Anatomic relationships after instrumentation of the midshaft clavicle with 3.5-mm reconstruction plating: an anatomic study

Clavicle Nonunion and Malunion: Surgical Interventions for Functional Improvement

Clavicle nonunion and malunion are relatively uncommon but, when symptomatic, can result in pain and dysfunction that requires surgical intervention. Various reconstructive and grafting techniques are available to achieve stable fixation and union. In the setting of persistent nonunion, vascularized bone grafting may be necessary. A thorough understanding of the patient's type of nonunion and potential for healing is crucial for achieving satisfactory results because is thoughtful preoperative planning and surgical fixation.

The relationship between the subclavian vessels and brachial plexus and the overlying clavicle: Anatomical study with application to plate osteosynthesis

A subclavian artery aneurysm after clavicle fracture and plate osteosynthesis in a suspected case of a screw that was too long led us to investigate body donor cadavers. The aim was to verify clavicle variability, and the course of the neurovascular bundle in relation to the clavicle and to the osteosynthesis plate, in order to clarify safe zones for plate and screw fixation. We used one fresh frozen and 25 embalmed donors for in situ measurements: (1) length and craniocaudal thickness of the clavicle, (2) distances between the sternal end of the clavicle and the center of parts of the neurovascular bundle. The clavicle was 15.15 cm long. The mean distances from the sternal end of the clavicle were 5.62 cm to the subclavian vein, 6.75 cm to the subclavian artery and 8.42 cm to the cords of the brachial plexus. The subclavius muscle was 1 cm thick. Because of sex differences in length and distances, we recorded the distances between the sternal end and parts of the neurovascular bundle as ratios of clavicle length (at-risk area) to provide sex-independent parameters: 0.379 for the vein, 0.449 for the artery and 0.554 for the nerve. The neurovascular bundle runs below the clavicle between the medial fourth and three fifths of clavicle length. To avoid iatrogenic neurovascular injuries, special caution is necessary during drilling and screwing the osteosynthesis. We also recommend using screws shorter than 1.4 cm.

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.

Axillary Artery Pseudoaneurysm After Revision Plate Osteosynthesis of a Midshaft Clavicle Fracture Nonunion: A Case Report

CASE

A patient with history of nonunion repair of traumatic midshaft clavicle fracture was referred to our orthopaedic trauma clinic for new-onset shoulder pain and paresthesias involving the ipsilateral arm. Computed tomography angiography revealed an axillary artery pseudoaneurysm adjacent to the instrumentation and recurrent nonunion of the fracture site. The patient underwent coil embolization of the pseudoaneurysm and nonunion repair.

CONCLUSION

This case demonstrates that iatrogenic neurovascular injury during clavicle fracture nonunion repairs can present in a delayed fashion requiring more thorough clinical and imaging evaluation to achieve successful treatment.

Free vascularized medial femoral condyle corticoperiosteal flap with non-vascularized iliac crest graft for the treatment of recalcitrant clavicle non-union

Clavicle non-union is a challenging problem. Open reduction with internal fixation and autologous bone grafting is usually the first line treatment. In case of failure, the medial femoral condyle corticoperiosteal flap in association with a non-vascularized bone graft is one of the therapeutic options, which is well adapted to the clavicle anatomical characteristics. We performed a retrospective study of all patients treated with this technique in our department. Between 2014 and 2017, five patients with recalcitrant post traumatic clavicle non-unions received this surgical treatment. The average nonunion time period was 50.2 month (range 10 to 108 months), and the mean defect length was 3.4 cm (between 2 and 5 cm), defects were all located in the medial third of the clavicle Three patients achieved full consolidation with an average time of consolidation of 8,7 months (range 6 to12 months). Patients with radiological consolidation had better functional improvement and pain reduction with an average DASH score improved from 53,6 before surgery to 19,6 after consolidation (at the last follow up visit). There was one donor site complications (hematoma). The medial femoral condyle corticoperiosteal flap with non-vascularized iliac crest graft is a good option for the management of recalcitrant clavicle non-union, especially when the bone defect is small.

The Anatomy of the Clavicle and Its In Vivo Relationship to the Vascular Structures: A 2D and 3D Reconstructive Study Using CT Scans

OBJECTIVES

To describe in detail both the proximity and location of the subclavian vessels relative to both the right and left clavicle. This will give surgeons a more precise knowledge of safe and dangerous areas for screw placement during operative stabilization of clavicle fractures.

