title: [Treatment of patellofemoral osteoarthritis with patello-femoral joint arthroplasty].
abstract: OBJECTIVE
  To study the outcome and surgical technique of patello-femoral joint arthroplasty (PFJ) for osteoarthritis of the knee.
  
  
  METHODS
  From January 2010 to June 2012, 17 patients (24 knees) with patello-femoral compartmental osteoarthritis treated by PFJ were reviewed retrospectively. There were 2 male patients (4 knees) and 15 female patients (15 knees), with an average age of (64 ± 9) years (52-77 years) . The mean body mass index was (24 ± 3) kg/m² (18.0-30.1 kg/m²) . Patients were asked to return for follow-up examinations at 3, 6 months and at every year after PFJ. The range of motion (ROM), visual analogue scale(VAS), Hospital for Special Surgery score (HSS score) , Feller patella score, quadriceps muscle strength were evaluated before and after PFJ. The paired sample t-test and one-way analysis of variance (ANOVA) with replicate measures were used to determine whether there were statistically significant differences between the mean data.
  
  
  RESULTS
  All of the patients were followed up for 18-47 months, with a mean time of (29 ± 10) months, 75.0% patients were satisfied with the outcome of this surgical procedure 1 year postoperative, and 87.5% were satisfied 2 years postoperative. HSS score was increased from 61 ± 11 to 90 ± 6 at the final follow-up (t = 12.24, P = 0.000). VAS score was reduced from 6.7 ± 1.0 to 2.4 ± 1.0 (t = 15.84, P = 0.000). The mean post-operative ROM of the knees was 126° ± 7° (t = 3.25, P = 0.003). Feller patella scores were 18.0 ± 3.2 before operation, and 18.5 ± 4.5, 19.7 ± 3.4, 24.0 ± 3.8, 26.0 ± 3.3, 26.6 ± 2.5 at 3, 6, 12, 24 months after operation, final follow-up, respectively. Quadriceps muscle strength were 3.9 ± 0.5 before operation, and 3.7 ± 0.5, 3.9 ± 0.5, 4.2 ± 0.5, 4.3 ± 0.5, 4.3 ± 0.5 at 3, 6, 12, 24 months after operation, final follow-up, respectively. Repeated measures ANOVA found significant time effects for Feller patella scores (F = 38.97, P = 0.000) and quadriceps muscle (F = 6.89, P = 0.000). Feller patella scores and quadriceps muscle strength were low at 3, 6 months after operation, with no significant differences compared with pre-operation data (P > 0.05). The improvements of Feller patella scores and quadriceps muscle strength after 6 months were of significant difference compared with pre-operation and postoperative 6 months data (t = 5.65-10.65 and t = 2.18-2.73, P < 0.05) . Three knee reported continuing pains with quadriceps muscle strength less than 4 level.
  
  
  CONCLUSIONS
  PFJ is an effective method for patello-femoral compartmental osteoarthritis with less trauma. The early term outcome of PFJ is encouraging. Quadriceps muscle strength should be enhanced.
authors.affiliation: Department of Joint Surgery, China-Japan Friendship Hospital, Beijing 100029, China.
authors.forename: Qidong
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Department of Joint Surgery, China-Japan Friendship Hospital, Beijing 100029, China. Email:guowanshou@263.net.
authors.forename: Wanshou
authors.initials: W
authors.lastname: Guo
authors.affiliation: Department of Joint Surgery, China-Japan Friendship Hospital, Beijing 100029, China.
authors.forename: Zhaohui
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Department of Joint Surgery, China-Japan Friendship Hospital, Beijing 100029, China.
authors.forename: Liming
authors.initials: L
authors.lastname: Cheng
authors.affiliation: Department of Joint Surgery, China-Japan Friendship Hospital, Beijing 100029, China.
authors.forename: Debo
authors.initials: D
authors.lastname: Yue
authors.affiliation: Department of Joint Surgery, China-Japan Friendship Hospital, Beijing 100029, China.
authors.forename: Weiguo
authors.initials: W
authors.lastname: Wang
authors.affiliation: Department of Joint Surgery, China-Japan Friendship Hospital, Beijing 100029, China.
authors.forename: Nianfei
authors.initials: N
authors.lastname: Zhang
authors.affiliation: Department of Joint Surgery, China-Japan Friendship Hospital, Beijing 100029, China.
authors.forename: Zhencai
authors.initials: Z
authors.lastname: Shi
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000601:surgery*; D057071:Patellofemoral Joint / Q000601:surgery*; D012189:Retrospective Studies; D016896:Treatment Outcome