Biomechanical evaluation of clavicle fracture plating techniques: does a locking plate provide improved stability?

Lateral clavicle fracture-plating options and considerations

Clavicle fractures are among the most prevalent types of fractures with numerous treatment strategies that have evolved over time. In the realm of lateral-third clavicle fracture management, several surgical methods are available, with plate and screw constructs being one of the most frequently employed options. Within this construct, numerous choices exist for fixing the fracture. This editorial provides an overview of the common plate options utilized in the management of distal third clavicle fractures underscoring the critical considerations and approaches that guide clinicians in selecting the most appropriate fixation techniques, considering the complex landscape of clavicle fractures and their challenging management.

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.

Biomechanical and clinical evaluation of minimal invasive plate osteosynthesis for two-part clavicle shaft fractures

BACKGROUND

Many surgical treatment methods exist for clavicle shaft fractures. A locking compression plate (LCP) fixation with three screws per fracture side is commonly used. For certain fractures a stabilization with 2 screws per side is potentially suitable, offering the advantage of reduced soft tissue approach, while avoiding the disadvantages of minimally-invasive nailing at the same time. This hypothesis was evaluated biomechanically and clinically.

METHODS

Four treatment procedures were investigated biomechanically using composite human clavicle specimens. A load-to-failure test was performed using a three-point cantilever test. In group 1, a simple shaft fracture was simulated and stabilized with 2 screws per fracture side (5-hole LCP). In the second group 3 screws per side (7-hole LCP) were used. In group 3, a non-reduced fracture zone was simulated and treated with 3 screws per side (7-hole LCP). In group 4, an anatomically reduced fracture zone was simulated and treated with 3 screws per side (7-hole LCP). Furthermore 27 patients treated with a short plate and 2 screws per side (similar to group 1) were assessed after a minimum follow-up of 12 months (Constant and DASH Score).

RESULTS

The maximum load-to-failure of group 1 was 367N. We observed the highest load-to-failure in group 2 with 497N and the lowest in group 3 with 90N. In group 4 a maximum load-to-failure of 298N could be evaluated. There was no significant difference in load-to-failure between the treatment of a simple clavicle fracture using 5- or 7-hole LCP (p = 0.121). However, we found a significant difference of load-to-failure between the simple and anatomically reduced fracture using a 7-hole plate (p = 0.014). The mean constant score of the surgically treated patients was 95 and the DASH score 3.0. Fracture consolidation was observed in 96.3%.

CONCLUSIONS

For certain non-fragmented and well interlocking 2-part fractures, a plate osteosynthesis fixed with only 2 screws per fracture side might offer sufficient biomechanical stability, better soft tissue preservation and comparable fusion rates compared to the operative treatment with 3 screws per side. However, the maximum load-to-failure of the 7-hole LCP was higher than of the 5-hole LCP, but this difference was not statistically significant.

TRIAL REGISTRATION

Approval from the ethics committee of the Technical University of Dresden was retrospectively obtained (EK 588122019).

The fifty most-cited articles regarding midshaft clavicle fractures

Introduction

The clavicle is the most frequently fractured bone in the human body, and up to 80% of clavicle fractures occur in the middle third diaphyseal region of the clavicle (midshaft). We conducted a bibliometric analysis to identify and evaluate the 50 most-cited publications pertaining to midshaft clavicle fractures (MCF).

Materials and methods

Two independent reviewers conducted separate queries on Web of Science in December 2021 for "midshaft clavicle fractures". The publications yielded were organized from highest to lowest number of citations. We included articles, review articles, and editorial materials and excluded other document types. Both reviewers independently reviewed all abstracts until 50 studies pertaining to MCF were included.

Theory

We hypothesized that most articles would be published between 2000 and 2019, pertain to outcomes, and those with a greater (lower numeric) level of evidence would correlate with number of citations.

Results

The most prolific decade was from 2010 to 2019, with 50% (25/50) of articles published. Average citation density was 6.3 ± 5.5 (range, 1.3-33.1), defined as the average number of citations per year since publication. The median level of evidence (LOE) was 3.5 (IQR: 3). One-way ANOVA tests were used to compare the effects of LOE on total citations and citation density. There were statistically significant differences in total citations (F value = 12.07, p = 0.001) and citation density (F value = 21.14, p < 0.001) between LOE groups. The median number of total citations, grouped by LOE of 1 through 5, were as follows: 110, 66, 66, 51, 52.

Conclusions

This review provides an overview of the 50 most cited papers regarding MCF. This should be used as a reference for physicians and other providers who treat patients with MCF for treatment guidance and for those in teaching roles as a student and resident/fellow educational resource.

Locking versus nonlocking superior plate fixations for displaced midshaft clavicle fractures: A prospective randomized trial comparing clinical and radiografic results

BACKGROUND

It is unknown whether locking or nonlocking superior plate fixation is better for managing displaced midshaft clavicle fractures. Therefore, we aimed to compare the clinical and radiographic outcomes of locking and nonlocking superior plate fixation of displaced midshaft clavicle fractures.

METHODS

A total of 102 consecutive patients with displaced midshaft clavicle fractures (2B1 and 2B2 in Robinson classification) participated in this randomized controlled trial; 12 patients were excluded. Surgeries were performed using a 3.5-mm Locking Compression Plate (LCP) between 2007 and 2015. Patients were treated either with a locking plate (group L, n = 45) or a nonlocking plate (group N, n = 45). In both groups, the plates were fixed to the proximal and distal clavicle with two and/or three screws, respectively. The main outcome measures were complication rates, time to bone union, and Constant score.

RESULTS

Forty-two patients in group L (mean age, 45.9 years) and 41 in group N (mean age, 43.6 years) were followed. The overall complication rates in groups L and N were 7.2% (three peri-implant fractures) and 7.3% (non-union, deformed plate, and peri-implant fracture), respectively (p = .98). The average time to union significantly differed between groups (L vs. N: 13.0 ± 4.1 vs. 17.5 ± 6.3 weeks; p < .01). However, the Constant score at the final follow-up was not significantly different between groups (L vs. N: 87.0 ± 12.3 vs. 89.8 ± 9.1).

CONCLUSIONS

Similar complication rates and clinical results were found for locking and nonlocking superior plate fixation for displaced midshaft clavicle fractures. However, the time to bone union was shorter with the locking plate. This study suggests that both plating systems are effective for treating displaced midshaft clavicle fractures.

LEVEL OF EVIDENCE

Therapeutic, level I.

Examining the novel use of continuous compression implants in clavicle reconstruction: A biomechanical study

BACKGROUND

Current implants for clavicle fractures are known to cause poor cosmesis and irritation, which may require implant removal. Low-profile shape-memory staples provide an attractive alternative, but their biomechanical utility in clavicle reconstruction is unknown. We hypothesized that shape-memory reconstructions would be more compliant compared to traditional constructs but would also outperform conventional plates during cyclic loading to failure.

METHODS

This study was performed with 36 synthetic clavicles and 12 matched pairs of cadaveric specimens. The synthetic study tested four reconstructions: a single superiorly placed staple (n = 6), a single anteroinferiorly-placed staple (n = 6), a 3.5 mm reconstruction plate (n = 12), and two orthogonally placed staples (n = 12). The cadaveric study tested three constructs: reconstruction plate (n = 8), two orthogonal staples (n = 8), and a 2.7 mm reconstruction plate combined with a superior staple (n = 8). Non-destructive 4-point bending, compression, and torsion assays were performed prior to destructive cantilever bending and cyclic torsion tests.

FINDINGS

The single staple and double staple groups demonstrated significantly decreased resistance to bending (p < 0.001) and torsion (p ≤ 0.027) when compared to reconstruction plate groups. The double staple group sustained significantly fewer cycles to failure than the reconstruction plate group in cyclic torsional tests (p = 0.012). The synthetic models produced higher stiffness and failure mechanisms that were completely different from cadaveric specimens.

INTERPRETATION

Shape memory alloy implants provided inadequate stiffness for clavicle fixation but may have utility in other orthopaedic applications when used as a supplementary compression device in conjunction with traditional plated constructs. Synthetic bones have limited capacity for modeling fragility fractures.

