Fatal Air Embolus During Internal Fixation of the Clavicle: A Case Report

Subclavian vessels injury: An underestimated complication of clavicular fractures

Clavicle fractures are frequent orthopedic injuries, often resulting from direct trauma or a fall. Most clavicle fractures are treated conservatively without any complications or adverse effects. Concomitant injuries of the subclavian vein or artery are rarely encountered and most commonly associated with high-energy trauma or comminuted clavicle fractures. They are potentially life-threatening conditions leading to hemorrhage, hematoma, pseudoaneurysm or upper limb ischemia. However, the clinical presentation might be obscure and easily missed, particularly in closed and minimally displaced clavicular fractures, and timely diagnosis relies on early clinical suspicion. Currently, computed tomography angiography has largely replaced conventional angiography for the assessment of subclavian vessel patency, as it demonstrates high accuracy and temporal resolution, acute turnaround time, and capability of multiplanar reconstruction. Depending on the hemodynamic stability of the patient and the severity of the injury, subclavian vessel lesions can be treated conservatively with observation and serial evaluation or operatively. Interventional vascular techniques should be considered in patients with serious hemorrhage and limb ischemia, followed by stabilization of the displaced clavicle fracture. This review aims to provide a comprehensive overview of the incidence, clinical presentation, diagnostic approaches, and current management strategies of clavicle fractures associated with subclavian vessel injuries.

Neurovascular Complications Following Clavicle Fracture Fixation: Timing, Mechanisms, and Clinical Implications

This review addresses the neurovascular complications associated with the surgical treatment of clavicle fractures through open reduction and internal fixation (ORIF). Despite being a generally safe procedure, it can lead to severe complications including brachial plexopathy, pseudoaneurysm, arteriovenous fistulas (AVF), deep vein thrombosis (DVTs), and thoracic outlet syndrome (TOS). One significant observation, not often highlighted in previous literature, is that neurovascular complications are more common in cases involving delayed fixation, nonunion, or malunion, compared to those treated acutely. This review emphasizes the impact of the timing of surgery on the frequency of these rare complications and examines their underlying mechanisms.

Clavicular osteotomy to assess subclavian vein injury during internal fixation of midshaft clavicle fractures

Midshaft clavicle fractures are commonly fixed with locking plates. The subclavian vein risks injury during this procedure and the consequences can be fatal. The purpose of this present study is to describe a clavicular osteotomy technique in order to equip orthopaedic surgeons with a means of rapidly accessing a subclavian vein injury. The osteotomy should only be performed following an urgent intraoperative vascular surgery assessment. There must be shared consensus from both orthopaedic and vascular surgery that direct repair of the subclavian vein is necessary, and further exposure is required. The results of the technique performed on thirteen embalmed cadaveric specimens are also included. The osteotomy was able to expose 3.16 cm (SD = 0.60) of the subclavian vein and both the fracture and osteotomy site of all clavicles (100%) were able to be reduced and fixed using a single pre-contoured fifteen-hole lateral plate intended for use on the contralateral shoulder. This surgical technique study confirms that in the rare circumstance that the osteotomy is utilized, adequate exposure of the subclavian vein is achieved.

Plunging Dangerously: A Quantitative Assessment of Drilling the Clavicle

Bicortical drilling of the clavicle is associated with risk of iatrogenic damage from plunging given the close proximity of neurovascular structures. This study determined plunge depth during superior-to-inferior clavicle drilling using a standard drill vs drill-sensing technology. Two orthopedic surgeons drilled 10 holes in a fresh cadaveric clavicle with drill-sensing technology in freehand mode (functions as standard orthopedic drill) and another 10 holes with drill-sensing technology in bicortical mode (drill motor stops when the second cortex is breached and depth is measured in real time). The drill-measured depths were compared with computed tomography-measured depths. Distances to the neurovascular structures were also measured. The surgeons' plunge depths were compared using an independent t test. With freehand (standard) drilling, the mean plunge depth was 8.8 mm. For surgeon 1, the range was 5.6 to 15.8 mm (mean, 10.9 mm). For surgeon 2, the range was 3.3 to 11.0 mm (mean, 6.4 mm). The surgeons' plunge depths were significantly different. In bicortical mode, the drill motor stopped when the second cortex was penetrated. Drill-measured depths were verified by computed tomography scan, with a mean difference of 0.8 mm. Mean distances from the clavicle to the neurovascular structures were 15.5 mm for the subclavian vein, 18.0 mm for the subclavian artery, and 8.0 mm for the brachial plexus. Plunge depths differed between surgeons. However, both surgeons' plunge depths were greater than distances to the neurovascular structures, indicating a risk of injury due to plunging. Although a nonspinning drill bit may still cause soft tissue damage, drill-sensing technology may decrease the risk of penetrating soft tissue structures due to plunging. [Orthopedics. 2021;44(1):e36-e42.].

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

BACKGROUND

Fixation of clavicle shaft fractures with a plate and screws can endanger the neurovascular structures if proper care is not taken. Although prior studies have looked at the risk of clavicular plates and screws (for example, length and positions) to vulnerable neurovascular structures (such as the subclavian vein, subclavian artery, and brachial plexus) in the supine position, no studies to our knowledge have compared these distances in the beach chair position.

QUESTIONS/PURPOSES

(1) In superior and anteroinferior plating of midclavicle fractures, which screw tips in a typical clavicular plating approach place the neurovascular structures at risk of injury? (2) How does patient positioning (supine or beach chair) affect the distance between the screws and the neurovascular structures?

