Conservative interventions for diaphyseal fractures of the forearm bones in children
Abstract
This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:
To assess the effects of different conservative interventions for diaphyseal forearm fractures in children, including adolescents.
Background
Description of the condition
Fractures of one or both forearm bones (radius and ulna) are common injuries in children. A survey of paediatric fractures in Edinburgh in 2000 found diaphyseal (shaft) fracture of the forearm bone was the sixth most common fracture, amounting to 5.4% of fractures in children under 16 years of age (Rennie 2007a). Nearly twice as many males as females incurred these fractures, which occurred at an average age of 7.8 years. The majority of fractures resulted from falls.
Diaphyseal or shaft fractures of the radius and ulna are defined as those occurring between the proximal (upper) and distal (lower) metaphyses of each bone. (Metaphyses are the diverging areas of bone between the diaphysis (shaft) and the physes (growth plates)). A commonly used method to classify diaphyseal forearm fractures in children is the descriptive labelling into (1) bone ‐ single, i.e. radius or ulna; (2) level of fracture ‐ upper, mid or lower third; and (3) pattern of fracture ‐ plastic deformation (the bone bends but does not break), greenstick (one side of the bone is broken while the other is bent), complete, and comminuted (splintered or crushed into several pieces) (Van Herpe 1976). Radius and ulna fractures are also classified as 22‐D and its subtypes according to the Pediatric Expert Group of the AO Foundation and the International Association for Pediatric Traumatology's AO Paediatric comprehensive classification of long bone fractures (Slongo 2006).
Injuries associated with these fractures include elbow or wrist trauma and neurological injuries. One serious complication arising from closed management is Volkmann's ischaemia, also referred to as a compartment syndrome, where there is a lack of blood flow due to increased tissue pressure, perhaps from overly tight bandages, often resulting in contractures of the forearm muscles. Other complications include infection in open injuries, nerve damage (neuropraxia), malunion, stiffness or rigidity (ankylosis) of the elbow or wrist joints, cross‐union, re‐fracture and reflex sympathetic dystrophy (now generally termed complex regional pain syndrome type 1).
Description of the intervention
Forearm fractures in children are traditionally and predominantly treated with closed reduction (external manipulation to restore alignment of fracture fragments) and immobilisation, usually with plaster casts that immobilise the elbow in flexion (Ouattara 2007). Loss of reduction (redisplacement) has been recorded in 7% to 13%, with rates as high as 62% for older children (Kay 1986).
Plastic deformations of diaphyseal fractures of the forearm occur in children aged up to 10 years of age and are frequently missed. The treatment for these involves gradual reduction over a sandbag or rolled towel; this procedure is often successful in reversing the deformation. Vorlat 2003, in a study in children aged six years or over, reported that greater than 10 degrees of plastic deformation in either the radius or ulna resulted in an unacceptable outcome. Price 2001 has published limits of angulation and malrotation for an acceptable outcome in displaced fractures. These were 15 degrees and 45 degrees respectively in children aged under nine years, and 10 and 30 degrees respectively in children aged over nine years.There is a general consensus that greenstick and undisplaced fractures in children should be managed conservatively. In the greenstick fracture, where one cortex is broken and the opposite cortex is bent, the surgeon may purposefully complete the break as this may decrease the tendency for the fracture to deform.
There is debate on the degree of rotation of the forearm that is required for immobilisation after reduction of forearm fractures. Distal radius fractures (those close to the wrist) are usually immobilised in the prone position (palm faces downwards and the radius and ulna are crossed), whereas proximal radius fractures (those closer to the elbow) are generally immobilised in the supine position (palm faces upwards and the forearm bones are not crossed). Less commonly, proximal forearm fractures are immobilised in a cast extending above the elbow, with the elbow in extension.
Traditionally, the material favoured for casting is plaster of Paris. More recently, as many as eight synthetic casting materials have been reported in use (Bowker 1992). These are more expensive than plaster of Paris casts, but may be considered appropriate when there is a high probability of structural failure of a plaster cast (Marshall 1992).
