Introduction
Clavicular fracture accounts for 2.6–10% of all fractures, and approximately 80% of the sites involved in adult patients were mid-shaft clavicle [
1-
4]. Furthermore, displacement occurs in over 70% of the mid-shaft clavicular fractures [
4,
5]. Traditionally, non-operative treatment has been labeled as the “standard” for mid-shaft fractures regardless of displacement, with the expectation that even severe radiographic malalignment would not influence functional results [
6]. However recently, increasing evidence has challenged this due to the relatively high incidence of complications, deficits in functional recovery in shoulder and disappointing cosmetic results in up to 30% of the patients sustaining mid-shaft clavicular fracture [
7-
9]. With recent advancement in technique and implants for fracture fixation, internal fixation is therefore generally considered as the better choice for these fractures and admirable outcomes have been observed. However, substantial controversies exist in surgeons regarding the optimal fixation pattern (plate or intramedullary fixation) for treating these injuries and further research is necessitated.
To date, there are various techniques for fixation of mid-shaft clavicle fractures including multiple forms of plating and intramedullary devices. For plating fixation (PF), precontoured locking plates (DCP) [
10,
11] and reconstruction plate [
12-
14] are the most commonly used devices. For intramedullary fixation (IF), the common devices in clinics are Knowles pinning [
14,
15], elastic stable intramedullary nailing [
12,
16], Rockwood Clavicle Pin (RCP) [
17,
18] and Acumed Clavicle Rod (ACR) [
17]. PF emerged as a popular technique affording a more rigid fixation that is necessitated for early rehabilitation protocols [
19]. Recently, precontoured plates that are designed to parallel the S-shaped curve of the clavicle have become popular alternatives. However, the advantages are compromised by extensive soft tissue dissection that potentially result in damage to the superior clavicular nerves and subsequent paresthesias, implant prominence, infection, scarring, hardware failure and refracture after the removal of the plate [
20-
23]. On the other hand, IF advantaged over PF in preserving the soft tissue envelope, periosteum, and vascular integrity [
24,
25] and even early hardware migration appears to be solved by improved device of locked IM, but the biomechanical property of less stability has to be addressed [
26].
Houwert et al [
27] and Barlow et [
28] conducted systematic reviews on related articles comparing both methods with equivocal conclusions. Duan et al [
29] conducted a meta-analysis with RCT studies, but only 2 studies were included to investigate the comparative outcomes between both methods. From then on, several original studies have been performed to address this key issue [
10,
14,
17,
21,
30,
31], which necessitated this updated meta-analysis.
Therefore, the purpose of this study is to evaluate whether one method of fixation is preferable over the other in terms of intraoperative variables, postoperative complications, shoulder motion and functional recovery for the treatment of acute mid-shaft clavicle fractures.
Discussion
Management of acute mid-shaft clavicular fractures in patients has been undergoing controversy on which fixation pattern was preferable when making a clinic decision. We therefore performed this systematic and meta-analysis from 13 studies including 457 IFs and 479 PFs to the compare the effectiveness and complications between the both techniques. In this meta-analysis, IF advantaged over PF groups with reduced surgery time, smaller incision, less blood loss and better functional recovery at 6-mon follow-up postoperatively. Meanwhile, the shoulder motion range was not significantly different in term of forward flexion, abduction, external rotation and internal rotation. Regarding postoperative complications, IF was confirmed to be associated with lower incidence of superficial infection, symptomatic hardware, hypertrophic scar and refracture after implant removal while not increasing the risk of implant failure, nonunion, malunion, delayed union, major revision needed and temporary brachial plexus lesion.
In regard to perioperative variables including surgery time, incision length and blood loss, significant heterogeneity was investigated due to the various types of intramedullary devices and plates. However, we did not perform corresponding sensitive analysis because of the reported significance by each study for any item; therefore the pooled results could be reliable and convincing. Although IF did outperform PF in the functional recovery with a higher should constant score at 6-mon follow-up, no significance was observed at 12- and 24-mon follow-up. Furthermore, regarding shoulder motion range at the last follow-up in each study, IFs performed similarly as PFs. Therefore, the rapid fracture union might contribute primarily to the functional recovery and shoulder motion at early-stage but did not work at late-stage.
Patients’ complication status was commonly documented in the literature, which was determined by patients’ systemic conditions (underlying disease), the local operation and the implant fixation per se. In this meta-analysis, participants included in each original study were almost young (mean age from 23.8 to 43.3), and the study which investigated only patients aged above 65 years was excluded from this meta-analysis at the literature-search stage. Therefore, underlying diseases might contribute little to the incidence of complications and the major causes for complications were operation and fixation pattern.
It is notable that, the refracture after hardware removal occurred only in PFs with the incidence rate of 6.3% (10/158) but none in IFs. In the study by Wijdicks et al [
31], two explanations are used by authors to clarify the causes: subsequent reduced mechanical strength after implant removal when fracture healing and the weak spots of the screw holes after implant removal both potentially initiated a refracture in thin clavicles. Implant failure is an important complication that necessitates secondary operation and causes over 80% of revisions [
31], but no significant difference was observed between both fixations. Despite this, the common implant failure modes are different. Wijdicks et al [
31] suggested intramedullary device’ movement restore the fracture segment to the original form and in PFs, the plate might bend or break due to excessive movement. Therefore, the favorable solutions for this might improve stability in IFs and reduce excessive movement in PFs especially in early-stage, postoperatively. In Harnroongroj’ and Lee’s studies, implant failure was attributed to the length of intramedullary pin engagement and small pin could provide better stability [
17,
39]. Authors suggested patients treated by PFs should gradually increase should motion range and keep within 90°during the first 3 weeks after surgery [
21]. However, different plates and pins were used in above-mentioned studies. Therefore, how to effectively prevent this complication in certain fixations is worth surgeons’ consideration and patients’ cooperation.
The present study suffers from some weaknesses. Firstly, most of the studies (9/13) in this meta-analysis were retrospective, case-control studies and only 4 RCTs were included, which might lower the assessing quality of this study. Secondly, the types of fixations applied in studies were varied and the follow-up periods in studies ranged largely from several months to years. Thirdly, the age between both fixations in most studies was comparable but not in all the studies, which might affect the results. Although with limitations that might lead to heterogeneity, no significant heterogeneity was observed in most variables except for several intraoperative items, indicating the results reliable. Due to the relative lower quality of studies, the conclusion should be treated cautiously and further prospective studies with better design should be performed to verify the conclusions.
This study has own merits. First, the search style based on the computer and manual search ensures a complete inclusion of relevant studies. Secondly, this meta-analysis to date gives a definitive conclusion of preference for either of the 2 methods in treatment of mid-shaft fractures, reflecting the current status on this issue.
In conclusion, IF advantaged over PF groups with reduced surgery time, smaller incision, less blood loss and better functional recovery at 6-mon follow-up postoperatively. Meanwhile, fewer superficial infections, symptomatic hardware, hypertrophic scar and refracture after implant removal occurred in IFs. Clinical decision should be skewed to IFs if medical conditions are indicated.
Competing interests
The authors declare that they have no competing interests.
Authors’ contributions
YZ designed the study; FZ and YT searched relevant studies and abstracted the data; WC analyzed and interpreted the data; BZ and YZ wrote the manuscript and YZ approved the final version of the manuscript. All authors read and approved the final manuscript.