56 Talus Neck Open Reduction Internal Fixation (ORIF) Abstract The goals of ORIF) of the talar neck are an anatomic reduction and stable internal fixation. This is best achieved through two surgical approaches, anterolateral and medial. Reduction is performed through both approaches, as is fixation. Fixation typically consists of lag screws, positioning screws, minifragment plates, or a combination thereof. Reduction techniques and fixation strategies will be discussed. Examples will be shown. Keywords: fracture, neck of talus, surgical approach, reduction, fixation • Displaced fractures of the talar neck. • Nondisplaced fractures in order to allow for early motion and to ensure healing without displacement. • Often occur in conjunction with other injuries, both local and remote. Timing and surgical incisions need to take this into account. • Swelling and contusion around the ankle. • Varus alignment of the hindfoot. • Beware of tenting of the skin with displaced fractures, which can lead to skin ischemia. • Neurovascular evaluation must be carefully done as the talar body fragment can displace posteromedially and injure the neurovascular bundle. • Approximately 15% of injuries are open fractures. • High vigilance for associated injuries in high-velocity injuries: • Imaging includes anteroposterior (AP), lateral, oblique of foot, AP and mortise, and lateral of the ankle. • The Canale view of the foot gives a true AP of the talar neck. This is performed with the foot 15 degrees internally rotated on the X-ray plate, and the beam aimed 15 degrees from vertical, aimed cephalad and centered over the talar neck. • Computed tomography (CT) scan of the ankle is recommended in most cases to define displacement and comminution. • Most commonly high-velocity trauma (motor vehicle injury; fall from height). • Hyperdorsiflexion of the foot on the leg with axial loading. • Non-weight-bearing cast immobilization can be used for undisplaced fractures. • Surgical reduction and fixation is recommended for all displaced fractures unless the patient is not a surgical candidate for medical reasons. The classification was described by Hawkins into four types and is dependent on the congruency of the peritalar joints. The degree of comminution or displacement is not addressed by this classification. • Hawkins I: Undisplaced vertical fracture of the talar neck. • Hawkins II: Displaced fracture of the talar neck with subluxation or dislocation of the subtalar joint (the ankle joint remains well aligned): • Hawkins III: Displaced fracture of the talar neck with subluxation or dislocation of the subtalar and ankle joints (the talonavicular joint remains congruent). • Hawkins IV: Displaced fracture of the talar neck with subluxation or dislocation of the subtalar, ankle, and talonavicular joints. With each increasing Hawkins type, the risk of talar osteonecrosis and posttraumatic arthritis increases. • Nonviable limb due to unreconstructable vascular or server soft-tissue/nerve injury. • Active infection at the surgical site. • Medically unstable patient. The primary goals of the procedure are to obtain an anatomic reduction of the fracture fragments and achieve stable internal fixation. Additionally, there are often fragments loose in the subtalar joint and occasionally in the tibiotalar joint. These must be removed in order to prevent later symptoms and degenerative arthritis. In the attempt to achieve these goals, it is important to remember the blood supply to the talus and to preserve it as much as possible. This will facilitate healing and help minimize the risk of avascular necrosis (AVN). Given the tenuous nature of the blood supply to the talus, direct reduction and stable internal fixation will greatly increase the likelihood of union after fracture. The talus is the vital connection between the hindfoot and the midfoot. It is a functional part of the ankle, subtalar, and transverse tarsal joints, all of which are essential to normal foot function. Alteration of the talar morphology, by malunion in particular, will affect foot position and function. • Two approaches required. • Preserve dorsal soft-tissue attachments. • Reduction with direct control of fragments, using joysticks, clamps, picks. • Reduction assessment by interdigitating fracture on tension side. • Canale, mortise, and lateral views to assess reduction on fluoroscopy. • Fixation must also be bicolumnar, corresponding with the two approaches. • Screw fixation when the fracture is simple. • Miniplates can span areas of comminution. • Historically, displaced talar neck fractures have been considered surgical emergencies. While we advocate these to be fixed in a timely fashion, it is better and safer to wait for the soft-tissue envelope swelling to resolve prior to surgery than to operate early and risk wound-healing complications. • No correlation with timing of surgery and incidence of osteonecrosis or posttraumatic arthritis.2,3 Diagnosis and planning will require radiographs of the foot and ankle. Fracture features are often seen well on the plain X-rays. Include mortise and lateral views of the ankle and AP, lateral, and oblique views of the foot. However, the detail of a CT scan is often invaluable (Fig. 56.1). The additional information gained in the CT scan is generally worth the extra cost and radiation exposure. It is also important to remember that a significant number of talar neck fractures will have associated injuries, both locally and systemically. For example, many neck fractures of the talus will also have a fracture of the lateral process of the talus, which can be seen much better on a dedicated CT scan. Fig. 56.1 (a,b) Mortise and lateral views of talar neck fracture. (c) CT scan with axial cut showing comminution not seen on