Immediate Versus Semi-Elective Treatment of Stable Slipped Capital Femoral Epiphyses (SCFE)

Background/Objectives: Timing of fixation of stable slipped capital femoral epiphysis (SCFE) is controversial. As pressure mounts to limit inpatient admissions and procedures, our aim was to investigate whether treatment of SCFE in a delayed manner is a safe alternative to immediate fixation. Our hypothesis was that there would be no difference in complications for stable slips treated immediately (<24 h) versus semi-electively (>24 h) with screw fixation. Methods: A retrospective review was performed at two academic institutions during a 10-year-period yielding 91 SCFEs. Data collected included patient demographics, time to treatment, radiographic measurements (Southwick angle), and complications. Between-group analysis was performed using Welch's t-test and Fisher's exact test. Results: 91 stable SCFEs were identified with a median age of 12.3 years (IQR: 11.4-13.3). A total of 62 (68%) slips were treated immediately while 29 (32%) were treated in a semi-elective manner with a median time from diagnosis to surgery of 4 days (range: 2-11 days). There were no instances of >18° increase in Southwick angle in either group or conversion from stable to unstable slips during the semi-elective period. Overall, 12 (13%) patients experienced complications, but no difference in complication rate was observed between groups (15% vs. 10%, p = 0.75). However, the complication profile varied between groups. Of note, two patients (2%, 2/91) experienced AVN, both of which were treated in a semi-elective manner and underwent in situ pinning. Conclusions: There was no difference in complication rate between stable SCFEs treated immediately or semi-electively; however, the complication profile differed by group. No SCFEs in either group had >18° worsening of the Southwick angle between the time of diagnosis and the time of fixation and there were no conversions of stables slips to unstable slips while waiting for semi-elective surgery. These findings suggest that performing semi-elective surgical fixation within 11 days of diagnosing stable, mild SCFEs appears to be a safe alternative to inpatient admission at the time of diagnosis.