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

Primary stability of nailing versus low-profile dual plating of mid-clavicular fractures- a biomechanical cadaveric study

INTRODUCTION

Low-profile dual plating techniques have gained popularity for diaphyseal clavicula fractures due to their potential to reduce soft tissue irritation. Intramedullary nailing is also an established surgical option for treatment of diaphyseal clavicle fractures. The present study therefore aimed to evaluate whether a 2 × 2.0 mm dual plating system can achieve biomechanical performance comparable to intramedullary nailing while reducing implant-related complications.

METHODOLOGY

Twelve paired human cadaveric clavicles with simulated unstable diaphyseal shaft fractures AO/OTA 15.2 C were stabilized via elastic nailing (Group 1) or dual plating using a superior and an anterior 2.0 mm plate (Group 2). Specimens underwent biomechanical testing with initial quasistatic superior-inferior and anterior-posterior bending, followed by cyclic superior-inferior loading to failure. Interfragmentary movements were monitored by optical motion tracking.

RESULTS

Dual plating demonstrated significantly higher initial construct stiffness in all bending directions and a reduced neutral zone compared to intramedullary nailing (p ≤ 0.016). In addition, fracture displacement amplitudes over all cycles were significantly higher in Group 1 versus Group 2 (p = 0.002). The number of cycles required to reach the test endpoint at a 45 mm displacement did not differ significantly between the groups (p = 0.160), with Group 1 averaging 24,420 cycles (SD ± 3,615) and Group 2 averaging 28,232 cycles (SD ± 5,417).

CONCLUSION

Low-profile dual plating may offer improved initial stability of midshaft clavicle fractures without compromising their long-term performance, making it a promising alternative to elastic nailing. In selected patients with simpler unstable midshaft clavicle fractures, 2 × 2.0 mm dual plating may offer effective biomechanical stability.

Clinical outcomes of Nice knot-assisted locking plate for preserving periosteum internal fixation in comminuted clavicle fractures: A retrospective study

IntroductionClavicular fractures, particularly comminuted fractures, are common injuries that can affect shoulder function and upper limb mobility. The management of these fractures, especially using surgical approaches and fixation methods, remains a key area of clinical focus. Preserving the periosteum during surgery may improve fracture healing and reduce complications. This study explored the clinical efficacy of a periosteum-preserving surgical technique combined with a Nice knot-assisted locking plate for treating comminuted clavicular fractures.MethodsA total of 85 patients with comminuted clavicular fractures were included in this retrospective study. According to the Allman classification, 56 (65.9%) cases were type IC, 19 (22.4%) were type II, 9 (10.9%) were type III, and 1 (1.1%) involved comminuted fractures across the entire clavicle. All patients underwent surgical treatment using a periosteum-preserving approach combined with a Nice knot-assisted locking plate. Fracture healing time, upper limb function (measured via Constant-Murley score and disabilities of the arm, shoulder, and hand questionnaire), and postoperative complications were assessed 6 and 12 months postoperatively.ResultsThe median healing time was 13 weeks, with no cases of nonunion reported. At 6 months postoperatively, the Constant-Murley and disabilities of the arm, shoulder, and hand scores were excellent. Although a statistically significant difference (P < 0.05) was observed in these scores between 6 and 12 months, all patients reported satisfactory recovery of shoulder function and upper limb mobility. No significant differences (P > 0.05) in fracture healing time or upper limb function recovery were observed across different types of clavicular fractures. Six (7.1%) patients experienced temporary numbness in the subclavian region, which gradually resolved by the final follow-up.ConclusionThe periosteum-preserving approach with Nice knot-assisted locking plate fixation proved to be an effective and reliable treatment for comminuted clavicular fractures. The technique was associated with favorable healing times, excellent functional outcomes, and low complication rates. Preservation of the periosteum and soft tissue during surgery may considerably reduce intraoperative trauma and improve postsurgical recovery. Further studies with larger sample sizes and longer follow-up periods are needed to confirm the long-term benefits of this approach.

45° helical plates are a valid alternative to straight plates for treatment of proximal humeral shaft fractures

Helical plates used for proximal humeral shaft fracture fixation avoid the radial nerve distally as compared to straight plates. To investigate in a human cadaveric model the biomechanical competence of straight lateral plates versus 45° helical plates used for fixation of proximal comminuted humeral shaft fractures, eight pairs of human cadaveric humeri were instrumented using either a long straight PHILOS plate (Group 1) or a 45° helical plate (Group 2) for treatment of an unstable proximal humeral shaft fracture. All specimens were tested under non-destructive quasi-static loading in axial compression, internal and external rotation, and bending in four directions. Subsequently, progressively increasing cyclic loading in internal rotation was applied until failure and interfragmentary movements were monitored by motion tracking. Axial displacement (mm) was 3.13 ± 0.31 in Group 1 and 2.60 ± 0.42 in Group 2, p = 0.015. Flexion/extension deformation (°) in Group 1 and Group 2 was 0.56 ± 0.42 and 0.43 ± 0.23, p = 0.551. Varus/valgus deformation (°) was 6.39 ± 0.44 in Group 1 and 5.13 ± 0.87 in Group 2, p = 0.012. Shear (mm) and torsional (°) displacement were 5.36 ± 0.76 and 17.75 ± 1.06 in Group 1, and 5.03 ± 0.46 and 16.79 ± 1.36 in Group 2, p ≥ 0.090. Cycles to catastrophic failure were 10000 ± 1401 in Group 1 and 9082 ± 1933 in Group 2, p = 0.708. From a biomechanical perspective, 45° helical plating is associated with lower axial and varus/valgus displacement under axial loading and demonstrates comparable resistance to failure versus straight plating. Therefore, 45° helical plates can be considered as a valid alternative to straight plates for treatment of proximal humeral shaft fractures.

The precise location of "Midshaft" clavicle fractures: Scrimmaging from the 42 yard-line

Background

The realities of midshaft clavicle fracture distribution have not been described accurately. Consequently, a topographical depiction of midshaft clavicle fractures may help design implants that are more anatomically concordant with the fractured clavicle, leading to better outcomes and fewer complications.

Methods

This is a retrospective cohort study. One-hundred sixty-six surgically treated midshaft clavicle fractures of four fellowship-trained shoulder surgeons were evaluated to determine the precise "location" of the fracture on standard radiographs. This location was determined by noting the lateral, central, and medial endpoint of each fracture, expressed as a percentage (0%-100%) of the distance from the lateral to the medial end of the clavicle.