Biomechanical evaluation of an intramedullary clavicle screw in simple oblique and butterfly wedge fractures

This biomechanical study evaluates the performance of a solid titanium-alloy intra-medullary (IM) clavicular screw in torsion and cantilever bending in cadaveric clavicle specimens with simulated simple oblique and butterfly wedge midshaft fractures. Thirty-two fresh-frozen male clavicles were sorted into six experimental groups: Torsion Control, Torsion Simple Oblique Fracture, Torsion Butterfly Wedge Fracture, Bending Control, Bending Simple Oblique Fracture, and Bending Butterfly Wedge Fracture. The experimental groups were controlled for density, length, diameter, and laterality. All other samples were osteotomy-induced and implanted with a single 90 mm × 3 mm clavicle screw. All groups were tested to physiologically relevant cutoff points in torsion or bending. There were no statistically significant differences in the performance of the oblique and butterfly wedge fracture models for any torsion or bend testing measures, including maximum torsional resistance (p = 0.66), torsional stiffness (p = 0.51), maximum bending moment (p = 0.43), or bending stiffness (p = 0.73). Torsional testing of samples in the direction of thread tightening tended to be stronger than samples tested in loosening, with all groups either approaching or achieving statistical significance. There were no significant differences between the simple oblique or the butterfly-wedge fracture groups for any of the tested parameters, suggesting that there is no difference in the gross biomechanical properties of the bone-implant construct when the IM clavicle screw is used in either a simple midshaft fracture pattern or a more complex butterfly wedge fracture pattern.

Treatment of unstable distal clavicle fractures (Neer type IIb): a modified system using a miniature locking plate with a single button

Distal clavicle fractures are common in patients with shoulder injuries. We retrospectively evaluated the clinical outcomes of a novel fixation technique using a miniature locking plate with a single button in patients with distal clavicle fractures associated with coracoclavicular ligament disruption. The study involved seven patients with distal clavicle fractures with a follow-up period of 12 months. All patients were diagnosed with type IIb fractures according to the Neer classification. The distal clavicle fracture was fixed with a miniature locking plate, and the coracoclavicular ligaments were reconstructed using a single button. Functional outcomes were assessed at the final follow-up visit. At the 1-year follow-up, all patients had achieved radiographic union. There were no cases of nonunion or osteolysis. The mean Constant score at the final follow-up was 88 ± 5.13 (range, 78–93); the mean Disabilities of the Arm, Shoulder and Hand score was 19.17 ± 7.70 (range, 11.67–25); and the mean University of California Los Angeles score was 30 ± 2.52 (range, 25–33). In summary, internal fixation using a miniature locking plate and coracoclavicular reconstruction with a single button is a reliable surgical technique for restoring stability in patients with Neer type IIb distal clavicle fractures.

Surgical fixation of displaced midshaft clavicular fractures with precontoured plates in adolescents

BACKGROUND

The use of plate fixation to treat displaced midshaft clavicular fractures in adults reduces complications and residual shoulder disability. New features of the precontoured locking plates have been shown to reduce the need for hardware removal in adults. There is a lack of studies evaluating surgical fixation of displaced clavicular fractures with precontoured plates in adolescents. We evaluate outcomes and complications of adolescents with displaced midshaft clavicular fractures treated with precontoured locking plates.

MATERIALS AND METHODS

40 adolescents with displaced midshaft clavicular fractures were surgically treated from January 2010 to May 2017. Outcomes were evaluated using the Constant score, the 11- item version of the Disabilities of Arm, Shoulder and Hand (QuickDASH) questionnaires, and radiographs, and a visual analog scale. Return-to-sport rate, level achieved, and complications were recorded.

RESULTS

Mean follow-up was 50 months (18 - 108 months). Constant, Quick-DASH, and visual analog scale scores were 95.6, 2.8 and 0.5 points, respectively. 100% of adolescents returned to sports at the same level they had before injury. Mean time to return was 69 days and 95% of patients were able to return before 12 weeks. Complication rate was 12.5%, 3 patients (7.5%) required hardware removal.

CONCLUSIONS

Adolescents with displaced midshaft clavicular fractures treated with precontoured locking plates exhibited satisfactory outcomes and low complication rate. Compared to other reports, this study had lower rates, anatomic plates might reduce hardware-related complications.

Comparing internal fixation constructs for scapular spine insufficiency fractures following reverse shoulder arthroplasty

INTRODUCTION

There is limited research on the surgical management techniques for scapular spine fractures after reverse shoulder arthroplasty (RTSA). As such, the purpose of this in vitro biomechanical study was to compare 4 fixation constructs to stabilize scapular spine insufficiency fractures.

METHODS

Twelve paired fresh-frozen cadaveric scapulae (N = 24) were randomized into 4 fixation groups: subcutaneous border plating (± hook) and supraspinatus fossa plating (± hook). A Levy type II fracture was simulated. Each specimen was cyclically loaded incrementally up to 700 N in 50 N steps or until failure. Between 50 and 200 N construct stiffness was measured, and stability failure was defined as displacement greater than 2.5 mm.

RESULTS

Seventy-nine percent (19 of 24) of the specimens failed before the maximum load of 700 N. The average survival force with subcutaneous border plating was 480 ± 80 N compared with 380 ± 30 N for supraspinatus fossa plating (P = .3). Fixation construct failure was significantly more likely with fossa plating over subcutaneous plating (P = .012). The presence of the lateral plate hook was beneficial in preventing failure of the lateral acromion (P = .016).

CONCLUSION

When appropriately surgically indicated, a dorsally applied plate to the subcutaneous border of the scapular spine with a lateral inferior supporting hook may be advantageous for internal fixation of type II scapular spine insufficiency fractures after RTSA.

Two reconstruction plates provide superior stability of displaced midshaft clavicle fractures in comparison to single plating - A biomechanical study

BACKGROUND

Displaced midshaft fractures are the most common surgically treated clavicle fractures. However, they are associated with high complication rates following plating due to fixation failure in terms of plate breakage, screw breakage and/or screw loosening. The aim of this study was to compare the biomechanical competence of three different plating techniques for fixation of displaced midshaft clavicle fractures.

METHODS

Displaced midshaft fractures type 2B according to the Robinson classification were simulated by standardized osteotomy gap in 18 synthetic clavicles, assigned to three groups (n = 6) for plating with either superiorly placed Dynamic Compression Plate (width/thickness 11.0/4.0 mm), locked Superior Anterior Clavicle Locking Compression Plate (width/thickness 10.2/2.0 mm), or two non-locked Reconstruction Plates placed superiorly and anteriorly (width/thickness 10.0/2.8 mm). Each specimen was cyclically tested at 3 Hz under craniocaudal cantilever bending, superimposed with torsion around the shaft axis over 720'000 cycles or until failure occurred. The latter was defined by plate breakage, screw breakage or screw loosening.

FINDINGS

Initial construct stiffness (N/mm) and cycles to failure in group Reconstruction Plates (22.30 ± 4.07; 712'778 ± 17'691) were significantly higher compared with both groups Compression Plate (12.53 ± 2.09; 348'541 ± 212'941) and Locking Plate (4.19 ± 0.46; 19'536 ± 3'586), p ≤ 0.019. In addition, these two outcomes were significantly higher in group Compression Plate versus Locking Plate, p ≤ 0.029.

INTERPRETATION

Double plating of unstable midshaft clavicle fractures with reconstruction plates seems to provide superior fixation stability under dynamic loading, when compared to single compression or locked plating, whereas the latter is associated with inferior performance.

A Comparison of 3 Fixation Strategies in the Treatment of Neer Type IIB Distal Clavicle Fractures

OBJECTIVES

To compare the stability of NT2B clavicle fractures fixed with either a hook plating (HP), Superior Plating with Suture Augmentation (SPSA), or dual orthogonal plating (DP) with the hypothesis that DP would provide increased multiplanar stability across NT2B fractures.

METHODS

NT2B distal clavicle fractures were created in cadaveric specimens and fixed using (1) HP, (2) SPSA, or (3) DP. Specimens were cyclically loaded in 3 different planes of motion: (1) anteroposterior (AP), (2) superior-inferior, and (3) axial rotation while displacement was continually recorded. Afterward, a superiorly directed load was applied to the clavicle. Load to failure, stiffness, and mode of failure were recorded.

RESULTS

During AP loading, clavicles fixed with a DP had significantly lower mean posterior displacement compared to those fixed with SPSA at every 100-cycle interval of testing, P < 0.01. During inferior-superior loading, specimens fixed with a DP had less superior displacement than specimens fixed with an HP and SPSA, reaching significance at the 500-700 cycles of testing. There was no significant difference in axial rotation stability or load to failure between the 3 fixation techniques.

CONCLUSIONS

Orthogonally placed minifragment plates provide improved stability against anterior displacement with no significant difference in superior stability, axial rotational stability, stiffness, or load to failure. Further clinical studies are needed to confirm the long-term stability of dual plating and determine the risks and benefits of this novel method of distal clavicle fixation.

Single versus dual orthogonal plating for comminuted midshaft clavicle fractures: a biomechanics study

BACKGROUND

Dual orthogonal plating of clavicle fractures may provide greater stiffness and strength than unilateral plate constructs and allow the use of lower-profile plates. We aim to biomechanically compare three clavicle plating constructs in a comminuted clavicle fracture model.

