Intraoperative spinal cord monitoring: Lesional level diagnosis.

BACKGROUND: In spinal deformity surgery, iatrogenic spinal cord injury is the most feared complication. Intraoperative monitoring (IOM) of the spinal cord assesses its functional integrity and allows significant reduction of the rate of spinal cord injury. HYPOTHESIS: In case of severe IOM alert, lesional level diagnosis constitutes supplementary and useful information. MATERIAL AND METHODS: This study was retrospective and monocentric. In our institution, 1062 pediatric spinal deformity surgeries have been monitored since 2004. We review the records of the six patients who presented a severe and prolonged IOM alert with lesional level determination. Somatosensory evoked potentials (SSEP), neurogenic mixed evoked potentials (NMEP) and D-waves were performed. In cases of IOM alert, sequentially moving an epidural electrode along the spinal cord allows lesional level determination, using this electrode either for stimulation or recording. RESULTS: Six patients, aged 12 to 17 years, characterized by severe IOM alerts during spinal deformity surgery are reported. Postoperative neurological examination was normal for five out of six cases. For patient 2, lesional level diagnosis allowed to determine a bi-laminar claw between T2 and T3 as the etiology of IOM alert. This IOM alert was delayed in time, being detectable only 30minutes after the placement of this claw. Postoperative neurological examination was normal. For patient 6, a Stagnara wake-up test demonstrated paraplegia. Lesional level was established. Following corrective surgical maneuvers, postoperative neurologic deficit was limited to a pyramidal syndrome in one lower limb. Postoperative MRI demonstrated a spinal cord lesion at the determined lesional level. CONCLUSION: During an IOM alert, lesional level determination allows localization of spinal cord dysfunction. This data, obtainable whatever the IOM device, constitutes supplementary information in order to rapidly identify the etiology of IOM alert and thus to react in the most appropriate way. LEVEL OF EVIDENCE: IV, retrospective study.

Interest of T1 parameters for sagittal alignment evaluation of adolescent idiopathic scoliosis patients.

PURPOSE: In the last few years several reports stressed the importance of sagittal alignment in adolescent idiopathic scoliosis (AIS) patients. It was recently reported that T1 slope, defined as the angle between the superior endplate of T1 and the horizontal, correlates strongly with overall sagittal parameters. The aim of this study was to assess the impact of T1 parameters (T1-slope and T1-tilt) on sagittal alignment of AIS hypokyphotic patients preoperatively and postoperatively. METHODS: Twenty-nine AIS patients with <20° preoperative hypokyphosis were included in a retrospective study. Surgery systematically comprised hybrid construct with screws below T11, sublaminar bands at thoracic level and a lamino-laminar claw on the upper instrumented vertebra. Preoperative, postoperative and 2-year follow-up radiological assessment included Cobb angle, T1 slope, T1 sagittal tilt, regional sagittal parameters and pelvic parameters. RESULTS: In the series as a whole, coronal Cobb angle was significantly reduced postoperatively (58° vs. 17°; p < 0.001), thoracic kyphosis significantly improved (12.4° vs. 25.6°; p < 0.001) and cervical lordosis significantly restored (6.2° kyphosis vs. 4.1° lordosis; p < 0.001). There was a significant modification in T1-slope (10.2° vs. 18.2°; p < 0.001). Preoperatively, T1 slope was significantly correlated with T1 tilt (r = 0.427; p = 0.029). Postoperatively, T1 slope was significantly correlated with T1 tilt (r = 0.549; p = 0.002), thoracic kyphosis (r = 0.535, p = 0.005) and cervical lordosis (r = -0.444, p = 0.03). Restoration of cervical lordosis was significantly correlated to changes of T1-slope (r = -0.393, p = 0.032), which was significantly correlated to postoperative thoracic kyphosis. CONCLUSION: According to these results, T1 seems to be of major interest in postoperative modifications of sagittal alignment. T1 slope and sagittal tilt are good indicators of postoperative changes for regional (cervical lordosis and thoracic kyphosis) and global parameters. We therefore consider these parameters as essential in the assessment of AIS patients. Further studies and correlation with clinical scores will, however, be necessary in order to confirm the present findings.

Planovalgus foot deformity in cerebral palsy corrected by botulinum toxin injection in the peroneus longus: Clinical and radiological evaluations in young children.

