title: Optimal patellar alignment with minimally invasive approaches in total knee arthroplasty after a minimum five year follow-up.
abstract: OBJECTIVE
  Patellofemoral syndrome is still a common complication after total knee arthroplasty (TKA). However, the effects of specific surgical approaches on patellar tracking and alignment remain incompletely understood. In this study, we compared patellar alignment in patients who underwent TKA via three different techniques.
  
  
  METHODS
  A total of 96 patients who completed a minimum follow-up of five years were involved in three groups: 30 patients were treated with the traditional medial parapatellar approach (MPP group), 35 patients were treated with the mini-medial parapatellar approach (MMP group) and 31 were treated with a quadriceps-sparing approach (QS group). Radiographic data for patellar alignment and clinical results were compared.
  
  
  RESULTS
  Patellar tilt and patellar displacement at the final follow-up evaluation differed significantly among the three groups [P < 0.01, analysis of variance (ANOVA)]. The MMP and QS groups exhibited more proper patellar alignment than the MPP group. The clinical results did not differ significantly among the groups (P > 0.05, ANOVA). In addition, there were no correlations between postoperative patellar alignment and clinical scores.
  
  
  CONCLUSIONS
  The results of this study indicate that TKA performed using minimally invasive approaches yields superior patellar alignment compared to the traditional MPP approach.
authors.affiliation: Institute of Sports Medicine, Peking University Third Hospital, No. 49, North Garden Road, Haidian District, Beijing, 100191, China.
authors.forename: Ai-Bing
authors.initials: AB
authors.lastname: Huang
authors.affiliation: Institute of Sports Medicine, Peking University Third Hospital, No. 49, North Garden Road, Haidian District, Beijing, 100191, China.
authors.forename: Hai-Jun
authors.initials: HJ
authors.lastname: Wang
authors.affiliation: Institute of Sports Medicine, Peking University Third Hospital, No. 49, North Garden Road, Haidian District, Beijing, 100191, China. yujiakuo@126.com.
authors.forename: Jia-Kuo
authors.initials: JK
authors.lastname: Yu
authors.affiliation: Institute of Sports Medicine, Peking University Third Hospital, No. 49, North Garden Road, Haidian District, Beijing, 100191, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Yang
authors.affiliation: Institute of Sports Medicine, Peking University Third Hospital, No. 49, North Garden Road, Haidian District, Beijing, 100191, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Ma
authors.affiliation: Institute of Sports Medicine, Peking University Third Hospital, No. 49, North Garden Road, Haidian District, Beijing, 100191, China.
authors.forename: Ji-Ying
authors.initials: JY
authors.lastname: Zhang
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000379:methods*; D020370:Osteoarthritis, Knee / Q000601:surgery*; D010329:Patella / Q000601:surgery*; D011184:Postoperative Period; D052097:Quadriceps Muscle / Q000601:surgery; D012189:Retrospective Studies
keywords: Minimally invasive surgery; Patellar alignment; Total knee arthroplasty