METHODS

A radiology storage database was reviewed to obtain a total sample of 103 clavicles with no evidence of periclavicular pathology. Each clavicle was divided along its length into 13 specific points of measurement. At each point, the distance and angular position between the clavicle and each subclavian vessel were measured.

RESULTS

The mean distance of the subclavian artery was greater than 10 mm at all positions. At the most medial point of the clavicle, the right subclavian artery was on average 1 cm closer to the clavicle than on the left. From medial to lateral, in the sagittal plane, the position of the subclavian artery transitions obliquely across the clavicle from a 2 to 6 o'clock position. The mean distance to the subclavian vein is less than 10 mm along the medial half of the clavicle on both sides of the body. In these areas, the position of the subclavian vein to the clavicle transitions from the 3 to 5 o'clock positions from medial to the mid-point of the clavicle.

CONCLUSIONS

The subclavian vein is the vascular structure at highest risk during clavicle fracture fixation. The major area of danger in our study is the medial clavicle with distance being less than 1 centimeter over the entire medial half of the clavicle on both right and left. In this danger area, the subclavian vein courses from 3 to 5 o'clock positions. The subclavian artery is more distant and relatively safer but is closer at the right medial clavicle than the left.

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.

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.

Meta-analysis of differences in Constant-Murley scores for three mid-shaft clavicular fracture treatments

There is no consensus on the optimal treatment for mid-shaft clavicular fracture. We conducted a meta-analysis to compare the effectiveness of non-operative treatment, plate fixation, and intramedullary pin fixation in terms of the Constant-Murley Score (CMS) for treatment of mid-shaft clavicular fracture. Comprehensive search of the Embase, Cochrane Library and PubMed was conducted to retrieve relevant randomized controlled trials (RCTs). A random-effect network meta-analysis was conducted within a Bayesian framework using Markov Chain Monte Carlo (MCMC) in OpenBUGS 3.2.2. Differences in CMS among the three treatments analyzed were evaluated with weighted mean difference (WMD) and surface under the cumulative ranking curves (SUCRA). Eleven studies met our inclusion criteria and were included in our network meta-analysis. Our results revealed that in terms of CMS followed-up for six months, the efficacies of plate fixation and intramedullary pin fixation were higher than non-operative treatment (plate fixation: WMD = 4.70, 95% CI = 1.21 ∼ 7.83; intramedullary pin fixation: WMD = 6.71, 95% CI = 3.20 ∼ 10.39), and intramedullary pin fixation had better efficacy than plate fixation, had better efficacy. However, no differences were found between the efficacies of the three treatments in pairwise comparisons with respect to CMS followed-up for six weeks, three months, 12 months and 24 months. In addition, the cluster analysis showed that intramedullary pin fixation had the best efficacy for patients with mid-shaft CF, followed by plate fixation and non-operative treatment. These analyses suggest intramedullary pin fixation may be the optimal therapeutic approach for mid-shaft clavicular fracture patients.

Superior versus anteroinferior plating of displaced midshaft clavicular fracture in patients older than 60 years

Objective

To compare superior versus anteroinferior plating for displaced midshaft clavicular fracture in elderly patients.

Methods

We retrospectively compared the functional result, parameters, and perioperative course of displaced midshaft clavicular fracture in 42 patients >60 years treated with a 3.5-mm reconstruction plate placed superiorly versus anteroinferiorly.

Results

Groups were similar with regard to age, sex, bone mineral density, cause of injury, and fracture pattern. The superiorly-plated group had a significantly longer operation time and greater blood loss, complications and implant prominence. Constant scores were significantly higher for the anteroinferiorly-plated group than the superiorly-plated group at 3 months postoperatively; however, there was no difference between groups at final follow-up.

Conclusion

While both anteroinferior and superior plate placement are safe and effective for displaced midclavicular fractures in patients >60 years, the anteroinferior approach involves less operation time, blood loss, complications and implant prominence, and enables faster return to normal activities.

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.

Minimally invasive plate osteosynthesis for midshaft clavicular fractures using superior anatomic plating

BACKGROUND

The minimally invasive plate osteosynthesis procedure has been widely applied for long-bone fixations; however, this technique is not commonly used for clavicular midshaft fractures. In this study, we introduced this technique for midshaft clavicular fractures using superior anatomic locking plates and evaluated its clinical and radiographic outcomes.

