Pathophysiological mechanisms underlying shoulder stiffness in children with obstetric brachial plexus palsy (OBPP)

Au cours de l’accouchement, une traction importante sur le bras du nourrisson peut entraîner des lésions des racines nerveuses du plexus brachial (racines cervicales C5–C8 et/ou thoracique T1). Le nouveau-né présente alors une paralysie du bras à la naissance (Paralysie Obstétricale du Plexus Brachial : POPB). Une macrosomie du nouveau-né et une adiposité de la mère sont des facteurs de risque.Un tiers des enfants atteints de POPB vont présenter des séquelles malgré une rééducation quotidienne. Le handicap le plus fréquent est une raideur d’épaule. L’hypothèse actuelle est que cette raideur est due à un déséquilibre permanent entre des muscles de l’épaule touchés (rotateurs latéraux : infraspinatus, supraspinatus) et des muscles peu touchés par la paralysie (rotateurs médiaux : subscapularis, pectoralis major, latissimus dorsi). En effet, les muscles rotateurs latéraux sont exclusivement innervés par le plexus brachial alors que les muscles rotateurs médiaux peuvent avoir une innervation indépendante du plexus. A cause de ce déséquilibre, l’épaule lésée évolue alors en une position permanente tournée vers l’intérieur. Cette position conduirait à des rétractions à l’avant de l’articulation malgré la rééducation. Sans prise en charge, une modification de la tête humérale et de la glène (dysplasie) apparait aboutissant à une limitation des amplitudes articulaires passives et actives, des douleurs et une diminution de la qualité de vie des enfants et des parents. Au cours de cette thèse, nous avons mis en évidence que les enfants atteints de POPB avaient des déficits de force en rotation latérale comme attendu, mais aussi en rotation médiale, suggérant une atteinte des muscles rotateurs médiaux. L'analyse IRM de nos patients réalisée dans ce travail a d'ailleurs mis en évidence la présence d'une infiltration graisseuse dans ces muscles. La prise en charge, à partir de l’âge de 2 ans, en cas de raideur de l’épaule évaluée par des critères fonctionnels comme le score de Mallet, est une chirurgie pour retrouver de la mobilité. L’opération consiste à lever des rétractions grâce à une arthrolyse d’épaule. Au cours de cette intervention, un transfert musculaire peut aussi être effectué pour renforcer les muscles rotateurs latéraux. Ainsi, nous avons testé l'évolution des forces des muscles rotateurs de l'épaule après transfert de trapezius inférieur sur l'infraspinatus, et montré que malgré l'amélioration clinique significative, les tests de force ont démasqué des anomalies qui nous font nuancer nos résultats. En cas de dysplasie sévère, une ostéotomie de réorientation de la glène de la scapula peut être réalisée. Nous avons ainsi évalué l'évolution des paramètres radiologiques après ce type de chirurgie et mis en évidence un effet bénéfique de glénoplastie non décrit jusqu'à présent.Cependant, malgré la chirurgie, les déficits de mobilités récidivent souvent en quelques années. Pour comprendre l’origine des déficits en rotation latérale et médiale, nous avons mené une étude anatomopathologique sur les muscles rotateurs chez ces enfants. Nos résultats préliminaires montrent une atteinte importante des muscles rotateurs avec la présence de fibrose ce qui pourrait tout à fait expliquer la raideur en rotation et l’atteinte fonctionnelle. Pour mieux comprendre les mécanismes physiopathologiques, nous allons mettre en place un modèle de POPB en culture cellulaire permettant d'appréhender les capacités de régénération et de tester de nouvelles approches pharmacologiques. En conclusion, ce travail de thèse a déjà permis de modifier la prise en charge et le suivi des patients POPB. Le développement d'un modèle cellulaire de cette pathologie permettra de tester de nouvelles perspectives thérapeutiques et de valider notre hypothèse.During delivery, significant traction on the infant's arm can result in damage to the nerve roots of the brachial plexus (cervical C5-C8 and/or thoracic T1 roots). The newborn presents at birth a paralysis of the arm (Obstetrical Brachial Plexus Paralysis: OBPP). Macrosomia of the newborn and adiposity of the mother are risk factors.One third of children with OBPP will have sequelae despite daily rehabilitation. The most frequent disability is shoulder stiffness. The current hypothesis is that this stiffness is due to a permanent imbalance between the affected shoulder muscles (lateral rotators: infraspinatus, supraspinatus) and the muscles not affected by the paralysis (medial rotators: subscapularis, pectoralis major, latissimus dorsi). Indeed, the lateral rotator muscles are exclusively innervated by the brachial plexus, whereas the medial rotator muscles may have an independent innervation from the plexus. Because of this imbalance, the injured shoulder evolves into a permanent position in medial rotation. This position would lead to retractions at the front of the joint despite rehabilitation. If left untreated, a modification of the humeral head and the glenoid (dysplasia) will occur, leading to a limitation of the passive and active joint range of motion, pain and a decrease in the quality of life of the children and parents. During this thesis, we have demonstrated that children with OBPP had strength deficits in lateral rotation as expected, but also in medial rotation, suggesting an impairment of the medial rotator muscles. The MRI analysis of our patients carried out in this work also revealed the presence of fatty infiltration in these muscles. The management, from the age of 2 years, in case of shoulder stiffness evaluated by functional criteria such as the Mallet score, is surgery to regain mobility. The operation consists of removing retractions through shoulder arthrolysis. During this operation, a muscle transfer can also be performed to strengthen the lateral rotator muscles. Thus, we tested the evolution of the shoulder rotator muscle forces after transfer of the inferior trapezius to the infraspinatus, and showed that despite the significant clinical improvement, the force tests unmasked abnormalities that make us qualify our results. In case of severe dysplasia, a reorientation osteotomy of the glenoid of the scapula can be performed. We have thus evaluated the evolution of the radiological parameters after this type of surgery and highlighted a beneficial effect of glenoplasty not described until now.However, despite surgery, mobility deficits often recur within a few years. To understand the origin of the lateral and medial rotation deficits, we conducted an anatomopathological study of the rotator muscles in these children. Our preliminary results show a significant damage of the rotator muscles with the presence of fibrosis which could explain the rotational stiffness and the functional impairment. To better understand the pathophysiological mechanisms, we will set up an OBPP model in cell culture to understand the regenerative capacities and to test new pharmacological approaches. In conclusion, this thesis work has already led to changes in the management and follow-up of OBPP patients. The development of a cellular model of this pathology will allow to test new therapeutic perspectives and to validate our hypothesis