How the intervention might work
In adults, almost all displaced diaphyseal fractures of forearm are now treated surgically. Children differ from adults because of their growth potential and the mechanical properties of their bones. Their bones have the ability to heal faster and are capable of a greater degree of remodelling, thereby allowing for minor degrees of malreduction (imperfect restoration of anatomy) during treatment. As described above, acceptable limits of angulation and malrotation between fracture fragments have been proposed (Price 2001).
This 'remodelling capacity' means that a satisfactory outcome from closed reduction and external immobilisation such as plaster of Paris casts and splints is achievable. Open fractures necessitate surgical intervention to debride (clean) the wound; however, even in these situations, closed treatment of fractures can be undertaken. Redisplacement may occur in unstable fractures and is usually discovered by inspection of radiographs carried out within the first two weeks (Bochang 2008).
Casting techniques involve the reduction of the displaced fracture and holding the fractured ends of the bone in place by neutralising deforming muscle forces. The position of bones is maintained by carefully moulding the cast (shaping the cast) to fit snugly around the forearm and applying appropriate corrective pressure. A well‐moulded cast which snugly fits the forearm is considered essential for maintaining reduction, and in order for healing without deformity to occur (Webb 2006). Theoretically, casting with the elbow in extension eliminates the deforming force of gravity and the supination pull of the biceps, thus helping to maintain the reduction, especially in children with unstable fractures (Bochang 2005; Shaer 1999). However, elbow stiffness and sliding of the cast distally are recorded drawbacks of casting with the elbow in the extended position. There is some evidence that the 'cast index', which is a measure of the moulding of a cast at the fracture site, can be used to predict redisplacement of forearm fractures (Singh 2008).
Usually, surgical intervention is indicated where closed reduction is unsuccessful or for unstable fractures. A Cochrane systematic review evaluating surgical interventions in paediatric forearm fractures is in progress (Abraham 2009).
Why it is important to do this review
The vast majority of these common injuries in children are managed conservatively. However, the results are not always satisfactory and it is important to assess the role of modifiable factors, such as the positions of the elbow and of the forearm in the cast, in order to prevent treatment failures and complications, and to ensure good functional recovery.
Objectives
To assess the effects of different conservative interventions for diaphyseal forearm fractures in children, including adolescents.
Methods
Criteria for considering studies for this review
Types of studies
Included will be randomised or quasi‐randomised controlled trials (trials where the method of allocating participants to a treatment is not strictly random and where allocation can be predicted: e.g. by date of birth, hospital record number, alternation).
Types of participants
Children, including adolescents, with diaphyseal fractures of the forearm (either of the radius or ulna, or both). We will exclude Monteggia and Galeazzi fractures. Fractures of the distal radius and ulna are excluded also: these are reviewed in Abraham 2008.
Types of interventions
Conservative interventions included in this review include the following categories.
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Method of reduction for displaced fractures.
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'Completing the fracture' (extending the fracture to the opposite cortex or breaking the intact opposite cortex) of greenstick fractures versus control.
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Extent of cast: above elbow versus below elbow.
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Forearm position in cast: e.g. extension versus flexion casting techniques; supination versus pronation flexion casting techniques.
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Type of cast material: synthetic versus plaster of Paris.
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Duration of immobilisation.
Types of outcome measures
Primary outcomes
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Measures, preferably validated, of musculoskeletal function in children such as the PODCI (Paediatric Outcome Data Collection Instrument) (Daltroy 1998) or Daruwalla Score (Daruwalla 1979).
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Treatment failure (composite outcome defined as either the need for a second procedure (reduction or surgical intervention) or the presence of a malunion (defined as radiological angular or rotational deformity beyond acceptable range for age) (Beaty 2001).
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Serious adverse effect: compartment syndrome, elbow and forearm (supination and pronation) ankylosis, complex regional pain syndrome type 1 and refractures.
Secondary outcomes
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Minor functional impairment (e.g. stiffness of elbow, wrist and hand).
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Minor complications (e.g. cast slippage, skin breakage).
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Costs and use of resources (economic analysis, if reported).
We will consider grouping outcomes under short term (less than three months) and longer term (preferably one year or more) follow‐up.