BACKGROUND: In children with cerebral palsy (CP), overactivity of the peroneus longus (PL) muscle is a major contributor to pes planovalgus. This retrospective study assessed whether abobotulinumtoxinA injections into a PL showing premature activity on electromyography (EMG) clinically improved foot morphology in children with CP. METHODS: Study participants were <6 years old, had a diagnosis of CP, good functional abilities (Gross Motor Function Classification System level 1 or 2), equinovalgus (initial contact with the hallux or head of the first metatarsal) and overactive PL on EMG. The fore-, mid- and hindfoot were evaluated clinically and radiologically before and after injection of abobotulinumtoxinA (6-7 U/kg) into the PL. Radiological data were compared with reference values for children without pes planovalgus. RESULTS: In total, 16 children (8 males; 10 hemiplegia, 6 diplegia; mean age: 3.2±1.5 years) received treatment. Mean pre-and post-treatment angles in clinical assessment of dorsiflexion of the talocrural articulation did not differ with both knees flexed (24.4±7.5 vs. 22.2±8.0 degrees; P=0.19) or extended (17.2±8.0 vs. 16.6±6.8 degrees; P=0.36). Radiographic data pre-treatment versus reference data revealed forefoot pronation (metatarsal stacking angle 2.1±8.3 vs. 8.0±2.9 degrees; P=0.002), midfoot planus (lateral talo-first metatarsal 28.5±15.0 vs. 13.0±7.5 degrees; P<0.001; talocalcaneal angle 54.6±8.6 vs. 49.0±6.9 degrees; P=0.004) and significantly decreased calcaneus dorsiflexion, without hindfoot equinus (calcaneal pitch angle 7.9±6.0 vs. 17.0±6.0 degrees; P<0.001). After treatment, the metatarsal stacking angle did not differ from reference values (P=0.15). As compared with before treatment, treatment improved mean angles for metatarsal stacking (2.1±8.3 vs. 7.1±3.9 degrees, respectively, P=0.002), lateral talo-first metatarsal and talocalcaneal (both P<0.001), with no change in the hindfoot. CONCLUSION: PL may be an early target for abobotulinumtoxinA treatment in pes planovalgus associated with premature PL activity in children with CP.

[Vitamin D deficiency rickets complicating Dorfman-Chanarin syndrome]. / Rachitisme carentiel compliquant une maladie de Chanarin-Dorfman.

Vitamin D deficiency rickets remains a public health issue in many parts of the world. In France, this diagnosis has almost disappeared since 1992 with routine vitamin D supplementation for children. Therefore, it is more difficult for doctors to identify risk factors and early signs of this disease. In this article, we report a rickets diagnosis acquired by vitamin D deficiency in a child who presented with the onset of a genu valgum and difficulty walking at the age of 9½ years. This patient was a Comorian child followed up from his birth for Dorfman-Chanarin syndrome. Dorfman-Chanarin syndrome is a rare disease, with about 80 cases reported in the literature. It belongs to the group of neutral lipid storage diseases (NLSD) characterized especially on the skin by ichthyosis. This child presented risk factors for vitamin D deficiency (dark skin color, prolonged and exclusive breastfeeding, premature end of supplementation, and particularly severe ichthyosis) that should have alerted us to the risk of vitamin D deficiency and the need for supplementation. This case highlights the importance of vitamin D, especially if there are risk factors such as ichthyosis, and the need to remain watchful in monitoring all chronic diseases.

Sublaminar bands: are they safe?

