title: What is the evidence supporting the prevention of osteoarthritis and improved femoral coverage after shelf procedure for Legg-Calvé-Perthes disease?
abstract: BACKGROUND
  The evidence supporting continued use of shelf acetabuloplasty in Legg-Calvé-Perthes disease (LCPD) is not well-defined, and there is controversy regarding the long-term benefits related to clinical and functional improvement.
  
  
  OBJECTIVE
  Our goals were to determine whether shelf arthroplasty for LCPD (1) prevents the onset of early osteoarthritis; (2) improves pain, ROM, activity, and functional outcomes; (3) maintains or improves femoral head containment, sphericity, and congruency; (4) changes the acetabular index; and (5) is associated with a low rate of complications.
  
  
  METHODS
  We performed a systematic review of the medical literature from 1966 to 2009 using the search terms Perthes, shelf procedure, and acetabuloplasty. We excluded reports using multiple/combined treatment methods and those not clearly stratifying outcomes. Thirteen studies met the criteria. There were no Level I studies, one Level II prognostic study, five Level III therapeutic studies, and seven Level IV studies. Mean followup ranged from 2.6 to 17.9 years.
  
  
  RESULTS
  Only one study reported progression to early osteoarthritis in one patient. We found no evidence for improvement in ROM and continued pain relief at long-term followup. Mean decrease in lateral subluxation ratio was 13% to 30%, demonstrating an improvement in femoral head containment. Mean acetabular cover percentage improved 16% to 38%, and mean acetabular and center-edge angles improved 4° to 14° and 8° to 33°, respectively. There were no reports of any major complications after the procedure.
  
  
  CONCLUSIONS
  While radiographic measurements indicate improved coverage of the femoral head after shelf acetabuloplasty for LCPD, available evidence does not document the procedure prevents early onset of osteoarthritis or improves long-term function.
authors.affiliation: Department of Orthopaedic Surgery, Hospital of the University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Jason E
authors.initials: JE
authors.lastname: Hsu
authors.forename: Keith D
authors.initials: KD
authors.lastname: Baldwin
authors.forename: Moritz
authors.initials: M
authors.lastname: Tannast
authors.forename: Harish
authors.initials: H
authors.lastname: Hosalkar
mesh_terms: D000077:Acetabulum / Q000000981:diagnostic imaging / Q000601:surgery*; D000293:Adolescent; D001696:Biomechanical Phenomena; D002648:Child; D002675:Child, Preschool; D019317:Evidence-Based Medicine; D005260:Female; D005270:Femur Head / Q000000981:diagnostic imaging / Q000601:surgery*; D006621:Hip Joint / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D007873:Legg-Calve-Perthes Disease / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D019637:Orthopedic Procedures / Q000009:adverse effects; D015207:Osteoarthritis, Hip / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D010149:Postoperative Pain / Q000209:etiology / Q000517:prevention & control; D011859:Radiography; D016059:Range of Motion, Articular; D020127:Recovery of Function; D013997:Time Factors; D016896:Treatment Outcome