Malunion of the distal radius in children: accurate prediction of the expected remodeling.

J A Van Der Sluijs,J L Bron

doi:10.1007/s11832-016-0741-9

J A Van Der Sluijs, J L Bron

Open Access

https://doi.org/10.1007/s11832-016-0741-9

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Abstract

PurposeMalunions of fractures in children have a natural tendency to remodel. However, quantitative data of this well-known process are scarce. The extent of the correction depends inter alia on the type of bone and the location of the deformity and growth remaining. The aim of this study was to quantify the remodeling process of distal radius malunions in children to allow better future prediction.MethodsData were derived from two published patient series. Analysis included 63 malunions of distal radius fractures in 62 children (38 boys), with a mean age of 8.5 years (range 2–14.5 years).ResultsThe mean initial dorsovolar angulation was 25º [standard deviation (SD) 7.8°], remodeling time 22 (SD 18) months, and angulation at follow-up 6.7° (SD 5.8°). Based on these findings, the remodeling process can be described as an exponential function with angulation (A0) as a factor and the remodeling time (RT) as a negative exponent of e (R2 = 0.47). The function allows accurate prediction of the expected correction in over 76 % of the malunions. From this model, a formula was derived for calculation of the time needed for complete remodeling, but this formula lacked precision when compared to findings in the literature and needs to be validated.ConclusionsThe remodeling of distal radius malunions can be described as an exponential function with starting speed dependent on the initial angulation. The current model proves to be more accurate than models described previously in the literature. These findings allow for better patient information and optimal planning of eventual surgical intervention. The postulated model could serve as a basis for the description of correction of other malunions by adaptation of the coefficients in this model.

Highlights

Distal radius fractures are the most common fractures occurring in childhood and a substantial proportion of these patients will develop malunions initially
The remodeling process can be described as an exponential function with angulation (A0) as a factor and the remodeling time (RT) as a negative exponent of e (R2 = 0.47)
A formula was derived for calculation of the time needed for complete remodeling, but this formula lacked precision when compared to findings in the literature and needs to be validated

Summary

Introduction

Distal radius fractures are the most common fractures occurring in childhood and a substantial proportion of these patients will develop malunions initially. Malunions in children often show a tremendous remodeling potential and initial treatment can usually be restricted to the reassurance of the parents of the involved child. This is a well-known practice for most doctors treating children with fractures, surprisingly few studies (n = 7) are available with quantitative data on the dynamics of remodeling. Reported remodeling times (RT) to full correction vary between a mean of 4 months [1,2,3] and 5 years [4] in the literature. The speed of remodeling has been shown to vary between 0.9° to 2.5°/month [5,6,7]. Greater angulated fractures tend to remodel at a faster rate [5, 7]

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