BACKGROUND: Sublaminar bands (SB) are frequently used as implants in spine deviation correction. PURPOSE: Our purpose is to demonstrate their safety on a large series of patients. STUDY DESIGN: This is a retrospective study. METHODS: Our department treated 378 spine deviations on children and adolescents via a hybrid posterior technique (lumbar screws, hook and thoracic SB). Each surgery was undertaken using anesthesiologic and a neurophysiologic monitoring using somatosensory evoked potentials (SSEP) and neurogenic mixed evoked potentials (NMEP). An alert was described as an amplitude decrease of 50 % and/or a latency increase of 10 %. Data were analyzed using Student or Wilcoxon tests. RESULTS: We used 2,223 SB in 378 operative procedures. We described ten neurophysiologic alerts during the passage of the band under the lamina. There were no significative differences between the two groups concerning the age and the severity of the deformation (p > 0.05). These neurophysiologic alerts were associated with a dysautonomic trouble (hypertension and bradycardia). The lesional level was determined using a spinal electrode. In six cases, the responsible SB was removed. Three patients had post-operative neurologic deficiency (0.8 %) without complete recovery for one of them (localized incomplete sensitive deficiency). Within the group of 378 patients, 21 alerts were reported due to a screw or a hook, or during the correction manoeuver, without dysautonomic trouble. CONCLUSION: SB neurologic complications rate is as high as other implants' complication rate. Simultaneous hemodynamic and neurophysiologic change is an argument for vegetative response due to SB passage. Their optimal use requires a strict learning of their insertion under the lamina to be as less traumatic as possible. SB are as safe as any other spine implants.

Proximal ulnar osteotomy in the treatment of neglected childhood Monteggia lesion.

INTRODUCTION: The aim of our study was to analyze medium and long-term results of proximal ulnar osteotomy with and without ligament injury in neglected Monteggia injury in children. MATERIAL AND METHODS: This retrospective, multicenter study included 28 patients. Clinical criteria concerned the range of motion, pain and MEPI score, and radiologic criteria comprised of Storen line, head-neck ratio, radial neck angle, and signs of osteoarthritic remodeling. RESULTS: Twenty-eight patients were reviewed, at a mean 6 years' follow-up (range, 2-34y). Sixteen had proximal ulnar osteotomy without ligament reconstruction, and 12 had associated ligamentoplasty. Both groups showed significant clinical and radiological improvement, with no significant difference. Patients operated within less than 1 year had better clinical and radiographic results. There was no correlation between age at surgery and quality of results. The 5 patients who underwent condyloradial pinning showed early recurrence of dislocation and osteoarthritic remodeling. The three cases of Bado type-3 lesion had early recurrence of dislocation. DISCUSSION: Proximal ulnar osteotomy gives good long-term results in Bado type-1 lesions, regardless of age, if performed before 1 year, in the absence of osteoarthritic remodeling. Associated ligamentoplasty does not seem to be useful. LEVEL OF EVIDENCE: IV (retrospective).

Proximal migration of fibular malleolus during tibial lengthening despite syndesmotic screw fixation: a series of 22 cases.

INTRODUCTION: During tibial lengthening procedures, it is recommended to prevent fibular malleolus proximal migration using a distal tibiofibular syndesmotic screw, which is removed at 6 months. We have observed proximal migrations of the fibular malleolus despite placement of this syndesmotic screw. OBJECTIVE: The objective of this study was to demonstrate this migration and to study the influence of two factors that may favor its occurrence: positioning of the syndesmotic screw and union of the fibula at the time of removal. HYPOTHESIS: An unhealed fibula at the time the distal tibiofibular syndesmotic screw is removed and its tricortical position promote the proximal migration of the fibular malleolus. MATERIAL AND METHODS: This was a retrospective, single-center, analytical study that included 22 lengthening procedures in 18 patients from 5 to 17 years of age who had undergone tibial lengthening and presented a preoperative continuous fibula. The position of the fibular malleolus, union of the fibula, and the tri- or quadricortical position of the screw were assessed based on four successive x-rays. RESULTS: Tricortical positioning of the syndesmotic screw was significantly associated with proximal migration of the fibular malleolus during lengthening (P=0.0248<0.05). However, there was no significant relation between an unhealed fibula and proximal migration of the fibular malleolus when the screw was removed (P=0.164>0.05). DISCUSSION: Proximal migration of the fibular malleolus during lengthening is promoted by placing a non-quadricortical syndesmotic screw. Quadricortical positioning of the screw should be recommended. Migration of the fibular malleolus after ablation of the syndesmotic screw seems to be related to absence of fibular union but this series was too small to demonstrate this clearly. LEVEL OF EVIDENCE: Level IV: Retrospective study.

Dynamic EMG of peroneus longus in hemiplegic children with equinovarus.