METHOD

Fifteen clavicle sawbones were osteotomised, simulating a comminuted midshaft fracture and allocated to either: group 1, single superior plate (3.5 mm superior plate); group 2, combination plating (3.5 mm superior plate, 2.8 mm anterior plate) and group 3, dual mini-plates (two 2.8-mm orthogonal mini-plates). Specimens were biomechanically tested under torsion and cantilever bending. Construct stiffness (Nm/degree) and load to failure (Nm) were measured.

RESULTS

Group 2 had higher torsional (0.70 vs. 0.60 Nm/deg, p = 0.017) and cantilever bending stiffness (0.61 vs. 0.51 Nm/deg, p = 0.025) than group 1. Group 3 had lower cantilever bending stiffness (0.39 vs. 0.51 Nm/deg, p < 0.004) and load to failure (40.87 vs. 54.84 Nm, p < 0.01) than group 1. All dual plate constructs that catastrophically failed did so from fracture at the lateral ends of the plates. Single plate constructs failed due to plate bending.

CONCLUSION

Dual orthogonal fixation with mini-plates demonstrated lower stiffness and strength than traditional superior plating. The addition of an anterior mini-plate to a traditional superior plating improved construct stiffness and may have a role in patients seeking early return to activity.

LEVEL OF EVIDENCE

Basic science biomechanical study.

Comparison of radiological and clinical outcomes, complications, and implant removals in anatomically pre-contoured clavicle plates versus reconstruction plates - a propensity score matched retrospective cohort study of 106 patients

Background

Plate fixation is frequently used to treat displaced midshaft clavicular fractures, however the ideal plate choice remains subject to discussion; reconstruction locking compression plates (RLCPs) are cheaper and can be easily contoured, whereas anatomically pre-contoured locking compression plates (ALCPs) are thought to provide better stability and therefore lower rates of mechanical failure.

To compare the incidence of mechanical failures, functional and radiological outcomes in patients with midshaft clavicular fractures treated with ALCPs versus RLCPs.

Methods

A propensity score matched retrospective cohort study was conducted across two centers. One hundred and six consecutively recruited patients with displaced midshaft clavicular fractures, who were treated with plate fixation and had a minimum follow-up of 6 months, were matched on gender, age, fracture grading, energy of injury, and fracture location. The resulting groups included 53 ALCP-treated fractures and 53 matched controls treated with RLCPs.

Results

During a mean follow-up of 20.5 months, there were no implant deformities in the ALCP group whereas the RLCP group had 6 patients (11.3%, p = 0.012) with implant deformities (5 occurrences of plate bending with fracture union, and 1 plate breakage with nonunion). Despite the higher rate of plate deformities in the RLCP group, there were no statistically significant differences in number of patients recovering full shoulder range of motion (ALCP 90.6%, RLCP 88.7%, p = 0.751), incidence of rest pain (ALCP 13.2%, RLCP 9.4%, p = 0.542), or implant removals (ALCP 49.1%, RLCP 56.6%, p = 0.439).

Conclusion

ALCPs may be superior to RLCPs in terms of implant stability but appear to produce similar clinical results.

TREATMENT OF MIDSHAFT CLAVICLE FRACTURE WITH SUPERIOR PLATE PLACEMENT

Objective:

To evaluate the late clinical and radiological results of patients had locking plate anatomically compatible from superior surface and muscle cover on plate due to clavicle mid-region.

Materials and Methods:

Forty patients were included retrospectively. Patients had a routine right shoulder anterior posterior graph after examination. The results were assessed by returning to the patient's daily activities, Constant score, the Disability of the Arm, and Shoulder and Hand scoring, followed by radiological and clinical examination.

Results:

Fourteen (35%) patients were female and 26 (65%) were male. The mean age was 36.2 years. Twenty-six patients had right clavicle fracture and 14 patients had left. Twenty-three fractures were type 2B1 and 17 fractures were type 2B2. Mean follow-up time was 36.4 months. Radiologic union was at a mean of 9.1 ± 1.3 weeks. All patients had excellent results. The mean Constant score was 97.2 ± 1.8, the mean Disability of the Arm, and Shoulder and Hand score was 3.8 ± 2.4.

Conclusion:

It is possible to obtain complete union with high patient satisfaction by avoiding the complications and difficulties of the conservative treatment with the use of the anatomically compatible locking plates in superior fixation and our surgical dissection. Level of Evidence III, Retrospective Case controlled study.

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.

Biomechanical performance of an intramedullary Echidna pin for fixation of comminuted mid-shaft clavicle fractures

BACKGROUND

Surgical fixation of comminuted mid-shaft clavicle fractures commonly employs intramedullary devices; however, pins with smooth surfaces are prone to migration, whilst threaded pins can be challenging to remove post-operatively. The aim of this study was to evaluate the biomechanical performance of fractured clavicles repaired using a novel intramedullary Echidna pin device and a non-threaded Knowles pin. The Echidna pin features retractable spines that engage with the bone to minimize migration and facilitate ease of device removal.

METHODS

A total of 28 cadaveric clavicle specimens were harvested and a mid-shaft wedge-shaped osteotomy was performed to simulate a comminuted butterfly fragment. Specimens were allocated randomly to either the Echidna pin or Knowles pin fracture repair groups. Following surgery, eight specimens in each group underwent 200 cycles of four-point bending, whilst six specimens in each group underwent torsional testing and pull-out. Cyclic construct bending stiffness, torsional stiffness and ultimate strength were recorded.

RESULTS

Echidna pin intramedullary repair constructs showed significantly greater bending stiffness (mean difference 0.55 N.m/°, 95% confidence interval -0.96, -0.14, P = 0.01) and pull-out strength (mean difference 146.03 N, 95% confidence interval 29.14, 262.92, P = 0.019) in comparison to Knowles pin constructs. There was no significant difference in torsional stiffness between Echidna pin and Knowles pin repair constructs (P > 0.05).

CONCLUSION

The intramedullary Echidna pin device, which exhibits greater bending strength and pull-out strength than that of the Knowles pin, may produce a more stable clavicle fracture reduction compared to that of commercially available threadless intramedullary pins.

Low-Profile Dual Small Plate Fixation Is Biomechanically Similar to Larger Superior or Anteroinferior Single Plate Fixation of Midshaft Clavicle Fractures

BACKGROUND

Limited biomechanical data exist for dual small plate fixation of midshaft clavicle fractures, and no prior study has concurrently compared dual small plating to larger superior or anteroinferior single plate and screw constructs.

PURPOSE

To biomechanically compare dual small orthogonal plating, superior plating, and anteroinferior plating of midshaft clavicle fractures by use of a cadaveric model.

STUDY DESIGN

Descriptive laboratory study.

METHODS

The study used 18 cadaveric clavicle specimens (9 pairs total), and 3 plating techniques were studied: anteroinferior, superior, and dual. The dual plating technique used smaller diameter plates and screws (1.6-mm thickness) than the other, single plate techniques (3.3-mm thickness). Each of the 9 clavicle pairs was randomly assigned a combination of 2 plating techniques, and randomization was used to determine which techniques were used for the right and left specimens. Clavicles were plated and then osteotomized to create an inferior butterfly fracture model, which was then fixed with a single interfragmentary screw. Clavicle specimens were then potted for mechanical testing. Initial bending, axial, and torsional stiffness of each construct was determined through use of a randomized nondestructive cyclic testing protocol followed by load to failure.

RESULTS

No significant differences were found in cyclical axial (P = .667) or torsional (P = .526) stiffness between plating groups. Anteroinferior plating demonstrated significantly higher cyclical bending stiffness than superior plating (P = .005). No significant difference was found in bending stiffness between dual plating and either anteroinferior (P = .129) or superior plating (P = .067). No significant difference was noted in load to failure among plating methods (P = .353).

CONCLUSION

Dual plating with a smaller plate-screw construct is biomechanically similar to superior and anteroinferior single plate fixation that uses larger plate-screw constructs. No significant differences were found between dual plating and either superior or anteroinferior single plating in axial, bending, or torsional stiffness or in bending load to failure. Dual small plating is a viable option for fixing midshaft clavicle fractures and may be a useful low-profile technique that avoids a larger and more prominent plate-screw construct.

CLINICAL RELEVANCE

Plate prominence and hardware irritation are commonly reported complaints and reasons for revision surgery after plate fixation of midshaft clavicle fractures. Dual small plate fixation has been used to improve cosmetic acceptability, minimize hardware irritation, and decrease reoperation rate. Biomechanically, dual small plate fixation performed similarly to larger single plate fixation in this cadaveric model of butterfly fracture.

