Eric Mascard

Le traitement orthopédique dans la pathologie vertébrale du petit enfant

Resume Le traitement des deformations rachidiennes du petit enfant (c’est-a-dire arbitrairement âge de moins de 6 ans) est particulierement difficile s’il s’agit de deformations touchant l’ensemble de la colonne vertebrale comme peuvent l’etre celles secondaires a une scoliose idiopathique maligne ou un rachis paralytique. Le traitement chirurgical en effet ne peut pretendre resoudre le probleme malgre toutes les tentatives faites ou le plus souvent le patient et sa deformation ont ete aggraves plutot que corriges. Il faut l’opposer aux deformations tres localisees de type malformatif par exemple ou un traitement chirurgical local simple peut guerir definitivement l’enfant. Il faut connaitre le traitement non operatoire par plâtres souvent repetes et corsets orthopediques alternes, souvent pendant de longues annees, avant de pouvoir effectuer une arthrodese a un âge suffisant qui ne corrigera pas totalement la deformation, mais stabilisera le rachis de maniere durable. Ce traitement long, astreignant, peu brillant, est tres souvent mal connu, mal realise, alors qu’il peut etre extremement utile si la prise en charge est correcte. Chaque cas est different selon l’etiologie, l’etendue et la localisation des deformations et les problemes associes au niveau des autres appareils. Le but de cet article est de faire connaitre ces techniques et leurs indications en se rappelant que chaque patient est unique et doit etre considere comme tel, mais que les techniques et les recommandations exposees peuvent parfaitement etre adaptees a chaque cas.

CD163-positive tumor-associated macrophages and CD8-positive cytotoxic lymphocytes are powerful diagnostic markers for the therapeutic stratification of osteosarcoma patients: An immunohistochemical analysis of the biopsies fromthe French OS2006 phase 3 trial

ABSTRACT The French phase 3 trial (OS 2006) testing zoledronic acid, an osteoclast inhibitor, with chemotherapy and surgery did not improve the outcome of patients with osteosarcoma (OS). To understand this unexpected result, the presence of infiltrating immune cells was investigated in 124 pre-therapeutic biopsies of patients enrolled in the trial. The percentage of CD68/CD163 tumor-infiltrating macrophages (TAMs), CD8+ lymphocytes, osteoclasts, and the PD1/PDL-1 checkpoint were assessed by immunohistochemistry. M1/M2 macrophage polarization was characterized by pSTAT1/CMAF staining. The expression of these biomarkers was correlated with clinical outcome. No statistical correlations were found with response to chemotherapy. High CD163 levels (>50% of cells per core; 43.8% of patients) were associated with CMAF nuclear expression and significantly correlated with better overall survival (p = 0.0025) and longer metastasis progression-free survival (MPFS, p = 0.0315) independently of metastatic status (p = 0.002). Only a trend was observed for patients with high CD68-positive cells (p = 0.0582). CD8+ staining was positive in >50% of cases with a median staining of 1%. Lower CD8+ levels were associated with metastatic disease at diagnosis and the presence of CD8-positive cells significantly correlated with improved overall survival in zoledronate-treated patients (p = 0.0415). PD1/PDL-1 staining was negative in >80% of cases and was not correlated with outcome. Finally, CD163-positive TAMs and CD8 positive cells are crucial prognostic biomarkers in OS, whereas PD1/PDL-1 checkpoint plays a minor role. For the first time, we described a correlation between CD8 positive cells and survival in zoledronate-treated patients. The immunohistochemical analysis of the microenvironment in biopsies may represent a novel tool for therapeutic stratification.

Preoperative imaging study of the spinal cord vascularization: Interest and limits in spine resection for primary tumors

The necessicity to localize the anterior spinal arteries before anterior approach of the spine stays controversial by orthopaedic surgeons. On the other hand the surgical treatment of thoracoabdominal aneurisms routinely sacrifices many segmental arteries pairs without spinal arteries localization. This, associated with spinal cord protection, results to few neurological complication. However, during vertebrectomies, the roots ligation completely interrupts the spinal cord blood supply at this level. In our experience the spinal arteries localization was systematically done before ninety-eight spine resections. In five cases an anterior radiculomedullary artery was ligated (four anterior radiculomedullary and one great anterior radiculomedullary arteries) without neurological complication, in two cases of extended resection (more than four levels) a neurological complication occurred. No spinal artery was identified at the resection level and the neurological complications were resolutive and did not seem related to definitive vascular problem. These accomplishments lead to discuss the importance of spinal arteries localization and preservation in this surgery. The discovery of an anterior radiculomedullary artery is not a contraindication to en-bloc vertebrectomy at this level, nevertheless in the case of great anterior radiculomedullary artery (Adamkiewicz) the surgical indication must be seriously debated. In fact, this case and those where multilevel resections (more than three levels) are indicated seem the most dangerous situations and the use of the different means of spinal cord protection could be indicated to decrease neurological risk. So before spine resection the spinal arteries localization could improve patient information and give more deciding factors for planning treatment.

