title: Does the Hip Capsule Remain Closed After Hip Arthroscopy With Routine Capsular Closure for Femoroacetabular Impingement? A Magnetic Resonance Imaging Analysis in Symptomatic Postoperative Patients.
abstract: OBJECTIVE
  The purpose of this study was to examine the hip capsule in a subset of symptomatic patients who underwent capsular closure during hip arthroscopy.
  
  
  METHODS
  All patients undergoing primary hip arthroscopy for femoroacetabular impingement (FAI) with routine capsular closure between January 1, 2012, and December 31, 2015, were eligible. Only patients with unilateral surgery and a postoperative magnetic resonance imaging (MRI; ordered for persistent symptoms) were included. Four independent reviewers evaluated each hip capsule for thickness and the absence or presence of defects.
  
  
  RESULTS
  During the study, 1,463 patients had hip arthroscopy for FAI with routine capsular closure, and 53 (3.6%) underwent a postoperative MRI. Fourteen of the 53 were excluded owing to revision status or additional procedures. The final study population included 39 patients (23 female patients and 16 male patients), with an average patient age of 31.7 ± 11.4 years and an average body mass index of 23.3 ± 2.9. There were 3 (7.5%) capsular defects, and the intraclass correlation coefficient (ICC) was 0.82. The operative hip capsule was significantly thicker in the zone of capsulotomy, and subsequent repair as compared with the unaffected, contralateral hip capsule (5.0 ± 1.2 mm vs 4.6 ± 1.4 mm; P = .02), ICC 0.83. Additionally, males had thicker hip capsules as compared with their female counterparts, on the operative side (5.4 ± 1.1 mm vs 4.5 ± 1.2 mm; P = .02) and the nonoperative side (4.8 ± 1.6 mm vs 4.1 ± 0.9 mm; P = .08).
  
  
  CONCLUSIONS
  In a subset of symptomatic patients after hip arthroscopy for FAI, the majority (92.5%) of the repaired hip capsules remained closed at greater than 1 year of follow-up. The hip capsule adjacent to the capsulotomy and subsequent repair is thickened compared with the same location on the contralateral, nonoperative hip. Aside from gender, patient-related and FAI-related factors do not correlate with capsular thickness nor do they seem to correlate with the propensity to develop a capsular defect.
  
  
  METHODS
  Level IV, prognostic case series.
authors.affiliation: Section of Young Adult Hip Surgery, Division of Sports Medicine, Department of Orthopedic Surgery, Rush Medical College of Rush University, Chicago, Illinois, U.S.A.. Electronic address: weber.ae@gmail.com.
authors.forename: Alexander E
authors.initials: AE
authors.lastname: Weber
authors.affiliation: Section of Young Adult Hip Surgery, Division of Sports Medicine, Department of Orthopedic Surgery, Rush Medical College of Rush University, Chicago, Illinois, U.S.A.
authors.forename: Benjamin D
authors.initials: BD
authors.lastname: Kuhns
authors.affiliation: Section of Young Adult Hip Surgery, Division of Sports Medicine, Department of Orthopedic Surgery, Rush Medical College of Rush University, Chicago, Illinois, U.S.A.
authors.forename: Gregory L
authors.initials: GL
authors.lastname: Cvetanovich
authors.affiliation: Department of Radiology, University of Illinois Hospital, Chicago, Illinois, U.S.A.
authors.forename: Paul B
authors.initials: PB
authors.lastname: Lewis
authors.affiliation: Section of Sports Medicine, Department of Orthopedic Surgery, Duke University Medical Center, Durham, North Carolina, U.S.A.
authors.forename: Richard C
authors.initials: RC
authors.lastname: Mather
authors.affiliation: Division of Sports Medicine, Department of Orthopedics, University Hospital, Case Western Reserve University School of Medicine, Cleveland, Ohio, U.S.A.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Salata
authors.affiliation: Section of Young Adult Hip Surgery, Division of Sports Medicine, Department of Orthopedic Surgery, Rush Medical College of Rush University, Chicago, Illinois, U.S.A.
authors.forename: Shane J
authors.initials: SJ
authors.lastname: Nho
mesh_terms: D000328:Adult; D001182:Arthroscopy / Q000009:adverse effects* / Q000379:methods; D005260:Female; D057925:Femoracetabular Impingement / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000209:etiology; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000209:etiology; D011859:Radiography; D012189:Retrospective Studies; D014481:United States / Q000453:epidemiology; D014945:Wound Healing