plain X-rays. (d) CT scan showing osteochondral fragment in the subtalar joint. Assessment of reduction and proper hardware placement will require use of intraoperative fluoroscopy. A completely radiolucent operating table will facilitate use of fluoroscopy. In order to avoid interference with the operating team, a table with a cantilever radiolucent extension is preferred. The patient is positioned supine, with a small bump placed under the ipsilateral hip. A completely radiolucent positioning “ramp” can be placed under the lower leg prior to the prep. This will greatly facilitate the ability to obtain lateral images without having to move the operative limb. Additionally, a sterile triangle positioning support can be placed under the knee, which will position the foot in a more plantigrade position relative to the table. This greatly enhances use of fluoroscopy. Two approaches are necessary to adequately reduce and fix the vast majority of talar neck fractures. The approaches are used simultaneously, so it does not matter which is made first. The incision for the medial approach is centered between the anterior tibialis and posterior tibialis tendons. It should reach from the anterior tip of the medial malleolus to the navicular. Prior to making the incision, draw a proximal extension that will curve across the medial malleolus as it proceeds proximally, from the anterior tip of the medial malleolus to the posterior border of the tibial shaft (Fig. 56.2a). This proximal extension can be used if the need for a medial malleolar osteotomy arises. Skin flaps are kept full thickness. Deep dissection involves cutting the capsule of the tibiotalar joint just anterior to the deltoid ligament. Distally, the talonavicular joint capsule is incised and it can be exposed dorsally. The dorsomedial talar neck is exposed subperiostally. Care is taken, however, to limit the amount of subperiostal dissection carried out dorsally, in order to preserve the soft-tissue attachments that may provide some blood supply to the fragments. In the proximal part of the dissection, the ankle capsule and dorsal soft tissues can be safely retracted to allow visualization of the articular surface all the way across to the lateral side. Exposure should include the articular dome of the talus, the dorsomedial cortex of the neck, and the medial aspect of the head. More lateral exposure of the head can be obtained by abducting the foot at the talonavicular joint. The lateral incision is in line with the distal tibiofibular joint and the medial side of the fourth metatarsal, or the third interspace. The dissection should elevate full-thickness flaps, but care needs to be taken proximally to look for and preserve the superficial peroneal nerve, which is generally encountered. The extensor retinaculum is incised and the long toe extensors are retracted medially. The extensor brevis musculature is generally retracted laterally (Fig. 56.2b). The sinus tarsi fat can be excised, and the lateral cortex can be exposed subperiosteally. Proximally, the ankle capsule is incised, and the anterior retraction of the capsule and dorsal soft tissues allows for the visualization of the lateral dome, across to the medial exposure. As with the medial side, the dorsal dissection is limited to the ankle capsule, to avoid stripping the dorsal blood supply from the neck fragments and remainder of the talus. The lateral dissection of the ankle capsule can be extended distally, along the lateral facet of the talus, to the lateral process. Dissection in the plantar direction beyond the lateral process will expose the posterior facet of the subtalar joint. The capsule of the subtalar joint and the interosseous ligament can be excised, facilitating the visualization. There is often osteochondral debris in the subtalar joint. Excision of these fragments is important in minimizing the effect they can have on the subtalar joint. The majority of talar neck fractures occur because of forced dorsiflexion and some inversion. This means that the anteromedial neck is loaded in compression, leading to comminution of the bone in this part of the neck. The lateral neck and sometimes the inferomedial neck are often loaded in tension and will therefore fail with a simple fracture pattern. Reduction should begin at the zone of the fracture that lacks comminution. The goal is to use the interdigitation of the fracture edges to help guide reduction in these areas. The fracture edges need to be exposed subperiostally to allow for the use of these edges for a fracture “read.” Often, a more vertical fracture will exit through the chondral surface of the talar dome. In these cases, assessment of the reduction is facilitated by using the edge of the chondral surface as a landmark for fracture alignment. After the simple fracture line is reduced, attention can be turned to the areas of comminution. Obviously, cases with more comminution will be harder to accurately reduce.
56.1 Indications
56.1.1 Clinical Evaluation
Thirty percent of displaced fractures have concomitant medial malleolar fractures.
Calcaneal or pilon fractures.
Pelvic or spinal fractures.
56.1.2 Radiographic Evaluation
56.1.3 Mechanism of Injury
56.1.4 Nonoperative Options
56.1.5 Classification of Talar Neck Fractures
Vallier et al divided Hawkins II fractures into IIA (where the subtalar joint was subluxated) and IIB (where the subtalar joint was dislocated).1
56.1.6 Contraindications
56.2 Goals of Surgical Procedure
56.3 Advantages of Surgical Procedure
56.4 Key Principles
56.5 Preoperative Preparation and Patient Positioning
56.5.1 Timing of Surgery
56.5.2 Preparation and Positioning
56.6 Operative Technique
56.6.1 Surgical Exposure
56.6.2 Reduction
Musculoskeletal Key
Fastest Musculoskeletal Insight Engine
