal tibial plafond. The absence of routine distal tibial injury with this injury calls into question the legitimacy of this proposed mechanism [11]. A reproducible mechanism was described as sudden and significant vertically oriented force directed caudally at the forefoot on a locked and stable hindfoot. At injury, while the talar body compressed between the calcaneus and the tibia, a dorsally directed force applied to the plantar forefoot distal to the tibial plafond results in cantilever bending at the talar neck, cleaving off the neck resulting in the fracture. Immediately following the fracture, with continued application of force, the posterior ankle capsule is opened and the talar body is pinched outward and posteriorly as seen in Hawkins II and III fractures [17]. Describing this injury as a hyperdorsiflexion injury may not be entirely incorrect but may inaccurately presume that the ankle goes through range of motion during the injury.

Hawkins in 1970 provided the current classification system most commonly relied upon to describe these injuries [18]. Hawkins further sought to correlate the rate of avascular necrosis with associated periarticular dislocation in addition to the neck fracture. The Hawkins type I injury describes an isolated talar neck fracture with absent to minimal fracture displacement without periarticular subluxation/dislocation. The type II fracture involves concomitant neck fracture with subtalar joint subluxation/dislocation with posterior and medial dislocation of the body on the intact deltoid ligament. The type III fracture involves subluxation/dislocation of both the subtalar and tibiotalar articulation in the presence of the neck fracture. In this injury, the deltoid ligament along with the deltoid artery is disrupted. Kelly and Canale described the type IV fracture which describes pantalar subluxation/dislocation with the neck fracture [19]. This injury is even more rare and not necessarily the final progression of the Hawkins classification.

Hawkins classically described avascular necrosis rates in zero of six type I fractures, in 10 of 24 type II fractures, and in 25 of 27 type III fractures corresponding to 0 %, 42 %, and 91 %, respectively. The cumulative vascular disruption with each progressive articular discontinuity he theorized was the reason behind the progression of AVN rates with each respective fracture/dislocation type.

Talar neck fractures are typically high-energy injuries, and as a result there is little diagnostic ambiguity [10, 20]. Patients routinely report catastrophic mechanisms with severe and generalized ankle and hindfoot pain. The physical exam and the lateral radiographic foot or ankle projection are useful. The anteroposterior ankle radiographic projection is helpful when isolating the type II form the type III injury. Because they are high-energy injuries, concomitant injuries are not uncommon and computed tomographic evaluation is critical [4, 10].

Initial closed reduction is crucial to relieve stress on intact vascular supply. This typically involves longitudinal distraction in line with the longitudinal orientation of the native talus and casting/splinting with the foot plantarflexion. Casting with the ankle in neutral is intuitive but unfortunately with these injuries will result in re-displacement of the neck fracture (Fig. 18.6). If closed reduction is unsuccessful, urgent operative reduction is critical and must not be delayed. Repeated attempts at closed reduction should be avoided unless in rare cases when the operating room staff are preoccupied with other life-threatening emergencies. Operative reduction may involve reduction via small open approaches with temporary external fixation. Definitive open reduction with internal fixation may be performed at a later date following meticulous computed tomographic evaluation after the surrounding soft tissue is supportive for the iatrogenic insult of surgery. Urgent open reduction of these injuries has been reported to reduce the incidence of avascular necrosis; not only has this been unsubstantiated, but recent literature report that this may actually be an incorrect belief [10].

Nondisplaced type I injuries may be treated non-operatively with non-weight-bearing immobilization. If displaced, open reduction with internal fixation is indicated. Unlike most fractures, even minimal displacement with these injuries may have profound effects on late arthrosis and hindfoot stiffness [21]. Thus, the threshold for open reduction should be low. The surgical approaches and fixation concepts for type I–III fractures are virtually identical. Because type IV injuries are inherently unique, the same approaches may not fully support the fracture orientation, and as such, these should be approached on a case by case basis following extensive computed tomographic evaluation and preoperative surgical planning.

The postoperative course for operatively treated type I–IV injuries typically involves non-weight bearing for 12 weeks or until radiographic union occurs. However, non-weight-bearing passive range of motion exercises is initiated as soon as the incisions are healed in 2 weeks. Full cast immobilization of operatively treated fractures should be avoided to limit postoperative stiffness.

For operative type I–III fractures, dual anteromedial and anterolateral approaches are recommended to reduce varus malalignment in the frontal plane that may occur with the isolate anteromedial incisional approach [6, 22]. The concern for the additional soft tissue dissection of the dual approach has been theorized to further compromise vascular supply but has not been substantiated to further disrupt vascular supply significantly enough to increase risk of avascular necrosis [6]. Both incisions are centered along the bisection of the neck. The lateral incision runs adjacent the lateral branch of the intermediate dorsocutaneous nerve and the extensor digitorum longus (Fig. 18.3). The medial incision runs just medial and inferior to the course of the tibialis anterior tendon and superior to the posterior tibial tendon (Fig. 18.3). This allows for excellent visualization of both the fracture and the subtalar joint where evacuation of fracture debris may help reduce posttraumatic of the subtalar joint, a common postoperative complication (Fig. 18.7). The medial incision may course proximally, turning upward in line with the central orientation of the medial malleolus, in instances where a medial malleolar osteotomy is needed to facilitate reduction. A small transversely oriented Schanz pin placed into the head of the talus is helpful in controlling frontal plane rotation and fracture reduction. Small wire fixation helps to temporarily maintain the reduction prior to delivery of definitive fixation. These wires are placed from both surgical sites oriented into the body from entry points distal to the neck fracture, adjacent to the talar head (Fig. 18.7). When possible, mini fragment plate fixation contoured adjacent to the lateral neck near the insertion of the anterior talofibular ligament facilitates delivery of stable fixation in a fan-like orientation with two screws on either side of the fracture (Fig. 18.3). Along the medial aspect of the talus, the area for plate fixation is further limited and is located just inferior to the comma-shaped facet and just distal to the deep deltoid ligament (Fig. 18.8). In lieu of plate fixation medially, mini or small fragment screws may be delivered with the same retrograde orientation as the temporary wires countersunk below the articular cartilage of the medial talar head. In the absence of significant comminution and good cortical fracture interdigitation, lag screw fixation may be employed (Fig. 18.3). In the presence of comminution, lag screw fixation may promote varus malreduction, and as such, bridge plating and positional screw fixation are preferred. Anterograde screw fixation may also be employed but requires significant skill (Fig. 18.9). The heads of these screws may also be prominent at the posterior aspect of the tibiotalar articulation, blocking normal sagittal plane ankle kinematics. Countersinking the screws below the chondral surface may avoid this. Following fracture reduction intraoperatively and postoperatively, standard anteroposterior and lateral ankle radiographic projection, standard dorsoplantar and medial oblique foot radiographic projections, and the Canale radiographic projection are helpful in confirming anatomic reduction [23]. This radiographic projection is also helpful in assessing radiographic avascular necrosis because the lateral ankle radiographic projection superimposes the medial and lateral talar domes and the medial and lateral malleoli, potentially resulting in a falsely positive diagnosis. Utilization of titanium fixation may be useful in cases where evaluation of avascular necrosis may warrant magnetic resonance imaging.