Results

Fractures on average began at the 36% line (SD = 6%), were centered at the 42% line (SD = 6%), and ended at the 48% line (SD = 7%). Ninety percent of fractures were centered lateral to the midpoint, and 64% were completely lateral to the midpoint. Thirty-two percent of midshaft fractures extended into the lateral third of the clavicle, but no fractures extended into the medial third.

Conclusion

Midshaft clavicle fractures in skeletally mature individuals appear to occur predominantly within the lateral metadiaphyseal half of the clavicle, and rarely extend into the medial third. Industry professionals and surgeons alike should consider this when designing and selecting implants. To note, our study relied on two-dimensional radiographs, and future studies should work on fully capturing the complex three-dimensional anatomy of the clavicle.

Level of evidence

IV.

Evaluating the Outcomes of Managing Displaced Clavicular Fractures by Using Precontoured Clavicular Plates

Background and objective Midshaft clavicular fractures were managed conservatively in the past, with a significant incidence of nonunion and poor functional outcomes in displaced fractures. Anatomically precontoured clavicle plates, since their introduction, have proved to be a superior method for managing these fractures. While open reduction and internal fixation of displaced clavicular fractures with plates have produced successful functional outcomes, complications like plate prominence, scar, postoperative numbness, wound dehiscence, refracture, and infection continue to discourage surgeons from plating these fractures. This study aimed to evaluate whether the precontoured 3.5-mm locking compression plate (LCP) for the clavicle is effective in the management of displaced clavicular fractures with minimum risk of complications. Methods A prospective observational study was conducted among 26 patients with displaced clavicular fractures that were managed with 3.5-mm precontoured LCP. The functional outcome was assessed by using the Constant-Murley Score (CMS) and healing was assessed radiographically six months postoperatively. Results Twenty-five patients were available for the final follow-up at the end of 24 weeks. All of them achieved excellent functional scores. The mean CMS was 94.9. No complication was observed in 85% of the cases. Implant failure was observed in both fractures of a bilateral clavicle fracture patient within a month of surgery. Implant irritation without prominence was seen in one patient and another had a prominent postoperative scar. The mean time for the radiological union was 13.8 weeks with union time ranging from three to five months. Conclusions Based on our findings, employing 3.5-mm precontoured clavicular LCPs is a useful technique that can provide good functional outcomes in displaced clavicular fractures.

New generation of superior single plating vs. low-profile dual minifragment plating in diaphyseal clavicle fractures: a biomechanical comparative study

BACKGROUND

Recently, a new generation of superior clavicle plates was developed featuring the variable-angle locking technology for enhanced screw positioning and a less prominent and optimized plate-to-bone fit design. On the other hand, minifragment plates in dual plating mode have demonstrated promising clinical results. The aim of the current study was to compare the biomechanical competence of single superior plating using the new-generation plate vs. dual plating using low-profile minifragment plates.

METHODS

Sixteen paired human cadaveric clavicles were pairwise assigned to 2 groups for instrumentation with either a superior 2.7-mm variable-angle locking compression plate (group 1), or with one 2.5-mm anterior combined with one 2.0-mm superior matrix mandible plate (group 2). An unstable clavicle shaft fracture (AO/OTA 15.2C) was simulated by means of a 5-mm osteotomy gap. Specimens were cyclically tested to failure under craniocaudal cantilever bending, superimposed with bidirectional torsion around the shaft axis, and monitored via motion tracking.

RESULTS

Initial construct stiffness was significantly higher in group 2 (9.28 ± 4.40 N/mm) compared to group 1 (3.68 ± 1.08 N/mm), P = .003. The amplitudes of interfragmentary motions in terms of axial and shear displacement, fracture gap opening and torsion, over the course of 12,500 cycles were significantly higher in group 1 compared to group 2, P ≤ .038. Cycles to 2 mm shear displacement were significantly lower in group 1 (22,792 ± 4346) compared to group 2 (27,437 ± 1877), P = .047.

CONCLUSION

From a biomechanical perspective, low-profile 2.5/2.0-mm dual plates could be considered as a useful alternative for diaphyseal clavicle fracture fixation, especially in less common unstable fracture configurations.

Screw Stress Distribution in a Clavicle Fracture with Plate Fixation: A Finite Element Analysis

Clavicle midshaft fractures are mostly treated surgically by open internal reduction with a superior or anteroinferior plate and screws or by intramedullary nailing. Screw positioning plays a critical role in determining the stress distribution. There is a lack of data on the screw position and the appropriate number of cortices required for plate fixation. The aim of this study is to evaluate the mechanical behavior of an anterior plate implanted in a fractured bone subjected to 120° of lateral elevation compared to a healthy clavicle using numerical simulations. Contact forces and moments used were obtained from literature data and applied to the healthy and fractured finite element models. Stresses of about 9 MPa were found on the healthy clavicle, while values of about 15 MPa were calculated on the plate of the fractured one; these stress peaks were reached at about 30° and 70° of elevation when the stress shielding on the clavicle sums all the three components of the solicitation: compression, flexion, and torsion. The stress distribution in a clavicle fracture stabilized with plates and screws is influenced by several factors, including the plate's position and design, the type of screw, and the biomechanical forces applied during movements.

Unicortical versus bicortical plate fixation for midshaft clavicular fractures

BACKGROUND

The aim of this study was to compare the functional and radiological outcomes of unicortical vs bicortical fixation in patients with midshaft clavicular fractures who were treated using pre-contoured locking plates.

METHODS

We performed a prospective multicenter study of 45 individuals who underwent open reduction and internal fixation of midshaft clavicular fractures with precontoured locking plates between March 2017 and December 2019. Twenty-five patients were treated with bicortical screws and 20 patients with unicortical screws. Functional outcomes were assessed at 6 months and 12 months after surgery using the Constant score, the 11-item version of the Disabilities of Arm, Shoulder and Hand (Quick- DASH) score and the Single Assessment Numeric Evaluation (SANE) score. Pain was evaluated using a visual analog scale (VAS). The rate of return to work and sports was also recorded. Radiologic evaluation was obtained in the immediate postoperative day, monthly until fracture consolidation, at 6 months and 12 months. All intraoperative and postoperative complications were documented.

RESULTS

At both 6 and 12 months, the follow-up rates were 100%, and the mean age was 28.5 years (range, 20 to 45 years). The mean postoperative Constant score, Quick DASH, and SANE score at 12 months were 93.5 (±6), 2.3 (±3), and 92% (±7), respectively. There were no significant differences in the functional scores between the groups neither at 6 months nor at 12 months. Of the 30 active workers, 97% were able to return to their previous working routine and from the 25 patients who practiced sports before the injury,92% returned to sports all at the same level. All the fractures healed in both groups. There were 6 complications (13%).

