Introduction: The management of the small unstable subgroup of slipped upper femoral epiphysis is controversial. This group has a high risk of developing avascular necrosis. Clinicians are keen to treat in a way as to not contribute to this risk, but the optimum treatment pathway is unclear in the literature.

Meta analysis of the available data was done to address two main areas of concern with regards to treatment: Reduction and the timing of treatment.

Methods: Review of the literature revealed 4 relevant studies (with 85 patients) that met the inclusion criteria, which contained adequate data allowing comparison between two patient groups regarding the role of reduction and 5 studies (with 130 patients) regarding the timing of treatment.

Results: All studies were retrospective reviews; no relevant randomised controlled trials have been performed. Analysis of the collected data gave an odds ratio of 2.204 with regards to reduction. Compilation of the data available therefore favoured the unreduced group. They had a lower risk of developing avascular necrosis. In the analysis relating to timing of treatment, there was an odds ratio of 0.591. This showed the evidence in the literature to favour the group treated in less than 24 hours from symptom onset.

Conclusions: Following discussion of the results, it was concluded that reduction should always be undertaken cautiously as it has an association with increased AVN. The ideal time for management is within 24 hours of symptom onset. There are suggestions in the literature that if this is not possible, it should be postponed for one week.