OBJECTIVE: In hemiplegic children the appearance of equinovarus is correlated with premature electromyography (EMG) activity of the gastrocnemius medialis (GM) prior to initial contact. The goal was to analyze the onset of EMG activation in the GM and, more particularly, the peroneus longus (PL) in cases of equinovarus: is PL activity likewise premature? MATERIAL AND METHODS: As 15 hemiplegic children (age 5 years±1.5) with equinovarus walked, their PL and GM EMG activity was being recorded. The latter was normalized in terms of gait cycle percentage (0-100%) and detected through semi-automatic selection with activation threshold set at 20µV. A paired t-test compared activation onset of the PL versus the GM muscles. RESULTS: As regards the healthy limb, activity onset of the GM (+14.55%) and the PL (+19.2%) muscles occurred only during the ST. In cases of equinovarus, activation of the GM (-5.2%) and the PL (-6.1%) occurred during the SW and was premature. For each muscle, comparison between the healthy and the hemiplegic side was highly significant (P<0.001). CONCLUSION: Premature PL and GM EMG activity preceding initial contact corresponds not to a disorder secondary to imbalance but rather, more probably, to motor command dysfunction. While the PL consequently contributes to equinus deformity, its possible role in varus genesis is less evident. EMG study needs to be completed by comparing PL and tibialis posterior strength while taking foot bone morphology into full account.

Intraoperative neurophysiologic monitoring in spine surgery. Developments and state of the art in France in 2011.

Intraoperative spinal cord monitoring consists in a subcontinuous evaluation of spinal cord sensory-motor functions and allows the reduction the incidence of neurological complications resulting from spinal surgery. A combination of techniques is used: somatosensory evoked potentials (SSEP), motor evoked potentials (MEP), neurogenic motor evoked potentials (NMEP), D waves, and pedicular screw testing. In absence of intraoperative neurophysiological testing, the intraoperative wake-up test is a true form of monitoring even if its latency long and its precision variable. A 2011 survey of 117 French spinal surgeons showed that only 36% had neurophysiological monitoring available (public healthcare facilities, 42%; private facilities, 27%). Monitoring can be performed by a neurophysiologist in the operating room, remotely using a network, or directly by the surgeon. Intraoperative alerts allow real-time diagnosis of impending neurological injury. Use of spinal electrodes, moved along the medullary canal, can determine the lesion level (NMEP, D waves). The response to a monitoring alert should take into account the phase of the surgical intervention and does not systematically lead to interruption of the intervention. Multimodal intraoperative monitoring, in presence of a neurophysiologist, in collaboration with the anesthesiologist, is the most reliable technique available. However, no monitoring technique can predict a delayed-onset paraplegia that appears after the end of surgery. In cases of preexisting neurological deficit, monitoring contributes little. Monitoring of the L1-L4 spinal roots also shows low reliability. Therefore, monitoring has no indication in discal and degenerative surgery of the spinal surgery. However, testing pedicular screws can be useful. All in all, thoracic and thoracolumbar vertebral deviations, with normal preoperative neurological examination are currently the essential indication for spinal cord monitoring. Its absence in this indication is a lost opportunity for the patient. If neurophysiological means are not available, intraoperative wake-up test is a minimal obligation.

Fracture following lower limb lengthening in children: a series of 58 patients.

INTRODUCTION: Fracture is one of the main complications following external fixator removal used in cases of progressive lower limb lengthening; rates as high as 50% are found in the literature. The aim of this study was to determine the factors influencing this complication. MATERIALS AND METHODS: One hundred and eleven cases of lower limb lengthening were performed in 58 patients (40 femurs and 71 tibias). The mean age at surgery was 10.1years old. Lengthening was performed in all cases with an external fixator alone, associated in 39.6% of cases with intramedullary nailing. The patients were divided into three groups according to disease etiology (congenital, achondroplasia and other). The fractures were classified according to the Simpson classification. RESULTS: Twenty fractures were recorded (18%). Sixteen fractures were found in patients with congenital disease, four with achondroplasia and none in the group of other etiologies. The fracture was more often in the femur (27.5%) than in the tibia (12.7%). DISCUSSION: The rate of fracture is influenced by different factors depending on the etiology of disease. In congenital diseases, the fracture rate is higher when there is lengthening of more than 15% of the initial length and a delay between surgery and the beginning of lengthening of less than 7days. In patients with achondroplasia, the influence of a relative percentage of lengthening is less important than in those with congenital disease. However, to avoid fractures, lengthening should not be started in children under the age of nine. Moreover, lengthening should begin at least 7days after the fixator has been placed. TYPE OF STUDY: Retrospective. LEVEL OF EVIDENCE: Level IV.