CONCLUSION

In young, active patients with displaced midshaft clavicular fractures, both unicortical and bicortical locked plates achieved 100% bone consolidation, with excellent functional outcomes and a low rate of complications without significant differences between the groups. Therefore, locked plates with unicortical fixation could be a very good alternative for the management of young patients with midshaft clavicular fractures, potentially avoiding severe neurovascular complications.

LEVEL OF EVIDENCE

Prospective comparative (Level II).

Evidence on treatment of clavicle fractures

Depending on the severity of the injury and the involvement of the soft tissue envelope, clavicle fractures can be treated operatively or non-operatively. In the past, displaced fractures of the clavicle shaft in adults have been treated non-operatively. However, the rate of nonunion following non-operative treatment seems to be higher than previously reported. In addition, publications reporting better functional outcomes following operative treatment are increasing. In recent years this has led to a paradigm shift towards an increase of operative fracture treatment. The aim of this review article was to summarize the currently available evidence on the treatment of clavicle fractures. Classifications, indications, and treatment options for different fracture patterns of the medial, midshaft, and lateral clavicles are presented and discussed.

Getting Athletes Back on the Field: Management of Clavicle Fractures and Return to Play

This chapter provides an overview of the prevalence of clavicle fractures in athletes. The evaluation and management of clavicle fractures in athletes is summarized, including surgical considerations, rehabilitation protocols, and return to sport guidelines. In this population, high rates of union are observed, but careful timing of return to sport is paramount to optimize performance and prevent reinjury.

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).

Low rate of secondary surgery and implant removal following superior, precontoured plating of midshaft clavicle fractures

Background

Surgical fixation of midshaft clavicle fractures with a single 3.5 mm superior clavicular plate has been associated with a high rate of hardware removal due to symptomatic hardware. Because of this, dual-plating techniques with lower-profile implants have been proposed. However, dual-plating systems have disadvantages, including increased cost and increased surgical morbidity. The aim of this study was to define the rate of symptomatic hardware removal for all midshaft clavicle fractures.

Methods

We retrospectively reviewed information on all patients from 2014 to 2018 at a single level 1 trauma institution with surgeries performed by two fellowship-trained orthopedic trauma surgeons. Documented removal of hardware and the reason for removal were recorded. We then contacted all patients at their listed telephone number to confirm the hardware was still in place and to administer patient outcome questionnaires. If patients did not answer, attempts were made to contact them multiple times on multiple days. Those who were not reached but had documented hardware removal were included in the total number of patients with hardware removal.

Results

The search revealed 158 patients, of whom 89 (61.8%) were included in the study. Average follow up was 4.09 years (range 2.02-6.50 years). Five patients (5.56%) underwent hardware removal. Removal was for symptomatic or irritating hardware in two of these patients (2.22%). Average abbreviated Disability of Arm, Shoulder, and Hand score was 6.27, and average American Society of Shoulder and Elbow Surgeons shoulder score was 93.6.

Conclusion

In our series, the rate of symptomatic hardware removal was 2.22%, well below reported removal rates. Hardware removal rates for prominent symptomatic superior clavicular plates may be significantly lower than previously reported, and these fractures may be adequately treated with a single, superior plate.

Refracture after plate removal of midshaft clavicle fractures after bone union-incidence, risk factors, management and outcomes

INTRODUCTION

There is a great debate on the routine use of open reduction and internal fixation (ORIF) for midshaft clavicle fractures, and one concern is the adverse events after ORIF, such as implant removal after bone union. In this retrospective study, we assessed the incidence, risk factors, management and outcomes of refracture after plate removal of midshaft clavicle fractures after bone union.

MATERIALS AND METHODS

Three hundred fifty-two patients diagnosed with acute midshaft clavicle fractures who had complete medical records from primary fractures to refracture were recruited. Details of imaging materials and clinical characteristics were carefully reviewed and analysed.

RESULTS

The incidence rate of refracture was 6.5% (23/352), and the average interval from implant removal to refracture was 25.6 days. Multivariate analysis showed that the risk factors were Robinson type-2B2 and fair/poor reduction. Females were 2.4 times more likely to have refracture, although it was not significant in multivariate analysis (p = 0.134). Postmenopausal females with a short interval (≤ 12 months) from primary surgery to implant removal had a significant risk for refracture. Tobacco use and alcohol use during bone healing were potential risk factors for male patients, although they were not significant in multivariate analysis. Ten patients received reoperation with or without bone graft, and they had a higher rate of bone union than 13 patients who refused reoperation.

CONCLUSION

The incidence of refracture following implant removal after bone union is underestimated, and severe comminute fractures and unsatisfactory reduction during primary surgery are risk factors. Implant removal for postmenopausal female patients is not recommended due to a high rate of refracture.

Insertion sites of the muscles attached to the clavicle: a cadaveric study of the clavicle

BACKGROUND

Clavicle fractures are common injuries, especially in young, active individuals. Operative treatment is recommended for completely displaced clavicle shaft fractures, and plate fixation is stronger than the use of intramedullary nails. Few studies have reported on iatrogenic injuries to the muscle attached to the clavicle during fracture surgery. The aim of this study was to clarify the area of the insertion sites of muscles attached to the clavicle in Japanese cadavers using gross anatomy and three-dimensional (3D) analysis. We also aimed to compare the effects of anterior plate templating and superior plate templating on clavicle shaft fractures using 3D images.

METHODS

Thirty-eight clavicles from Japanese cadavers were analyzed. We removed all clavicles to identify the insertion sites and measured the size of the insertion area of each muscle. Three-dimensional templating was performed on both the superior and anterior plates of the clavicle using data obtained from computed tomography. The areas covered by these plates on the muscles attached to the clavicle were compared. Histological examination was performed on four randomly selected specimens.

RESULTS

The sternocleidomastoid muscle was attached proximally and superiorly; the trapezius muscle was attached posteriorly and partly superiorly; and the pectoralis major muscle and deltoid muscles were attached anteriorly and partially superiorly. The non-attachment area was located mainly in the posterosuperior part of the clavicle. It was difficult to distinguish the borders of the periosteum and pectoralis major muscles. The anterior plate covered a significantly broader area (mean 6.94 ± 1.36 cm²) of the muscles attached to the clavicle than did the superior plate (mean 4.11 ± 1.52 cm²) (p < 0.0001). On microscopy, these muscles were inserted directly into the periosteum.

CONCLUSION

Most of the pectoralis major and deltoid muscles were attached anteriorly. The non-attachment area was located mainly from the superior to posterior part of the clavicle midshaft. Both macroscopically and microscopically, the boundaries between the periosteum and these muscles were difficult to demarcate. The anterior plate covered a significantly broader area of the muscles attached to the clavicle than that by the superior plate.

