Introduction

Since 2001 we use the flexible intramedullary nailing (FIN) in bone lengthening in children. This study estimates results of EF+FIN association considering the duration of external fixation and complications.

Purpose of the study: Intramuscular injection of the botulinum toxin into the psoas can be proposed for permanent hip flexion due to spastic disorders. Several approaches have been described: retrograde subinguinal, anterolateral suprailiac, and posterior. Ultrasound or computed tomography can be used to guide needle position. These approaches are however limited to access to the L4 region, i.e. far from the motor points and with the risk of injury to the ureter. The purpose of this work was to determine the innervations of the psoas muscle that would be best adapted to this type of injection and thus to describe the most effective and reliable approach.

Material and methods: This anatomy study included 20 dissections to: describe vertebral insertions of the psoas major and the psoas minor and to measure their distance from the iliac crest; define the region where the ureter crosses in front of the psoas.

Results: More than 80% of the psoas muscles presented a proximal insertion on the transverse process of T12 and the body of L1; the mean length of the psoas in the adult is 27 cm above the inguinal ligament; the nerve roots collateral to the lumbar plexus are: 33% L2, 25% L3, 19% L1, 9% L4, 3% L5 and 1% T12, the remainder arising directly from the femoral nerve; the L2-L3 region is situated 4.6 cm on average above the iliac crest.

Discussion: The region facing the L2-L3 space enables access to more than 50% of the psoas nerve branches. Injection via a posterior approach situated in adults 4.6 cm above the iliac crest and identified fluoroscopically is the most reliable access. This will avoid injury to the ureter which lies lower.

Conclusion: This anatomy study described a new more effective less dangerous approach for botulinum toxin injections into the psoas muscle.

Purpose of the study: There is a link between complications and duration of instrumentation. Since 2001, we have associated circular external fixation (EF) and stable elastic centromedullary nailing (SECMN) to shorten the duration of the external fixation in bone lengthening in children. This study was designed to assess the results of the EF+SECMN for this indication.

Material and methods: From 2001 to 2009, progressive bone lengthening was performed in 250 children aged 3 to 16 years. There were 295 progressive lengthening procedures involving 339 segments. Indications were congenital (n=163) and acquired (n=87) length discrepancy. In group I (195 lengthenings, 222 segments), the Ilizarov EF was used alone. In group II, the Ilizarov (n=92, 108 segments) or the TSF (n=8, 9 segments) EF was associated with SECMN. After insertion of the EF, the centromedullary nails were introduced after the osteotomies. The healing date was the date the EF was removed; the nails were left in place to protect the bone. The healing index was calculated from duration of the EF (in days) divided by lengthening (in cm).

Results: Use of SECMN shortens the duration of EF irrespective of the aetiology, the segment, the lengthening method (mono- or polysegmental, mono- or poly-focal), with a statistically significant difference between the two groups (gain of 6 to 12 d/cm). In group I, deformities or fractures of the regenerated bone after removal of the EF occurred in 21 cases (10.77%), deep infections in 4 (2.05%), osetomyelitis in 2 (1.03%). In group II, the only complications were late healing (1%) and 10° angulation at the lengthening site (1%). The centromedullary nails migrated in eight patients, with no impact on the lengthening results.

Discussion: With SECMN, the lengthening procedure is achieved with an elastic but resistant system. It is hypothesised that this system stimulates osteogenesis since the healing index is improved. SECMN does not prevent progressive correction of shaft or diaphyseal deviations. By shortening the duration of external fixation, this method had a great impact on reducing serious complications such as fractures and deep infections.

Conclusion: SECMN can considerably reduce the duration of external fixation during bone lengthening procedures in children and reduce (or eliminate) most of the serious complications.

Purpose of the study: In the growing pig, we have been able to achieve localized control of vertebral body growth by selective destruction ofhte physis using the thermal effect of a laser probe (first part of the study). The purpose of the second part of the study was to evaluate the mechanical effects in terms of 1) intersomatic disc mobility, and 2) bony resistance of the vertebral body and risk of fracture.

Material and methods: Thoracotomy was performed on two Yucatan micropigs (group A); a 510 nm 30W diode laser delivered heat applied to nine vertebral bodies. Four months later, the micropigs were sacrificed. Two normal micropigs (group B) served as controls. The specimens were dissected to the intersomatic disc-ligament complex. Three-level vertebral assemblies were thus obtained for mobility tests (flexion-extension, lateral inclination, right-left rotation). Destruction tests were pursued to fracture. Tests were performed with a Zebris 3D motion analyzer. Computed tomography images and histological findings were also assessed.

Results: Motion: In group A, when the discal space appeared normal on the specimen, no difference was noted in motion in comparison with group B. Conversely, when imaging demonstrated discal injury, joint stiffness was noted. The destruction tests showed that in group A specimens the fracture did not occur at the zone of lytic bone destruction caused by the heat delivery. Fractures observed were similar in the two groups, including epiphyseal detachements and sagittal fractures of the vertebral bodies.

Discussion: Applying laser-delivered heat to the vertebrae in micropigs enabled partial destruction of the physis without injuring the intervertebral disc. Heat delivery induced a modification in vertebral growth. When imaging showed an intact neighboring intervertebral disc, mechanical tests showed normal mobility and resistance. Bone resistance was not diminished. This result is important to consider for the treatment of vertebral osteoid osteomas with laser.

