CORR Insights®: Patient Position Is Related to the Risk of Neurovascular Injury in Clavicular Plating: A Cadaveric Study

Where Are We Now?

Clavicle fractures, which are generally located in the midshaft, account for up to 4% of all fractures [6-8]. Most patients are treated non-surgically, and in those patients, non-union rarely occurs [9, 10]. However, surgical treatment sometimes is indicated, and it may offer better function, improved cosmetic results, and perhaps even a greater likelihood of union compared to non-operative treatment [1].

Clavicular plates may be positioned either superiorly or antero-inferiorly during internal fixation, and the choice is controversial. When the plate is positioned superiorly, most fracture patterns occur on the tension side of the injury. Additionally, superior plating generally results in less soft-tissue disruption, and the plate is relatively easy to apply to the superior side of the bone. With antero-inferior plate positioning, longer screws can be placed, and they can be directed away from vital structures. In addition, an antero-inferior approach improves rotational stability of the plate, and is associated with less implant irritation and improved cosmesis [5, 11].

One study reported that up to 25% of patients treated operatively developed transient neurovascular complications [12]. Obviously, the risk of neurovascular injury is higher in patients treated surgically than non-operatively, but studies disagree about the frequency and cause of these complications [4]. However, the authors of a 2015 review [4] reported on seven patients with iatrogenic vascular injuries directly related to clavicle surgery, and in all but one instance, the surgical complication was due to a drill bit or the tip of a screw. In fact, in that study, one patient even died from these complications. The 2015 review highlighted both the close proximity of the neurovascular structures to our implants and that a standard, mostly straightforward surgery could potentially lead to a catastrophic, limb- and/or life threatening complication [4].

In the current study, Chuaychoosakoon and colleagues [2] provided a map for orienting the surgeon to important distances that should be considered during surgery. The authors showed that with superior plating, beach chair positioning provides greater distances to neurovascular structures. They also found that the supine position is safer with anteroinferior plating [2], as well as highlighted the close anatomical relationships between neurovascular structures and the implanted screws in both beach chair and supine positioning. They found that the close proximity between the screws and neurovascular structures increased the possible risk of injury during drilling or screw placement, for both positioning types, particularly in the area of the first and second medial hole [2].

Where Do We Need To Go?

Orthopaedic surgeons need to update existing strategies and create new ones for reducing neurovascular complications during surgical treatment of clavicle fractures. In particular, we need to develop a greater variety in the geometry of drill bits, standardize sleeves for depth limitation, and improve the drill handle ergonomics for greater grip strength. Also, a feedback system for the drilling machine with a drill-stop after perforation of the second cortex should be developed. In this area, collaboration with implant and instrument manufacturers is warranted.

Neurovascular injuries might be reduced through the use of segmental mono-cortical drilling and screw placement, the use of a locking construct, or the use of variable-angle systems. One advantage of the variable-angle construct is the possibility to orient the screws further away from important structures. Further biomechanical and clinical studies are necessary to verify and to determine the ideal osteosynthesis construct combination (locking, conventional, variable angle, or hybrid).

Both awareness and skill are needed during surgery to avoid catastrophic neurovascular injuries. During surgery, intraoperative imaging tools should be used more often. Through intraoperative three-dimensional (3-D) imaging with mobile C-arm, placement and lengths of implants could be detected immediately and revised if needed. However, use of these tools is cumbersome because the machines are bulky; their use also is time consuming, and exposes surgical teams to radiation, and refinements to these tools would be most welcome.

Our specialty needs standardized training to reduce complications. One effective teaching tool is cadaver courses during which new, safer osteosynthesis techniques can be disseminated. Additionally, the participants can follow the simulated osteosyntheses with dissection of blood vessels to gain a more-complete understanding of the proximity of these structures and the risks to them that surgery imposes.

How Do We Get There?

Standards and protocols for surgical procedures have to be established to provide a greater degree of patient safety. These protocols should include among other things, the positioning of the patient in relation to the intended position of the implant.

Pre-operative planning using 3-D imaging is a promising tool that could fill many of the gaps in our knowledge regarding neurovascular injury in clavicular plating. Printing a 3-D model of the fracture allows for better understanding and realistic planning for surgery. Plate positioning and screw length with desired orientation could be determined before surgery. For complex surgical procedures, the contralateral side could be used as a virtual template. Three-dimensional printers already exist, but they are expensive. Better dialogue and cooperation among orthopaedic surgeons with engineers, manufacturers, insurance companies and specialized laboratories can potentially help establish simple and more cost-effective methods.

Additionally, patient-specific instruments could be printed allowing for more-specific repositioning and placement of implants and screws during surgery. For screw orientation and length, patient-specific instruments could be produced with additional drill sleeves including a mechanical drill stop. This surgical approach could also be performed in combination with navigation.

Augmented reality-assisted surgery might improve the surgical options and procedures for treating fractures in the future, as it could potentially provide the surgeon with an overview of anatomical landmarks and guidance for the ideal placement of screws [3]. However, we are currently only in the initial stages of this promising surgical tool and will need additional studies to know more about its use and cost-effectiveness.