The anterior approach for the fixation of displaced talar neck fractures—A cadaveric study
Introduction
The talus is unique in structure and function. A bone without muscular attachment and largely covered by articular cartilage which is subjected to some of the greatest loads in the body. It provides the link between the lower leg and foot and its integrity is key in all weightbearing activities.
Fractures of the talus are rare, accounting for less than 1% of all fractures. They are usually high energy and are commonly associated with other injuries. There is an historical association with aircraft crashes, with injuries to pilots sustained in World War I. The mechanism of injury of axial loading and dorsiflexion being sustained with severe deceleration applied to the rudder feet [1], [2]. In modern times, falls from significant height and road traffic accidents are the most common mechanisms. Displaced fractures of the talar neck account for less than half of all talar fractures and are associated with high complication rates. Potential complications include mal-union, non-union, avascular necrosis (AVN) and post-traumatic arthritis [3], [4].
The Hawkins classification [5], modified by Canale and Kelly [3], is often used to describe these injuries. The classification is based on fracture displacement and associated joint dislocations. The classification is shown in Table 1 with the associated reported rates of AVN [6]. Whilst nonoperative treatment remains the treatment of choice for Type I fractures, open reduction and internal fixation is advisable for Type II to IV fracture-dislocations. The complication rate is associated with the severity of the initial injury [3], [4], [5], [6] and these can lead to poor outcomes, with significant morbidity and limited reconstructive options.
Adequate fracture visualization, with minimal further insult to the talar blood supply, is crucial to allow anatomical reduction and rigid internal fixation, to optimize outcome in these potentially devastating injuries.
Traditional methods of talar fracture fixation have utilized anteromedial, without or with medial malleolar osteotomy, anterolateral or combination approaches. Other methods described include fixation via open posterior approach and percutaneous reduction and fixation techniques [7], [8], [9].
The hypothesis of this study was that talar fracture fixation could be achieved successfully via an anterior approach and that this approach would perhaps offer superior access to the talus over the traditional approaches.
The aim of this study, therefore, was to compare the anterior approach with the anteromedial and anterolateral approaches with respect to the surface area of talus visible with each approach.
Section snippets
Materials and methods
In five fresh frozen cadaveric specimens the anterior, anteromedial and anterolateral approaches to the talus were performed. In each specimen and for each individual approach, the area of talus exposed and visible with standard retraction instrumentation was mapped using a digital microscribe (Immersion Corp. San Jose) and analyzed using Rhinoceros 3D software (McNeel, Seattle). Using the microscribe, multiple points are mapped on the surface of the talus visible in each approach. These
Results
The mean area of talus visible using the anterior approach was 1166 mm2. For the anterolateral approach a mean of 570 mm2 was visible. Via the anteromedial approach, a mean of 395 mm2 was visible before, and 474 mm2 after medial malleolar osteotomy.
The area visible via the anterior approach was significantly greater than that visible via the anteromedial (p < 0.001), anteromedial plus medial malleolar osteotomy (p < 0.001) and anterolateral (p < 0.001) approaches in isolation.
When considering combination
Operative technique
Under general anaesthetic and with the use of a thigh tourniquet, the patient is placed in the supine position on a radiolucent table. The affected extremity is appropriately draped to allow fluoroscopy access from the contralateral side. The talar neck is exposed, as described, allowing the fracture to be reduced under direct vision. Inferior fracture and subtalar articular reduction can be confirmed fluoroscopically. Following reduction, two parallel, cannulated screw guide wires are passed
Discussion
In treating these injuries operatively, adequate exposure is paramount to assess the injury, achieve anatomical reduction and carry out stable internal fixation. The anterior approach has been demonstrated, in our cadaveric study, to offer excellent visualization of the talus in terms of surface area, specifically of the neck.
The anterior approach is a familiar extensile approach. It is used in other, more commonly performed procedures around the foot and ankle, for example, distal tibial
Conclusion
The anterior, extensile approach to the talus offers superior visualization of the talus to traditional approaches both individually and in combination in terms of surface area visible. It is a familiar approach used in other, more commonly performed procedures including potential salvage options. It gives an excellent view of the entire superior aspect of the neck allowing accurate fracture reduction and fixation along the length of the talus perpendicular to the fracture direction. It is an
Conflict of interest
None.
Funding sources
None.
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The role of cadaveric simulation in talus fracture research: A scoping review
2022, Foot and Ankle SurgeryCitation Excerpt :To achieve an anatomic reduction of the talus, adequate visualisation of the talar articular surface is required. To explore this further, using a cadaveric model Mullen et al. [3] evaluated the area of talus exposed for the fixation of talar neck fractures comparing different surgical approaches. The mean area of the talus visible using the anterior approach was 1166 mm2.
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Anatomical study of surgical approaches to the talus
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2023, Unfallchirurgie (Germany)Technical Tip: Talar Neck Fixation Strategy Based on Fracture Variants
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