Semitendinosus tenodesis for repair of recurrent dislocation of the patella in children.

Recurrent dislocation of the patella is more common in girls than in boys. Although several predisposing factors may exist, patellar dislocation is most commonly associated with familial ligamentous laxity. Many surgical repairs have been described to stabilize the patella. We have found the semitendinosus transfer to the patella to result in a predictable, stable patellofemoral joint without risk of injury to the proximal tibial physis. Between January 1990 and December 1997, 29 children have been treated at the Children's Hospital of Eastern Ontario with a semitendinosus transfer for recurrent dislocation of the patella. Seven children were excluded from the study because of insufficient follow-up; consequently this series consisted of 22 children. Four children underwent bilateral repairs, hence 26 knees that have been operated on with this procedure were included in this study. There were three boys and 19 girls, with an average age at surgery of 14 years and 4 months, ranging from 8 years and 11 months to 17 years and 10 months. The average length of follow-up was 3 years and 2 months, ranging between 2 years and 7 years and 4 months. All children had experienced greater than three episodes of recurrent dislocation of the patella. Pain consistent with patellofemoral syndrome or chondromalacia was present in 17 of 26 knees. On clinical examination, 10 knees exhibited marked ligamentous laxity. There were nine positive patellar apprehension tests, and eight patellae were hypermobile. All children were treated with a semitendinosus transfer to the patella with concomitant tightening of the medial retinaculum and a lateral retinacular release. On long-term follow-up, 23 of the 26 knees (88%) were asymptomatic, and the child had returned to regular activities. Each child completed the Lysholm and the subjective component of the Zarins-Rowe questionnaire to determine the subjective results of the repair procedure. Three children complained of patellofemoral symptoms. One child experienced recurrence of the patellar dislocation, and one child developed medical patellar subluxation.