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
Authors: Lee Chihua , Feaker David A. , Ostrofe Amy A. , Smith Christopher S. 
Published: August 2019

Abstract

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.