A biomechanical comparison of two plating techniques in lateral clavicle fractures

BACKGROUND

Neer Type IIb lateral clavicle fractures typically lead to dislocation of the medial fragment. Therefore, most surgeons recommend surgical treatment for such a fracture pattern. The use of a locking compression plate with a lateral extension has produced satisfactory results in various studies over recent years. Double-plate fixation is a common technique in the treatment of complex distal radius fractures. The authors use this technique as a routine procedure in the treatment of Neer type IIb fractures. In this biomechanical testing study, the mechanical properties of the two techniques were compared.

METHODS

On 20 clavicles from fresh frozen cadavers a Neer Type IIb fracture-like osteotomy was performed. A cyclic loading test followed by a load-to-failure test was carried out. Parameters for statistical evaluation were the stiffness at cycles 1, 100 and 17,500 as well as the ultimate tensile load and the deformation at the point of failure.

FINDINGS

All specimens withstood the cyclic loading test without any noticeable damage. At cycles 100 and 17,500, the double-plate technique was less stiff. Failure loads were not significantly different from each other, but deformation at the point of failure was significantly greater for the double-plate technique.

INTERPRETATION

Both techniques provided sufficient fixation to the fracture site to endure the cyclic loading test, which is supposed to simulate an incident-free week postoperatively. In summary, the double-plate technique offers biomechanically a feasible alternative to the single-plate technique in lateral clavicle fractures of Neer Type IIb.

Mechanical testing of scapular neck fracture fixation using a synthetic bone model

BACKGROUND

Trauma can fracture the scapular neck. Typically, a single plate along the lateral scapula border affixes the glenoid fragment to the scapula. This method is limited by difficulty in screw placement, frequent excessive soft tissue dissection, and risk for neurovascular injury. Substituting 2 smaller plates bridging the scapular neck mitigates these limitations, but no comparative mechanical data between techniques exists. Therefore, we compared the mechanical properties of two constructs securing a simulated scapular neck fracture.

METHODS

Twenty synthetic human scapulae underwent a templated scapular neck fracture. Repairs were performed with a single plate on the lateral scapular border (Column method), or two small plates parallel to the lateral border (Neck method). Measures of displacement, force, and stiffness were quantified during cyclic testing (20-150 N, 1 Hz, 1000 cycles) and loading to failure. Statistical comparisons were made with t-tests (p ≤ 0.050).

FINDINGS

The column constructs had higher displacements than neck constructs after 1000 cycles, but differences were small (mean) 0.18 (SD 0.01) vs. 0.15 (0.02) mm (p ≤ 0.004). Cyclic stiffness was 655 (43) and 790 (88) N/mm for the column and neck constructs, respectively (p ≤ 0.003). Both techniques performed comparably in failure loading: at 1 mm of gap reduction the compressive loads were 426 (61) N and 428 (48) N and stiffness was 354 (129) and 334 (80) N/mm for the column and neck constructs, respectively.

INTERPRETATION

Given the surgical advantages, the neck fixation may be more suitable without biomechanical compromise compared to traditional lateral column fixation.

Biomechanical Analysis of Superior and Anterior Precontoured Plate Fixation Techniques for Neer Type II-A Clavicle Fractures

OBJECTIVE

There are limited biomechanical data supporting the use of anterior or superior-lateral precontoured clavicle plates for the treatment of displaced Neer type II-A clavicle fractures. The objectives of this study were as follows: (a) compare noncontoured versus precontoured superior plating; (b) compare use of locking versus nonlocking screws in the lateral fragment for superior precontoured plates; and (c) compare superior versus anterior precontoured plates with locking lateral fragment screws.

METHODS

The following constructs were tested on a synthetic clavicle model simulating a Neer type II-A fracture: (a) superior precontoured plate with locking (SUP-L, n = 6); (b) superior precontoured plate with nonlocking (SUP-NL, n = 8); (c) anterior precontoured plate with locking (ANT-L, n = 7); and (d) superior noncontoured locking compression plate (SUP-LCP, n = 6). Constructs were subjected to cyclical cantilever loads. Construct stiffness and survival (cycles to failure) were documented. Mann-Whitney U tests were performed for group-wise statistical comparison (α = 0.05) of data.

RESULTS

The SUP-L construct was significantly stiffer than both SUP-LCP and ANT-L constructs (P < 0.02). The SUP-NL construct was stiffer than the SUP-L (P = 0.03) construct. Both SUP-L and ANT-L precontoured constructs survived longer than the noncontoured SUP-LCP construct (P < 0.022). The SUP-L construct survived longer than the SUP-NL (P = 0.013) and the ANT-L (P = 0.008) constructs.

CONCLUSIONS

Superior precontoured plates yielded biomechanically superior constructs compared with anterior precontoured and superior noncontoured plates. Using locking screws in the lateral fragment over nonlocking screws may improve overall superior precontoured plate construct survivability. However, our results were limited to a synthetic biomechanical model and require further investigation to establish a clinical correlation.

Immediate Weight-bearing as Tolerated has Improved Outcomes Compared to Non–weight-bearing after Surgical Stabilisation of Midshaft Clavicle Fractures in Polytrauma Patients

Background

Clavicle fractures are common injuries in the polytrauma population and frequently limit early mobilisation. This study evaluates the effect of immediate crutch weight-bearing (WB) in polytrauma patients after surgical stabilisation of a displaced midshaft clavicle fracture.

Methods

A retrospective review identified 26 polytrauma patients with operatively managed displaced midshaft clavicle fractures and a non–weight-bearing (NWB) lower extremity injury. Patients were allowed immediate WB after surgery or NWB. The primary outcome was total hospital length of stay. Statistical analysis was done using Mann–Whitney U test.

Results

The WB group had decreased total hospital length of stay (10.4 vs. 17.0 days, p = 0.012) and improved physical therapy score (3.9 vs. 2.9, p = 0.054) and postoperative length of stay (6.8 vs. 12.7 days, p = 0.006) compared with the NWB group.

Conclusions

Our data suggest that an immediate WB as tolerated protocol for polytrauma patients after surgical fixation of displaced clavicle fractures may decrease the overall length of stay.

Management of Midshaft Clavicle Fractures in Adults

Fractures of the clavicle are common injuries that occur across all age groups but are most frequently seen in the young, active patient population. Among the different types of clavicle fractures, those occurring in the middle third of the clavicular shaft are the most common. Historically, most of these fractures were treated by closed means even when notable displacement was present. Recently, there has been a renewed interest in assessing the best treatment option for these patients. Although nonsurgical treatment is a reliable method for treating many of these fractures, more recent data suggest that fractures with notable displacement (>2 cm of shortening or >100% displacement) and/or comminution have better short-term outcomes and lower rates of nonunion with surgical management. Current surgical options include superior plating, anterior-inferior plating, dual plating, and intramedullary nail fixation.

Are commercially-available precontoured anatomical clavicle plating systems offering the purported superior optimum fitting to the clavicle? A cadaveric analysis and review of literature

PURPOSE

The indication for operative treatment of displaced midshaft clavicle fractures remains controversial. However, if plate fixation is considered, implant prominence and skin irritation are the most common causes for re-operation. Low profile implants as well as closely contouring plates to the individual anatomy may reduce these complications. The aim of this study was to compare the fitting accuracy and implant prominence of 3.5mm pelvic reconstruction plates (PRP) with pre-contoured anatomical clavicle plates (PACP) for midshaft clavicle fractures.

METHODS

Three-dimensional data of the largest, median and smallest male and female clavicle of an existing database of 89 cadaveric clavicles were included for analysis. A three-dimensional model of a commercially available PACP was used for digitally positioning of the plate on the segmented clavicles. Three-dimensional printouts of each clavicle were produced and the 3.5mm reconstruction plates were manually bent and positioned by the senior author. Computed tomography scans and three-dimensional reconstructions were then obtained to digitally compare the fitting accuracy and implant prominence.

RESULTS

Pelvic reconstruction plates offered superior fitting accuracy and lower implant prominence compared to PACP. The largest difference in implant prominence was observed in large sized female clavicles and measured 3.6mm.

CONCLUSION

Both, the less costly PRP plates and commercially available PACP for midshaft fractures of the clavicle demonstrated a clinically acceptable fitting accuracy. The manually bent pelvic-reconstruction plates demonstrated reduced implant prominence with superior fitting. Hypothetically this might contribute to a reduced rate of reoperation.

LEVEL OF EVIDENCE

Level IV cadaveric study.

Supplementary Technique for Unstable Clavicle Shaft Fractures: Interfragmentary Wiring and Temporary Axial K-Wire Pinning

Background

Treatment of unstable clavicle fractures remains a challenge for orthopedic surgeons, but the evolution of treatment strategies has allowed for reliable results with minimal complications. Although several surgical options exist, open reduction with plating remains the treatment of choice for clavicle fractures. The purpose of this study is to determine an easy way to achieve successful preplating reduction while minimizing surrounding soft tissue damage during treatment of midshaft fractures of the clavicle.