Fracture edge features of diaphyseal clavicular fractures: a morphologic study

BACKGROUND

Previous researchers used transverse fractures centered over the midpoint of the clavicle as the diaphyseal clavicular fracture models. However, as a result of shear stress concentration in sigmoid-shaped structures, most diaphyseal clavicular fractures have coronal fracture edges and are located distal to the midpoint. The purpose of this study was to quantify the morphology and utilize these parameters to establish clinically relevant fracture models.

METHODS

The computed tomographic DICOM data of 100 consecutive patients were included. We investigated the morphologic characteristics of the fracture edges after virtual fracture reduction. The fracture orientation was determined based on the normal vectors of the best-fit plane of the fracture edges. The fracture location was measured by the extreme points of the edges. The fracture configuration was evaluated using fracture maps.

RESULTS

There were 28 simple, 43 wedge, and 29 multifragmentary types. Coronal oriented fracture edges accounted for more than 70% of the simple, wedge, and multifragmentary types. The most proximal point of the proximal edge was located at 46.7% (42.0%-56.5%), 47.6% (42.5%-50.1%), and 46.3% (42.0%-49.3%) of the endpoint line in the simple, wedge, and multifragmentary types, respectively (P = .548). The most distal point of the distal edge was located at 72.2% (68.4%-75.0%), 73.2% (69.5%-76.9%), and 74.0% (69.6%-77.1%) of the endpoint line (P = .353). The longest proximal main fragments occurred in the simple types at 71.9% (66.3%-75.4%) of the endpoint line (P < .001), and the shortest distal main fragments occurred in the multifragmentary types at 55.8% (49.8%-59.3%) of the endpoint line (P = .001). The heatmaps showed a high concentration of anteriorly distributed wedge fragments (88%; n = 38/43) and coronally distributed multifragmentary fragments (62%; n = 18/29).

CONCLUSIONS

We showed that typical diaphyseal clavicular fractures have coronal fracture edges and are located within the distal half of the diaphyseal segment. The fractured fragments were initiated anteriorly in the wedge types and then propagated coronally in the multifragmentary types. The features of these fracture edges could be useful in designing osteotomy models and provide different perspectives of anterior and superior plating techniques.

A fluoroscopic view for midshaft clavicular fracture reduction and internal fixation: posteroanterior 25° skyline projection

Background

Open reduction and internal fixation have been frequently applied for displaced midshaft clavicular fracture. Plate and screw fixation of clavicular fractures could provide rigid fixation and rotational control. Proper implant positioning in surgical fixation is critical to prevent iatrogenic complications. Fluoroscopy plays an important role in the intraoperative evaluation of implants. This study aimed to introduce a new fluoroscopic projection to evaluate the positioning of plates and screws.

Methods

Adult patients with a diagnosis of acute displaced midshaft clavicular fracture were included in this study. The slope angle of the midshaft clavicle was measured on sagittal reconstructions of preoperative computed tomography (CT) scans. The incidence of screw revision based on intraoperative standard posteroanterior (PA) and PA 25° cephalic skyline projections was compared. The interobserver agreement for the two projections was calculated.

Results

Twenty-nine patients with midshaft clavicular fractures were enrolled from January 2020 to June 2021. The PA 25° skyline projection could clearly display the tangential line of the plate and inferior border of the clavicle. The slope angle on the superior surface of the midshaft clavicle was 26.0 ± 5.8° (range: 18.5–38.3°). The incidence of screw revision using the PA projection (72.4%) was significantly different from that using the PA 25° skyline projection (34.5%) (P < 0.05). The concordance of the screw revision rate based on the standard PA and PA 25° skyline projections was strong, with kappa coefficients of 0.680 (95% CI: 0.394–0.968) and 0.776 (95% CI: 0.537–0.998).

Conclusion

The PA 25° skyline projection corresponds to the slope angle of the midshaft clavicle. It can provide more accurate information regarding the proper screw length and be applied as a routine method for intraoperative evaluation.

Comparison of the Effectiveness of Simple Plate Fixation and Plate Combined with Local Fixation of Broken Ends in the Treatment of Oblique Fracture of Midshaft Clavicle

Objective

To compare the clinical efficacy of performing simple plate fixation with that using a plate combined with fracture end fixation to investigate the necessity of fracture end fixation outside the plate in cases of oblique fracture of the middle clavicle.

Methods

This was a retrospective follow‐up study of patients with middle clavicle oblique fractures (Robinson types 2A1 and 2A2) between 2015 and 2020. Patients were divided into two groups according to their treatment options: the simple plate fixation (SPF) group (n = 79; 43 men and 36 women; average age, 46.37 ± 14.54 years) and the plate combined with fracture local fixation (PLFP) group (n = 81; 36 men and 45 women; average age, 48.42 ± 12.55 years). Intraoperative blood loss, operation time, postoperative fracture healing time, postoperative shoulder function score (Constant–Murley and disabilities of the arm, shoulder, and hand [DASH] scores), clinical complications, and postoperative subjective satisfaction were compared between the two groups.

Results

One hundred sixty patients with a sufficient follow‐up period were included in the final analysis: 79 in the SPF group (follow‐up time: 16.24 ± 3.94 months) and 81 in the PLFP group (follow‐up time: 16.15 ± 3.43 months). Age, sex, body mass index, follow‐up duration, fracture classification, and cause of injury were not significantly different between the two groups. There was no significant difference in blood loss, Constant–Murley and DASH scores, follow‐up period, and postoperative subjective satisfaction between the two groups (P > 0.05). The fracture healing time was shorter in the PLFP group than in the SPF group (4.41 ± 0.99 vs. 4.87 ± 1.60 months, P < 0.05), but the operation duration was longer in the PLFP group than in the SPF group (65.48 ± 16.48 min, P < 0.05). There were seven (complication rate, 8.86%) and five (complication rate, 6.17%) cases that had complications in the SPF and PLFP groups, respectively. There was no significant difference in the complication rates between the two groups (P > 0.05).

Conclusion

Although the healing time was shorter in the PLFP group than in the SPF group, the clinical efficiency of the two methods in the treatment of oblique fracture of the middle clavicle was similar.

Dual mini-fragment plate fixation of midshaft clavicle fractures is biomechanically equivalent to anatomic pre-contoured plating

OBJECTIVES

To biomechanically compare the stiffness of midshaft synthetic clavicle osteotomies fixed with either superior anatomic pre-contoured locking plates, anterior anatomic pre-contoured locking plates, or short-segment dual orthogonal mini-plate fixation.