METHODS

The clavicles of 15 fresh-frozen cadavers were dissected. A hypothetical fracture line was marked at the midpoint of each clavicle. A precontoured six-hole 3.5-mm reconstruction locking compression plate was applied to the superior surface of the clavicle by using the fracture line to position the center of the plate. The direction of the drill bits and screws through screw holes that offer the greater risk of injury to the neurovascular structures were identified, and were defined as the risky screw holes, and the distances from the screw tips to the neurovascular structures were measured according to a standard protocol with a Vernier caliper in both supine and beach chair positions. Anteroinferior plating was also assessed following the same steps. The different distances from the screw tips to the neurovascular structures in the supine position were compared with the distances in the beach chair position using an unpaired t-test.

RESULTS

The risky screw holes were the first medial and second medial screw holes. The relative distance ratios compared with the entire clavicular length for the distances from the sternoclavicular joint to the first medial and second medial screw holes were 0.46 and 0.36 in superior plating and 0.47 and 0.37 in anteroinferior plating, respectively. The riskiest screw hole for both superior and anteroinferior plates was the second medial screw hole in both the supine and beach chair positions (supine superior plating: 8.2 mm ± 3.1 mm [minimum: 1.1 mm]; beach chair anteroinferior plating: 7.6 mm ± 4.2 mm [minimum: 1.1 mm]). Patient positioning affected the distances between the riskiest screw tip and the nearest neurovascular structures, whereas in superior plating, changing from the supine position to the beach chair position increased this distance by 1.4 mm (95% CI -2.8 to -0.1; supine 8.2 ± 3.1 mm, beach chair 9.6 ± 2.1 mm; p = 0.037); by contrast, in anteroinferior plating, changing from the beach chair position to the supine position increased this distance by 5.4 mm (95% CI 3.6 to 7.4; beach chair 7.6 ± 4.2 mm, supine 13.0 ± 3.2 mm; p < 0.001).

CONCLUSIONS

The second medial screw hole places the neurovascular structures at the most risk, particularly with superior plating in the supine position and anteroinferior plating in the beach chair position.

CLINICAL RELEVANCE

The surgeon should be careful while making the first medial and second medial screw holes. Superior plating is safer to perform in the beach chair position, while anteroinferior plating is more safely performed in the supine position.

Osteosynthesis for clavicle fractures: How close are we to penetration of neurovascular structures?

INTRODUCTION

Risks associated with drill plunging are well recognised in clavicle osteosynthesis. To date no studies have described plunge depth associated with clavicle osteosynthesis.

PRIMARY AIM

To determine whether plunge depth associated with clavicle osteosynthesis is great enough to penetrate neurovascular structures and whether surgical experience reduces the risk of neurovascular injury METHOD: Cadaveric clavicles were pressed into spongy phenolic foam to allow measurement of drill bit penetration beyond the far cortex (plunge depth). 15 surgeons grouped according to experience were asked to drill a single hole in the medial, middle and lateral clavicle in 2 specimens each. Each surgeon used fully a charged standard Stryker drill with a new 2.6mm drill bit and guide. Plunge depths were measured in 0.5mm increments. Depth measurements were compared amongst groups and to previously documented distances to neurovascular structures as outlined by Robinson et al. Kruskal-Wallis test was used for overall comparison and Mann-Whitney U test was used for comparing the groups individually.

RESULTS

Mean plunge depth across all groups was 3.4mm, (0.5-6.5), 4.0mm (1mm-8.5mm) and 4.0mm (0.5mm-15mm) in the medial, middle and lateral clavicle. Plunge depths were greater than previously documented distances to the subclavian vein at the medial clavicle on nine occasions. Plunge depths in the middle and lateral clavicle were well within the previously documented distances from neurovascular structures. There was no correlation between level of experience and median plunge depth (p=0.18). However, inexperienced surgeons plunged 1mm greater than intermediate and experienced surgeons (p=0.026). There was one significant outlier; a 15mm plunge depth by an inexperienced surgeon in the lateral clavicle.

CONCLUSION

Clavicle osteosynthesis has a relatively high risk of neurovascular injury. Plunge depths through the clavicle often exceed the distance of neurovascular structures, especially in the medial clavicle. A thorough understanding of the anatomy of these neurovascular structures and methods to prevent excessive plunging is important prior to undertaking clavicle osteosynthesis.

Major neurovascular complications of clavicle fracture surgery

Clavicle fracture fixation is becoming an increasingly common operation, with good clinical outcomes and a low rate of significant complications. However, there are several reports of rare but potentially life or limb threatening, neurovascular complications. Arterial injuries are usually pseudoaneurysms associated with prominent screws. These may be clinically silent for several years before presenting as subcritical upper limb ischaemia. Venous injuries are a result of tearing of the vessel wall by fracture manipulation, drills or implants. This produces intra-operative haemorrhage and potentially air embolism, which can be fatal if not rapidly recognized and managed. Brachial plexopathy is the result of traction on adherent plexus or impingement by fracture fragments or callus. It presents as severe arm pain and paralysis immediately postoperatively. Neurovascular injuries can be avoided by a combination of pre-operative planning, communication with anaesthetic staff and strategic surgical technique. The plane of the surgical exposure, release of the soft tissues, drill direction and depth and screw length are all important factors.