Methods

A retrospective study included all consecutive adult patients operated on by a single surgeon for acute displaced clavicular midshaft fracture between January 2010 and October 2014. Hybrid technique with interfragmentary cerclage wiring, temporary axial K-wire pinning, or their combination was used in all patients. The demographic data and clinical outcomes, including operation time, union time, restoration of anatomy, shoulder functional score, and complications were evaluated.

Results

There were 54 male and 19 female patients, with an average age of 39.3 years (range, 18 to 77 years) for males and 58.3 years (range, 39 to 77 years) for females. They were followed up for 24 months (range, 12 to 44 months). All patients had reliable bone union after surgery using interfragmentary cerclage wiring and temporary axial K-wire fixation; fracture union was obtained at an average of 11.7 weeks (range, 8 to 21 weeks) postoperatively. Additionally, there was no postoperative loss of fracture reduction or plate loosening. At the final follow-up, all patients had regained excellent functional outcomes.

Conclusions

The cognizant effort to achieve anatomic reduction without surrounding soft tissue insult before definitive plating allows excellent radiologic and functional outcomes. Interfragmentary cerclage wiring and temporary axial K-wire pinning can overcome difficulties associated with unstable clavicle fractures to allow proper fracture reduction. In this article, we introduce a concise technique for achieving the desired outcomes reliably and efficiently when treating unstable clavicle midshaft fractures.

Clavicula fractures: considerations when plating

The preferred treatment of clavicula midshaft fractures in adults has gone from being very conservative into surgery being frequently recommended. However, based on recent meta-analysis favorable outcome with internal fixation is not as consistent as previously reported. Probably due to a combination of indications for surgery becoming too wide and surgery being performed by a wider group of surgeons. When using plating for clavicula fractures there are several considerations to consider to improve outcome while reducing the risk for complications. Traditionally a horizontal approach along the clavicula is used as it provides good exposure. However, this incision is associated with a high risk for permanent anterior chest wall numbness that might be very disturbing for patients. A vertical incision can instead be used. Plates are traditionally placed in a superior position. An alternative can be an anterior-inferior position that allows better soft tissue coverage, less risk for hardware protrusion, longer screws can be used and the risk for damaging the underlying neurovascular bundle is reduced. Angle-stable screw-plate systems has not in a convincing way shown any benefit in clavicula fractures. In part because most patients have good bone quality where conventional screws will be sufficient.

Bioabsorbable plating in the treatment of pediatric clavicle fractures: A biomechanical and clinical analysis

BACKGROUND

Classic implants for operative intervention of mid-shaft clavicle fractures in adolescents can become symptomatic, requiring removal. This study compares 1) biomechanical properties and 2) clinical outcomes in adolescents of mid-shaft clavicle fracture fixation with bioabsorbable versus metal implants.

METHODS

Six synthetic clavicles with mid-shaft fractures underwent bioabsorbable plating. A testing frame applied 10 non-destructive torsion and 10 axial compression cycles, followed by cantilever bending to failure. Stiffness was calculated; maximum failure load and failure mode were recorded. Results were compared to previous data for locked metal constructs. Retrospective review of surgically treated clavicle fractures over three years included functional and radiographic outcomes.

FINDINGS

Bioabsorbable plates had lower torsional stiffness (P < 0.001) and maximum cantilever load (P < 0.0001) than locked metal plates. There was no significant difference in compression stiffness (P = 0.2) or cantilever bending stiffness (P = 0.4). Primary failure of metal plates was screw pull-out compared to plate bending in bioabsorbable constructs. Seven patients with bioabsorbable implants were included. All patients with bioabsorbable constructs achieved radiographic union, but 71% lost reduction. Despite fracture angulation, all achieved normal shoulder function after one year determined by QuickDASH evaluation. None required a second surgery.

INTERPRETATION

Bioabsorbable implants had lower torsional stiffness and cantilever failure load, but comparable compression stiffness to metal implants. Bioabsorbable implants failed via gradual bending versus the catastrophic failure seen in metal implants. The clinical review allows understanding of the sequelae of this lower failure load of bioabsorbable plates where their use allowed in fracture displacement, yet achievement of ultimate radiographic union and acceptable functional outcomes.

Surgical fixation of midshaft clavicle fractures: A systematic review of biomechanical studies

PURPOSE

Surgical treatment of displaced midshaft clavicle fractures requires a decision between plate fixation and intramedullary (IM) fixation. Numerous studies report on the biomechanical properties of various repair constructs. The goal of this systematic review was to provide an overview of studies describing the biomechanical properties of the most commonly used surgical fixations of midshaft clavicle fractures. Additionally, we aimed to translate these biomechanical results into clinically relevant conclusions.

METHODS

A computer-aided search of the EMBASE and PudMed/MEDLINE databases was conducted. Studies included for review compared biomechanical properties of plate fixation with IM fixation and superiorly positioned plates with anteroinferiorly positioned plates for midshaft clavicle fractures.

RESULTS

Fifteen studies were eligible for inclusion. Plate fixation seemed to form a more robust construct than IM fixation in terms of stiffness and failure loading. The remaining clavicle was stronger after removal of the IM device than after removal of the plate. Superior plating of transverse fractures generally seemed to provide greater stiffness and strength during bending loads than anteroinferior plating did. The absence of cortical alignment in wedge and comminuted fractures directly influenced the fixation stability for both IM fixation and plate fixation, regardless of location.

CONCLUSION

Each type of fracture fixation has biomechanical advantages and disadvantages. However, exact thresholds of stiffness for inducing healing and failure strength to withstand refractures are unknown. The clinical relevance of the biomechanical studies may be arguable. Since none of the studies investigate the effect of tissue adaptation over time they should be interpreted with caution.

Displaced midshaft clavicle fracture in athletes - should we operate?

Objective

To assess the results of the treatment of fractures of the middle third of the clavicle with a pre-contoured plate in athletes.

Methods

The authors performed 26 osteosyntheseis in 25 patients with fractures of the middle third of the clavicle. The fractures were classified according to Robinson as 16 type B1 and ten type B2. The mean age was 37 years, ranging from 15 to 63 years, 20 patients were male and five were female, and all play sports in an amateur or professional manner. All patients were operated on in the acute phase of fracture within five days after trauma. Patients were treated with open reduction and internal fixation using pre-contoured plates. The technique and the implant used were the same, but the time of immobilization and rehabilitation protocol were individualized for each patient according to physical activity. Mean follow-up was 16.8 months (6–48 months), with return to sport activities in 45.6 days.

Results

Functional assessment was performed using the University of California at Los Angeles (UCLA) score. The results averaged 34.07 of 35 points. No cases presented nonunion. Only one complication was observed (thrombosis of the subclavian vein with good response to conservative treatment); two patients required implant removal.

Conclusion

The surgical treatment of clavicle fractures in athletes presented satisfactory functional outcome and early return sport.

[Development and biomechanical study of anatomical locking plate of sternoclavicular joint]

Objective

To develop an anatomical locking plate in accordance with the anatomical characteristics of the sternoclavicular joint, which is reliable fixation and easy to operate, so as to provide an ideal internal fixation device for the treatment of sternoclavicular joint dislocation or peripheral fractures.

Methods

Gross measurement and CT measurement were performed on the 8 adult antiseptic and moist cadaver specimens (16 sides) to measure the parameters of surrounding bone structure of the sternoclavicular joint. The parameters included the thickness of presternum, sternal notch width, anteroposterior diameter of proximal 1/3 of clavicle, upper and lower diameters of proximal 1/3 of clavicle, angle between proximal end of clavicle and presternum in coronal plane, and angle of thoracoclavicular joint at anatomic position forward. According to the anatomical parameters and biomechanical properties of the specimens, the anatomical locking plate was designed and developed. The sternoclavicular ligament and joint capsule of all the specimens were completely cut off to make the sternoclavicular joint dislocation model. The left and right sternoclavicular joint of each specimen were randomly divided into experimental group (anatomic locking plate fixation) and control group (oblique T shape locking plate fixation). The sternoclavicular joint activity and common force mechanism was simulated on the universal mechanical testing machine, and the clavicular distal load test, sternoclavicular joint torsion test, and anti-pulling of steel plate manubrium part test were performed.

