title: Patellar dislocation due to iatrogenic quadriceps fibrosis: results of operative treatment in 54 cases.
abstract: OBJECTIVE
  To evaluate the clinical and functional results of a surgical treatment of patellar dislocation whose etiology was iatrogenic quadriceps fibrosis in children.
  
  
  METHODS
  A prospective study was undertaken from February 2004 to December 2009. The study included 54 pediatric patients (56 knees) that had developed dislocation of the patella after repeated intramuscular injections of antibiotic(s) into the quadriceps muscle. There were 11 males (20.4 %) and 43 females (79.6 %). The patients' mean age at surgery was 7 years, 9 months (range 6 years, 4 months to 12 years, 6 months). A complete history of each patient was recorded. The affected knees were evaluated preoperatively and postoperatively on the basis of the symptoms, signs, and roentgenographic findings. Patellar dislocation was classified according Bensahel's criteria. All patients had a three-part surgical procedure that combined capsulorrhaphy, quadricepsplasty, and transfer of the vastus medialis oblique to the superior border of the patella.
  
  
  RESULTS
  There has been no poor postsurgical result or recurrence so far; we have noted an ugly scar in nine knees (16.1 %), limitation of the knee flexion in five knees (8.9 %), and loss of extension of 5 °-20 ° in four knees (7.1 %). Overall, we attained excellent results in 39 knees (69.7 %), good results in 13 knees (23.2 %), and fair results in four knees (7.1 %).
  
  
  CONCLUSIONS
  In our cases of pediatric dislocation of the patella caused by iatrogenic quadriceps fibrosis, the introduced three-part surgical procedure has shown great success in restoring the realignment mechanism of the patella. The technique is simple, safe, and effective in skeletally immature children.
authors: Vietnam National Hospital of Pediatrics, 18/879 La Thanh Road, Dong Da District, Hanoi, Vietnam, ngocyenhung@gmail.com.
authors: Nguyen Ngoc
authors: NN
authors: Hung
authors: Do
authors: D
authors: Tan
authors: Nguyen
authors: N
authors: Do Ngoc Hien