The advent of Elastic Stable Intramedullary Nailing has revolutionised the conservative treatment of long human bone fractures in children (Metaizeau, 1988; Metaizeau et al., 2004). Unfortunately, failures still occur due to excessive bending and fatigue (Linhart et al., 1999; Lascombes et al., 2006), bone refracture or nail failure (Bråten et al., 1993; Weinberg et al., 2003). Ideally, during surgery, nail insertion into the diaphyseal medullary canal should not interrupt or injure cartilage growth; nails should provide an improved rigidity and fracture stabilisation.

This study aims at comparing deflections and stiffnesses of nail-bone assemblies: standard cylindrically-shaped nails (MI) vs. new cylindrical nails (MII) with a flattened face across the entire length allowing more inertia and a curved tip allowing better penetration into the cancellous bone of the metaphysis (Figure 1). MII exhibits a section with two parameters: a diameter C providing nail stiffness and a height C' providing practical dimension when both nails are crossed at the isthmus of the diaphysis: C/C' is set to 1.25 for all MII nails.

A CT scan of a patient aged 22 years was used to segment a 3D model of a 471mm-long right femur model. The medullary canal diameters at the isthmus are 10.8mm and 11.4mm in the ML and AP direction, respectively. Titanium-made CAD models of MI (Ø=4mm) and MII (flat face: Ø=5mm) were pre-curved to maintain their flat face and carefully placed and positioned according to surgeon's instructions. Both nails were inserted via lateral holes in the distal femur with their extremities either bumping against the cortex or lying in the trabecular bone.

Transverse and comminuted fractures were simulated (Figure 1). For each assembly, a Finite Element (FE) tetrahedral mesh was generated (∼100181 nodes and 424398 elements). Grey-scale levels were used to assign heterogeneous material properties to the bone (E=6850 ρ^1.49 (Morgan et al., 2003)). Two modes of loading were considered: 4-point bending (varus and recurvatum: F_max=6000N) and internal torsion (M_max=70kNmm). This led to the simulation of 15 FE models, including a reference intact femur.

Results show that in valgus, for the transverse (comminuted) fracture, the mean displacement of the assembly decreased by around 50%: from 15.24mm (27.49mm) to 8.15mm (13.85mm) for MI and MII, respectively, compared to 3.59mm for the intact bone. The assembly stiffness increased by 87% and 99% for transverse and comminuted fracture, respectively (Table 1). Similar trends were found in recurvatum with higher increases in assembly stiffness of 170% and 143% for transverse and comminuted fracture, respectively (Table 1). In torsion, for the transverse (comminuted) fracture, the measured angle of rotation decreased from: 0.43rad (0.66rad) to 0.22rad (0.43rad) for MI and MII, respectively, compared to 0.09rad for the intact bone. This corresponded to an increase of 95% and 55% in assembly stiffness for transverse and comminuted fracture, respectively.

In conclusion, using the 5mm-diameter new nails (MII) for the same intramedullar space, during either bending or torsion, assemblies were always stiffer than when using standard cylindrical nails.

Since 1987, we have treated 37 clubfeet with a continuous passive movement (CPM) machine rather than by surgical release.

After 6 months of physiotherapy and splintage, all feet still exhibited equinus and varus deformities. CPM treatment improved equinus and varus in all cases and in 33 feet there was no need for surgery.

However, there was progressive impairment: at 15-year follow-up, the results in six feet remained good, with some dorsiflexion possible, but recurrence of the equinus deformity in the other feet had necessitated surgical release, performed when patients were 2 to 10 years old.

CPM treatment can eliminate the need for surgery in mild clubfeet, and delay surgery in more severe cases. Performing a surgical release after 3 years will perhaps reduce the rate of recurrence of the deformity.

Purpose: Surgical epiphysiodesis is one technique used to correct lower limb length discrepancy. Methods described include: in situ graft (Phemister, 1993), stapling (Blount, 1949), percutaneous curettage (Bowen, 1984). The purpose of this work was to evaluate a new technique described in 1998 (Metaizeau) which uses two percutaneous transphyseal screws.

Material and methods: Forty-two patients (29 boys, 13 girls), mean age 13.1 years underwent the procedure. The cause of leg length discrepancy was unknown (n=12), fracture (n=16), congenital (n=7), other (n=7). Epiphysiodesis using two percutaneous screws was performed on the distal femur (n=24), the proximal tibia (n=7), both (n=11). Stance radiograms were obtained of the lower limbs before the intervention and at last follow-up to measure length of the lower limb, the tibia, and the femur. Difference with the healthy limb was determined as well as the percentage of growth comparing the healthy and epiphysiodesis sides. The operative time, duration of hospital stay and complications were studied.