MATERIALS AND METHODS

From June 2013 to July 2014, 15 patients with acute midshaft clavicular fractures were treated with the minimally invasive plate osteosynthesis technique using a 3.5-mm clavicular superior anatomic locking plate. Anteroposterior plain X-ray images of the clavicle were taken at 4-week intervals until union was observed. The last clinical follow-up assessments were performed postoperatively at a mean of 16.54 months (range, 10-23 months). In addition, for clinical evaluations, the Constant score and the Disability of the Arm, Shoulder and Hand score were assessed.

RESULTS

The average operative time was 60.2 ± 20.1 minutes (range, 40-80 minutes), with blood loss of 25 ± 5 mL (range, 20-30 mL) during the operation. The mean union time for the patients was 10.1 ± 1.4 weeks (range, 8-12 weeks), and no delayed union or nonunion was observed. There were no major complications, including infections, plate breakages, or neurovascular injuries. No skin irritation was observed, and only 2 patients felt local incision numbness. All patients obtained satisfactory shoulder functions. The mean Constant score was 99 ± 1.8 (range, 95-100), and the mean Disability of the Arm, Shoulder and Hand score was 3.8 ± 2.9 (range, 0-10) at the last control visit.

CONCLUSION

The minimally invasive plate osteosynthesis procedure that was introduced in this study for midshaft clavicular fractures with superior anatomic locking plate is a reproducible procedure and an alternative to conventional operative methods.

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.

Analysis of neurovascular safety between superior and anterior plating techniques of clavicle fractures

OBJECTIVES

Clavicle fractures are commonly plated as a method of fixation, with superior and anterior techniques described. Although advantages and disadvantages have been attributed to both, it is unclear if one approach provides a lower risk of neurovascular injury. The aim of this study was to compare the potential for neurovascular injury between these 2 plate locations in a cadaveric model.

METHODS

Seventeen adult fresh frozen cadavers underwent bilateral dissections exposing the clavicle and underlying neurovasculature. After taking baseline anatomical measurements, a superior and anterior clavicle plate was applied, removed and measurements were taken from the nearest screw exit site to the underlying subclavian vein/artery and brachial plexus. The differences between superior and anterior measurements were compared based on proximity with the neurovasculature.

RESULTS

Distance to the vessels were unobtainable in 6 specimens (35%) plated with the anterior technique due to the trajectory of the screws projecting cephalad to the vessels. In the remaining specimens, there was no significant difference in the distance to the subclavian vein/artery and brachial plexus in the superior plate position (9.2 ± 4.6, 12.2 ± 5.8, and 9.8 ± 5.2 mm, respectively) compared with the anterior plate position (8.3 ± 3.5, 12.2 ± 6.5, and 9.7 ± 5.3 mm, respectively). In addition, no significant difference in potential neurovascular injury with regard to body size or gender was found.

CONCLUSIONS

The majority of our specimens showed no significant difference between superior and anterior plating in regard to potential risk for injury to the underlying neurovasculature. However, there appears to be a subset of the population with a more caudal position of the neurovascular structures in which anterior plating may be potentially safer.

Superior versus anteroinferior plating of clavicle fractures

Plate fixation of displaced clavicle fractures has proven to be reliable and reproducible, leading to high union rates and a low rate of associated complications. However, the decision of whether to place the plate superiorly or anteroinferiorly on the clavicle has remained controversial. The authors performed a retrospective review on a consecutive series of patients who underwent plate fixation for a displaced midshaft clavicle fracture at a Level I urban trauma center. A review of surgical records identified 138 patients with a displaced midshaft clavicle fracture requiring operative stabilization. A total of 105 patients who met the inclusion criteria were included in the analysis. Both superior and anteroinferior techniques resulted in a similar time to radiographic union (12.6±4.8 vs 11.3±5.2 weeks, respectively) and identical union rates (95%). At final follow-up, patient-reported implant prominence was nearly double in patients with a retained superior plate (54% vs 29%, respectively; P=.04). No significant difference existed in mean visual analog scale score at a mean of 2.77 years postoperatively, although a significant difference existed in the Oxford Shoulder Score questionnaire, with a mean score of 41.4 in the superior group and 44.4 in the anteroinferior group (P=.008). Implant removal occurred more frequently after superior plating but was not significant. Both superior and anteroinferior clavicle plating are safe treatment methods for displaced clavicle fractures. Superior plating leads to an increased rate of patient-reported implant prominence and may prompt more requests for implant removal.