Superior versus anteroinferior plating of the clavicle revisited: a mechanical study

Effect of Sextant Fixating Angle of Spiral Clavicle Plate on Biomechanical Stability-A Preliminary Finite Element Study

INTRODUCTION

A spiral clavicle plate has been accepted for its superior multidirectional compatibility in the treatment of midshaft clavicle fractures from a biomechanical perspective. However, the influence of the sextant angle (spiral level) definition on biomechanical performance has not been clarified. A conceptual finite element analysis was conducted to identify the advantages and drawbacks of spiral clavicle plates with various sextant angle definitions.

METHODS

Conventional superior and three different conceptual spiral plates with sextant angle definitions ranging from 45 to 135 degrees were constructed to restore an OTA 15-B1.3 midshaft clavicle fracture model. Three major loading scenarios (cantilever downward bending, axial compression, and axial torsion) were simulated to evaluate the reconstructed structural stiffness and the stress on the clavicle plate and bone screws.

RESULTS

The spiral clavicle plate demonstrated greater capability in resisting cantilever downward bending with an increase in sextant angle and showed comparable structural stiffness and implant stress compared to the superior clavicle plate. However, weakened resistance to axial compression load was noted for the spiral clavicle plate, with lowered stiffness and increased stress on the clavicle plate and screws as the spiral level increased.

CONCLUSION

The spiral clavicle plate has been reported to offer multidirectional compatibility for the treatment of midshaft clavicle fractures, as well as geometric advantages in anatomical matching and reduced skin prominence after surgery. The current study supports that remarkable cantilever bending strength can be achieved with this plate. However, users must consider the potential drawback of lowered axial compression resistance in safety considerations.

Great debates in trauma biomechanics

At the 2021 annual meeting of the Orthopaedic Trauma Association, the Basic Science Focus Forum hosted its first ever debate-style symposium focused on biomechanics and fracture repair. The 3 subjects of debate were "Mechanics versus Biology-Which is 'More Important' to Consider?" "Locked Plate versus Forward Dynamization versus Reverse Dynamization-Which Way Should I Go?" and "Sawbones versus Cadaver Models-What Should I Believe Most?" These debates were held because fracture healing is a highly organized synergistic response between biological factors and the local mechanical environment. Multiple studies have demonstrated that both factors play roles in governing bone healing responses, and the causal relationships between the 2 remain unclear. The lack of clarity in this space has led to a spectrum of research with the common goal of helping surgeons make good decisions. Before reading further, the reader should understand that the questions posed in the debate titles are unanswerable and might represent a false choice. Instead, the reader should appreciate that the debates were held to gain a more thorough understanding of these topics based on the current state of the art of experimental and clinical studies, by using an engaging and thought-provoking format.

Anteroinferior plating is an independent factor for decreasing symptomatic implant removal rates after plate fixation for midshaft clavicle fractures

Objectives

The factors that significantly influence the symptomatic implant removal rates after plate fixation for midshaft clavicle fractures remain controversial. The purpose of this study was to compare the symptomatic implant removal rates between 2 different types of plating technique and to evaluate independently associated factors.

Design

Retrospective cohort study.

Setting

Acute care center.

Patients/Participants

A total of 71 patients 16 years or older who were diagnosed with displaced midshaft clavicle fractures from April 2016 to March 2020.

Intervention

Thirty-nine patients were treated with superior plating (Group SP), and the remaining 32 patients were treated with anteroinferior plating (Group AIP).

Main Outcome Measurements

Symptomatic implant removal rates after plate fixation for midshaft clavicle fractures.

Results

Symptomatic implant removal rates were significantly lower in Group AIP (28.1%) than in Group SP (53.8%) (P = 0.033). Multivariate analyses showed that symptomatic implant removal rates were significantly decreased by three independent factors, namely AIP (odds ratio [OR] = 0.323) (P = 0.037), greater age (45 years or older) (OR = 0.312) (P = 0.029), and high body mass index (≥25 kg/m²) (OR = 0.117) (P = 0.034).

Conclusions

AIP significantly and independently decreased the symptomatic implant removal rate. Among the three explanatory factors showing significant difference, plating technique is the only factor that can be altered by medical institutions. Therefore, we recommend this technique for displaced midshaft clavicle fractures to reduce a second surgery such as symptomatic implant removal.

Level of Evidence

Level 3, retrospective cohort study.

The anterior head of deltoid in relation to anterior clavicle plating: how much are we releasing?

Middle to distal-third clavicular shaft fractures are commonly treated with precontoured anterior plating. Some surgeons use mini-fragment plate fixation and position these plates on the anterior clavicle. Recent studies demonstrated the advantages of anterior clavicle plating, including a possible biomechanical advantage with cantilever bending forces and less subsequent implant removal. The insertion and positioning of anteriorly based clavicle plates requires the release of a portion of the anterior deltoid origin from the lateral clavicle. The purpose of this study is to evaluate the anatomy of the deltoid in relation to the clavicle and to determine the percentage of the deltoid origin released to place modern anterior precontoured plates.