Results

The differences between the anatomical parameters of gross measurement and CT measurement were not significant ( P>0.05). In the clavicular distal load test, when the anatomical position perpendicular to the distal clavicle back loading to 20 N, the displacement of loading point in the experimental group was (8.455±0.981) mm, which was significantly less than that in control group [(10.163±1.379) mm] ( t=-3.012, P=0.020); the distal clavicle displacement of loading point of experimental group and control group were (5.427±1.154) mm and (6.393±1.040) mm, respectively, showing no significant difference ( t=-1.459, P=0.188)。In the sternoclavicular joint torsion test, the torque of experimental group was significantly greater than that of control group when the clockwise torsion angle was at 2, 4, 6, 8, and 10 degrees and the counterclockwise torsion angle was at 4, 6, 8, and 10 degrees ( P<0.05). The torsional stiffness in the experimental group under clockwise and counterclockwise condition was 0.122 and 0.108 N·m/° respectively, which were significantly higher than those in the control group (0.083 and 0.078 N·m/° respectively) ( F=67.824, P=0.000; F=20.992, P=0.002). In the anti-pulling of steel plate manubrium part test, the maximum pullout force of experimental group [(225.24±16.02) N] was significantly higher than that in control group [(174.40±21.90) N] ( t=5.785, P=0.001).

Conclusion

The new type of anatomical locking plate can realize the sternoclavicular joint three-dimensional fixation, and has the advantages of reliable fixation, simple operation, less trauma, superior biomechanical properties, and earlier functional exercise. It may be an ideal internal fixation device in clinical treatment of sternoclavicular joint dislocation or peripheral fractures.

Ex vivo cyclic mechanical behaviour of 2.4 mm locking plates compared with 2.4 mm limited contact plates in a cadaveric diaphyseal gap model

Objectives: To compare the mechanical properties of locking compression plate (LCP) and limited contact dynamic compression plate (LC-DCP) constructs in an experimental model of comminuted fracture of the canine femur during eccentric cyclic loading.

Methods: A 20 mm mid-diaphyseal gap was created in eighteen canine femora. A 10-hole, 2.4 mm stainless steel plate (LCP or LC-DCP) was applied with three bicortical screws in each bone fragment. Eccentric cyclic loadings were applied at 10 Hertz for 610,000 cycles. Quasistatic loading / unloading cycles were applied at 0 and 10,000 cycles, and then every 50,000 cycles. Structural stiffness was calculated as the slope of the linear portion of the load-displacement curves during quasistatic loading / unloading cycles.

Results: No bone failure or screw loosening occurred. Two of the nine LCP constructs failed by plate breakage during fatigue testing, whereas no gross failure occurred with the LC-DCP constructs. The mean first stiffness of the LCP constructs over the course of testing was 24.0% lower than that of constructs stabilized by LC-DCP. Construct stiffness increased in some specimens during testing, presumably due to changes in boneplate contact. The first stiffness of LC-DCP constructs decreased by 19.4% and that of locked constructs by 34.3% during the cycling period. A biphasic stiffness profile was observed: the second stiffness was significantly greater than the first stiffness in both groups, which allowed progressive stabilization at elevated load levels.

Clinical significance: Because LCP are not compressed to the bone, they may have a longer working length across a fracture, and thus be less stiff. However, this may cause them to be more susceptible to fatigue failure if healing is delayed.

Preferences of orthopedic surgeons for treating midshaft clavicle fracture in adults

Objective

To determine the current clinical practice in Latin America for treating midshaft clavicle fractures, including surgical and non-surgical approaches.

Methods

A cross-sectional study using a descriptive questionnaire. Shoulder and elbow surgeons from the Brazilian Society of Shoulder and Elbow Surgery and from the Latin American Society of Shoulder and Elbow were contacted and asked to complete a short questionnaire (SurveyMonkey^®) on the management of midshaft fractures of the clavicle. Incomplete or inconsistent answers were excluded.

Results

The type of radiographic classification preferably used was related to description of fracture morphology, according to 41% of participants. Allman classification ranked second and was used by 24.1% of participants. As to indications for surgical treatment, only the indications with shortening and imminence of skin exposure were statistically significant. Conservative treatment was chosen in cortical contact. Regarding immobilization method, the simple sling was preferred, and treatment lasted from 4 to 6 weeks. Although the result was not statistically significant, the blocked plate was the preferred option in surgical cases.

Conclusion

The treatment of midshaft clavicle fractures in Latin America is in accordance with the current literature.

Biomechanical comparison of three different plate configurations for comminuted clavicle midshaft fracture fixation

BACKGROUND

The aim of this study was to compare the fixation rigidity of anterior, anterosuperior, and superior plates in the treatment of comminuted midshaft clavicle fractures.

METHODS

Six-hole titanium alloy plates were produced according to anatomic features of fourth-generation artificial clavicle models for anterior (group I; n = 14), anterosuperior (group II; n = 14), and superior (group III; n = 14) fixation. After plate fixation, 5-mm segments were resected from the middle third of each clavicle to create comminuted fracture models. Half the models from each group were tested under rotational forces; the other half were tested under 3-point bending forces. Failure modes, stiffness values, and failure loads were recorded.

RESULTS

All models fractured at the level of the distalmost screw during the failure torque, whereas several failure modes were observed in 3-point bending tests. The mean stiffness values of groups I to III were 636 ± 78, 767 ± 72, and 745 ± 214 N ∙ mm/deg (P = .171), respectively, for the torsional tests and 38 ± 5, 20 ± 3, and 13 ± 2 N/mm, respectively, for the bending tests (P < .001 for group I vs. groups II and III; P = .015 for group II vs. group III). The mean failure torque values of groups I to III were 8248 ± 2325, 12,638 ± 1749, and 10,643 ± 1838 N ∙ mm (P = .02 for group I vs. II), respectively, and the mean failure loads were 409 ± 81, 360 ± 122, and 271 ± 87 N, respectively (P = .108).

CONCLUSIONS

In the surgical treatment of comminuted midshaft clavicle fractures, the fixation strength of anterosuperior plating was greater than that of anterior plating under rotational forces and similar to that of superior plating.

Unicortical and bicortical plating in the fixation of comminuted fractures of the clavicle: a biomechanical study

BACKGROUND

Intraoperative neurovascular complications with clavicle fracture fixation are often due to far cortex penetration by drills and screws, but could be avoided using a unicortical construct. The objective of this study was to compare the bending and torsional strength of a unicortical locking screw plate construct and a hybrid (with central locked and outer non-locked long oblique screws) unicortical plate construct for clavicle fracture fixation with that of a conventional bicortical locking screw construct of plate fixation.

METHODS

Twenty-four human clavicle specimens were harvested and fractured in a comminuted mid-shaft butterfly configuration. Clavicles were randomly allocated to three surgical fixation groups: unicortical locking screw, bicortical locking screw and hybrid unicortical screw fixation. Clavicles were tested in torsion and cantilever bending. Construct bending and torsional stiffness were measured, as well as ultimate strength in bending.

RESULTS

There were no significant differences in bending stiffness or ultimate bending moment between all three plating techniques. The unicortical locked construct had similar torsional stiffness compared with the bicortical locked construct; however, the hybrid technique was found to have significantly lower torsional stiffness to that of the bicortical locking screw construct (mean difference: 87.5 Nmm/degree, P = 0.028).

CONCLUSIONS

Unicortical locked screw plate fixation and hybrid unicortical plating fixation with centrally locked screws and outer long, oblique screws may alleviate far cortex penetration, protecting nearby anatomical structures, and may ease implant removal and conversion to bicortical fixation for revision surgery; however, use of long oblique screws may increase the risk of early loosening under torsion.

A Biomechanical and Clinical Comparison of Midshaft Clavicle Plate Fixation: Are 2 Screws as Good as 3 on Each Side of the Fracture?

Background:

The standard of care for plating displaced midshaft clavicle fractures has been 6 cortices of purchase on each side of the fracture. The use of locking plates and screws may afford equivalent biomechanical strength with fewer cortices of purchase on each side of the fracture.

Purpose:

To compare the biomechanical and clinical performance of 3- versus 2-screw constructs for plating displaced midshaft clavicle fractures.

Study Design:

Controlled laboratory study/cohort study; Level of evidence, 3.

Methods:

Lateral fragments of simulated midshaft fractures in 10 pairs of cadaveric clavicles were randomly assigned to plate fixation with either 3 nonlocking screws or 2 locking screws. Cyclic tensile loads were applied along the long axis of the clavicle. The constructs were then loaded to failure with pullout forces applied parallel to the long axis of the screws. Additionally, clinical outcomes of patients who had midshaft clavicle fractures that were surgically repaired were retrospectively identified and compared; 21 patients were treated with 3-screw constructs and 20 with 2-screw constructs.

Results:

Biomechanically, there were no significant differences for cyclic displacement, stiffness, yield load, or ultimate load between groups. Forces required for screw pullout were considerably higher than physiologic forces experienced by a healing clavicle in vivo. Clinically, there were no significant differences in American Shoulder and Elbow Surgeons, Constant, visual analog scale, and Single Assessment Numeric Evaluation scores; complications; or mean time to union. Additionally, we found that the plates used in the 2-screw group were consistently shorter.