Influence of screw type on initial coronal and sagittal radiological correction with hybrid constructs in adolescent idiopathic scoliosis. Correction priorities.

BACKGROUND: Pedicle screw constructs for spinal instrumentation in patients with adolescent idiopathic scoliosis (AIS) are effective in providing coronal plane correction but can result in loss of kyphosis, which in turn can lead to loss of lordosis. Hybrid constructs have been found superior over pedicle screw constructs in terms of thoracic kyphosis restoration. In this study, our objective was to compare outcomes with monoaxial versus polyaxial screws in an AIS population treated with hybrid constructs. HYPOTHESIS: Monoaxial screws provide better correction in the coronal plane but result in loss of thoracic kyphosis, whereas thoracic kyphosis is preserved when polyaxial screws are used. MATERIAL AND METHODS: We retrospectively analysed data from 60 patients (mean age, 15years) with Lenke 1, 2, or 3 AIS treated using a hybrid construct with self-retaining bilaminar hook claws cranially, pedicle screws between the last instrumented vertebra and T11 caudally, and sublaminar universal clamps between the two extremities of the construct. Monoaxial screws were used in the first 30 patients (MS group) and polyaxial screws in the next 30 patients (PS group). Student's t test was performed to compare the two groups in terms of thoracic Cobb angle correction and T4-T12 kyphosis 3 months after surgery. RESULTS: No significant preoperative differences were found between the two groups. At last follow-up, the residual Cobb angle was significantly greater in the PS group than in the MS group (20.3° versus 15°) with a percentage of correction of 72.1% in the MS group versus 64.8% in the PS group. In the sagittal plane, the thoracic kyphosis was significantly greater in the PS group than in the MS group (26.6° versus 23°). DISCUSSION: This preliminary study shows that, even within a population managed using hybrid constructs, which are associated with less iatrogenic hypokyphosis, differences exist according to the technique used. The importance of sagittal spinal balance has been abundantly documented in the literature, and sagittal malalignment, particularly due to iatrogenic factors, is associated with poorer clinical outcomes in adults with spinal deformities. Therefore, there is a critical need to determine whether the treatment priority is optimal correction in the coronal plane or in the sagittal plane. We believe that the main focus should be sagittal plane correction, even at the expense of a slight decrease in coronal plane correction. Long-term studies are needed to confirm our preliminary findings.

Reciprocal sagittal alignment changes after posterior fusion in the setting of adolescent idiopathic scoliosis.

PURPOSE: Surgical adolescent idiopathic scoliosis (AIS) management can be associated with loss of thoracic kyphosis and a secondary loss of lumbar lordosis leading to iatrogenic flatback. Such conditions are associated with poorer clinical outcomes during adulthood. The aim of this study was to evaluate sagittal plane reciprocal changes after posterior spinal fusion in the setting of AIS. METHODS: Thirty consecutive adolescents (mean age 14.6 years) with AIS Lenke 1, 2 or 3 were included in this retrospective study with 2 year follow-up. Full-spine standing coronal and lateral radiographs were obtained preoperatively, at 3 and 24 months postoperatively. Coronal Cobb angle, thoracic kyphosis (TK) and lumbar lordosis (LL) were measured. Surgical procedure was similar in all the cases, with use of pedicular screws between T11 and the lowest instrumented vertebra (≥L2), sublaminar hooks applied in compression at the upper thoracic level and sub-laminar bands and clamps in the concavity of the deformity. Statistical analysis was done using t test and Pearson correlation coefficient. RESULTS: Between preoperative and last follow-up evaluations a significant reduction of Cobb angle was observed (53.6° vs. 17.2°, p < 0.001). A significant improvement of the instrumented thoracic kyphosis, TK (19.7° vs. 26.2°, p < 0.005) was noted, without difference between 3 and 24 months postoperatively. An improvement in lumbar lordosis, LL (43.9° vs. 47.3°, p = 0.009) was also noted but occurred after the third postoperative month. A significant correlation was found between TK correction and improvement of LL (R = 0.382, p = 0.037), without correlation between these reciprocal changes and the amount of coronal correction. CONCLUSION: Results from this study reveal that sagittal reciprocal changes occur after posterior fusion when TK is restored. These changes are visible after 3 months postoperatively, corresponding to a progressive adaptation of patient posture to the surgically induced alignment. These changes are not correlated with coronal plane correction of the deformity. In the setting of AIS, TK restoration is a critical goal and permits favorable postural adaptation. Further studies will include pelvic parameters and clinical scores in order to evaluate the impact of the noted reciprocal changes.

