Safe Drilling Angles and Depths for Plate-Screw Fixation of the Clavicle: Avoidance of Inadvertent Iatrogenic Subclavian Neurovascular Bundle Injury

Perspective on the integration of optical sensing into orthopedic surgical devices

SIGNIFICANCE

Orthopedic surgery currently comprises over 1.5 million cases annually in the United States alone and is growing rapidly with aging populations. Emerging optical sensing techniques promise fewer side effects with new, more effective approaches aimed at improving patient outcomes following orthopedic surgery.

AIM

The aim of this perspective paper is to outline potential applications where fiberoptic-based approaches can complement ongoing development of minimally invasive surgical procedures for use in orthopedic applications.

APPROACH

Several procedures involving orthopedic and spinal surgery, along with the clinical challenge associated with each, are considered. The current and potential applications of optical sensing within these procedures are discussed and future opportunities, challenges, and competing technologies are presented for each surgical application.

RESULTS

Strong research efforts involving sensor miniaturization and integration of optics into existing surgical devices, including K-wires and cranial perforators, provided the impetus for this perspective analysis. These advances have made it possible to envision a next-generation set of devices that can be rigorously evaluated in controlled clinical trials to become routine tools for orthopedic surgery.

CONCLUSIONS

Integration of optical devices into surgical drills and burrs to discern bone/tissue interfaces could be used to reduce complication rates across a spectrum of orthopedic surgery procedures or to aid less-experienced surgeons in complex techniques, such as laminoplasty or osteotomy. These developments present both opportunities and challenges for the biomedical optics community.

Power-Tool Use in Orthopaedic Surgery: Iatrogenic Injury, Its Detection, and Technological Advances: A Systematic Review

Power tools are an integral part of orthopaedic surgery but have the capacity to cause iatrogenic injury. With this systematic review, we aimed to investigate the prevalence of iatrogenic injury due to the use of power tools in orthopaedic surgery and to discuss the current methods that can be used to reduce injury.

Comparison of Minimally Invasive Fixation of Mid-Shaft Clavicular Fractures with Threaded Elastic Intramedullary Nail (TEIN) and Elastic Locking Intramedullary Nail (ELIN)

OBJECTIVE

To compare the effectiveness of threaded elastic intramedullary nail and elastic locking intradullary nail (ELIN) for mid-shaft clavicular fractures.

METHODS

The clinical data of 47 patients with middle clavicle fracture treated by TEIN and ELIN from August 2017 to March 2019 were analyzed retrospectively. Twenty-three patients received intramedullary fixation treatment with ELIN, nine males and 14 females, AO/OTA fracture classification type 2A (n = 17) and 2B (n = 6). Twenty-four patients received intramedullary fixation treatment with TEIN, including nine males and 15 females, AO/OTA classification: type 2A (n = 18) and 2B (n = 6). All patients were anesthetized with ipsilateral cervical plexus block. After internal fixation was removed, the clinical outcomes were assessed and evaluated. The Constant-Murley score and disabilities of the arm, shoulder and hand questionnaire (DASH) score were compared between the two groups to evaluate the functional status of all patients. The study was done accordingly to the guidelines provided by the ethics committee.

RESULTS

All patients in the two groups completed the operation successfully and were followed up. In the ELIN group, the operation time was 20.78 ± 7.71 min, intra-operative blood loss was 13.26 ± 9.72 mL, incision length was 1.60 ± 0.92 cm, internal fixation removal time was 12.86 ± 2.24 weeks, Constant-Murley score was 99.30 ± 1.36 points and DASH score was 1.43 ± 3.00 points. In the TEIN group, the operation time, intra-operative blood loss, incision length, internal fixation removal time, Constant-Murley and DASH scores were 22.83 ± 8.17 min, 22.08 ± 11.22 mL, 2.48 ± 0.84 cm, 15.66 ± 5.58 weeks, 95.79 ± 7.38 point and 6.69 ± 11.55 point respectively. In the ELIN group, four cases developed skin irritation, and the symptoms were relieved after removal of internal fixation. In the TEIN group, one patient's internal fixation broke and had an obvious scar at the incision, but there was no fracture after replacement of internal fixation; withdrawal of TEIN occurred in four patients, the nail did not shift again until the last follow-up; skin irritation and temporary bursitis occurred in six patients, and the symptoms were relieved after internal fixation was removed. No other conditions were found in the patients, and bony healing was achieved in all patients.