DESIGN AND SETTING

Controlled laboratory study. Specimens Twenty-one synthetic pre-osteotomized clavicles were separated into three groups: superior plating, anterior plating, or dual-plating. Each clavicle was sequentially tested in non-destructive cycles of axial compression, three-point bending, and torsion. Load and displacement were recorded. Stiffness was calculated.

RESULTS

No statistically significant differences were found between construct stiffness during axial compression, three-point bending, or torsional testing. One superior plated clavicle suffered catastrophic failure during axial compression. One dual mini-fragment plated clavicle suffered catastrophic failure during torsion.

CONCLUSIONS

Orthogonal dual mini-fragment fixation of transverse clavicle fractures is biomechanically similar to superior and anterior pre-contoured anatomic locking plate fixation. No statistically significant differences in construct stiffness were found in axial compression, three-point bending, or torsion testing. Further clinical research is required to determine the long-term stability of dual mini-fragment plate fixation.

LEVEL OF EVIDENCE

IV.

Low-profile dual mini-fragment plating of diaphyseal clavicle fractures. A biomechanical comparative testing

BACKGROUND

Implant removal rates after clavicle plating are high. Recently, low-profile dual mini-fragment plate constructs have revealed lower implant removal rates following fixation of diaphyseal clavicle fractures. However, they have not been subject to a biomechanical investigation.

AIMS

To: (1) investigate thebiomechanical competence of different dual plate designs and (2) compare them against single superoanterior plating.

METHODS

Twelve artificial clavicles with a simulated AO/OTA 15.2C unstable diaphyseal clavicle fracture were assigned to 2 groups and instrumented with dual titanium mandible plates as follows: Group 1 - 2.5 mm anterior plus 2.0 mm superior (2.5/2.0); Group 2 - 2.0 mm anterior plus 2.0 mm superior (2.0/2.0). Specimens were cyclically tested to failure under craniocaudal cantilever bending superimposed with torsion around the shaft axis and compared to previous published data acquired using 6 locking superoanterior plates tested under the same conditions (Group 3).

FINDINGS

Initial stiffness was highest in Group 1 followed by Group 2 and Group 3, being significantly different between Group 1 and Group 3 (p = 0.020). Displacement after 5000 cycles was biggest in Group 3, followed by Group 2 and Group 1, with significant differences between Group 3 and both Group 1 and Group 2 (p ≤ 0.027). Cycles to failure were highest in Group 3 followed by Group 1 and Group 2, being significantly different between Group 2 and Group 3 (p = 0.004).

INTERPRETATION

Low-profile 2.0/2.0 dual plates demonstrated similar initial stiffness compared with single 3.5 mm locking plates, however, they revealed significantly lower resistance to failure. Moreover, low-profile 2.5/2.0 dual plates demonstrated significantly higher initial stiffness and similar resistance to failure compared with single 3.5 mm locking plates and can therefore be considered as their useful alternative for diaphyseal clavicle fracture fixation.

Biomechanical Evaluation of Different Plate Configurations for Midshaft Clavicle Fracture Fixation: Single Plating Compared with Dual Mini-Fragment Plating

Background:

Dual-plate constructs have become an increasingly common fixation technique for midshaft clavicle fractures and typically involve the use of mini-fragment plates. The goal of this technique is to reduce plate prominence and implant irritation. However, limited biomechanical data exist for these lower-profile constructs. The study aim was to compare dual mini-fragment orthogonal plating with small-fragment clavicle plates for biomechanical noninferiority and to determine if an optimal plate configuration could be identified using a cadaveric model.

Methods:

Twenty-four cadaveric clavicles were randomized to 1 of 6 groups, stratified by computed tomography-based bone mineral content (BMC): precontoured superior or anterior fixation using a single 3.5-mm Locking Compression Plate (LCP), and 4 different dual-plating constructs utilizing 2.4-mm and 2.7-mm Adaptation plates or LCPs. An inferior butterfly fracture was created. Axial, torsional, and bending (anterior and superior surface loading) stiffnesses were determined through nondestructive cyclic testing, followed by a load-to-failure test in 3-point superior surface bending.

Results:

For axial stiffness, the 2 dual-plate constructs with a superior 2.4-mm and anterior 2.7-mm plate (either Adaptation or LCP) were significantly stiffer than the other 4 constructs (p = 0.021 and p = 0.034). For both superior and anterior bending, the superior 2.4-mm and anterior 2.7-mm plate constructs were significantly stiffer when compared with the 3.5-mm superior plate (p = 0.043). No significant differences were found in torsional stiffness or load to failure between the different constructs.

Conclusions:

Dual plating using mini-fragment plates is biomechanically superior for the fixation of midshaft clavicle fractures when compared with a single, superior, 3.5-mm plate and has biomechanical properties similar to those of a 3.5-mm plate placed anteriorly. With the exception of axial stiffness, no significant differences were found when different dual-plating constructs were compared with each other.

Clinical Relevance:

This study validates the use of dual plating for midshaft clavicle fractures.

No difference in mid-term outcome after superior vs. anteroinferior plate position for displaced midshaft clavicle fractures

To compare outcomes, complications, revisions, and rates of implant removal of superior compared to anteroinferior plating in displaced midshaft clavicle fractures at mid-term follow-up. We retrospectively reviewed 79 patients who underwent operative treatment for displaced midshaft clavicle fractures (Group A: 28 patients with superior plating; Group B: 51 patients with anteroinferior plating) that were at least 2 years postoperatively. Adjusted Constant Score (aCS), Visual Analog Scale (VAS), and Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) score were compared. Bone union, implant removal, complications and revision surgeries were assessed. Group A had a significantly higher aCS compared to group B (90, IQR: 85.0-91.0 vs. 91, IQR: 90.0-93.0; P = 0.037). No significant differences between groups were seen in VAS (P = 0.283) and QuickDASH (P = 0.384). Bone union was achieved in 76 patients (96.2%) with no significant differences between groups (Group A: 96.4% vs. Group B: 96.1%; P > 0.999). There were no significant differences in implant removal rates (Group A: 60.7% vs. Group B: 66.7%; P = 0.630), complications (Group A: 46.4% vs. Group B: 31.4%; P = 0.226) and revisions (Group A: 25% vs. Group B: 9.8%; P = 0.102). Superior and anteroinferior plating result in high bone union rates and good clinical outcomes with similar rates of plate removal.

