Background: The optimal course of treatment for moderate to severe stable slipped capital femoral epiphysis [SCFE] is still up for debate. There are a few acknowledged drawbacks to in situ pinning in these situations. Because of this, a number of writers have begun to contemplate using a modified Dunn technique on such individuals.
Aim: This study aimed to analyze literature comparing modified Dunn's approach and percutaneous in situ fixation in patients with moderate or severe SCFE
Methods: A search strategy was formulated firstly then we used it on different databases such as PubMed, Web of Science, Cochrane Library, and Scopus to reach the studies compared the modified Dunn procedure versus in situ fixation for SCFE. Screening was done followed by data extraction and statistical analysis of the outcomes.  
Results: The literature search process yielded 802 records. After primary and secondary screening the, meta-analysis incorporated six studies. The meta-analysis of avascular necrosis, based on data from four trials including a total of 240 patients, did not show a preference for either of the two groups [RR 2.95, 95% CI [0.55 to 15.72], P=0.21].
Conclusion: The clinical outcomes in the short- to medium-term were comparable between patients with moderate to severe SCFE who underwent in situ fixation and those who underwent the modified Dunn's operation.