title: Midterm Outcomes of Reverse (Anteverting) Periacetabular Osteotomy in Patients With Hip Impingement Secondary to Acetabular Retroversion.
abstract: BACKGROUND
  There is a paucity of data on the results of reverse (anteverting) periacetabular osteotomy (RPAO) for treatment of femoroacetabular impingement (FAI) secondary to acetabular retroversion.
  
  
  OBJECTIVE
  To evaluate the midterm outcomes of RPAO for FAI secondary to acetabular retroversion in those with and without hip dysplasia.
  
  
  METHODS
  Cohort study; Level of evidence, 3.
  
  
  METHODS
  A retrospective review identified RPAOs performed on patients with acetabular retroversion in isolation or in the setting of dysplasia (lateral center-edge angle [LCEA] ≤19°). Acetabular retroversion with FAI was diagnosed clinically and radiographically, with a positive crossover and posterior wall signs on pelvic radiographs. Twenty-three patients (30 hips) met the inclusion criteria; 20 hips with isolated retroversion and 10 hips with retroversion and hip dysplasia. The average age at the time of the procedure was 26 years (range, 13-45 years). The average length of follow-up was 5 years (range, 2-19 years). Harris Hip Score (HHS) and radiographs were evaluated preoperatively and at last follow-up.
  
  
  RESULTS
  The mean preoperative LCEA was 31° (range, 22°-49°) in the isolated retroversion group and 9° (range, -4° to 17°) in the dysplastic group. Postoperatively, the LCEA in the dysplastic group increased to 35° (range, 15°-46°) (P = .0001). The crossover sign corrected in 55% (11/20) of the isolated retroversion group and 80% (8/10) of the dysplastic group. The acetabular index (mean ± SD) improved from 1.3 ± 0.3 to 1.7 ± 0.6 (P = .0001), indicating improved anteversion. At the latest follow-up, the average HHS in the isolated retroversion group increased from 58 preoperatively (range, 23-77) to 93 (range, 68-100) (P = .0001); the HHS in the dysplastic group improved from 49 (range, 20-74) to 92 (range, 77-100) (P < .0001). Complication rates were similar in both groups. Excluding hardware removal, additional surgeries were performed in 13% (4/30).
  
  
  CONCLUSIONS
  RPAO performed for FAI in the young patient with isolated acetabular retroversion or retroversion in the setting of dysplasia successfully improved clinical and radiographic results at mid- to long-term follow-up.
authors.affiliation: Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Joshua A
authors.initials: JA
authors.lastname: Parry
authors.affiliation: Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Russell P
authors.initials: RP
authors.lastname: Swann
authors.affiliation: Department of Orthopedic Surgery, University of Utah, Salt Lake City, Utah, USA.
authors.forename: Jill A
authors.initials: JA
authors.lastname: Erickson
authors.affiliation: Department of Orthopedic Surgery, University of Utah, Salt Lake City, Utah, USA.
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Peters
authors.affiliation: Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Robert T
authors.initials: RT
authors.lastname: Trousdale
authors.affiliation: Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota, USA sierra.rafael@mayo.edu.
authors.forename: Rafael J
authors.initials: RJ
authors.lastname: Sierra
mesh_terms: D000077:Acetabulum / Q000601:surgery*; D000293:Adolescent; D000328:Adult; D001696:Biomechanical Phenomena; D005260:Female; D057925:Femoracetabular Impingement / Q000175:diagnosis / Q000601:surgery*; D005500:Follow-Up Studies; D006617:Hip Dislocation / Q000601:surgery; D006618:Hip Dislocation, Congenital / Q000175:diagnosis / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010027:Osteotomy / Q000379:methods; D012189:Retrospective Studies; D055815:Young Adult
keywords: acetabular retroversion; femoroacetabular impingement; hip dysplasia; periacetabular osteotomy