title: Severity of Asynchronous Slipped Capital Femoral Epiphyses in Skeletally Immature Versus More Skeletally Mature Patients.
abstract: BACKGROUND
  Routine prophylactic screw fixation for skeletally immature patients with slipped capital femoral epiphysis (SCFE) continues to be debated. The purpose of this study was to assess the slip severity of a second SCFE in skeletally immature versus more mature patients and determine necessity of contralateral hip prophylactic screw fixation.
  
  
  METHODS
  All patients treated for SCFE at 3 pediatric hospitals over a 10-year time period (January 1, 2002 to December 31, 2011) were evaluated. Patients were included if they had a unilateral SCFE and a contralateral asynchronous SCFE, and were divided into immature (Oxford triradiate score 1) versus more mature (Oxford triradiate score 2 and 3) groups. Data evaluation included age, time between slips, body mass index, Southwick angles of first then second SCFEs, and follow-up duration.
  
  
  RESULTS
  There were a total of 45 patients: 16 patients in the skeletally immature and 29 patients in the more mature group. Average age at first SCFE in immature patients was 10.9 years and in more mature patients 12.1 years (P=0.70). Age at second SCFE in immature patients was 11.5 years and in more mature patients 13.0 years (P=0.023). Average time between SCFEs was 6.6 months for immature and 11.4 months for more mature patients (P=0.093). Southwick angles for immature patient first and second SCFEs were 25 and 12.9 degrees, respectively, and for more mature patient first and second SCFEs were 31 and 21 degrees, respectively. Southwick angles were higher at first and second slips in the more mature group, significant only at the second slip (P=0.032). SCFE severity at initial event was predictive of severity of second SCFE regardless of maturity (P=0.043). Regression analysis of slip severity against multiple patient factors demonstrated triradiate score was not a factor assessing subsequent SCFE magnitude (P=0.099).
  
  
  CONCLUSIONS
  There was no significant difference between first and second SCFEs regardless of skeletal maturity but severity of initial SCFE did correlate with severity of the second SCFE. Deciding not to prophylactically pin an unaffected hip does not lead to worse deformity if a second SCFE occurs in skeletally immature or more mature patients, unless the initial event is severe. Prophylactic pin fixation in skeletally immature patients should occur as a shared decision between patient, guardians, and treating surgeon.
  
  
  METHODS
  Level III-retrospective comparative study.
authors.affiliation: *Department of Pediatric Orthopaedic Surgery, Helen Devos Children's Hospital, Michigan State University College of Human Medicine, Grand Rapids ‡Department of Orthopaedic Surgery, University of Michigan §Department of Orthopaedic Surgery, University of Michigan Health System, Ann Arbor, MI †Department of Orthopaedic Surgery, University of New Mexico, Albuquerque, NM.
authors.forename: Philip D
authors.initials: PD
authors.lastname: Nowicki
authors.forename: Selina
authors.initials: S
authors.lastname: Silva
authors.forename: Lisa
authors.initials: L
authors.lastname: Toelle
authors.forename: Greg
authors.initials: G
authors.lastname: Strohmeyer
authors.forename: Trevor
authors.initials: T
authors.lastname: Wahlquist
authors.forename: Ying
authors.initials: Y
authors.lastname: Li
authors.forename: Frances A
authors.initials: FA
authors.lastname: Farley
authors.forename: Michelle S
authors.initials: MS
authors.lastname: Caird
mesh_terms: D000293:Adolescent; D000367:Age Factors; D002648:Child; D002657:Child Development; D005260:Female; D005269:Femur / Q000254:growth & development / Q000601:surgery; D006801:Humans; D008297:Male; D019637:Orthopedic Procedures / Q000009:adverse effects / Q000379:methods / Q000706:statistics & numerical data; D010043:Outcome and Process Assessment, Health Care; D065286:Prophylactic Surgical Procedures / Q000009:adverse effects / Q000379:methods / Q000706:statistics & numerical data; D011859:Radiography / Q000379:methods; D012189:Retrospective Studies; D012307:Risk Factors; D060048:Slipped Capital Femoral Epiphyses / Q000175:diagnosis / Q000601:surgery