METHODS

Six right and 4 left cadaver shoulders were dissected, each from separate cadaveric specimens (6 male and 4 female). All measurements were made with digital calipers. The length of the clavicle was measured from the acromioclavicular joint to the sternoclavicular joint. The length of deltoid origin on the lateral clavicle was measured from the acromioclavicular joint to the most medial attachment of the deltoid on the clavicle. Percentage of clavicle with deltoid origin was subsequently calculated.

RESULTS

The average length of the cadaveric clavicles was 164.4 mm with a range from 134.3 to 178.1 mm. The average amount of deltoid origin on the clavicle was 58.7 mm with a range from 43.4 to 69 mm. On average 35.5% of the clavicle had deltoid origin, with a range from 30.2% to 38.8%.

CONCLUSION

On average, 35.5% of the clavicular osseous anatomy contains deltoid origin. This should be taken into consideration when performing anterior plating for clavicle fractures. With a significant portion of deltoid origin elevated, surgeons may consider altering postoperative protocols until some interval healing has occurred to this anterior head of the deltoid.

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.

Results of pre-contoured titanium anterior plating of midshaft clavicle fractures

BACKGROUND

Plating midshaft clavicle fractures anteriorly is gaining popularity because of low complication rates. Improvements in plate fixation constructs for midshaft clavicle fractures have unclear clinical significance. The purpose of this study was to present the early clinical and radiographic outcomes of pre-contoured titanium anterior plates for the treatment of midshaft clavicle fractures.

METHODS

Skeletally mature patients who underwent plate fixation of a midshaft clavicular fracture from 2008 to 2015 using pre-contoured titanium anterior plates were included in this retrospective investigation. The primary outcome measures were union rate and hardware removal rate. The secondary outcome measures included reoperation for all causes and mechanical implant failure.

RESULTS

A total of 26 patients were included. Complete healing occurred in 96% of patients without further surgical intervention, and all patients achieved union. Medical complications occurred in 2 patients (7.7%), consisting of cellulitis (n = 1) and chronic pain (n = 1). In 1 patient (3.8%), delayed union occurred and the use of a bone stimulator was required postoperatively to achieve union. Finally, 2 patients (7.7%) had symptomatic implants that required removal.

CONCLUSIONS

In the acute fracture setting, the anterior plating system used in this study led to a high rate of union with decreased rates of implant irritation. Only 7.7% of patients required hardware removal for symptomatic hardware, as opposed to the estimated 20%-60% reported in the literature in patients with symptomatic superior clavicle plates.

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.

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.

Management of comminuted mid-shaft clavicular fractures: Comparison between dual-plate fixation treatment and single-plate fixation

BACKGROUND

We consider dual-plate fixation to improve construct rigidity in cases with fracture complexity. The purpose of this study is to compare the rate of nonunion, prognosis, and complications at 6-12 months for surgically treated acute mid-shaft clavicle fractures when extra-periosteal dual-plate fixation is used in place of the conventional single-plate fixation.

MATERIALS AND METHODS

The comparative study was conducted on 47 patients who received acute mid-shaft clavicular fracture treatment in our hospital from March 2015 to July 2018. All patients were divided into dual-plate fixation treatment (group A) and single-plate fixation (group B). Patients undergoing single-plate fixation were compared to dual-plate fixation. Patients were followed up for 6-12 months. Charts were reviewed to assess union rates, prognosis, and complications.

RESULTS

Forty-seven clavicles (30 single plates and 17 dual plates) were evaluated. All patients (100%) in dual plating group and 128 (93.3%) in single plating group obtained bony union by 1 year. When comparing groups at 3 months, radiographic union was present in 50.0% of single plates and 64.7% in the dual plating group (p = 0.032). However, at 6 months, no significant difference existed (90.0% vs. 94.1%, p = 0.297). Comparing groups at 1.5 and 6 months, Constant-Murley outcome scores were present with no significant difference (p = 0.129, p = 0.054) between single plates and dual plating group. However, at 3 months, significance difference existed.

DISCUSSION

Three months after the operation, patients with dual-plate fixation showed good functional recovery. Extra-periosteal dual plating for acute mid-shaft clavicle fractures can be safely considered for the treatment of complex acute mid-shaft clavicle fractures without increasing the risk of nonunion or revision.

CONCLUSIONS

Open reduction and internal fixation with an extra-periosteal dual plating technique is a reliable option for treatment of acute mid-shaft clavicle fractures, especially in the setting of severely comminuted fractures and in situations where bone quality is questionable and additional fixation is desired.

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.