L'osteotomie haute de l'Ulna dans la prise en charge des lésions de Monteggia négligées chez l'enfant

MONTPELLIER-BU Médecine UPM (341722108) / SudocMONTPELLIER-BU Médecine (341722104) / SudocSudocFranceF

Esophageal perforation caused by a thoracic pedicle screw

International audienceThis grand round raises the risk of a rare complication that can be avoided with the knowledge of the particular anatomy of scoliosis vertebra. Transpedicular screws have been reported to enhance the operative correction in scoliosis surgery. The narrow and inconsistent shape of the thoracic pedicles makes the placement of pedicle screws technically challenging. Furthermore, in thoracic curves, the close proximity of the spinal cord and major soft tissue structures also adds a greater risk to the procedure. The esophagus lies close to the upper thoracic vertebras and, an anterior cortical perforation can cause esophageal injury. We report a case of anterior cortical perforation by a T4 pedicle screw complicated by an esophageal perforation in a 15-year-old girl with convulsive encephalopathy. She was operated for a severe neurological scoliosis (Rett syndrome). Her neurological condition deteriorated 3 years after the posterior spinal surgery, requiring a percutaneous gastrostomy. An intra-esophageal screw was discovered incidentally during an endoscopy. We decided not to remove this screw, because the patient's health status presented a surgical contraindication. The patient showed no apparent discomfort at the 10-year follow-up examination after spinal arthrodesis. Esophageal perforation caused by a posterior pedicle screw is very rare. We highlight the risk of injury to esophagus from pedicle screws in upper thoracic vertebra. The systematic removal of a malpositioned screw must be discussed, on a case-to-case benefit-risk basis, especially if the patient has numerous comorbidities, given the long-term tolerance of a number of these improperly positioned implants

How Can Surgeonfish Help Pediatric Surgeons? A Pilot Study Investigating the Antinociceptive Effect of Fish Aquariums in Adult Volunteers

International audienceBACKGROUND: Multiple distraction strategies have been proposed to reduce the incidence of anxiety and pain in children. Animal-assisted therapy is acknowledged and used in children as an adjunctive treatment with cognitive, physical, psychosocial and spiritual benefits.OBJECTIVE: To determine the effect of fish aquarium animal-assisted therapy (FA-AAT) on pain perception in a cohort of healthy volunteers.METHODS: Sixty-nine healthy subjects (mean age 27.3 years) were exposed to >20 different species of soft or hard corals and >25 fish in a 1000 L saltwater aquarium. Pain perception was assessed using an electrical stimulation device, the Pain Matcher (Cefar Medical AB, Sweden), after 5 min, 10 min, 20 min and 30 min of continuous aquarium viewing. The measurements were repeated 10 min after stopping aquarium viewing.RESULTS: A statistically significant pain perception threshold augmentation was observed after a 5 min aquarium viewing. This threshold augmentation was also increased after 10 min, 20 min and 30 min of FA-AAT. A remnant effect was noted up to 10 min after exposure. This short post-viewing time period could be useful in clinical practice to perform certain painful procedures in children, such as those involving needles, under improved conditions immediately after aquarium exposure.CONCLUSIONS: In the authors' department, FA-AAT is now used as a nonpharmacological antinociceptive technique in association with a protocol of inhalated oxygen⁄nitrous oxide mixtures for needle-related procedures. Children and parents are invited to watch the aquarium during the 10 min to 20 min before venous punctures

The Use of Perforator Flaps in Lower Extremity Traumatic Defect Reconstruction in the Pediatric Population

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Does arthroscopic resection of a too-long anterior process improve static disorders of the foot in children and adolescents ?

