Fractures of the patella in children and adolescents.

Fractures of the patella in children and adolescents are rare injuries with particular characteristics. The aim of this study was an analysis of epidemiology, treatment strategy and outcome of this injury. Between 1992 and 2006 all fractures of the patella in patients with an age 5 16 years were included in a case control study. Besides outcome analysis using the modified HSS knee score, radiological follow-up was evaluated. During that time period, 23 children (6 girls, 17 boys) with patella fractures were seen in our institution; the incidence of patellar fractures was 0.44%. The average age was 12.4 years. The fractures mainly occurred during sports and leisure activities, followed by traffic accidents. Specific to children are avulsions of the lower or upper pole of the patella. Eleven children were non-operatively treated. Surgical techniques used were screw osteosynthesis, tension band wiring, transosseous suture, and refixation with biodegradable pins. In 7 cases an arthroscopy was performed in order to evaluate intraarticular lesions. Twenty-one children were recruited for a follow-up examination after an average of 40 months. A very good result was achieved in 16 cases and a good result in 5 cases. The radiological result at short term did not correlate with the clinical outcome. Patella fractures in children are a rare injury with a good shortterm prognosis ; long term outcome may significantly depend on the accompanying cartilage damage. In two cases an Autologous Chondrocyte Implantation was performed two years after the injury.