Abstract
The treatment of fractures in children is essentially conservative because young bone heals rapidly and growth remodels many malunions. In addition, we do not have implants which respect the biomechanics of the growing bone. The techniques perfected for the adult skeleton have adverse effects in children and their disadvantages still outweigh their advantages.
Fixation which is too rigid encourages cortical union but inhibits the formation of periosteal callus which is of prime importance in the child. This approach evacuates the fracture haematoma, damages the periosteum, increases local devascularisation, and encourages infection and secondary hypertrophy. The rigidity of a plate also produces a rapid thinning of cortices in young bone, adding the risk of recurrent fractures.
However, conservative treatment does not always give perfect results. Some injuries are liable to sequellae which are not corrected by growth. Children with polytrauma, severe brain injuries, osteogenesis imperfecta, and neurological problems cannot always be treated orthopaedically and require surgery.
Stable intramedullary nailing (SIMP) seems to be particularly adaptable to growing bone. SIMP is carried out with two pre-bent pins that allow stabilisation of nearly all diaphyseal and metaphyseal fractures and also respects the healing process and the unique biomechanical properties of young bone. This technique presents many advantages and few disadvantages but it is not designed to supplant conservative treatment. The aim is primarily to treat fractures that cannot be treated conservatively without adding iatrogenic complications.
Pre-bent pins are placed in the medullary canal of the bone. Each pin gives a three- point fixation and the three points press on the bone. Two extremities of the pin press on metaphyseal cancellous bone, and the apex of the curve presses on the inner aspect of the cortex.
The principal feature of this osteosynthesis is its elasticity. If one deforms the pin, it resists by developing a force which opposes the deformation. This force returns the pin to it’s original form upon removal of the deforming force. Because the pinning is performed without opening the fracture site, the hematoma and the periosteum are preserved, which is essential for bone consolidation. The elasticity of the pinning allows slight movements in compression and distraction which are particularly favourable for consolidation.
A child is discharged from hospital after two days for fractures of the humerus, forearm or tibia and after five days for femoral shaft fractures. Cast immobilisation is not necessary. Function is recovered rapidly, with a minimal absence from school. If complications occur, they are infrequent and rarely severe.
The abstracts were prepared by David P. Davlin. Correspondence should be addressed to him at the Orthopedic Clinic Bulovka, Budínova 2, 18081 Prague 8, Czech Republic.