No Difference in Risk of Implant Removal Between Orthogonal Mini-fragment and Single Small-fragment Plating of Midshaft Clavicle Fractures in a Military Population: A Preliminary Study

BACKGROUND

Clavicle fractures are common, especially in military personnel. A persistent problem of open reduction and internal fixation (ORIF) of the clavicle is the high percentage of symptomatic implants needing removal. Prominent implants can lead to discomfort in military service members performing activities such as carrying rucksacks and firing high-caliber weapons, potentially resulting in a high removal of implant rate. Alternative approaches to plate fixation may mitigate this, but to our knowledge, only limited evidence is available comparing various plate-fixation approaches.

QUESTIONS/PURPOSES

In a military population, we asked (1) Is there a difference in implant removal rates after midshaft clavicle fixation using orthogonal plating with 2.7-mm reconstruction plates versus a single 3.5-mm locking compression plate? (2) What complications are associated with each fixation approach? (3) Is there a difference in surgical time between the approaches?

METHODS

Between January 2010 and May 2015, three surgeons performed 99 ORIF procedures of midshaft clavicle fractures, always using a single small-fragment plate, and one surgeon performed 34 procedures, always using two mini-fragment plates with an orthogonal plating construct. Of those, 89 (90%) in the small-fragment plating group were available for analysis in this retrospective study and 33 (97%) were available for analysis in the mini-fragment plating group, both groups with a minimum of 2 years of followup. There were no between-group differences in terms of gender, tobacco use, injured side, hand dominance, 100% displacement, comminution, shortening, and active-duty status. We analyzed the proportion of patients who had their plates removed for any complications recorded in their charts. Assessment bias for indications for symptomatic removal of implant was minimized as there was always another fellowship-trained trauma surgeon at our institution available for a second opinion if the operative surgeon did not agree with a patient request for implant removal. A posthoc power calculation indicated that with the numbers available, we had 80% power to detect a between-group difference in implant removal proportion of 14.5% at the p < 0.05 level.

RESULTS

We found no difference between the small-fragment plating group and the mini-fragment group in the frequency of plate removal (9% [8 of 89] versus 0% [0 of 33]; odds ratio, 3.38 [95% confidence interval 0.41 to 27.68]; p = 0.11); a worst-case analysis that assumed all patients lost to follow-up underwent plate removal did not change this no-difference finding. All cases of implant removal were performed secondary to a symptomatic implant. With the numbers available, there were no differences between the two groups in nonunion, delayed union, infection, or other complications. There was a longer mean operative time in the mini-fragment group than in the small-fragment group (173.7 minutes versus 118.7 minutes; mean difference, 55 minutes [95% CI 38.71 to 71.23]; p < .001). Our overall implant removal percentage for the two groups combined was 6.6% (8 of 122).

CONCLUSIONS

Our study was underpowered to show differences in implant removal but may serve as a pilot for larger randomized controlled trials or multi-institutional studies on this topic. Although there was increased operative time to insert two plates, there was no difference in overall complications.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Single-center experience in the treatment of extremely medial clavicle fractures with vertical fixation of double-plate: A retrospective study

Patients suffering from extremely medial clavicle fractures combined with distinct displacement generally need surgical intervention. Double-plate fixation is a widely applied technique in the treatment of distal radius fracture, which has been reported to fix lateral clavicle fracture as well. This study reveals the effect of double-plate fixation as an innovative procedure in the treatment of extremely medial clavicle fractures for the first time.Nine patients complaint of extremely medial clavicle fracture were enrolled in this research from May 2017 to March 2019. Patients were operated with an open reduction and internal fixation using the double-plate technique. Postoperative x-ray was taken regularly to observe the fracture healing at each visit, and the related complications were also recorded. The rating score systems of Constant Murley score of treated shoulder and contralateral shoulder, ROWE score as well as American Shoulder and Elbow Surgeons (ASES) were evaluated to comment on the postoperative shoulder joint function.All patients achieved postoperative fracture healing with no complications. Only 1 patient complained of slight restriction, 2 patients complained of pain during overhead work, and another patient was found with plate breakage. Meanwhile, the Constant Murley scores of treated and contralateral shoulder were 94.1 and 98.5 points, respectively, indicating the similar shoulder function. Furthermore, the ROWE and ASES scores of the involved shoulder were 96.7 and 96.3 points at average, respectively.It is the first time to introduce the surgical technique of vertical double-plate fixation implied in stable fixation of extremely medial clavicle fractures, which could provide the surgeons with an alternative method for this type of fracture.

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.

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.

Finite element analysis of spiral plate and Herbert screw fixation for treatment of midshaft clavicle fractures

Both spiral plate and Herbert screw fixations have been clinically adopted for treating midshaft displaced clavicle fractures. However, the biomechanical properties of the 2 implant fixations have not yet been thoroughly evaluated. Here we report the results of a finite element analysis of the biomechanical properties of midshaft clavicle fractures treated with Herbert screw and spiral plate fixation. Hebert screw fixation showed stress distribution similar to intact clavicle under all loading conditions, but provided less stability than did spiral plate fixation. Postoperatively, excessive shoulder activities and weight-bearing should be avoided. Spiral plate fixation provides greater stability, but is associated with stress shielding. These results demonstrate that Herbert screw fixation is suitable for the treatment of simple displaced clavicluar fractures, but excessive shoulder activity and weight-bearing should be avoided after the operation. Therefore, spiral plate fixation may be preferred for patients requiring an early return to activity.

