To Bury or Not to Bury—Kirschner Wire Fixation in Children and Adolescents

There is still no consensus on whether Kirschner wires (K-wires) should be unburied (epicutaneous) or buried under the skin (subcutaneous) for fixation of fractures in children and adolescents. Despite recommendations for the use of unburied K-wires in the specialist literature, our own web-based survey on the reality of care in Germany showed that two-thirds of all K-wires used to stabilize distal radius fractures and supracondylar humerus fractures are buried under the skin (1). The reasons given for not using unburied wires were subjective factors, including fear of infection, the lack of acceptance of this technique, and possible additional traumatization of the child due to visible wires, as well as also purely organizational reasons, such as increased counseling efforts.

The aim of this prospective multicenter study was to compare both techniques in terms of complication rates, parental satisfaction, and potential psychological traumatization, using distal radius and supracondylar humerus fractures as examples.

Methods

All distal radius or supracondylar humerus fractures stabilized with a K-wire were prospectively recorded from eleven German clinics with expertise in pediatric trauma (members of the pediatric traumatology section of the German Society for Trauma Surgery). Each clinic carried out the surgical method that was commonly used in-house—that is, the K-wires were buried subcutaneously after reduction or left exposed (epicutaneous). Randomization was deliberately avoided in order to rule out complications due to a lack of experience with the respective method. During the course of treatment, all complications related to the wire position, such as infections, wire perforation, and soft tissue irritations, were recorded.

Unburied wires were removed on an outpatient basis without anesthesia during consultation hours, while subcutaneous wires were normally removed in the operating room under general anesthesia in day surgery conditions. After the metal removal, a questionnaire was sent to all families to evaluate the potential psychological distress of the children and the parents‘ satisfaction with the respective method. The study was carried out in accordance with the current version of the Declaration of Helsinki. Ethics votes from the responsible ethics committees of all participating clinics and the responsible Bavarian State Medical Association (ID 2017–011) are available.

SPSS 19.0 (SPSS, Chicago, IL, U.S.A.) was used for the statistical analysis of the results. The statistical evaluation for the group comparison for the individual question points on patient satisfaction was carried out using the Mann-Whitney U test, and the statistical comparison of the complications, using the chi-square test. The p-values calculated for descriptive interpretation were adjusted for multiple testing using the Bonferroni-Holm correction.

A total of 291 patients (166 distal radius fractures, 125 supracondylar humerus fractures) were analyzed. In 167 cases (57%), the K-wires were buried under the skin (distal radius n = 95 [57%], supracondylar humerus n = 72 [58%]), and were left epicutaneous in 124 (43%) cases (distal radius n = 71 [43 %], supracondylar humerus n = 53 [42 %]). There were slight age differences in the unburied group as compared to buried treatment group (distal radius: 10 ± 3/11 ± 3 years; supracondylar humerus: 6 ± 2/7 ± 3 years). There were no relevant differences between the treatment methods in terms of gender distribution.

No relevant differences were found between the two groups in terms of patient satisfaction (Table 1) or complication rates (Table 2). The parents and children in the unburied group reported more fear of the forthcoming removal of the K-wires without anesthesia than those in the subcutaneous comparison group with metal removal under anesthesia. The K-wire removal itself was equally well tolerated in both groups.

Table 1

Results of the parent survey on patient satisfaction (excerpt from a total of 18 questions to the parents)

Table 2

Complications associated with K-wire fixation

Discussion

Despite the obvious advantages of epicutaneous K-wire osteosynthesis, such as avoiding a second anesthetic, less effort for families and hospitals, and greater cost efficiency, there is still relatively little acceptance of this method in Germany as compared to other countries (1).

In the present study, we did not find any relevant differences between the two techniques in terms of complication rates, thus confirming the available literature (2, 3). To our knowledge, there are no randomized controlled studies on the use of the K-wire in children. The slightly increased incidence of neurological symptoms in the unburied technique used for supracondylar humerus fractures can most likely be attributed to a higher risk of ulnar nerve damage from percutaneous drill wire osteosynthesis. In contrast to what was assumed a priori, slightly higher infection rates were found in the buried group in this study. However, the infection rates of < 4% for both techniques were low overall and therefore of less relevance for the group comparison. In the opinion of the authors, the basic prerequisite for the uncomplicated use of the unburied technique is, in addition to the correct surgical technique, an adequate postoperative plaster application, with a plaster-free zone or sufficient padding.

Limitations

For the reasons mentioned, no randomization was carried out. There were also differences in the way the operation was performed and in the casting and bandaging techniques. Due to the young age of the children, conclusions about patient satisfaction can only be drawn indirectly from the parents.

Conclusion

No relevant differences in parental satisfaction or pain were found, which is consistent with the results of previous studies (4, 5). A quick and routine removal of unburied K-wires without anesthesia by a doctor who exudes confidence seems to us to be the decisive factor. When used correctly, outpatient removal of unburied K-wires is well tolerated. Both techniques are safe procedures for fractures in the growing age. The potential fear or pain associated with outpatient removal of unburied K-wires must be weighed against the fear, risk, effort, and cost of using the buried technique.

Conflict of interest statement
Oliver Loose and Michael Kertai are board members of the Li-La e. V. association, which supported the study with a research award.

The remaining authors declare that no conflict of interest exists.

Manuscript received on 29 March 2022, revised version accepted on 17 June 2022.

Translated from the original German by Veronica A. Raker, PhD.

Cite this as:
Schneidmueller D, Eijkenboom A, Brand A, Langenhan R, Kertai M, Voth M, Adrian M, Loose O, Bohn B, Wagner F, von Rüden C: To bury or not to bury—Kirschner wire fixation in children and adolescents. Dtsch Arztebl Int 2022; 119: 818 –9.
DOI: 10.3238/arztebl.m2022.0259

References

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