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 mo st commonly associated with familial ligamentous laxity. Many surgical repa irs have been described to stabilize the patella. We have found the semiten dinosus transfer to the patella to result in a predictable, stable patellof emoral joint without risk of injury to the proximal tibial physis. Between January 1990 and December 1997, 29 children have been treated at the Childr en's Hospital of Eastern Ontario with a semitendinosus transfer for recurre nt 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 h ave 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 a nd 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 wit h patellofemoral syndrome or chondromalacia was present in 17 of 26 knees. On clinical examination, 10 knees exhibited marked ligamentous laxity. Ther e were nine positive patellar apprehension tests, and eight patellae were h ypermobile. All children were treated with a semitendinosus transfer to the patella with concomitant tightening of the medial retinaculum and a latera l retinacular release. On long-term follow-up, 23 of the 26 knees (88%) wer e asymptomatic, and the child had returned to regular activities. Each chil d completed the Lysholm and the subjective component of the Zarins-Rowe que stionnaire to determine the subjective results of the repair procedure. Thr ee children complained of patellofemoral symptoms. One child experienced re currence of the patellar dislocation, and one child developed medical patel lar subluxation.