Current concepts in the treatment of midshaft clavicle fractures in adults

Midshaft clavicle fractures are the most common fracture of the clavicle accounting for 80% of all clavicle fractures. Traditionally, midshaft clavicle fractures are treated with conservative treatment even when prominent displacement is observed; however, recent studies revealed that nonunion or malunion rate may be higher with conservative treatment. Moreover, recent studies have shown better functional results and patient satisfaction with surgical treatment. This review article provides a review of clavicle anatomy, describes the current clavicle fracture classification system, and outlines various treatment options including current surgical options for clavicle fracture in adults.

Does dual plating clavicle fractures increase the risk of refracture after hardware removal? A biomechanical investigation

BACKGROUND

Dual orthogonal plating of midshaft clavicle fractures is increasingly used for osteosynthesis. The risk of refracture after hardware removal remains unknown. The purpose of this study was to compare the torsional and 3-point bending loads to failure of the clavicle following removal of single-plane, superior 3.5-mm plate fixation vs. dual orthogonal plating 2.7-mm constructs.

METHODS

This study used 12 pairs of clavicles (N = 24) harvested from cadaveric specimens with a mean age at death of 56.5 years (range, 46-65 years). One clavicle from each pair was randomly assigned to either superior plating (SP, n = 12) or double plating (DP, n = 12). For SP, a superior 3.5-mm plate was used as a template to drill 3 bicortical 2.8-mm holes medial and lateral to the center of the clavicle. For DP, two 2.7-mm plates were used as a template to drill 4 bicortical 2.0-mm holes medial and lateral to the center of the clavicle. Clavicle pairs were randomly and evenly distributed to undergo either 3-point bending (n = 12) or posterior torsional loading (n = 12). Cyclic loading was performed, followed by load-to-failure testing. Stiffness, displacement at failure, load to failure, and failure mode were assessed and compared between SP and DP constructs.

RESULTS

No significant differences between the SP and DP groups were observed for stiffness (768.2 ± 281.3 N/mm vs. 785.5 ± 315.0 N/mm, P = .872), displacement at failure (8.1 ± 2.8 mm vs. 5.4 ± 1.2 mm, P = .150), and ultimate load at failure (1831.0 ± 229.6 N vs. 1842.0 ± 662.4 N, P = .964) under the condition of 3-point bending. Similarly, no significant differences between the SP and DP groups were observed for torsional stiffness (1.3 ± 0.8 N · m/° vs. 1.1 ± 0.4 N · m/°, P = .844), rotation at failure (17.3° ± 4.4° vs. 14.4° ± 1.2°, P = .205), and ultimate torque at failure (14.8 ± 6.5 N · m vs. 14.7 ± 6.9 N · m, P = .103) under the condition of posterior torsional loading. The most common mode of failure for 3-point bending testing was an oblique fracture (7 of 12 clavicles, 58.3%), with no significant difference between groups (3 of 6 in SP group [50%] vs. 4 of 6 in DP group [66.7%], P > .999). The most common mode of failure with posterior torsional loading was a spiral fracture (10 of 12 clavicles, 83.3%), with no significant difference between groups (4 of 6 in SP group [66.7%] vs. 6 of 6 in DP group [100%], P = .455).

CONCLUSION

Following clavicle plate removal of either DP or SP, there is no statistically significant difference in the amount of force, under the condition of 3-point bending or torsional loading, required to fracture the diaphyseal clavicle in vitro.

Bicortical versus unicortical fixation of plated clavicular fractures: A biomechanical study

PURPOSE

To compare the biomechanical properties of three plate stabilization techniques for midshaft clavicle fractures: anatomical bicortical locking construct, anatomical unicortical locking construct, and reconstruction bicortical locking construct.

METHODS

We analyzed superior plating of the clavicle using an anatomical clavicle plate (Acumed) with both bicortical or unicortical screw fixation and a locking reconstruction plate (DePuy-Synthes). Twenty-one fourth generation composite clavicles were used for non-destructive stiffness testing in axial loading, bending, and torsion. Fifteen composite clavicles and 17 foam clavicles were used for cyclic failure testing using a combined loading method that included all three loading modes.

RESULTS

No significant differences were found between the three constructs in torsional stiffness nor in vertical bending loading. In axial loading, the anatomical bicortical locking construct was significantly stiffer than either anatomical unicortical locking construct or the reconstruction bicortical locking construct. The unicortical fixation was also significantly stiffer than the reconstruction bicortical locking construct. Regarding failure testing, there was not a significant difference between the bicortical and unicortical anatomical locking constructs; however, both were significantly stronger than bicortical screw fixation in the reconstruction plate.

CONCLUSION

Based on the biomechanical performance of these constructs, unicortical locked plate fixation may be a reasonable option in the treatment of displaced midshaft clavicle fracture fixation.

A multicentric study on the newly developed reconstruction locking plate for midshaft clavicular fracture

Objectives: To examine the efficacy and clinical and radiological outcomes of the use of a streamlined clavicle plate^® (MEIRA, Aichi, Japan) for midshaft clavicular fractures. Methods: This was a retrospective cohort study of 155 patients with displaced midshaft clavicular fractures treated using a streamlined clavicle plate between 2015 and 2019 in 18 hospitals across Japan. A questionnaire regarding bone union and postoperative complications was used, and 136 cases were followed up for one year or until bone union. Plate fitting was evaluated retrospectively using surgical records, radiographic findings, and surgeon's opinion. Results: During surgery, plate bending was needed in 19 cases (12.3%), poor fitting was observed in 8 cases (5.2%), and bone union was achieved in 133 cases (97.8%). Total implantation failure, including plate breakage and screw loosening, occurred in 10 cases (6.5%) from the intraoperative to postoperative period. Subjective complications were observed in 26 cases (16.8%): incongruity around the surgical scar or in the anterior chest in 23, and contracture of the shoulder in three. Plate removal was performed in 66 cases (48.5%) per patient's request. Conclusion: The use of a streamlined clavicle plate is effective for midshaft fractures of the clavicle, and the success rates of bone union and implantation using this approach are comparable to those of other existing plates.

Clinical outcomes of doubled-suture Nice knot augmented plate fixation in the treatment of comminuted midshaft clavicle fracture

Background

Free bone fragments were difficult to be fixed in many comminuted midshaft clavicle fractures, and the absence of cortical alignment in comminuted fractures had direct influence on the stability of fixation. This survey was performed to assess the efficacy of doubled-suture Nice knot augmented plate fixation in the treatment of comminuted midshaft clavicle fractures.

Methods

Between 2013 and 2018, all patients with comminuted midshaft clavicle fractures treated with doubled-suture Nice knot augmented plate fixation were retrospectively reviewed and included in this research. Demographic data of the patients, characteristics of the fractures, intraoperative parameters and follow-up data of the patients were evaluated and summarized.