Conclusion: Laser application to vertebral bone is a reproducible method which can stop growth of the minipig vertebral bodies without injuring the intervertebral disc and without reducing bone resistance.

Purpose of the study: It is relatively rare to observe villonodular synovitis in children. The predominant localization is in the large joints. Histology is required for definitive diagnosis but specific sequences of magnetic resonance imaging (MRI) has greatly improved diagnostic performance.

Material ad methods: we report four cases of hemopigmented villonodular synovitis observed in four girls aged 11–16 years (mean age 12 years) at diagnosis. Localizations were the knee joint in two, the metacarpophalangeal joint of the third finger in one and an intracarpal joint with scaphoid defects in the fourth. Plain x-rays centered on the joint involved and MRI spin echo T1 and T2 with fat saturation were obtained for all four children. Echo gradient with long TE sequences were also performed for the last two children because of the anomalies observed in the first two.

Results: The MRI findings enabled the diagnosis of hemopigmented villonocular synovitis in all four patients and was confirmed histologically (two biopsy specimens followed by dissection and two first-intention dissection specimens).

Discussion: The large joint localizations are often reported but the two cases involving the wrist and fingers are less common. The condition is usually revealed by repeated joint effusion which if punctured generally reveals a hematic discharge. Pain is classical and a mass is often palpated. Standard x-rays show intraosseous defects and MRI, using the three sequences together, generally provides the diagnosis. On the spin echo T1 sequence the synovial mass gives an intermediate signal compared with the low intensity signal of the joint fluid since the cholesterol deposits enhance the signal. In spin echo T2 sequence with fat saturation, the lesion produces a heterogeneous signal which is still intermediary because of the hemosiderin and cholesterol deposits which decrease the inflammatory aspect of the synovitis. These signs are highly suggestive and should be followed by an echo gradient long TE sequence. This is not a routine sequence but provides objective evidence of hyposignals within the synovial mass. This type of signal is specific for the presence of iron and thus hemosiderin.

Conclusion: MRI is the exploration of choice for the diagnosis of hemopigmented villonodular synovitis. It enables postoperative monitoring in search of recurrence.

Purpose of the study: Joint puncture-wash-out is generally recommended for septic arthritis in children, but the debate is still open concerning the proper attitude for the hip joint. The purpose of this work was to examine our failure cases after treatment of septic hip arthritis using the puncture-wash-out option. We wanted to know whether first-intention primary arthrotomy might be a valid option.

Material and methods: We reviewed retrospective 29 cases of septic hip arthritis treated initially by puncture-wash-out between January 1996 and June 2003. We excluded all cases of first intention arthrotomy. The series included 19 boys and ten girls aged four years three months on average at time of diagnosis (age range 8 months to 9 years). Mean follow-up was one year five months (range 1 month the 4 years). Mean delay to diagnosis was two days (range 0–6 days). In addition to intravenous antibiotics, the 29 hips were drained and washed out with saline solution under general anesthesia until a clear wash-out was obtained. Surgical revision (arthrotomy) was required for seven patients within 3 to 21 days.

Results: Outcome was assessed at days 2, 5, and 10. Assessment variables were pain relief, normal blood tests, and apyrexia. Seven children required surgical revision for arthrotomy due to persistent clinical or biological disorders. Cure was achieved after all seven arthrotomies. At last follow-up, there was no difference, clinically or radiographically, between the children treated by puncture-wash-out or by arthrotomy. The factors which appeared to be the most significant to distinguish the two groups were, at admission: time to diagnosis and management greater than four days and C-reactive protein > 100. On day 5, the most significant factors were persistent joint pain and C-reactive protein > 100.

Discussion: These results suggest that puncture-wash-out remains a simple and reliable treatment but that it has its limitations: a synovial biopsy cannot be obtained, visual examination of the joint cartilage is not possible, trepanation of the metaphysis is not possible. Our factors favoring poorer outcome are similar to those reported in the literature to which can be added age less than one year. When these factors are present, first-intention arthrotomy should be discussed.

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.

Eight children developed osteochondroma (OS) at a mean of 88 months, after hematopoietic stem cell transplantation (HSCT). The mean age at HSCT was 56 months (12-84). This represents a cumulative incidence of 20% among patients less than 18 years of age transplanted from 1981 to 1997. These eight patients underwent allogeneic (n=2) of autologous (n=6) transplantation for either acute leukemia (n=6) or neuroblastoma (n=2) after a conditioning regimen including total body irradiation (n=7) or a combination of Busulfan and Cyclophosphamide.Multiple OS were indentified in seven patients and a solitary OS in one. Locations included: clavicle (2), ribs (2), superior iliac epiphysis (1), metaphy-sis of the distal femur (2), distal (2) and proximal (1) tibia, proximal humerus (1), distal radii (3), scapula (3), proximal metaphysis of the proximal phalanges of the fingers (2) and parietal bone (1). OS were asymptomatic in four children. Eight lesions in five patients were resected and all were benign. No recurrence occured.Four children received growth hormone before diagnosis of OS, but there was no clinical, radiological or histological difference between those who did not. Univariate analysis showed an increased rate associated only with autolo-gous HSCT, with a 31,7% probability of a new OS et 12 years after HSCT.Ostoechondroma should be added to the other adverse effects of HSCT in children.