Conclusion:

Plate fixation of displaced midshaft clavicle fractures with 4 cortices of purchase with 2 locking screws demonstrated no significant differences biomechanically when compared with fixation with 6 cortices of purchase and 3 nonlocking screws. Clinically, there were no significant differences in outcomes or complications seen in patients receiving 2- or 3-screw constructs.

Clinical Relevance:

Clinical benefits of using the 3-screw construct for plate fixation include decreased surgical exposure, morbidity, and cost, and the use of shorter and noncontoured straight plates eliminates the extra time and technical difficulty associated with matching longer contoured plates to the complex morphology of the clavicle.

Comparison of 2 plating techniques for lateral clavicle fractures, using a new standardized biomechanical testing setup

BACKGROUND

Conservative treatment of lateral clavicle fractures (Neer type II) often ends with unsatisfactory results for patients. Operative treatment is thus gaining acceptance. A retrospective study found success using a double plate technique for these injuries. For the current study, a standardized testing setup was developed to compare the mechanical properties of single versus double plate technique for lateral clavicle fractures.

METHODS

Six synthetic bones were tested for each technique. Neer type IIB fractures were created using computer-aided design (CAD). Fatigue testing was carried out with a cantilever bending test. Parameters measured were cycles undergone, failure load and stiffness at the point of failure.

RESULTS

The standardized testing setup was able to provide reproducible failures. The double plate technique lasted about 16,000 more cycles and withstood an additional 22.4 N on average.

CONCLUSIONS

The new modified standardized testing setup produced reproducible fixation failures for both clavicle fracture fixation techniques. The double plate technique seems to be mechanically superior to the single plate technique.

An intramedullary Echidna pin for fixation of comminuted clavicle fractures: a biomechanical study

Background

Intramedullary fixation of comminuted mid-shaft clavicle fractures has traditionally been employed with satisfactory clinical outcomes; however, pins with smooth surfaces may protrude from the bone and are prone to migration, while some threaded pins are difficult to remove post-operatively. The aim of this proof-of-concept study was to develop and evaluate the biomechanical strength of a novel intramedullary Echidna pin device designed to maintain fracture reduction, resist migration and facilitate ease of post-operative removal.

Methods

Thirty human clavicle specimens were harvested and fractured in a comminuted mid-shaft butterfly configuration. Each specimen was randomly allocated to three surgical repair groups including intramedullary fixation using the Echidna pin and Herbert Cannulated Bone Screw System, as well as plate fixation using bi-cortical locking screws. Using a biomechanical testing apparatus, construct bending and torsional stiffness were measured, as well as ultimate bending strength.

Results

There was no significant difference in torsional stiffness and ultimate bending moment between the Echidna pin and Herbert screw repair constructs (p > 0.05); however, the Echidna pin construct demonstrated a significantly greater bending stiffness compared to that of the Herbert screw construct (mean difference 0.55 Nm/deg., p = 0.001). The plate construct demonstrated significantly greater torsional stiffness, bending stiffness and ultimate bending moment compared to those of the Herbert screw and Echidna pin (p < 0.05).

Conclusions

An intramedullary Echidna pin device was designed to stabilize comminuted fractures of the clavicle, maintain fracture compression and provide ease of removal post-operatively. Since the results suggest equivalent or superior torsional and bending stability in the Echidna pin compared to that of the Herbert screw, the Echidna pin concept may represent an alternative fixation device to conventional intramedullary screws, nails and pins; however, superior plating using bi-cortical locking screws provides substantially higher construct structural rigidity than intramedullary devices, and may therefore be useful in cases of osteoporotic bone, or where high fracture stability is required.

Anterior inferior plating versus superior plating for clavicle fracture: a meta-analysis

Background

The position of plate fixation for clavicle fracture remains controversial. Our objective was to perform a comprehensive review of the literature and quantify the surgical parameters and clinical indexes between the anterior inferior plating and superior plating for clavicle fracture.

Methods

PubMed, EMBASE, and the Cochrane Library were searched for randomized and non-randomized studies that compared the anterior inferior plating with the superior plating for clavicle fracture. The relative risk or standardized mean difference with 95% confidence interval was calculated using either a fixed- or random-effects model.

Results

Four randomized controlled trials and eight observational studies were identified to compare the surgical parameters and clinical indexes. For the surgical parameters, the anterior inferior plating group was better than the superior plating group in operation time and blood loss (P < 0.05). Furthermore, in terms of clinical indexes, the anterior inferior plating was superior to the superior plating in reducing the union time, and the two kinds of plate fixation methods were comparable in constant score, and the rate of infection, nonunion, and complications (P > 0.05).

Conclusions

Based on the current evidence, the anterior inferior plating may reduce the blood loss, the operation and union time, but no differences were observed in constant score, and the rate of infection, nonunion, and complications between the two groups. Given that some of the studies have low quality, more randomized controlled trails with high quality should be conduct to further verify the findings.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-017-1517-1) contains supplementary material, which is available to authorized users.

Symptomatic Implant Removal Following Dual Mini-Fragment Plating for Clavicular Shaft Fractures

OBJECTIVES

To determine the proportion of patients requiring secondary surgery for symptomatic implant removal after open reduction, internal fixation using dual mini-fragment plating technique for clavicular shaft fractures.

DESIGN

Retrospective observational study.

SETTING

Single university Level 1 trauma center.

PATIENTS

Eighty-one patients treated with open reduction, internal fixation using dual mini-fragment plating technique for clavicular shaft fractures (OTA/AO 15-B1, B2, and B3) with minimum 12-month follow-up (median 477 days; range 371-1549 days).

INTERVENTION

Open reduction, internal fixation using dual mini-fragment plating technique for clavicular shaft fractures.

MAIN OUTCOME MEASUREMENTS

Incidence of secondary surgery, QuickDASH (Disabilities of the Arm, Shoulder, and Hand) scores.

RESULTS

Six of 81 patients (7.4%) underwent secondary surgery for implant removal for any reason. Of these, 3 (3.7%) underwent symptomatic implant (soft-tissue irritation) removal, 2 (2.5%) required implant removal in the setting of infection, and 1 patient (1.2%) required revision open reduction internal fixation for early implant failure. The mean QuickDASH score in this series was 8.44 (±6.94, range 0-77.27). The associated implant cost of the typical construct utilized in this series was $1511.38. The mean surgical time was 97 minutes (range 71-143 minutes).

CONCLUSIONS

The utilization of a dual mini-fragment plating technique in the treatment of clavicular shaft fractures results in a low rates of secondary surgery for symptomatic implant removal (3.7%) and similar QuickDASH scores when compared with historical controls treated with 3.5-mm plates placed on the superior clavicle. Potential disadvantages in using this technique include a higher surgical implant cost and length of surgery.

LEVEL OF EVIDENCE

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

Biomechanical Comparison of Superior Versus Anterior Plate Position for Fixation of Distal Clavicular Fractures: A New Model

OBJECTIVES

Although most clavicular fractures are amenable to nonoperative management, metadiaphyseal fractures are considerably more complex, with rates of suboptimal healing as high as 75% when treated nonoperatively. The poor results are ascribed to the deforming forces on the distal clavicle from the surrounding muscles and the weight of the arm. It recently has been noted that some operative fixations of these fractures are also failing when a standard superiorly placed plate is used. We hypothesized that anterior plating, when compared with superior plating, improves the strength and durability of the construct by redirecting the axis of the major deforming force across rather than in line with the screws of the construct.

METHODS

Six pairs of fresh-frozen human cadaveric clavicles with the scapula attached by the coracoclavicular ligaments were osteotomized just medial to the ligaments and plated with a standard 3.5-mm limited-contact dynamic compression plate. Specimens were potted and mounted on a materials testing system machine, preserving the anatomic relationship of the clavicle and scapula. They were then loaded through the coracoclavicular ligaments to mimic the weight of the arm pulling inferiorly. Each specimen was loaded with 375 N at 1 Hz for 2000 cycles. Sequential loading was then applied at 25-N intervals until failure. Statistical analysis was performed using a Wilcoxon signed-rank test.

RESULTS

The superiorly plated specimens failed after fewer cycles and with lower force than the anteriorly plated specimens. The median number of cycles to failure was 2082 for anterior plated specimens and 50 for superiorly plated (P = 0.028). The median load to failure was 587.5 N in the anterior group and 375 N in the superior group (P = 0.035). The median stiffness was 46.13 N/mm for anterior and 40.45 N/mm for superior (P = 0.375) plates.

CONCLUSIONS

Anteriorly plated distal third clavicular fractures have superior strength and durability compared with fractures plated superiorly when using a physician-contoured, 3.5-mm, limited-contact, dynamic compression plate in this cadaver model.