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.

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.

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.

Anterior-Inferior Plating Results in Fewer Secondary Interventions Compared to Superior Plating for Acute Displaced Midshaft Clavicle Fractures

OBJECTIVES

To determine whether a difference in plate position for fixation of acute, displaced, midshaft clavicle fractures would affect the rate of secondary intervention.

DESIGN

Retrospective Comparative Study.

SETTING

Two academic Level 1 Regional Trauma Centers.

PATIENTS

Five hundred ten patients treated surgically for an acutely displaced midshaft clavicle fracture between 2000 and 2013 were identified and reviewed retrospectively at a minimum of 24 months follow-up (F/U). Fractures were divided into 2 cohorts, according to plate position: Anterior-Inferior (AI) or Superior (S). Exclusion criteria included age <16 years, incomplete data records, and loss to F/U. Group analysis included demographics (age, sex, body mass index), fracture characteristics (mechanism of injury, open or closed), hand dominance, ipsilateral injuries, time between injury to surgery, time to radiographic union, length of F/U, and frequency of secondary procedures.

INTERVENTION

Patients were treated either with AI or S clavicle plating at the treating surgeon's discretion.

MAIN OUTCOME MEASURES

Rate and reason for secondary intervention.

STATISTICAL ANALYSIS

Fisher exact test, t test. and odds ratio were used for statistical analysis.

RESULTS

Final analysis included 252 fractures/251 patients. One hundred eighteen (47%) were in group AI; 134 (53%) were in group S. No differences in demographics, fracture characteristics, time to surgery, time to union, or length of F/U existed between groups. Seven patients/7 fractures (5.9%) in Group AI underwent a secondary surgery whereas 30 patients/30 fractures (22.3%) in group S required a secondary surgery. An additional intervention secondary to superior plate placement was highly statistically significant (P < 0.001). Furthermore, because 80% of these subsequent interventions were a result of plate irritation with patient discomfort, the odds ratio for a second procedure was 5 times greater in those fractures treated with a superior plate.

CONCLUSIONS

This comparative analysis indicates that AI plating of midshaft clavicle fractures seems to lessen clinical irritation and results in significantly fewer secondary interventions. Considering patient satisfaction and a reduced financial burden to the health care system, we recommend routine AI plate application when open reduction internal fixation of the clavicle is indicated.

LEVEL OF EVIDENCE

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

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

Objective

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

Methods

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

Results

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

Conclusion

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

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.

Plate fixation and bone grafting of distal clavicle nonunions: radiologic and functional outcomes

INTRODUCTION

The optimal treatment for distal clavicle nonunions remains unknown. Small series have reported outcomes following distal fragment excision and various fixation techniques. We present the clinical, radiographic and functional outcomes after superior plating or double (superior and anteroinferior) plating in combination with bone grafting as treatment for distal clavicle nonunions.

METHODS

We collected demographic and radiographic data from a consecutive series of ten patients with symptomatic nonunion of the distal clavicle treated since 1998. Functional outcomes were assessed, as well as the visual analogue scale (VAS) score.

RESULTS

The mean clinical follow-up was 41.4 months (range of 12-158 months). The mean radiological follow-up was 30.6 months (range of 3-158 months). All nonunions healed as demonstrated by subsidence of clinical symptoms and radiographic criteria. The average time to union was 3.7 months (range of 2-8 months). The mean The Disabilities of the Arm, Shoulder and Hand (DASH) score was 11.9 (range of 0-62.5) and mean VAS score was 0.9 at follow-up.

CONCLUSION

This study illustrates good clinical, radiologic and functional outcomes in ten patients with distal clavicle nonunion treated with superior or double (superior and anteroinferior) plating in combination with bone grafting. Double-plating can be considered an alternative to superior plating offering better resistance against the pulling effect of the arm with the use of smaller fixation plates.

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.].

Anteroinferior 2.7-mm versus 3.5-mm plating of the clavicle: A biomechanical study

INTRODUCTION

Lower patient satisfaction and high rates of plate prominence has led to the use of lower profile, smaller plates in the treatment of midshaft clavicle fractures. Specifically regarding the use of 2.7mm reconstruction plates, there lacks biomechanical comparison to its more robust 3.5mm counterpart. This study was designed to compare the mechanical properties of anteroinferior plate fixation on a clavicle fracture model using either 2.7mm or 3.5mm reconstruction plates.

