[External fixation in fractures of the lower limb in children]

The indications, morbidity and results of the use of external fixation for fractures of the lower limbs in children is presented.

We studied 72 fractures of the lower limbs (femur: 25; tibia: 47) in 63 children over a seventeen year period. Average age at fracture was 10 yrs 6 mos. (range 4 yrs 5 mos to 14 yrs 6 mos). Forty fractures were open fractures. The indication for external fixation was decided in three different situations: 39 isolated fractures, 11 patients with multiple fractures, and 13 polytraumatized patients. Three different devices were used: Illizarov: 4, Judet: 16, Orthofix: 52. The fixators were left in place until fracture union was demonstrable.

Final results were classed into three groups: good, good following reoperation and sequelae. Comparison of the three different series was made using Student's T test. 9 axial deviations or malrotations occurred: 6 times correction was possible with the device in place. Three cases of osteomyelitis occurred at the fracture site. 23 pin tract infections occurred (23 per cent) 5 of which were persistent and 4 required reoperation. The average healing time was different in the three groups: 4.5 mos for isolated fractures: 8.1 mos for multiple fractures and 5.7 mos for polytraumatized patients. Reoperation was required for 4 patients: 2 bone grafts, 1 decortication, 1 bone transport. Ten refractures occurred following removal of the device, 8 times in patients presenting multiple injuries. In 46 patients with a follow-up greater than 18 months, 9 presented an overgrowth between 1 and 2 cm. Following an average follow-up of 2 years 4 months, 7 patients presented sequelae, 56 had good results, 18 following reoperation.

The use of external fixation remains an irreplaceable method for osteosynthesis of open fractures with severe soft tissue injuries, multiple fractures or in the polytraumatized patient. Some disadvantages such as pin tract infections and refracture following device removal should be taken into consideration before using it for the treatment of simple, isolated closed fractures of the lower limbs in children.

When external fixation is chosen for treating fractures, it is preferable to use a modular device which allows axial corrections. Local pin site care is essential to prevent early infection. Early weight bearing and dynamization as soon as possible will promote callus mineralization, removal of the device must be progressive and cast protection is recommended.