CONCLUSION

ELIN prevents shortening and malunion of the clavicle, reduces secondary damage to related tissues, and leads to restoration of clavicle length and faster osseous healing.

Structures Endangered During Minimally Invasive Plate Osteosynthesis of the Upper Extremity

Minimally invasive plate osteosynthesis is a surgical technique that is becoming increasingly common because radiographic images and implant technologies advance in capabilities. It is imperative for surgeons to enhance their understanding of the surgical anatomy related to new approaches for fracture fixation. While performing minimally invasive plate osteosynthesis, there is a danger of injuring structures in the common percutaneous and submuscular pathways. We describe the critical anatomical structures in these pathways and tips for injury avoidance when operating on the clavicle, scapula, humerus, and wrist.

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.].

Screws are at a safe distance from critical structures after superior plate fixation of clavicle fractures

INTRODUCTION

Injuries to the critical structures underlying the clavicle are possible during open reduction and internal fixation (ORIF) and afterward secondary to prominent screws. The purpose of this study was to identify patients who received chest computerized tomography (CT) scans after clavicle ORIF to evaluate the distance between the screws and the subclavian vessels.

METHODS

A retrospective review was performed at a single level-one trauma center. Nineteen patients with chest CT scans after superior plate fixation were included. Coronal CT reconstructions were analyzed to determine distances between the subclavian vessels and screw tips along with the prominence of the screws. Vessels within 15 mm of the screw were considered at risk.

RESULTS

None of the screws (0/142) were within 15 mm of the subclavian vessels. Average screw prominence was 1.3 ± 1 mm (range, 0-3.6 mm). One of the 19 patients had a complication, a re-fracture requiring revision ORIF. The remaining 18 patients had no complications, including neurovascular or pulmonary, at the last follow-up.

CONCLUSIONS

None of the screws were excessively prominent or within 15 mm of the subclavian vessels. Attentive superior plate fixation of the clavicle with screws is a safe technique.

LEVEL OF EVIDENCE

Level IV, case series.

A hybrid approach to mid-shaft clavicle fixation

BACKGROUND

The purpose of this study was to demonstrate the strength characteristics of a hybrid uni-cortical construct for clavicle fixation. The technique reported aims to combine benefits of uni-cortical fixation with stability comparable to traditional bi-cortical fixation. The approach utilises long, oblique uni-cortical screws at the distal ends of the plate acting as surrogate bi-cortical screws. Locked uni-cortical screws positioned centrally provide bending and torsion strength to the construct. This alternative hybrid uni-cortical technique does not require far cortex screw or drill penetration required in bi-cortical fixation techniques, thus avoiding potentially catastrophic vascular and or neurologic injury. The purpose of this study was to compare the mechanical behaviour of the hybrid uni-cortical construct to standard bi-cortical fixations under both torsion and bending loads.

METHOD

Thirty osteotomized human cadaveric clavicles were randomly allocated to three surgical fixation techniques: bi-cortical locked screw fixation, bi-cortical non-locked screw fixation and hybrid uni-cortical screw fixation. Each clavicle construct was tested non-destructively under torsional loading, and then under cantilever bending to failure. Construct bending and torsional stiffness, as well as ultimate failure strength, were measured.

RESULTS

There were no significant differences between uni-cortical or bi-cortical fixation constructs in either bending stiffness or ultimate bending moment (p>0.05); however, there was a trend towards greater bending stiffness in the hybrid construct. The uni-cortical hybrid fixation technique displayed a significantly lower mean torsional stiffness value when compared with the bi-cortical locked screw fixation (mean difference: 134.4 Nmm/degrees, 95% confidence interval [32.3, 236.4], p=0.007).

CONCLUSION

A hybrid uni-cortical approach to clavicle plate fixation that may improve screw purchase and reduce risk of intra-operative vascular damage demonstrates comparable bending strength to current bi-cortical approaches.

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.

Association between screw prominence and vascular complications after clavicle fixation

Context:

Fixation of clavicle fractures has become more common to prevent symptomatic malunion and nonunion. The subclavian and axillary vessels are in close proximity to the medial two-thirds of the clavicle, placing them at risk from prominent metalware. Injury to these major vessels has the potential to be life or limb-threatening. Despite this anatomical risk, iatrogenic vascular injury associated with clavicle fixation is rare.

Aims:

The aim of this study was to identify risk factors associated with modern fixation techniques in reported cases of vascular injury after clavicle fixation.