METHODS

Forty-eight synthetic left clavicles were divided into two groups based on the type of fixation: 3.5mm or 2.7mm pelvic reconstruction plate fixed in the anteroinferior position. Fixation was tested on AO/OTA 15B1.3 transverse midshaft fractures. Each specimen underwent the following three mechanical tests: axial compression, torsion, and four-point bending.

RESULTS

Significant differences were observed in axial (p=0.016) and torsional (p=0.00097) stiffness between the two groups. The average bending rigidity (EI) was found to be significantly lower for the 2.7-mm plates as compared to the 3.5-mm plates (p=0.03). The loading scenarios performed in the mechanical tests did not lead to failure of any implants.

CONCLUSION

While our results show clear mechanical superiority of 3.5-mm reconstruction plates over 2.7-mm plates, superior results in the clinical setting may not necessarily translate. With exceptional mechanical strength also noted for the 2.7mm plate, well above the biomechanical properties of an intact clavicle, these results may obviate the need for robust plates in general.

Finite element analysis of locking plate and two types of intramedullary nails for treating mid-shaft clavicle fractures

BACKGROUND

Both plate and intramedullary nail fixations, including straight and anatomic nails, have been clinically adopted for the treatment of displaced mid-shaft clavicle fractures. However, the biomechanical performances of these fixations and implants have not been well evaluated. This study aims to compare the construct stability, stress distribution and fracture micro-motion of three fixations based on finite element (FE) method.

METHODS

The FE model of clavicle was reconstructed from CT images of a male volunteer. A mid-shaft fracture gap was created in the intact clavicle. Three fixation styles were simulated including locking plate (LP), anatomic intramedullary nail (CRx), and straight intramedullary nail (RCP). Two loading scenarios (axial compression and inferior bending) were applied at the distal end of the clavicle to simulate arm abduction, while the sternal end was fixed.

RESULTS

Under both conditions, the LP was the stiffest, followed by the CRx, and the RCP was the weakest. LP also displayed a more evenly stress distribution for both implant and bone. RCP had a higher stress compared with CRx in both conditions. Moreover, all implants sustained higher stress level under the loading condition of bending than compression.

CONCLUSIONS

The plate fixation significantly stabilizes the fracture gap, reduces the implant stress, and serves as the recommended fixation for the mid-shaft clavicle fracture. The CRx is an alternative device to treat clavicle shaft fracture, but the shoulder excessive activities should be avoided after operation.

Intramedullary Fixation of Clavicle Fractures: Anatomy, Indications, Advantages, and Disadvantages

Historically, management of displaced midshaft clavicle fractures has consisted of nonsurgical treatment. However, recent literature has supported surgical repair of displaced and shortened clavicle fractures. Several options exist for surgical fixation, including plate and intramedullary (IM) fixation. IM fixation has the potential advantages of a smaller incision and decreased dissection and soft-tissue exposure. For the last two decades, the use of Rockwood and Hagie pins represented the most popular form of IM fixation, but concerns exist regarding stability and complications. The use of alternative IM implants, such as Kirschner wires, titanium elastic nails, and cannulated screws, also has been described in limited case series. However, concerns persist regarding the complications associated with the use of these implants, including implant failure, migration, skin complications, and construct stability. Second-generation IM implants have been developed to reduce the limitations of earlier IM devices. Although anatomic and clinical studies have supported IM fixation of midshaft clavicle fractures, further research is necessary to determine the optimal fixation method.

Biomechanical analysis of intramedullary vs. superior plate fixation of transverse midshaft clavicle fractures

BACKGROUND

Middle-third clavicle fractures represent 2% to 4% of all skeletal trauma in the United States. Treatment options include intramedullary (IM) as well as plate and screw (PS) constructs. The purpose of this study was to analyze the biomechanical stability of a specific IM system compared with nonlocking PS fixation under low-threshold physiologic load.

METHODS

Twenty fourth-generation Sawbones (Pacific Research Laboratories, Vashon, WA, USA) with a simulated middle-third fracture pattern were repaired with either an IM device (n = 10) or superiorly positioned nonlocking PS construct (n = 10). Loads were modeled to simulate physiologic load. Combined axial compression and torsion forces were sequentially increased until failure. Data were analyzed on the basis of loss of rotational stability using 3 criteria: early (10°), clinical (30°), and terminal (120°).

RESULTS

No significant difference was noted between constructs in early loss of rotational stability (P > .05). The PS group was significantly more rotationally stable than the IM group on the basis of clinical and terminal criteria (P < .05 for both). All test constructs failed in rotational stability.

CONCLUSIONS

When tested under physiologic load, fixation failure occurred from loss of rotational stability. No statistical difference was seen between groups under early physiologic loads. However, during load to failure, the PS group was statistically more rotationally stable than the IM group. Given the clavicle's function as a bony strut for the upper extremity and the biomechanical results demonstrated, rotational stability should be carefully considered during surgical planning and postoperative advancement of activity in patients undergoing operative fixation of middle-third clavicle fractures.

