Avulsion fractures of the tibial tuberosity in adolescent athletes treated by internal fixation and tension band wiring.

Avulsion of the tibial tuberosity is a rarely reported fracture. It is mainly considered as an athletic injury accounting for less than 3% of all epiphyseal lesions. In this study, we hypothesized that the use of tension band wiring as a supplement of the internal fixation for the avulsion fractures of the tibial tuberosity would lead the adolescent athletes to a more effective rehabilitation program and an earlier resumption of their previous activity level. Ten patients were treated in our department over a period of 11 years (1985-1995). Operative treatment was thought necessary for all our cases due to tibial tuberosity displacement. Open reduction and internal fixation in combination with tension band wiring was used. The result in all cases was that the reduction was maintained intact and the fracture united. The functional results were excellent, and all patients returned to their previous athletic activities. Our conclusion is that the combination of internal fixation and tension band wiring for avulsion fractures of the tibial tuberosity seems to be more effective and advantageous than conservative or other surgical methods. Avoiding the need of external support and allowing early joint motion, the method described prevents serious quadriceps atrophy, allowing the young athletes to return earlier to their previous sport activities.

Articular changes in experimentally induced patellar trauma.

Only a few studies have described the microscopic pathology of the articular cartilage after trauma. In the present animal study, we demonstrate the effect of trauma on the articular cartilage of the patella and determine the histological changes. Traumatic injury of the patella was experimentally induced in 45 white New Zealand rabbits aged 4 to 6 months old. The articular cartilage of the patella was observed after the sacrifice of the animals immediately and at days 1, 2, 4, 8, and 15 as well as at months 1, 2 and 3 after the traumatic injury. Macroscopic, light and electron microscopic findings showed progressive articular cartilage changes with failed effort of cartilage repair. Osteoarthritic-like degeneration of the articular cartilage was found in all specimens. According to this experimental study, trauma to the articular cartilage may progress to arthritis. The reversibility of cartilage damage or the progression to arthritis seem to be associated with many factors such as the intensity and frequency of the trauma, the mechanism of injury, the intrinsic remodeling of the cartilage matrix and the capability of the articular cartilage to regenerate.