Value of diffusion-weighted images in differentiating mid-course responders to chemotherapy for osteosarcoma compared to the histological response: preliminary results.

BACKGROUND: Preoperative diffusion-weighted MRI (DW-MRI) has been described as an efficient method to differentiate good and poor responders to chemotherapy in osteosarcoma patients. A DW-MRI performed earlier during treatment could be helpful in monitoring chemotherapy. OBJECTIVE: To assess the accuracy of DW-MRI in evaluating response to chemotherapy in the treatment of osteosarcoma, more specifically at mid-course of treatment. MATERIALS AND METHODS: This study was carried out on a prospective series of adolescents treated for long-bone osteosarcoma. MR examinations were performed at diagnosis (MRI-1), at mid-course of chemotherapy (MRI-2), and immediately before surgery (MRI-3). A DW sequence was performed using diffusion gradients of b0 and b900. The apparent diffusion coefficients (ADC1, ADC2, ADC3, respectively), their differentials (ADC2 - ADC1 and ADC3 - ADC1), and their variation (ADC2 - ADC1/ADC1 and ADC3 - ADC1/ADC1) were calculated for each of these three time points. RESULTS: Fifteen patients were included. Patients with no increase in ADC showed a poor response to chemotherapy on their histology results. At mid-course, the three calculated values were significantly different between good and poor responders. ADC2 - ADC1 enabled us to detect, with 100% specificity, four out of seven of the poor responders. There was no significant difference in the values at MRI-3 between the two groups. CONCLUSION: DW-MRI performed both at baseline and mid-course of neoadjuvant chemotherapy is an efficient method to predict further histological response of osteosarcoma. This method could be used as an early prognostic factor to monitor preoperative chemotherapy.

Sagittal spine posture assessment: feasibility of a protocol based on intersegmental moments.

Evaluation of spinal posture has recently benefited from the contribution of three-dimensional reconstruction technologies that have helped improve our understanding of this dynamic balance. The aim of this study was to present the preliminary results of a three-dimensional protocol to analyze postural balance. This analytical method is not limited by certain constraints of the radiological approach and evaluates postural balance using a new approach taking into account the net efforts of different intersegmental centers. These preliminary results show the technical feasibility of the protocol. Its future development and clinical use could provide a better understanding of postural balance disorders, and help evaluate the impact of surgical correction on spinal balance.

Depistage echographique de la maladie luxante de hanche : qu'en est-il de la gemellite comme facteur de risque ?

Objectif : Le depistage echographique de la maladie luxante de hanche repond a des indications particulieres; dont l'existence de facteurs de risque. La gemellite fait partie de ces facteurs derisque. Le but de cette etude etait d'apprecier l'incidence reelle de la grossesse gemellaire dans la survenue de la maladie luxante de hanche. Materiels et Methodes : Nous avons realise une etude retrospective; de fevrier 1991 a mars 2004; de 316 dossiers d'echographies de hanche; realisees de maniere systematique chez des jumeaux; par une equipe pratiquant la methode morphologique de GRAF. Resultats : L'age moyen des nourrissons au premier examen etait de 2 mois en moyenne (de 1 a 3;4 mois). Dans 81 des cas; l'examen echographique initial etait normal. Les enfants presentant une hanche de type IIa etaient ages de 1;7 mois en moyenne. Ces hanches de type IIa; controlees dans un delai moyen de 1;8 mois; se sont normalisees dans 98;4 des cas. Seulement deux nourris- sons ont ete traites; un pour une hanche de type IIb unilateral; l'autre pour des hanches de type IIc bilateral. Ces deux nourrissons etaient nes en presentation de siege des cas. Seulement deux nourrissons ont ete traites; un pour une hanche de type IIb unilateral; l'autre pour des hanches de type IIc bilateral. Ces deux nourrissons etaient nes en presentation de siege

Limb lengthening using ankle joint distraction (arthrodiastasis) followed by arthrodesis. Experience with one case.