Materials and Methods:

A literature search was performed, and all identified cases of iatrogenic vascular injury associated with prominent clavicle fixation were analyzed. Clinical details, the total length of the prominent screws and the distance that they protruded from the far cortex were recorded.

Results:

Five cases were identified; there were four pseudoaneurysms and one arteriovenous fistula. The total length of the offending screw was identifiable in two cases, measuring 26 and 30 mm. The length of screw prominence was identifiable in 3 cases (8, 10 and 10 mm). The pseudoaneurysms presented at 2-10 years following clavicle fixation. Three of these cases developed limb-threatening ischemia.

Conclusions:

Vascular complications associated with clavicle fixation are uncommon but potentially limb-threatening. Several associated factors are identified. The authors provide a number of detailed recommendations aimed at preventing these complications.

Clavicular caution: an anatomic study of neurovascular structures

Open reduction and internal fixation of the clavicle is used to treat displaced fractures of the midshaft of the clavicle. Complications of operative intervention include injuries to major neurovascular structures including the subclavian artery and vein. Unlike other surgical approaches, palpation or visualization of the deep neurovascular structures at risk is rarely performed and is not part of the routine approach. This study aims to further elucidate the relationship of major neurovascular structures in the shoulder to the clavicle using sectioned fresh frozen cadaveric specimens. Using five cadaveric specimens, sagittal sections were performed using a band saw. Sections were taken every 15mm. Using these sections, structures were identified and photos were taken using a standardized approach to allow for precise and accurate measurements. Measurements taken included the distance from the nearest clavicular cortex to the centre of the subclavian artery, vein, and brachial plexus. These measurements were taken from five limbs on five different cadavers. Our results were consistent with previous studies. Medially, the subclavian vein was intimately related medially (4.8mm) to the clavicle, whereas the artery and brachial plexus were both >2cm from the clavicle. At about the junction of the middle and second-thirds of the clavicle, all three structures were within 2cm of the clavicle. Moving laterally, these structures moved further away and at the acromioclavicular (AC) joint were at least 4.5cm away from the clavicle on average. This study reiterates that the medial third of the clavicle is closely associated with neurovascular structures and that care should be taken here when using drills, depth gauges, and clamps.

Rate of and Risk Factors for Reoperations After Open Reduction and Internal Fixation of Midshaft Clavicle Fractures: A Population-Based Study in Ontario, Canada

BACKGROUND

Reoperation rates following open reduction and internal fixation (ORIF) of midshaft clavicle fractures have been described, but reported rates of nonunion, malunion, infection, and implant removal have varied. We sought to establish baseline rates of, and risk factors for, reoperations following clavicle ORIF in a large population cohort.

METHODS

Administrative databases were used to identify patients sixteen to sixty years of age who had undergone an ORIF of a closed, midshaft clavicle fracture from April 2002 to April 2010. The primary outcome was a reoperation within two years (isolated implant removal, irrigation and debridement [deep infection], pseudarthrosis reconstruction [nonunion], or clavicle osteotomy [malunion]). The secondary outcome was rare perioperative complications, including pneumothorax, subclavian vasculature injury, and brachial plexus injury. A multivariable logistic regression analysis was performed to determine the influence of patient and provider factors on these outcomes.

RESULTS

We identified 1350 patients who underwent midshaft clavicle ORIF (median age, thirty-two years [interquartile range, twenty-one to forty-four years]; 81.3% male). One in four patients (24.6%) underwent at least one clavicle reoperation. The most common procedure was isolated implant removal (18.8%), and females were at highest risk (odds ratio [OR], 1.7; p = 0.002). The median time to implant removal was twelve months. A reoperation secondary to nonunion, deep infection, and malunion occurred in 2.6%, 2.6%, and 1.1% of the patients after a median of six, five, and fourteen months, respectively. Risk factors for clavicle nonunion included female sex (OR, 2.2; p = 0.04) and a high comorbidity score (OR, 2.8; p = 0.009). For surgeons, fewer years in practice was associated with a small risk of the patient developing an infection (OR, 1.1; p < 0.001). Sixteen pneumothoraces (1.2%) were identified; however, brachial plexus and subclavian vessel injuries were each found in five or fewer patients.

CONCLUSIONS

Following clavicle ORIF, one in four patients underwent a reoperation. The most common procedure was implant removal, and although the rates of reoperations secondary to nonunion, malunion, and infection were low they were higher than previously reported. Pneumothoraces and neurovascular injuries were infrequent and should continue to be considered rare complications of clavicle ORIF.

LEVEL OF EVIDENCE

Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.