Search methods for identification of studies
Electronic searches
We will search the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (to present), the Cochrane Central Register of Controlled Trials (The Cochrane Library current issue), MEDLINE (1950 to present), EMBASE (1980 to present), CINAHL (1982 to present) and reference lists of articles. No language restrictions will be applied. In MEDLINE a subject‐specific strategy will be combined with the Cochrane Highly Sensitive Search Strategy for identifying randomised trials in MEDLINE: sensitivity‐maximizing version (Lefebvre 2009) and modified for use in other databases (seeAppendix 1).
We will also search the WHO International Clinical Trials Registry Platform and the metaRegister of Controlled Trials (mRCT) for ongoing and recently completed trials.
We plan to search available online conference proceedings of the Paediatric Orthopaedic Society of India, Paediatric Orthopaedic Society of North America, the paediatric section of Asia Pacific Orthopaedic Association, and the European Pediatric Orthopaedic Society for randomised controlled trials of conservative interventions in diaphyseal fractures of forearm bones in children.
Searching other resources
We will attempt to contact experts in the field and the contact authors of identified trials for information on existing or ongoing trials.
Data collection and analysis
Selection of studies
Two authors (AG and VD) will independently assess potentially eligible trials for inclusion. Full texts of trials that fulfil our inclusion criteria and those that are unclear from perusal of the abstracts will be obtained. Any disagreements will be resolved through discussion and, where necessary, consultation with a third author (VM). Where necessary, we will attempt to contact trial authors for clarification of study methods and characteristics.
Data extraction and management
All authors will independently extract information on study characteristics and results using a piloted data extraction form. Any disagreement will be resolved through discussion. We will attempt to contact trial authors where there are incomplete details on study methods or data.
Assessment of risk of bias in included studies
All authors will independently assess the risk of bias in each included trial using The Cochrane Collaboration's 'Risk of bias' assessment tool (Higgins 2008a) on the following six domains: sequence generation, allocation concealment, blinding or masking, incomplete outcome data, selective outcome reporting, and other biases (seeAppendix 2). We will consider subjective outcomes (e.g. pain, patient‐reported function) and 'hard' outcomes (e.g. adverse events) separately in our assessment of blinding and completeness of outcome data. Other biases will include assessment of bias resulting from major imbalances in key baseline characteristics (e.g. isolated versus combined fractures, age and gender); and performance bias such as resulting from lack of comparability in the experience of care providers. We will attempt to contact the trial authors for clarification when methodological details are unclear. We will resolve differences by discussion.
For each of these six domains, we will assign a judgement regarding the risk of bias as 'yes' for low risk, 'no' for high risk, or 'unclear' based on the criteria summarised in Table 8.5.c of the Cochrane Handbook (Higgins 2008a). We will record these assessments in the standard 'risk of bias' tables in RevMan 5 (Review Manager 2008), and summarise them in 'risk of bias' summary figures and graph. We will use these judgements when assessing limitations in study design of the trials contributing to important outcomes in 'Summary of findings' tables.
Measures of treatment effect
We will calculate risk ratios (RR) and 95% confidence intervals (95% CI) for dichotomous outcomes and mean differences (MD) with 95% confidence intervals for continuous outcomes.
Unit of analysis issues
Though the unit of randomisation in these trials is usually the individual patient, trials including children with bilateral fractures may present results for fractures or limbs rather than for individual patients. Where such unit of analysis issues arise and appropriate corrections have not been made, we will consider presenting the data for such trials where the disparity between the units of analysis and randomisation is small. Where data are pooled, we will perform a sensitivity analysis to examine the effects of excluding incorrectly reported trials from the analysis.
Dealing with missing data
We shall attempt to obtain missing data from trial authors. Where possible, we will extract data to allow an intention‐to‐treat analysis in which all randomised participants are analysed in the groups to which they were originally assigned. If there is discrepancy in the number randomised and the numbers analysed in each treatment group, we will calculate the percentage loss to follow‐up in each group and report this information. If drop‐outs exceed 10% for any trial, we shall assign the worst outcome to those lost to follow‐up for dichotomous outcomes and assess the impact of this in sensitivity analyses with the results of completers. Where possible, we will calculate missing standard deviations from other available data such as standard errors (Higgins 2008b). However, we will not impute missing values in order to present these in the analyses. We shall not make any assumptions about loss to follow‐up for continuous data and shall analyse results for those who completed the trial.
