title: [EFFECTIVENESS OF KNEE EXTENSOR MECHANISM RECONSTRUCTION FOR RECURRENT PATELLAR SUBLUXATION WITH BONE ANCHOR IN ADOLESCENTS].
abstract: OBJECTIVE
  To explore the effectiveness of knee extensor mechanism reconstruction in the treatment of recurrent patellar subluxation with bone anchor in adolescents.
  
  
  METHODS
  Between January 2010 and December 2013, 20 patients with patellar subluxation were treated by knee extensor mechanism reconstruction with bone anchor. There were 11 males and 9 females, aged from 12 to 17 years (mean, 15.3 years). The left knee was involved in 12 cases and the right knee in 8 cases. The disease duration was 5-10 years (mean, 7 years). All the patients had knee pain and lateral subluxation of the patella. Preoperative Lysholm knee score was 71.4 ± 4.7. All the patients received the MRI examination to exclude menisci or ligaments lesion. CT examination showed the tibial tuberosity trochlear groove spacing ranged from 15 to 20 mm (mean, 17 mm). X-ray film examination indicated that no varus or valgus was observed, and bony structure was normal.
  
  
  RESULTS
  All the incisions healed at first stage. The patients received follow-up of 12-24 months (mean, 13 months). Knee pain occurred in 2 cases and were cured after symptomatic treatment. The axial X-ray films showed good position of the patella and normal anatomic relationship of the patellofemoral joint. No anchor loosening and pulling out, internal fixation failure, pseudoarthrosis formation, and postoperative recurrent patellar subluxation occurred during follow-up. At 1 year, the Lysholm knee score was significantly improved to 94.2 ± 3.4 (t = 22.705, P = 0.000). According to Insall criterion, the results were excellent in 9 cases, good in 9 cases, and fair in 2 cases, with an excellent and good rate of 90%.
  
  
  CONCLUSIONS
  The bone anchor for extensor mechanism reconstruction is a convenient and reliable way to treat the recurrent patellar subluxation, with a satisfactory early effectiveness and less complications; however, its long-term effectiveness is required a further follow-up.
authors.forename: Yanlin
authors.initials: Y
authors.lastname: Li
authors.forename: Guoliang
authors.initials: G
authors.lastname: Wang
authors.forename: Guofeng
authors.initials: G
authors.lastname: Cai
authors.forename: Di
authors.initials: D
authors.lastname: Jia
authors.forename: Linsong
authors.initials: L
authors.lastname: Ji
authors.forename: Chuan
authors.initials: C
authors.lastname: He
authors.forename: Jiali
authors.initials: J
authors.lastname: Zheng
mesh_terms: D000293:Adolescent; D002648:Child; D005260:Female; D006801:Humans; D031221:Knee Dislocation / Q000601:surgery*; D007719:Knee Joint; D008297:Male; D010329:Patella; D031222:Patellar Dislocation / Q000601:surgery*; D057071:Patellofemoral Joint / Q000601:surgery*; D020127:Recovery of Function; D012008:Recurrence; D053441:Suture Anchors; D013977:Tibia; D016896:Treatment Outcome