Results: Preoperatively, mean limb length discrepancy was 22.3 mm (10 to 70); at skeletal maturity, the difference measured 11 mm (28 to −20). Mean percent growth from epiphysiodesis to last follow-up was 3.15% for the epiphysidesis side and 6.26% for the contralateral side. Mean operative time was 20 min per bone (15–40). Complication rate was 16% including 7% stiff knee postoperatively with total recovery in two weeks, and 9% discomfort due to the presence of the screws. The growth curves showed that the epiphysiodesis was effective before three months. Mean hospital stay was 1.3 days (1–4).

Discussion: The final outcome in terms of leg length discrepancy were comparable with other techniques. The rate of complications appears to be more favourable since there were no infections, no frontal or sagittal deviations, no vascular or nerve injuries, and since all complications resolved without sequelae. This intervention can be proposed as an outpatient procedure. Epithysiodesis is always obtained within three months.

Conclusion: Epiphysiodesis using a percutaneous transphyseal screw is a simple method with minimal complications which provides reliable results and many advantages compared with other methods.

Purpose: The Harrington instrumentation without vertebral grafting associated with corset treatment was described by Joe Moe in 1978 for the treatment of severe scoliosis in young children. In 1989, Jean Dubousset described the ratchet-brace process which occurs after isolated posterior vertebral grafting performed before the end of growth. Thus several options should be discussed for young children with a severe evolving scoliosis inaccessible to orthopaedic treatment: a subcutaneous rod to be lengthened repeatedly without grafting, anterior epiphysiodesis fusion, or a combination of these methods. The purpose of this retrospective analysis was to examine the posterior approach using a subcutaneous rod without grafting.

Material and methods: Fourteen children with scoliosis were treated over a ten-year period: infantile spinal amyotrophy (n=10), cerebral palsy (n=3), congenital (n=1). Mean age at the first operation was 8.6 years. Mean preoperative Cobb angle was 72.5° (45–105°). From the third case onward, the treatment protocol was the same for all patients using proximally three hooks on three thoracic vertebrae mounted on a rod and distally two hooks (L4-L5) mounted on a second rod. The two subcutaneous rods were connected with a connecting device and the fusion grafts were inserted. The first lengthening was planned at about six months. Further lengthenings were planned for about once a year until Risser 2 when spinal fusion could be undertaken.

Results: The first operation corrected the curvature to 43.7° (28–70°) On average, four lengthenings were performed before definitive fusion. Each lengthening (mean 13.7 mm (10–20) produced an average 16.4° (4–31°) correction. Mechanical complications (one proximal hook pull out, one rod fracture) occurred during the learning period (first patient) before the present technique was instituted.

Discussion: The absence of mechanical complications with the described method and the quality of the results suggests this technique should be pursued, avoiding the anterior approach in certain patients where respiratory function is compromised. The inconvenience of the annual operations for lengthening may be avoided with the self-lengthening Phenix #1666 rods.

Fractures of the femur are the most incapacitating fractures in children. Conservative treatment necessitates a long stay in hospital for traction and subsequent immobilisation in an uncomfortable cast. This treatment is not well tolerated, especially in adolescents. Moreover, near the end of growth, accurate reduction is necessary, as malunion is no longer correctable by growth. Stable elastic intramedullary nailing uses two flexible nails which are introduced percutaneously either through the lower metaphysis or the subtrochanteric area. This technique does not disturb the healing of the fracture. The elasticity of the device allows slight movement at the fracture site which favours union. Reduction and stabilisation are adequate and the operative risk is very low. A cast is not required, functional recovery is rapid and the patient is allowed to walk with crutches after seven to ten days according to the type of fracture. This technique is very efficient in adolescents and can be used after the age of seven years when conservative treatment is unsuccessful.

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.

We report the use of elastic stable intramedullary nailing (ESIN) in 123 fractures of the femoral shaft in children. Flexible rods are introduced through the distal metaphyseal area, and the aim is to develop bridging callus. Early weight-bearing is possible and is recommended. There was one case of bone infection and no delayed union. Complications were minimal, the most common being minor skin ulceration caused by the ends of the rods. A surprising feature was the low incidence of growth changes, with a mean lengthening of only 1.2 mm after an average follow-up of 22 months. Compared with conservative treatment, ESIN obviates the need for prolonged bed rest and is thus particularly advantageous for treating children.