Abstract: We included 10 trials (six randomised and four quasi-randomised) involving a total of 527 children (531 fractures). All trials were at some risk of bias, including performance bias as care provider blinding was not practical, but to a differing extent. Just one trial was at low risk of selection bias. Reflecting both the risk of bias and the imprecision of findings, we judged the quality of evidence to be 'low' for most outcomes, meaning that we are unsure about the estimates of effect. Most trials failed to report on self-assessed function or when children resumed their usual activities. The trials evaluated 10 different comparisons, belonging to three main categories. Surgical versus conservative treatment Four trials presenting data for 264 children aged 4 to 12 years made this comparison. Low quality evidence (one trial, 101 children) showed children had very similar function assessed using the RAND health status score at two years after surgery (external fixation) compared with conservative treatment (spica cast): mean 69 versus 68. The other three trials did not report on function. There was moderate quality evidence (four trials, 264 children, aged 4 to 12 years, followed up 3 to 24 months) that surgery reduced the risk of malunion (risk ratio (RR) 0.29, 95% confidence interval (CI) 0.15 to 0.59, 4 trials). Assuming an illustrative baseline risk of 115 malunions per 1000 in children treated conservatively, these data equate to 81 fewer (95% CI 47 to 97 fewer) malunions per 1000 in surgically-treated children. Conversely, low quality evidence indicated that there were more serious adverse events such as infections after surgery (RR 2.39, 95% CI 1.10 to 5.17, 4 trials). Assuming an illustrative baseline risk of 40 serious adverse events per 1000 for conservative treatment, these data equate to 56 more (95% CI 4 to 167 more) serious adverse events per 1000 children treated surgically. There was low quality evidence (one trial, 101 children) of similar satisfaction levels in children and parents with surgery involving external fixation and plaster cast only. However, there was low quality evidence (one trial, 46 children) that more parents were satisfied with intramedullary nailing than with traction followed by a cast, and that surgery reduced the time taken off from school. Comparisons of different methods of conservative treatment The three trials in this category made three different comparisons. We are very unsure if unacceptable malunion rates differ between immediate hip spica versus skeletal traction followed by spica in children aged 3 to 10 years followed up for six to eight weeks (RR 4.0, 95% CI 0.5 to 32.9; one trial, 42 children; very low quality evidence). Malunion rates at 5 to 10 years may not differ between traction followed by functional orthosis versus traction followed by spica cast in children aged 5 to 13 years (RR 0.98, 95% CI 0.46 to 2.12; one trial, 43 children; low quality evidence). We are very unsure (very low quality evidence) if either function or serious adverse events (zero events reported) differ between single-leg versus double-leg spica casts (one trial, 52 young children aged two to seven years). Low quality evidence on the same comparison indicates that single-leg casts are less awkward to manage by parents, more comfortable for the child and may require less time off work by the caregiver. Comparisons of different methods of surgical treatment The three trials in this category made three different comparisons. Very low quality evidence means that we are very unsure if the rates of malunion, serious adverse events, time to return to school or parental satisfaction actually differ in children whose fractures were fixed using elastic stable intramedullary nailing or external fixation (one trial, 19 children). The same applies to the rates of serious adverse events and time to resume full weight-bearing in children treated with dynamic versus static external fixation (one trial, 52 children). Very low quality evidence (one trial, 47 children) means that we do not know if malunion, serious adverse events and time to resume weight-bearing actually differ between intramedullary nailing versus submuscular plating. However, there could be more difficulties in plate removal subsequently. There is insufficient evidence to determine if long-term function differs between surgical and conservative treatment. Surgery results in lower rates of malunion in children aged 4 to 12 years, but may increase the risk of serious adverse events. Elastic stable intramedullary nailing may reduce recovery time. There is insufficient evidence from comparisons of different methods of conservative treatment or of different methods of surgical treatment to draw conclusions on the relative effects of the treatments compared in the included trials.

Plain-language summary: We searched for studies in the medical literature until August 2013. The review includes 10 randomised or quasi-randomised controlled trials that recruited 527 children. Four trials compared different surgical versus non-surgical treatments; three compared different methods of non-surgical treatment and three compared different methods of surgical treatment. Generally we are unsure about the results of these trials because some were at risk of bias, some results were contradictory and usually there was too little evidence to rule out chance findings. Most trials failed to report on self-assessed function or when children resumed their usual activities. Comparing surgical versus non-surgical treatment Low quality evidence (one trial, 101 children) showed children had similar function at two years after having surgery, involving external fixation, compared with those treated with a plaster cast. The other three trials did not report this outcome. There was moderate quality evidence (four trials, 264 children, aged 4 to 12 years, followed up for 3 to 24 months) that surgery reduced the risk of malunion (the leg is deformed) compared with non-surgical treatment. However, low quality evidence (four trials) indicated that there were more serious adverse events such as infections after surgery. There was low quality evidence (one trial, 101 children) of similar satisfaction levels in children and parents with surgery involving external fixation and plaster cast only. However, there was low quality evidence (one trial, 46 children) that more parents were satisfied with surgery involving an internal nail than with traction followed by a cast and that surgery reduced the time taken off from school. Comparing various non-surgical treatments Very low quality evidence means that we are very unsure if the rates of malunion differ or not between children treated with immediate plaster casts versus with traction followed by plaster cast (one trial, 42 children), or between children treated with traction followed by either a functional orthosis (a brace or cast that allows some movement) or a cast (one trial, 43 children). We are very unsure if either function or serious adverse events differ between young children (aged two to seven years) immobilised in single-leg versus double-leg casts (one trial, 52 children). However, single-leg casts appear to be easier to manage by parents and more comfortable for the child. Comparing various surgical treatments Very low quality evidence means that we are very unsure if the rates of malunion, serious adverse events, time to return to school or parental satisfaction actually differ in children whose fractures were fixed using internal nails or external fixation (one trial, 19 children). The same applies to the rates of serious adverse events and time to resume full weight-bearing in children treated with dynamic (less rigid) versus static external fixation (one trial, 52 children). Very low quality evidence (one trial, 47 children) means that we do not know if malunion, serious adverse events and time to resume weight-bearing actually differ between intramedullary nailing versus submuscular plating. However, there could be more difficulties in plate removal subsequently. Conclusions This review found insufficient evidence to determine if long-term function differs between surgical and conservative treatment of thigh bone fractures in children aged 4 to 12 years. It found surgery resulted in lower rates of malunion but increased the risk of serious adverse events, such as infections. It found internal nailing may speed up recovery. The review found there was insufficient evidence from comparisons of different methods of non-surgical treatment to clearly show that any type of non-surgical treatment is better than any other. The same conclusion applies to comparisons of different methods of surgical treatment.