LEVEL OF EVIDENCE

Basic Science Study; Biomechanics.

A hybrid approach to mid-shaft clavicle fixation

BACKGROUND

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

METHOD

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

RESULTS

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

CONCLUSION

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

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.

Dual mini-fragment plating for midshaft clavicle fractures: a clinical and biomechanical investigation

BACKGROUND

We sought to evaluate clinical and biomechanical outcomes of dual mini-fragment plate fixation for clavicle fractures. We hypothesized that this technique would produce an anatomical reduction with good clinical outcomes, be well tolerated by patients, and demonstrate equivalent biomechanics to single plating.

METHODS

Dual mini-fragment plating was performed for 17 isolated, displaced midshaft clavicle fractures. Functional outcomes and complications were retrospectively reviewed. A sawbones model compared dual plating biomechanics to a (1) superior 3.5-mm locking reconstruction plate, or (2) antero-inferior 3.5-mm locking reconstruction plate.

RESULTS

On biomechanical testing, with anterior loading, dual plating was significantly more rigid than single locked anterior-plating (p = 0.02) but less rigid than single locked superior-plating (p = 0.001). With superior loading, dual plating trended toward higher rigidity versus single locked superior-plating (p = 0.07) but was less rigid than single locked anterior-plating (p = 0.03). No statistically significant differences in axial loading (p = 0.27) or torsion (p = 0.23) were detected. Average patient follow-up was 16.1 months (12-38). Anatomic reduction was achieved and maintained through final healing (average 14.7 weeks). No patient underwent hardware removal. Average 1-year DASH score was 4.0 (completed in 88 %).

CONCLUSIONS

Displaced midshaft clavicle fractures can be effectively managed with dual mini-fragment plating. This technique results in high union rates and excellent clinical outcomes. Compared to single plating, dual plating is biomechanically equivalent in axial loading and torsion, yet offers better multi-planar bending stiffness despite the use of smaller plates. This technique may decrease the need for secondary surgery due to implant prominence and may aid in fracture reduction by buttressing butterfly fragments in two planes.

A biomechanical comparison of four different fixation methods for midshaft clavicle fractures

Clavicle fractures may occur in all age groups, and 70%-80% of clavicle fractures occur in the midshaft. Many methods for treating midshaft clavicular fractures have been reported and remain controversial. To provide some guidance for clinical treatment, 30 artificial polymethyl methacrylate models of the clavicle were sewn obliquely at the midshaft to simulate the most common type of clavicular fractures, and the fracture models were divided into five groups randomly and were fixed as follows: the reconstruction plates were placed at the superior position of the fracture model (R-S group), the reconstruction plates were placed at the anteroinferior position of the fracture model (R-AI group), the locking plates were placed at the superior position (L-S group), the locking plates were placed at the anteroinferior position (L-AI group); and the control models were unfixed (control group). The strain gauges were attached to the bone surface near the fracture fragments, and then, the biomechanical properties of the specimens were measured using the compression test, torsion test and three-point bending test. The results showed that plate fixation can provide a stable construct to help with fracture healing and is the preferred method in the treatment of clavicle fractures. The locking plate provides the best biomechanical stability when placed at the anteroinferior position, and this surgical method can reduce the operation time and postoperative complications; thus, it would be a better choice in clinical practice.

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.

Biomechanical comparison of two locking plate constructs under cyclic torsional loading in a fracture gap model. Two screws versus three screws per fragment

OBJECTIVES

The number of locking screws required per fragment during bridging osteosynthesis in the dog has not been determined. The purpose of this study was to assess the survival of two constructs, with either two or three screws per fragment, under cyclic torsion.

METHODS

Ten-hole 3.5 mm stainless steel locking compression plates (LCP) were fixed 1 mm away from bone surrogates with a fracture gap of 47 mm using two bicortical locking screws (10 constructs) or three bicortical locking screws (10 constructs) per fragment, placed at the extremities of each LCP. Constructs were tested in cyclic torsion (range: 0 to +0.218 rad) until failure.

RESULTS

The 3-screws constructs (29.65 ± 1.89 N.m/rad) were stiffer than the 2-screws constructs (23.73 ± 0.87 N.m/rad), and therefore, were subjected to a greater torque during cycling (6.05 ± 1.33 N.m and 4.88 ± 1.14 N.m respectively). The 3-screws constructs sustained a significantly greater number of cycles (20,700 ± 5,735 cycles) than the 2-screws constructs (15,600 ± 5,272 cycles). In most constructs, failure was due to screw damage at the junction of the shaft and head. The remaining constructs failed because of screw head unlocking, sometimes due to incomplete seating of the screw head prior to testing.

