title: Survival and clinical results of a modified "crosse de hockey" procedure for chronic isolated patellofemoral joint osteoarthritis: mid-term follow-up.
abstract: BACKGROUND
  The optimum treatment for isolated patellofemoral joint osteoarthritis (PFJ-OA) remains controversial. The aim of this study was to assess the mid-term clinical results of a modified crosse de hockey procedure for the treatment of isolated PFJ-OA.
  
  
  METHODS
  We assessed 37 knees in 31 patients treated by a modified crosse de hockey procedure. The mean age was 57.6 years (range, 46-75 years) and mean follow-up was 90.1 months (range, 24-216 months). We evaluated clinical and radiographic outcomes, as well as complication rates at the mid-term follow-up.
  
  
  RESULTS
  The Kujala score (mean improvement of 46.7, P < 0.001) and the Fulkerson score (mean improvement of 19, P = 0.001) were significantly higher compared to preoperative values. Overall clinical results rated excellent in 24.3 %, very good in 21.6 %, good in 35.1 %, fair in 13.5 %, and poor in 5.4 % of knees. Patellar tilting (P = 0.015) and congruence angle (P = 0.018) significantly improved postoperatively. On the other hand, the Insall-Salvati index decreased at the time of follow-up, although it remained in the physiologic range. Postoperatively, consecutive disease progression in the tibiofemoral joint and patellofemoral joint osteoarthritis were 18.9 and 5.4 %, respectively. The operative complication rate was 5.4 % in this case series. These percentages were lower than those of alternative tibial tuberosity osteotomy techniques.
  
  
  CONCLUSIONS
  In most patients with chronic isolated PFJ-OA, tibial tuberosity osteotomy by modified crosse de hockey is a reliable procedure that provides good/excellent mid-term clinical results.
  
  
  METHODS
  Level IV.
authors.affiliation: Department of Orthopaedic Surgery, Juntendo University Urayasu Hospital, 2-1-1 Tomioka, Urayasu-shi, Chiba, 279-0021, Japan. hiroakimed@yahoo.co.jp.
authors.forename: Hiroaki
authors.identifier: http://orcid.org/0000-0003-1770-3899
authors.initials: H
authors.lastname: Kanazawa
authors.affiliation: Department of Orthopaedic Surgery, Juntendo University Urayasu Hospital, 2-1-1 Tomioka, Urayasu-shi, Chiba, 279-0021, Japan.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Maruyama
authors.affiliation: Department of Orthopaedic Surgery, Juntendo University Urayasu Hospital, 2-1-1 Tomioka, Urayasu-shi, Chiba, 279-0021, Japan.
authors.forename: Katsuo
authors.initials: K
authors.lastname: Shitoto
authors.affiliation: Tanaka Neurosurgical Hospital, 3-9-23, Seikimachi minami, Nerima-ku, Tokyo, 177-0053, Japan.
authors.forename: Minoru
authors.initials: M
authors.lastname: Yokoyama
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medicine, Juntendo University, 2-1-1, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Kaneko
mesh_terms: D000368:Aged; D002908:Chronic Disease; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000601:surgery*; D010027:Osteotomy; D057071:Patellofemoral Joint; D016059:Range of Motion, Articular; D013977:Tibia / Q000601:surgery*; D016896:Treatment Outcome
keywords: Chronic patella femoral joint osteoarthritis; Crosse de hockey procedure; Tibial tuberosity osteotomy