Purpose of the study: Attempts to control growth of the spine without provoking epiphysiodesis is a promising area of investigation. The purpose of our experimentation was to achieve localized interruption of vertebral body growth without damaging the adjacent disc and ligament structures.

Material and methods: Two Yucatan micropigs weighing 7 and 9 kg were used for this study. Before initiating the experiment, a complete imaging work-up (x-ray, computed tomography, magnetic resonance imaging) of the spine of the two pigs was obtained. The animals were anesthetized for thoracotomy and a 810 nm 30W laser diode (Diomed Ltd) was implanted in the superolateral part of nine vertebral bodies (3 mm under the cartilage endplate and 3 mm in depth) in order to apply a certain quantity of heat. The nine vertebrae were divided into three groups of three vertebrae. Each group received 2W for 200, 300, or 400s (groups 1, 2 and 3 repectively). The temperature generated by the thermal delivery was recorded in the growth cartilage and in the disc using thermal probes. A complete imaging series of the spine was again obtained four months later, before sacrifice. The results presented correspond to the CT-scan findings used to analyze the effect on vertebral growth and to the MRI findings used to check for discal injury. Each vertebral level was sampled for a histological examination and (in the second part of the study) a biomechanical analysis was undertaken.

Results: Among the 18 vertebral levels studied (two micropigs), 11 levels exhibited localized interruption of growth without any alteration of the adjacent discs. We were unable to observe any significant correlation between the temperature recorded in the disc and the discal structure observed at sacrifice, although above 52°C, there appeared to be a greater risk of definitive discal damage. As disc growth can be controlled (as demonstrated in this study) without damaging the adjacent disc (which will require further study to demonstrate) is would be possible to use this technique as an alternative to treatment by corset for progressive idiopathic scoliosis in growing children.

Purpose of the study: Assessment of limb reconstruction results using vascularized fibular grafts after bony resection for malignant tumors in children.

Material and methods: Thirty children (9 girls and 21 boys)underwent surgery between 1993 and 2000. Mean age was 11 years. Tumor localizations were: femur (n=17), tibia (n=6), humerus (n=5), radius (n=1) and distal ulna (n=1). Mean length of bone resection was 16 cm (range 10–26 cm). For 22 children, the adjacent epiphysis was preserved. For the eight others, fusion was also performed. Two surgical teams operated sequentially: the first team performed the tumor resection and the second (an orthopedist for the osteosynthesis and a plastician for the vascularized fibular transfer) the limb reconstruction. Radiographic and clinical assessment was completed with bone scintigraphy. The index of graft hypertrophy was determined with the De Boer and Wood method. Functional outcome was assessed with Enneking criteria.

Results: Mean follow-up was 51 months (range 2 – 9 years). Early amputation was necessary for two children due to local oncological complications. One patient died of pulmonary metastasis eight months after limb reconstruction. Among the 27 other patients, primary healing was achieved in 22. In the five with primary nonunion, bone scintigraphy showed objective signs of a lack of blood supply to the graft. Secondary union was achieved with a complementary autologous bone graft in four cases. All cases of stress fracture healed with orthopedic treatment. For the 22 patients with primary union, the graft hypetrophy was 22–190% (mean 61%). For the five patients without bone vascularization on the scintigraphy, the fibular graft failed to hypertrophy. Functional outcome was satisfactory. The modified Enneking score (30 point scale) was 26 (range 19–30 points).

Discussion: Limb reconstruction results are directly related to good patency of vascular anastomoses. Postoperative bone scintigraphy is useful to determine blood supply to the graft and to establish the final prognosis. In the case of vascular failure, an autologous bone graft can be proposed early to enable union. Close collaboration between the plastic surgery and the orthopedic team is the key to successful limb reconstruction with a vascularized fibular graft.

Purpose of the study: In spina bifida, independently of limb paralysis, spinal deformation can cause significant static disorders (scoliosis, kyphosis, or hyperlordosis) which in turn cause significant disability. These deformations generally develop during growth. We wanted to determine the predictive value of a clinical classification based on the neurological examination at five years for risk of spinal deformation.

Material: This retrospective study included 163 patients. Groups were defined on the basis of motor function determined by the neurological examination at five years: group I: L5 or below (all patients in this group had motor deficit leaving at least one L5 segment intact); group II: L3–L4; group III: L1–L2; group IV: T12 and above.

Results: Results showed that group I was a factor predictive of an absence of future spinal deformation. Groups III and IV were predictive of presence of a future spinal deformation. Group IV was predictive of future kyphosis.

Discussion: It is well known that the higher the neurological lesion in spina bifida, the higher the rate of spinal deformation. No work has however set the limits nor provided predictive rules useful in clinical practice. Our work demonstrated that this classification based on the motor function established by neurological examination at five years can predict which children have a risk of developing a spinal deformation and thus enabling early detection and treatment.

Conclusion: This neurological classification can be used as a clinical tool for the prognostic evaluation of spina bifida.