Results

A total of 56 patients were included in this study. The mean follow-up time was 25.6 months (range, 12–60 months). The number of male patients was 38 (67.9 %) and of the female patients was 18 (32.1 %). The average age of all patients was 47.89 ± 16.5 years. The mean time of surgery was 85.6 ± 24.0 min. The average length of incision was 9.2 ± 1.9 cm. The number of doubled-suture Nice knot applied ranged from 1 to 5 knots. All the patients reached bone union after the treatment. There was no implant failure or neurovascular injury observed. And most of the patients showed good functional outcome.

Conclusions

The doubled-suture Nice knot could provide reliable fixation for small bone fragments in comminuted clavicle fractures. Combination of the doubled-suture Nice knot and plate screws fixation was a safe and effective method in comminuted midshaft clavicle fractures treatment.

Intraoperative Nice knots assistance for reduction in displaced comminuted clavicle fractures

PURPOSE

The Nice knots have been widely used in orthopedic surgeries to fix torn soft tissue and fracture in recent years. The study aims to investigate the clinical efficacy and prognosis of intraoperative and postoperative Nice Knots-assisted reduction in the treatment of displaced comminuted clavicle fracture.

METHODS

From Jan 2014 to Dec 2019, 75 patients diagnosed with unilateral closed displaced comminuted clavicle fracture were treated with open reduction and internal fixation (ORIF) in this study. Nice knot group (the NK group) included 38 patients and the other 37 patients were in the traditional group (the TK group). The time of operation and the amount of bleeding during operation were recorded. Post-operative clinical outcomes and radiographic results were recorded and compared between these two groups. The Visual Analogue Scale (VAS), Neer score, Rating Scale of the American Shoulder and Elbow Surgeons, Constant-Murley score and complications such as infection, nonunion, implant loosening, fragment displacement and hardware pain were observed in the two groups.

RESULTS

In the comparison between the two groups, there was no significant difference in age, sex, the cause of displaced clavicle fracture, and other basic information between the two groups. The operation time, intraoperative fluoroscopy time, and intraoperative blood loss were significantly reduced in the NK group (P < 0.01). There were 2 cases of plate fracture in the TK group. The follow-up results showed that there was no significant difference in VAS, Neer score, ASES, and Constant-Murley scores between the two groups.

CONCLUSION

The use of Nice knot, in comminuted and displaced clavicle fractures can reduce intraoperative blood loss, shorten operation time, facilitate intraoperative reduction, and achieve satisfactory postoperative clinical results. This study demonstrates that Nice knot is a simple, safe, practical and effective auxiliary reduction method.

Comparable results using 2.0-mm vs. 3.5-mm screw augmentation in midshaft clavicle fractures: a 10-year experience

Purpose

Absence of cortical alignment in wedge-shaped and multifragmentary fractures (Fx) results in decreased fixation stability. The aim of this study was to compare the outcome using 2.0- vs. 3.5-mm screws for open reduction and internal fixation (ORIF) in dislocated, wedge-shaped or fragmentary midshaft clavicle fractures.

Materials and methods

Patients suffering from AO/OTA 15 2.A-C midshaft clavicle fractures were operatively treated between 2008 and 2018. 2.0- or 3.5-mm cortical screws were used to restore anatomic alignment in dislocated, wedge-shaped and fragmentary clavicle fractures. Data of radiologic outcome were collected until fracture consolidation was identified.

Results

80 consecutive patients with a mean age of 44.5 ± 16.3 years, who were operatively treated for dislocated midshaft clavicle fractures were enrolled. 40 patients were treated using 2.0-mm and 40 patients using routine 3.5-mm cortical screws, respectively. Time to fracture consolidation was 12.8 ± 7.8 months. No mal- or non-unions occurred during routine follow-up until 18 months postoperatively.

Conclusion

Restoring anatomic alignment in wedge or fragmentary clavicle fractures can ultimately be addressed using cortical screw augmentation. Both groups showed comparable results with respect to fracture reduction, fixation and stability as well as time to consolidation of the fracture, while the 2.0-mm screw diameter was associated with easier handling of small Fx fragments.

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.

S-shaped titanium endomedullary nail reduces telescoping of comminuted midshaft clavicular fractures

BACKGROUND

The surgical treatment of displaced midshaft clavicular fractures (DMCF) is clinically relevant and a much discussed topic. The axial stability of DMCF after intramedullary nailing (IMN) is still a matter of debate.

OBJECTIVE

Our objective was to present a modification of IMN of DMCF with S-shaped titanium endomedullary nail (TEN) and determine fracture telescoping from day one after surgery to the time of fracture healing.

METHOD

In a prospective analytic cohort study over a 6-year period (2012-2017) at a Level II trauma care centre, a total of 128 patients with DMCF were included and classified according to the AO/OTA classification system. Group I was AO/OTA type 15.2A/15.2B (N = 68) and group II was AO/OTA type 15.2C (N = 60). After a modified open stabilization technique of each DMCF with IMN (S-shaped TEN), the dynamics of radiological assessed telescoping until union and rate of surgical adverse events were measured. Significance was assumed for p < 0.05.

RESULTS

One day after surgery, fractured clavicles were lengthened slightly in both groups compared to the unfractured clavicules (group I: 1.2%; group II: 0.9%). After osseus consolidation, the fractured clavicules were significantly shortened in both groups (group I: - 2.9%; group II: - 3.6%). Measurement of the clavicular shortening at one day postsurgically and at consolidation revealed a mean telescoping of - 3.99% in group I and of - 4.6% in group II. The difference between the two groups was not significant (P = 0.522). The overall rate of major surgical adverse events was 2.3%.

CONCLUSION

The proposed operative technique of IMN (stabilization of the DMCF with a long, S-shaped, tight-fitting TEN) provides enough axial stability to prevent significant telescoping of the comminuted fractures. The rate of nonunion is low and the overall rate of major adverse events is similar to the reported events after plate fixation in the literature.

An evaluation of treatment options for medial, midshaft, and distal clavicle fractures: a systematic review and meta-analysis

Background

The majority of clavicle fractures are midshaft injuries, although fractures of the distal or medial fragment also occur. The aim of this study was to review the current evidence on these injuries to help inform future treatment plans.

Methods

We searched for studies comparing interventions for medial, midshaft, or distal clavicle fractures; however, we did not identify any comparative studies on medial fractures and performed a secondary search on this topic. We conducted Bayesian network meta-analyses, although this was not feasible with studies on medial fractures and we described their results qualitatively.