Clavicle Fractures are Associated With Arthritis of the Glenohumeral Joint in a Large Osteological Collection

OBJECTIVES

Recent data has challenged the historical precedent of nonoperative care for many clavicle fractures; clinical and biomechanical studies have shown altered joint-contact forces occur in the glenohumeral joint (GHJ) after fracture and shortening of the clavicle. However, to date, there have been no analyses documenting the long-term effects of these altered shoulder girdle mechanics on the GHJ.

METHODS

The clavicles of 2899 cadaveric skeletons were manually inspected for evidence of fracture. Shortening, fracture location, and laterality were recorded along with demographic information. Degenerative joint disease of the GHJ was graded. Correlations between the presence of a clavicle fracture and ipsilateral GHJ osteoarthritis were evaluated with multiple regression analysis using an age-, gender-, race-, and laterality-matched control group of 1154 GHJs.

RESULTS

One hundred three specimens had 104 clavicle fractures, a prevalence of 3.6% (103/2899) in this collection. There was a strong correlation between the presence of an ipsilateral clavicle fracture (standardized beta 0.108, P < 0.001), age (standardized beta 0.332, P < 0.001), male gender (standardized beta -0.069, P = 0.009), and laterality (right sided, standardized beta 0.056, P = 0.032) on the development of GHJ arthritis. There was a trend toward increased GHJ arthritis in specimens with shortening >20 mm (standardized beta 0.156, P = 0.109), although this subanalysis may have been underpowered.

CONCLUSIONS

This is the first study to report long-term consequences of clavicle fracture on the development of ipsilateral GHJ osteoarthritis; clavicle fractures were shown to have a higher degree of GHJ osteoarthritis. Future clinical studies are needed to confirm these relationships.

Midshaft Clavicle Fractures: A Critical Review

The clavicle is the most commonly broken bone in the human body, accounting for up to 5% to 10% of all fractures seen in hospital emergency admissions. Fractures of the middle third, or midshaft, are the most common, accounting for up to 80% of all clavicle fractures. Traditional treatment of midshaft clavicle fractures is usually nonoperative management, using a sling or figure-of-eight bandage. The majority of adults treated nonoperatively for midshaft clavicle fractures will heal completely. However, newer studies have shown that malunion, pain, and deformity rates may be higher than previously reported with traditional management. Recent evidence demonstrates that operative treatment of midshaft clavicle fractures can result in better functional results and patient satisfaction than nonoperative treatment in patients meeting certain criteria. This article provides a review of relevant anatomy, classification systems, and injury mechanisms for midshaft clavicle fractures, as well as a comparison of various treatment options. [Orthopedics.2016; 39(5):e814-e821.].

Biomechanical Comparison of Bicortical, Unicortical, and Unicortical Far-Cortex-Abutting Screw Fixations in Plated Comminuted Midshaft Clavicle Fractures

PURPOSE

The objective of this study was to assess the biomechanical properties of bicortical locking screws, unicortical locking screws, and unicortical far-cortex-abutting locking screw fixation in a cadaver model of comminuted midshaft clavicle fractures stabilized with a locking plate placed on the superior surface of the clavicle.

METHODS

Nine pairs of adult fresh-frozen cadaver clavicles were allocated into 3 groups for either bicortical, unicortical, or unicortical far-cortex-abutting locking plate fixation. After a 1-cm osteotomy to simulate a comminuted fracture and instrumentation with an 8-hole locking plate placed on the superior surface of the clavicle, the specimens were mounted in a custom dual-gimbal fixture in a materials-testing system and tested in axial compression, torsional, and torsional load to failure.

RESULTS

Axial stiffness and axial osteotomy site stiffness did not demonstrate differences between constructs. In cyclical torsion, both the bicortical and the unicortical far-cortex-abutting constructs were significantly stiffer than the unicortical construct. For torsional failure stiffness, both the bicortical and the unicortical far-cortex-abutting constructs were significantly stiffer than the unicortical construct. There was no difference between bicortical and unicortical far-cortex-abutting for torsional failure stiffness. The bicortical construct exhibited significantly higher peak failure torque compared with the unicortical construct.

CONCLUSIONS

Unicortical far-cortex-abutting locking screw fixation provides comparable mechanical properties under axial and torsional loads to bicortical fixation, without penetrating the far cortex.

CLINICAL RELEVANCE

Unicortical far-cortex-abutting locking screw fixation obviates far cortex penetration, and thereby protects nearby anatomical structures, may ease symptomatic implant removal, alleviates refracture risk, and eases conversion to bicortical fixation in the case of revision surgery.

Anteroinferior versus superior plating of clavicular fractures

BACKGROUND

Open reduction and plate fixation has gained recognition as an effective treatment for certain types of clavicular fractures. However, 88% of cases report some implant-related problems. To determine the optimal plate position, the aim of the present study was to compare implant-related irritation and proportion of plate removal in patients with clavicular fractures undergoing plate fixation by an anteroinferior or superior approach.

METHODS

Retrospectively collected data of 39 patients who underwent anteroinferior plating for displaced midshaft clavicular fractures were compared with prospectively collected data of 60 patients who were treated with superior plate fixation as part of a multicenter randomized controlled trial. Electronic medical records were reviewed for reports of complications, in particular, implant-related irritation and implant removal during follow-up. In addition, all patients were contacted in June 2014 to obtain additional information. The primary outcome parameter was implant-related irritation.

RESULTS

Univariate and multivariate regression analysis showed plate position was not significantly associated with implant-related irritation. Higher rates of asymptomatic patients with the plate still in place were observed in the anteroinferior group (46% vs 22%, P = .01). Almost an equal percentage of implant removals was seen in both groups because of implant irritation (36% vs 37%, P = .938).

CONCLUSIONS

The present study found the surgical approach of clavicular plating was not associated with implant-related irritation. Future studies are needed to determine whether there is an optimal approach for clavicle plating.

SEGMENTAL CLAVICLE FRACTURE

The aim here was to present an unusual case of segmental clavicle fracture associated with ipsilateral rib fracture. Although the clavicle is very superficial, undetected cases of both types of fracture may occur, because these patients usually suffer multiple trauma. The case of a patient with a fracture of the diaphysis and lateral extremity of the clavicle is described: the patient was treated surgically and an excellent result was achieved. Similar cases in the literature are reviewed and their management is discussed.

The Treatment of Mid-shaft Clavicle Fractures

OBJECTIVE

Through reviewing the relevant literature from the past decades, to summarize the assessment and management of fractures of the clavicle, and provide an overview of the clinical results of a range of treatment options.

DATA SOURCES

The data analyzed in this review are mainly from articles included in PubMed and EMBASE, published from 1960 to 2015.

STUDY SELECTION

Studies involving assessment of fractures of the clavicle were reviewed. Further literatures were gathered regarding the conservative and surgical treatment of these fractures, including the methods of fixation and the surgical approaches used. Both conservative and surgical treatments were then compared and contrasted.

RESULTS

Through retrieving and reading the abstract, a total of 42 representative articles were selected, which covered all aspects of the conservative treatment and surgical treatment, and compared the advantages and disadvantages of different treatment options.

CONCLUSIONS

Although the majority of recent data suggest that surgery may be more appropriate as it improves functional outcome and reduces the risk of complications, we recommend that the treatment should be individually assessed.

Clinical comparison of two different plating methods in minimally invasive plate osteosynthesis for clavicular midshaft fractures: A randomized controlled trial

AIM

The aim of this study was to compare the clinical and radiographic outcomes between two different plating methods (superior vs. anteroinferior) in minimally invasive plate osteosynthesis (MIPO) for acute displaced clavicular shaft fractures.

MATERIALS AND METHODS

A prospective, randomized controlled trial was performed in a single centre. Nineteen patients were treated with superior plating and 18 with anteroinferior plating using the MIPO technique. A 3.5-mm locking reconstruction plate was bent preoperatively and applied to either the anteroinferior or superior aspect of the clavicle through two separate incisions. The operating time, time to union, the proportional length difference, complications, and functional outcome of the shoulder joint were evaluated using the Constant score and the University of California Los Angeles (UCLA) score.

RESULTS

There was no statistically significant difference in the Constant score and UCLA score. The mean time to union was 16.8 weeks for superior plating and 17.1 weeks for anteroinferior plating (p=0.866). The average operation time was 77.2min in superior plating and 79.4min in anteroinferior plating (p=0.491). One patient in the superior plating group showed plate failure. Despite no significant difference, one patient had nonunion in the superior plating group (p>0.999).

CONCLUSIONS

From a clinical perspective, although MIPO with anteroinferior plating provides better outcomes especially in complications without statistically significant difference, both plating methods provided satisfactory clinical and radiographic outcomes.

LEVEL OF EVIDENCE

Level I, a single-centre, prospective, randomized controlled trial.