International audiencePURPOSE:A too-long anterior process of the calcaneus is a common cause of pain and hind-foot instability. Our goal was to evaluate the early results of arthroscopic resection in terms of static foot disorders in children and adolescents.METHODS:We retrospectively studied 11 ft (10 patients). The inclusion criteria were treatment of TLAP by arthroscopic resection and a minimum follow-up period of six months. Surgery was indicated in cases with persistent symptomatic TLAP resistant to orthopaedic treatment.RESULTS:The mean age at surgery was 11 (range, 7-15) years. The mean follow-up duration was 15 (range, 8-28) months. Pre-operatively, we diagnosed four flat feet, two cavus feet and five feet with normal footprints, but loss of physiological hind-foot valgus. All patients presented with subtalar joint stiffness. At the last follow-up, four feet with no hind-foot valgus were normal, two were unchanged and the other feet had improved. The mean AOFAS increased from 61.9 (range, 47-73) to 89.1 (range, 71-97; P = 0.009). The mean radiological angles were near normal, exhibiting significant improvements in the lateral talo-metatarsal and Djian-Annonier angles.CONCLUSIONS:Arthroscopic resection of a TLAP is safe. In the short term, the restoration of subtalar mobility reduces pain, and improves instability and static disorders. Longer follow-up of a larger patient series is required

Change in shoulder external rotation strength and motion after lower trapezius transfer to the infraspinatus in children with obstetric brachial plexus palsy

International audienceQuantifying changes in shoulder external rotation range of motion and strength after lower trapezius transfer in children with obstetric brachial plexus palsy (OBPP).Methods. This prospective study included five children with sequelae of OBPP, with a mean age of 6.4 years (range: 4–12 years) who underwent lower trapezius tendon transfer to restore active external rotation (ER) of the shoulder. Pre-operatively and at a 12-month follow-up assessment, we analyzed the passive and active shoulder ER, the modified Mallet score, and the shoulder rotator muscles strength using an isokinetic device.Results. Clinical parameters improved significantly after trapezius transfer pre-operative passive ER from −8° (range: −20–0°) to 37° (range: 15–50°) (p = 0.035), the modified Mallet score from 13 (range: 10–15) to 18 (range: 17–19) (p = 0.035). Strength testing revealed improved ER muscle strength in all five cases; the mean Peak Torque increased from 1.95 to 4.46 N·m, albeit non-significantly (p = 0.062). Two patients exhibited a winged scapula post-operatively.Conclusion. Lower trapezius transfer seems encouraging to restore shoulder external rotation in OBPP children but with non-significant strength improvement

Response to the letter to the editor concerning: “Change in shoulder external rotation strength and motion after lower trapezius transfer to the infraspinatus in children with obstetric brachial plexus palsy”

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Weakness of shoulder rotator muscles in children with brachial plexus palsy under age 5 years: not only in lateral rotation.

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Differential Accumulation and Activation of Monocyte and Dendritic Cell Subsets in Inflamed Synovial Fluid Discriminates Between Juvenile Idiopathic Arthritis and Septic Arthritis

International audienceDespite their distinct etiology, several lines of evidence suggest that innate immunity plays a pivotal role in both juvenile idiopathic arthritis (JIA) and septic arthritis (SA) pathophysiology. Indeed, monocytes and dendritic cells (DC) are involved in the first line of defense against pathogens and play a critical role in initiating and orchestrating the immune response. The aim of this study was to compare the number and phenotype of monocytes and DCs in peripheral blood (PB) and synovial fluid (SF) from patients with JIA and SA to identify specific cell subsets and activation markers associated with pathophysiological mechanisms and that could be used as biomarkers to discriminate both diseases. The proportion of intermediate and non-classical monocytes in the SF and PB, respectively, were significantly higher in JIA than in SA patients. In contrast the proportion of classical monocytes and their absolute numbers were higher in the SF from SA compared with JIA patients. Higher expression of CD64 on non-classical monocyte was observed in PB from SA compared with JIA patients. In SF, higher expression of CD64 on classical and intermediate monocyte as well as higher CD163 expression on intermediate monocytes was observed in SA compared with JIA patients. Moreover, whereas the number of conventional (cDC), plasmacytoid (pDC) and inflammatory (infDC) DCs was comparable between groups in PB, the number of CD141+ cDCs and CD123+ pDCs in the SF was significantly higher in JIA than in SA patients. CD14+ infDCs represented the major DC subset in the SF of both groups with potent activation assessed by high expression of HLA-DR and CD86 and significant up-regulation of HLA-DR expression in SA compared with JIA patients. Finally, higher activation of SF DC subsets was monitored in SA compared with JIA with significant up-regulation of CD86 and PDL2 expression on several DC subsets. Our results show the differential accumulation and activation of innate immune cells between septic and inflammatory arthritis. They strongly indicate that the relative high numbers of CD141+ cDC and CD123+ pDCs in SF are specific for JIA while the over-activation of DC and monocyte subsets is specific for SA