Results

For midshaft fractures, we found statistically significant improvements in function and time to radiographic union with plating, an elastic stable intramedullary nail (ESIN), and the Sonoma CRx intramedullary nail over nonoperative treatments. Both plating and an ESIN also showed significantly lower risks of nonunion and malunion relative to nonoperative methods. For distal fractures, a locking plate (LP) with or without coracoclavicular (CC) suturing yielded significantly better outcomes over K-wires with or without tension bands, CC suturing alone, an LP with a CC screw, a hook plate, and a sling. For medial fractures, plating may result in more favorable functional and union-related outcomes, although implant irritation may occur. In addition, K-wires, tension bands, and a screw with sutures demonstrated success when plating was technically not feasible in a few cases, whereas treatment with a sling may result in reduced function and a higher risk of complications relative to surgery.

Conclusion

This study can provide guidance on the management of medial, midshaft, and distal clavicle fractures. The current evidence suggests that plating, an ESIN, and a CRx intramedullary nail are all good options for midshaft fractures; an LP with or without CC suturing should be preferred for distal fractures; and plating is also acceptable for medial fractures, provided that the patient is deemed suitable for surgery and has the adequate bone stock and sufficiently sized medial fragment necessary to implant the device. Patient preferences for certain outcomes should be considered, which may result in different treatment recommendations.

Finite element analysis comparison between superior clavicle locking plate with and without screw holes above fracture zone in midshaft clavicular fracture

Background

Midshaft clavicular fractures are common fractures and generally treated conservatively. Among the surgical options, plate fixation is the most popular and has been biomechanically and clinically proven in numerous studies. However, implant failures caused by plate deformations or breakage still occur in up to 16.7% of cases, and recent studies showed that screw holes above fracture zone (SHFZ) might be the at-risk location. Using finite element analysis, this study aimed to test the biomechanical property of the superior clavicle locking plate (SCLP) with and without SHFZ in comminuted midshaft clavicular fracture.

Methods

Finite element models of comminuted midshaft clavicular fracture fixed with standard 8-hole titanium SCLP with screw holes (SHFZ plate) and without screw holes above fracture zone (No-SHFZ plate) were built. Both groups were tested under three different loading models (100-N cantilever bending, 100-N axial compression, and 1-Nm torsion). The average peak stress on medial clavicle, fracture zone, and lateral clavicle, and the peak stress on each screw hole (or the same position in the No-SHFZ plate) were measured and compared.

Results

The highest average peak stress on the fracture zone was higher than those on medial and lateral clavicles under all loading conditions in both plates. However, the No-SHFZ plate significantly reduced the average peak stress value on the fracture zone, compared to the SHFZ plate (45.0% reduction in cantilever bending, 52.2% reduction in axial compression, and 54.9% reduction in axial torsion). The peak stress value on the maximal stress point in the SHFZ and No-SHFZ plates with cantilever bending, axial compression, and torsion loads were 1257.10 MPa vs. 647.21 MPa, 186.42 MPa vs. 131.63 MPa, and 111.86 MPa vs. 82.41 MPa, respectively.

Conclusion

The weakest link of the SCLP construct in comminuted midshaft clavicular fracture fixation is the SHFZ, especially in the cantilever bending load. Additionally, the biomechanical property of the SCLP without SHFZ model (No-SHFZ plate) is superior to the standard SCLP model (SHFZ plate), with a significantly lower peak stress on the SHFZ location in all loading conditions. We recommend a new SCLP design with SHFZ to prevent implant failure and improve surgical outcomes.

Forces acting on the clavicle during shoulder abduction, forward humeral flexion and activities of daily living

BACKGROUND

The forces acting on the human clavicle in vivo are difficult if not impossible to measure. The goal of this study is to quantify the forces acting on the human clavicle during shoulder abduction, forward humeral elevation and three activities of daily living using the Delft Shoulder and Elbow Model.

METHODS

The Delft Shoulder and Elbow Model and a computed tomography scan of a clavicle were used to calculate the forces and moments acting on the entire clavicle and on three planes within the middle third of the clavicle during the simulated movements.

FINDINGS

The largest resultant force simulated across the clavicle was 126 N during abduction. Maximum resultant moments of 2.4 Nm were identified during both abduction and forward humeral elevation. The highest forces in the middle third of the clavicle were of a compressive nature along the longitudinal axis of the clavicle, increasing to 97 N during forward humeral elevation and 91 N during abduction. Forces in opposite direction along the y-axis were identified on either side of the conoid ligament. The three simulated activities of daily living had similar ranges of forces and moments irrespective of the sagittal plane in which these activities were performed.

INTERPRETATION

Peak forces occurred at different locations on the middle third of the clavicle during different movements. The results create an understanding of the forces and their distribution across the clavicle during activities of daily living. These data may be helpful in the development of clavicular fixation devices.

LEVEL OF EVIDENCE

Biomechanical study.

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.

Biomechanical comparison between solid and cannulated intramedullary devices for midshaft clavicle fixation

Background

A method of closed reduction and internal fixation with cannulated screws was proposed as a surgical treatment of midshaft clavicle fractures. However, there are no mechanical studies about the cannulated screw used in the fixation of midshaft clavicle fracture. We conducted this study to compare the construct bending stiffness of a fixation midshaft clavicle fracture with a Knowles pin, cannulated screw and reconstruction plate. In addition, purchase lengths of both intramedullary devices were measured.

Methods

After transverse osteotomy over the midpoint for fracture simulation, eighteen synthetic clavicles were assigned to 3 groups and fixed with reconstruction plate, Knowles pin or cannulated screw. Purchase length was defined as the engaged length of the intramedullary portion of the two intramedullary devices Stiffness, yield load and maximum load of the cantilever bending test were calculated of each tested synthetic bones.

Results

The Knowles pin group had a significantly longer average intramedullary purchase length compared with that of the cannulated screw group. The construct stiffness in the reconstruction plate group (5.6 ± 0.9 N/mm) was higher than that of the intramedullary devices; the Knowles pin group (3.1 ± 0.6 N/mm) provided a greater construct stiffness than did the cannulated screw group (1.7 ± 0.4 N/mm) (p = 0.007). The cannulated screw group had the lowest yield and maximum load compared with the reconstruction plate and Knowles pin groups. Both the reconstruction plate and Knowles pin failed at the implant-bone interface. However, the cannulated screw group failed at the osteotomy site with broken implants.

Conclusion

This study suggests that fixation of midshaft clavicle fractures with cannulated screws may lead to early failure due to inadequate mechanical strength. Ideal intramedullary clavicle devices should supply adequate intramedullary purchase lengths and mechanical strength.