Abstract: We included seven studies that involved a total of 444 adults with distal femur fractures. Each of the included studies was small and assessed to be at substantial risk of bias, with four studies being quasi-randomised and none of the studies using blinding in outcome assessment. All studies provided an incomplete picture of outcome. Based on GRADE criteria, we assessed the quality of the evidence as very low for all reported outcomes, which means we are very uncertain of the reliability of these results. One study compared surgical (dynamic condylar screw (DCS) fixation) and non-surgical (skeletal traction) treatment in 42 older adults (mean age 79 years) with displaced fractures of the distal femur. This study, which did not report on PROMs, provided very low quality evidence of little between-group differences in adverse events such as death (2/20 surgical versus 1/20 non-surgical), re-operation or repeat procedures (1/20 versus 3/20) and other adverse effects including delayed union. However, while none of the findings were statistically significant, there were more complications such as pressure sores (0/20 versus 4/20) associated with prolonged immobilisation in the non-surgical group, who stayed on average one month longer in hospital. The other six studies compared different surgical interventions. Three studies, including 159 participants, compared retrograde intramedullary nail (RIMN) fixation versus DCS or blade-plate fixation (fixed-angle devices). None of these studies reported PROMS relating to function. None of the results for the reported adverse events showed a difference between the two implants. Thus, although there was very low quality evidence of a higher risk of re-operation in the RIMN group, the 95% confidence interval (CI) also included the possibility of a higher risk of re-operation for the fixed-angle device (9/83 RIMN versus 4/96 fixed-angle device; 3 studies: RR 1.85, 95% CI 0.62 to 5.57). There was no clinically important difference between the two groups found in quality of life assessed using the 36-item Short Form in one study (23 fractures). One study (18 participants) provided very low quality evidence of there being little difference in adverse events between RIMN and non-locking plate fixation. One study (53 participants) provided very low quality evidence of a higher risk of re-operation after locking plate fixation compared with a single fixed-angle device (6/28 locking plate versus 1/25 fixed-angle device; RR 5.36, 95% CI 0.69 to 41.50); however, the 95% CI also included the possibility of a higher risk of re-operation for the fixed-angle device. Neither of these trials reported on PROMs. The largest included study, which reported outcomes in 126 participants at one-year follow-up, compared RIMN versus locking plate fixation; both implants are commonly used in current practice. None of the between-group differences in the reported outcomes were statistically significant; thus the CIs crossed the line of no effect. There was very low quality evidence of better patient-reported musculoskeletal function in the RIMN group based on Short Musculoskeletal Function Assessment (0 to 100: best function) scores (e.g. dysfunction index: MD -5.90 favouring RIMN, 95% CI -15.13 to 3.33) as well as quality of life using the EuroQoL-5D Index (0 to 1: best quality of life) (MD 0.10 favouring RIMN, 95% CI -0.01 to 0.21). The CIs for both results included a clinically important effect favouring RIMN but also a clinically insignificant effect in favour of locking plate fixation. This review highlights the major limitations of the available evidence concerning current treatment interventions for fractures of the distal femur. The currently available evidence is incomplete and insufficient to inform current clinical practice. Priority should be given to a definitive, pragmatic, multicentre randomised controlled clinical trial comparing contemporary treatments such as locked plates and intramedullary nails. At minimum, these should report validated patient-reported functional and quality-of-life outcomes at one and two years. All trials should be reported in full using the CONSORT guidelines.

Plain-language summary: We searched the scientific literature up to September 2014 and found seven relevant studies with 444 participants with these fractures. One study compared surgery with non-surgical treatment and the other six studies compared the use of different surgical implants. Each of the studies was small and was designed in a way that may affect the reliability of their findings. Most studies did not report on patient-reported outcomes measures of function. We judged the quality of the reported evidence was very low and thus we are not certain that these results are true. The study comparing surgical fixation with non-surgical intervention (traction and wearing a brace) did not confirm there was any difference between the two treatments in terms of re-operations or repeat traction and bone healing. However, there were more complications such as pressure sores associated with prolonged immobilisation in the traction group, who stayed on average one month longer in hospital. Five studies compared one type of nail versus one of three different types of plate fixation. One study compared locked with non-locked plate fixation. The evidence available for the four comparisons did not confirm that any of the surgical implants were superior to any other surgical implant for any outcomes, including re-operation for complications such as lack of bone healing and infection. The review found that the available evidence was very limited and insufficient to inform current clinical practice. Further research comparing commonly used surgical treatments is needed.