Tibial aplasias are difficult entities to manage and sometimes require significant limb lengthening. Preserving the joint is the preferred option in these cases. However, when function is not ensured, lengthening beginning in the joint can be attempted followed by arthrodesis. This report presents the clinical and radiological results of a patient treated with intra-articular lengthening (or arthrodiastasis) associated with talocrural arthrodesis. Although this original technique provided satisfactory results, this surgical program remains complicated.

High-grade child spondylolisthesis: a custom-made canulated screw to treat the so-called double instability.

STUDY OBJECTIVES: Describing and assessing of a new surgical procedure to achieve circumferential fusion and translumbosacral fixation using a custom-made canulated screw. PATIENTS AND METHODS: Seven patients aged 13-18 years old underwent surgery with this technique (mean age: 15). All patients had high-grade spondylolisthesis (Meyerding stage III or IV). There were five girls and two boys. A posterior surgical approach alone was used in all cases. The posterior neural arch of L5 was removed and a sacral laminectomy, extending to S2, was performed. Sacral nerve roots S2 and S3 were carefully dissected and transposed. A K-wire was placed medially across the vertebrae from the posterior edge of S2 extending to the anterosuperior corner of L5. Fluroscopic perioperative fluroscopic control confirmed correct K-wire placement. The custom-made 10mm diameter canulated screw was then inserted along the K-wire as a guide. Screw fixation was obtained by placing a specific large diameter screw head to obtain compression by a lag screw effect. Once fixation was obtained, the sacral dome was excised and interbody fusion was performed (tricorticocancellous graft on each side of the screw). Additional bilateral posterolateral fusion was then performed. A half body custom fit thoracolumbar orthosis brace was prescribed 3 months postoperatively, followed by a Lombostat flexible lumbar support for an additional 3 months period. RESULTS: One neurological complication occurred. A dural tear occurred during dissection requiring simple repair. All of the patients were on their feet on the fifth postoperative day and began walking. The half bodybrace was worn for 4 months in four patients and 2 months in the three others. At final follow-up patients had no residual pain. DISCUSSION: The lumbar spine in children with high-grade spondylolisthesis adapts to the new mechanical conditions after surgery. Therefore the principal goal of treatment is to obtain stable osseous fusion. Our treatment philosophy is based on the concept of a dual instability. We believe that a general instability exists which causes the development of spondylolisthesis; this must be respected by not attempting to correct the displacement beyond what can be obtained on the operating table with complete muscle release. The other, locoregional instability, must be stabilized during circumferential fusion. The custom-made, 10mm screw has been shown to be effective in neutralizing the mechanical stress during circumferential fusion with a posterior approach alone, thus avoiding the risks of an anterior approach. Long-term results show that the preoperative posture is not the sole mechanical determinant in children and adolescents but that this posture is largely a reaction to pain. LEVEL OF EVIDENCE: Level IV. Retrospective study.

A study of 28 flat bone osteosarcomas: prognostic factors and early and long-term outcome.

Limited information is available on clinical management of Flat Bone Osteosarcomas (FBOS). We retrospectively analysed prognostic factors and outcome. Twenty-eight patients were treated in our institution. Survival curves were obtained by the Kaplan-Meier method and compared with the log-rank test. The overall survival (OS) rates at 5 and 10 years were 52.4% and 45.8% respectively. The event-free survival (EFS) rates at 5 and 10 years were 41.5%. The factors influencing EFS in univariate analysis were location, metastatic disease at diagnosis, effect of neoadjuvant chemotherapy, histological response and adequate local tumour control. Location, metastatic disease at diagnosis, effect of neoadjuvant chemotherapy, histological response and local recurrence were statistically correlated with OS. Multivariate analysis retained metastatic disease at diagnosis as prognostic factors of EFS and OS. Our results suggest a more favourable outcome of FBOS as the use of a treatment scheme based on the protocols for long bone osteosarcomas. However, an adequate local treatment is essential to ensure a better outcome.