CLINICAL SIGNIFICANCE

Omitting the third innermost locking screw during bridging osteosynthesis led to a reduction in fatigue life of 25% and construct stiffness by 20%. Fracture of the screws is believed to occur sequentially, starting with the innermost screw that initially shields the other screws.

Unicortical versus bicortical locked plate fixation in midshaft clavicle fractures

Higher rates of poor outcomes in displaced midshaft clavicle fractures treated nonoperatively have recently been reported. Along with expanding indications for operative fixation and increasing application of locked plate constructs, it is unknown whether complications related to bicortical penetration of the clavicle can be avoided using unicortical fixation. The purpose of this study is to compare the biomechanical properties of unicortical and bicortical fixation in precontoured vs manually contoured locking clavicle plates. Forty-eight Sawbone composite human clavicle specimens (item #3408; Pacific Research Laboratories, Vashon, Washington) with a midshaft clavicle osteotomy were reduced and plated in 8 specimens each using a bicortical and unicortical fixation for each of 3 locked plate constructs (3.5-mm LCP Reconstruction Plate; 3.5-mm LCP Superior Clavicle Plate; 3.5-mm LCP Superior Anterior Clavicle Plate; Synthes, Inc, West Chester, Pennsylvania). Specimens were tested for stiffness in axial torsion and cantilever bending and then loaded to failure in 3-point bending. Data were analyzed using 2-way analysis of variance and Tukey's test (P<.05). No significant differences were found between unicortical and bicortical fixation in failure load, cantilever bending, and cross body stiffness. Bicortical fixation was significantly stiffer than unicortical fixation in torsion only for the same plates. Significant differences also existed between plates in torsion. Unicortical locked plate fixation may be a reasonable option in the treatment of displaced midshaft clavicle fracture fixation to avoid complications associated with posteroinferior hardware penetration following clavicle fracture fixation based on the biomechanical performance of these constructs. However, it remains unclear whether these differences will be clinically significant.

Single, superiorly placed reconstruction plate compared with flexible intramedullary nailing for midshaft clavicular fractures: a prospective, randomized controlled trial

BACKGROUND

Previous studies have shown good clinical results in patients with midshaft clavicular fractures treated with reconstruction plate fixation or elastic stable intramedullary nailing. The objective of this study was to compare these methods in terms of clinical and radiographic results.

METHODS

In this prospective, randomized controlled trial, fifty-nine patients with displaced midshaft clavicular fractures were randomly assigned to receive fixation with either a reconstruction plate (thirty-three patients), known as the plate group, or elastic stable intramedullary nailing (twenty-six patients), known as the nail group. The primary outcome was the six-month Disabilities of the Arm, Shoulder and Hand (DASH) score. The secondary outcomes included the Constant-Murley score, time to fracture union, residual shortening, level of postoperative pain, percentage of satisfied patients, and complication rates.

RESULTS

The mean six-month DASH score was 9.9 points in the plate group and 8.5 points in the nail group (p = 0.329). Similarly, there were no differences in the twelve-month DASH and Constant-Murley scores. Time to union was equivalent (p = 0.352) between the groups at 16.8 weeks for the plate group and 15.9 weeks for the nail group, whereas the residual shortening was 0.4 cm greater in the plate group (p = 0.032). The visual analog scale pain score and the satisfaction rate were similar between the groups. Implant-related pain was more frequent in the nail group (p = 0.035). There were no differences in terms of major complications.

CONCLUSIONS

Reconstruction plates and elastic stable intramedullary nailing yielded similar functional results, time to union, level of postoperative pain, and patient satisfaction rates. Both methods were safe in terms of major complications.

Strength analysis of clavicle fracture fixation devices and fixation techniques using finite element analysis with musculoskeletal force input

In the cases, when clavicle fractures are treated with a fixation plate, opinions are divided about the best position of the plate, type of plate and type of screw units. Results from biomechanical studies of clavicle fixation devices are contradictory, probably partly because of simplified and varying load cases used in different studies. The anatomy of the shoulder region is complex, which makes it difficult and expensive to perform realistic experimental tests; hence, reliable simulation is an important complement to experimental tests. In this study, a method for finite element simulations of stresses in the clavicle plate and bone is used, in which muscle and ligament force data are imported from a multibody musculoskeletal model. The stress distribution in two different commercial plates, superior and anterior plating position and fixation including using a lag screw in the fracture gap or not, was compared. Looking at the clavicle fixation from a mechanical point of view, the results indicate that it is a major benefit to use a lag screw to fixate the fracture. The anterior plating position resulted in lower stresses in the plate, and the anatomically shaped plate is more stress resistant and stable than a regular reconstruction plate.

Hot topics in biomechanically directed fracture fixation

The evolution of locking plates and modern nail constructs provides the orthopaedic trauma surgeon with a myriad of options with regard to implant selection for common fractures. There is a significant amount of biomechanical literature comparing modern constructs with those conventionally used. A basic understanding of this literature is required to make informed decisions with regard to implant selection in the management of these injuries. This article reviews the most recent biomechanical literature regarding implant selection and application for a variety of commonly treated injuries, including fractures of the clavicle, proximal humerus, distal humerus, intertrochanteric hip region, distal femur, and bicondylar tibial plateau.