Assessment of heterogeneity
We will judge the appropriateness of pooling by assessing clinical heterogeneity in terms of the trial participants, interventions and outcomes of the included studies. We will assess heterogeneity between trials by visual examination of the forest plot, primarily to check for overlapping confidence intervals, and using the Chi² test for homogeneity and the I² statistic to assess inconsistency (the percentage of the variability in effect estimates that is due to heterogeneity rather than random error). We will base our judgements of substantial heterogeneity on the advice provided by Deeks 2008 on interpreting Chi² and I² values.
Assessment of reporting biases
We plan to reduce reporting bias by: a) performing a comprehensive search for published, unpublished and ongoing trials; b) placing no language restrictions on the search strategy; c) checking for multiple trial reports of the same trial; (d) attempting to obtain the protocol or the trial registration document of trials; and e) contacting the authors in cases where the pre‐specified primary (favourable or adverse) outcomes are not reported.
We will assess all included studies for adequacy of reporting of data for pre‐stated outcomes and for selective reporting of outcomes. We shall incorporate judgements about reporting biases in the risk of bias assessments for each trial.
We will assess the likelihood of potential publication bias using funnel plots, provided that there are at least 10 trials assessing particular outcomes.
Data synthesis
If considered appropriate, results of comparable groups of trials will be pooled. Initially we will use the fixed‐effect model and 95% confidence intervals. We will also consider using the random‐effects model, especially where there is substantial and/or unexplained heterogeneity.
Continuous data measured using the same scale will be combined using the mean difference. The standardised mean difference (SMD) will be used where data are measured on different scales that cannot be calculated back to a common scale. If the scales used in the trials differ in the direction of scoring, then the mean values from one set of scales will be multiplied by ‐1 in order to ensure that the direction of scores across trials are comparable (Deeks 2008). We will attempt to interpret the combined standardised mean differences by re‐expressing them as odds ratios and numbers needed to treat or harm using the methods described in Schünemann 2008.
Subgroup analysis and investigation of heterogeneity
If substantial heterogeneity is present (e.g. I² ≥ 75%) and cannot be explained by differences across the trials in terms of clinical or methodological features or by subgroup analyses (see below), we will not combine the trials in a meta‐analysis, but will present the results in a forest plot.
If data permit, the following subgroup analysis will be done for each comparison:
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Fracture of radius or ulna versus fracture of both bones
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Site of fracture: upper, mid or lower third
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Age: age less than 5 years, 6 to 10 years and more than 11 years
For fixed‐effect meta‐analyses, we will assess subgroup differences by interaction tests (Altman 2003). For random‐effects meta‐analyses, we will use non‐overlapping confidence intervals to indicate a statistically significant difference in treatment effect between the subgroups.
Sensitivity analysis
We will conduct sensitivity analyses to investigate the robustness of the results for the primary outcomes by excluding trials at high risk of bias.
We shall also undertake sensitivity analyses if trials report dropout rates of 10% or greater, to ascertain differences in outcomes of intention‐to‐treat (ITT) analysis (all dropouts will be assigned to the worst outcome for dichotomous outcomes) and analysis of completers.
If significant heterogeneity is detected and if one or two outlying studies with results that conflict with the other studies are identified to have clinical or methodological characteristics that differ from the other trials, we shall perform analyses with and without these outlying studies as part of a sensitivity analysis.
Summarising and interpreting results
We shall use the GRADE approach to interpret findings (Schünemann 2008) and use GRADE Profiler (GRADE 2004) to import data from RevMan 5 (Review Manager 2008) to create 'Summary of findings' tables for each comparison. These tables will provide information concerning the quality of the evidence, the magnitude of effect of the interventions examined, and the sum of available data on all primary outcomes and for the secondary outcomes of wrist and hand stiffness, re‐fractures, reflex sympathetic dystrophy and satisfaction outcome scores from each included study in the comparison.
