title: Arthroscopic treatment of femoroacetabular impingement shows persistent clinical improvement in the mid-term.
abstract: BACKGROUND
  The concept of femoroacetabular impingement (FAI) and the indication for surgical intervention have been established in the last decade. Despite promising short-term results and emerging arthroscopic techniques, it remains unclear whether patients benefit from surgical correction in the mid- to long-term and whether progressive joint degeneration can be prevented.
  
  
  METHODS
  A retrospective study of our first 50 consecutive patients who underwent arthroscopic correction for FAI was conducted. The modified Harris hip score (mHHS) was assessed preoperatively and at final follow-up. In addition, the Western Ontario and McMaster Universities osteoarthritis index (WOMAC) and a subjective hip value (SHV) were added at final follow-up. Degenerative changes according to Kellgren and Lawrence scale and the α angle were analyzed preoperatively and on the most recent radiograph.
  
  
  RESULTS
  Of a total of 50 patients, 44 (24 male, 20 female) with a mean age of 34.3 years (17-65) were available with complete follow-up. Of these 44 patients, 39 were treated with correction of the femoral offset for isolated cam deformity, 5 with additional focal pincer correction and partial labral resection. After a mean follow-up of 66.3 ± 14.5 months the mHHS had improved significantly from 67.2 ± 6.4 preoperatively to 86.4 ± 13.5 (p < 0.001). The WOMAC score (converted to 0 = best/100 = worst) resulted in mean indices for the subcategories pain, stiffness and function of 11.8 ± 16.5, 12.2 ± 17.8 and 9.1 ± 16.1. The SHV was reported with a mean of 77.7 ± 21.8 % at final follow-up. The α angle was reduced significantly from 57.2° ± 10.1° to 46.3° ± 7.4° (p < 0.001). The Kellgren and Lawrence score showed a non-significant trend from 2.0 ± 0.8 preoperatively to 2.2 ± 0.9 in the most recent radiograph (p = 0.46). 5 patients had been converted to a total hip arthroplasty a mean of 28 ± 7.1 months postoperatively. These patients were significantly (p < 0.01) older with a mean age of 49.8 ± 7.8 years and showed significantly higher present osteoarthritic changes with an average Kellgren and Lawrence score of 2.6 ± 2.5 before FAI correction (p < 0.01).
  
  
  CONCLUSIONS
  Arthroscopic correction of femoroacetabular impingement results in a persistent clinical improvement without significant progression of degenerative changes in the majority of patients. The indication for surgery should be established cautiously when degenerative changes are present.
  
  
  METHODS
  Level IV, Case series with no comparison group.
authors.affiliation: Center for Musculoskeletal Surgery, Charité-University Medicine, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353, Berlin, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Hufeland
authors.affiliation: Center for Musculoskeletal Surgery, Charité-University Medicine, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353, Berlin, Germany.
authors.forename: David
authors.initials: D
authors.lastname: Krüger
authors.affiliation: Center for Musculoskeletal Surgery, Charité-University Medicine, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353, Berlin, Germany.
authors.forename: Norbert Peter
authors.initials: NP
authors.lastname: Haas
authors.affiliation: Center for Musculoskeletal Surgery, Charité-University Medicine, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353, Berlin, Germany.
authors.forename: Carsten
authors.initials: C
authors.lastname: Perka
authors.affiliation: Center for Musculoskeletal Surgery, Charité-University Medicine, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353, Berlin, Germany. joerg.schroeder@charite.de.
authors.forename: Jörg Hartmut
authors.initials: JH
authors.lastname: Schröder
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip; D001182:Arthroscopy; D005260:Female; D057925:Femoracetabular Impingement / Q000000981:diagnostic imaging / Q000601:surgery*; D005269:Femur / Q000601:surgery; D005500:Follow-Up Studies; D006621:Hip Joint / Q000000981:diagnostic imaging / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D011859:Radiography; D012189:Retrospective Studies; D016896:Treatment Outcome; D055815:Young Adult
keywords: Arthroscopy; Femoroacetabular impingement; Hip joint; Osteoarthritis; Sports medicine