Impact of tunnels and tenodesis screws on clavicle fracture: a biomechanical study of varying coracoclavicular ligament reconstruction techniques

PURPOSE

The purpose of this study was to compare the load to fracture of distal clavicles with no tunnels, one tunnel, or 2 tunnels and to evaluate the effect of inserting tenodesis screws in the tunnels on load to fracture of the distal clavicle.

METHODS

Fifty right sawbone clavicles were obtained and divided into 5 groups (n = 10): group 1, normal clavicle; group 2, one tunnel, no tenodesis screw; group 3, 2 tunnels, no tenodesis screws; group 4, one tunnel with tenodesis screw; and group 5, 2 tunnels with 2 tenodesis screws. Tunnels were created using a 5-mm-diameter reamer, and 5.5 × 10 mm polyethyl ethyl ketone tenodesis screws were used. A 4-point bending load was applied to the distal clavicles. Load to failure was noted for each specimen.

RESULTS

Load to failure in clavicles without tunnels was significantly higher (1,157.18 ± 147.10 N) than in all other groups (P < .0005). No statistical differences were noted between groups 2, 3, 4, and 5. Load to failure was not statistically different in clavicles with one versus 2 tunnels. In addition, the use of tenodesis screws in the tunnels did not affect the load required to fracture.

CONCLUSIONS

The use of tunnels in the clavicle for coracoclavicular (CC) ligament reconstruction significantly reduces the load required to fracture the distal clavicle. The addition of tenodesis screws does not appear to significantly increase the strength of the clavicle in this construct.

CLINICAL RELEVANCE

CC ligament reconstruction techniques commonly use tunnels in the distal clavicle, which may render the clavicle more susceptible to fracture. This study helps quantify the effect of these tunnels on the strength of the distal clavicle.

Superior versus anteroinferior plating of clavicle fractures

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

Biomechanical comparison of the Locking Compression superior anterior clavicle plate with seven and ten hole reconstruction plates in midshaft clavicle fracture stabilisation

PURPOSE

The purpose of this study was to characterise the biomechanical properties of the seven hole superior anterior clavicle LCP (locking compression plate) and to compare these with the properties of commonly applied implants used for the stabilisation of clavicular midshaft fractures such as the locking 7- and ten hole reconstruction plate.

METHODS

Twenty-four synthetic clavicles were used. A transverse midshaft fracture was induced. The clavicles were fixed with angle stable clavicle LCPs, seven hole and ten hole reconstruction plates (n = 8 each). Twenty cycles of axial compression and torsion were performed for each sample, which was followed by 1,000 cycles of three point bending and ultimately bending to failure. Axial, torsional and cantilever bending stiffness were calculated from the data recorded.

RESULTS

The clavicle LCP showed the highest overall stiffness compared to the seven and ten hole reconstruction plate. Significantly higher stiffness values were found for axial compression and external rotation. In the load-to-failure tests, the ten hole reconstruction plate especially showed early signs of plastic deformation, which might account for early plate insufficiency so frequently observed clinically.

CONCLUSION

The results indicate that the clavicle LCP, as compared to the reconstruction plates, leads to superior biomechanical stability in the treatment of midshaft clavicle fractures.

Comparison of dynamic and locked compression plates for treating midshaft clavicle fractures

The purpose of this study was to compare the parameters of perioperative course and cost-effectiveness for patients with midshaft clavicle fractures treated by dynamic compression plates or locked compression plates.This retrospective, case-controlled study involved 54 patients with midshaft clavicle fractures who received dynamic compression plates (n=21) or locked compression plates (n=33) between January 2002 and December 2008. Indications for surgery included displacement or shortening >2 cm, comminuted fractures, and skin tenting. Patients with previous malunion, nonunion, multiple injuries of the shoulder girdle, or open fractures were excluded. Preoperative demographics showed no statistically significant differences between the 2 groups. Eighteen patients with dynamic compression plates and 28 patients with locked compression plates with postoperative follow-up >1 year were included for comparison. Statistical analyses for operative time, blood loss, complication rate, hospital stay, and union rate demonstrated no statistically significant difference between the 2 groups. The only statistically significant difference was a higher rate of plate removal requests in the dynamic compression plate group. Considering medical expenditure, locked compression plates cost 6 times more than dynamic compression plates in the authors' institution (US $600 vs $100, respectively).Other than more plate removal requests in the dynamic compression plate group and greater expense in the locked compression plate group, dynamic compression plates and locked compression plates achieved satisfactory operative outcomes in treating midshaft clavicle fractures, with no statistically significant difference between perioperative course and eventual fracture union observed between the 2 groups.