How to read a pathology report of a bone tumor.

The interpretation of a biopsy specimen involving bone is one of the most challenging feats for a pathologist, as it is often difficult to distinguish between benign or reactive lesions and malignant tumors on microscopic analysis. Therefore, correlation with the clinical data and imaging is essential and sometimes it is only the evolution of certain characteristics over time or information garnered from molecular analysis that can provide an accurate diagnosis. The pathology report is critical in that it will define subsequent patient management; its wording must precisely reflect those elements that are known with certainty and those that are diagnostic hypotheses. It must be systematic, thorough, and complete and should not be limited to a simple conclusion. The pathologist must first ensure the completeness and correct transcription of the information provided with the specimen, then describe and analyze the histology as well as the quality and representative nature of the sample (as they relate to the radiographic findings and preliminary/final diagnoses), and finally, compare what is seen under the microscope with the assessment made by the radiologist and/or surgeon. This analysis helps to identify difficult cases requiring further consultation between the radiologist and pathologist. There are multiple reasons for misinterpretation of a pathology report. An important and largely underestimated reason is varied interpretations of terms used by the pathologist. Standardized pathology reports with concise phrases as well as multidisciplinary meetings may limit errors and should be encouraged for optimal diagnostic accuracy.

A Case of Osteosarcoma in a Patient With Pycnodysostosis

Pycnodysostosis is a rare sclerosing bone dystrophy. The main clinical features are short stature and oral and maxillofacial abnormalities such as a large head, a small and underdeveloped face with prominent nose and eyes, irregular dentition, small hands and feet with dystrophic nails, and trunk deformities such as scoliosis. The differential diagnosis is established with other skeletal dysplasias such as osteopetrosis, cleidocranial dysplasia, and idiopathic acro-osteolysis. Since its first description in 1962 by Maroteaux and Lamy, about 100 cases have been published, some of these with uncommon features. We describe the case of a 22-year-old European man with pycnodysostosis who developed a chondroblastic osteosarcoma of the right femur. No case of bone cancer in this sclerosing bone disease had been described so far.

Forefoot reconstruction after lesser intermediate metatarsal bone resection for aggressive or malignant tumors in children: report of three cases.

Primary malignant or aggressive tumors of the foot are rare in children. Only 13 have been reported in the literature,1,2,8,10,11,16,18,21,23,26 five of which involved the metatarsal bones.1,16,18,21 In line with advances in chemotherapy,12,13 preoperative imaging,29 and operative techniques,28 the current treatment of malignant or aggressive tumors of the limbs most often involves neoadjuvant and adjuvant chemotherapy along with en bloc resection of the tumor followed by reconstruction.5,13,24,30 As described in the literature, amputation is the usual treatment of malignant tumors of the forefoot.1,11,16,18,21,26 Only one study described reconstruction with a vascular fibular bone graft.10 Wide excision of one or more intermediate metatarsals and partial foot preservation raises two potential problems. The first is oncologic and the second is mechanical.14,19,27 Resection of the lesser metatarsal bones may disrupt the normal tripod architecture of the foot22,25 and compromise static and dynamic function of the foot. We developed an operative technique that allows selective resection of the second, third, and fourth metatarsals through the tarsometatarsal joint, providing adequate tumor resection while preserving foot function.

Traitement chirurgical des ostéosarcomes : améliorations récentes

RésuméIl y a 30 ans la chimiothérapie néoadjuvante a radicalement transformé le pronostic et le traitement local de la maladie. Cependant, malgré des résultats encourageants le traitement conservateur a montré rapidement ses limites mettant à jour trois principaux problèmes: faillite mécanique des reconstructions articulaires, inégalité de longueurs lors du traitement des tumeurs de l’enfant, contrôle local déficient après exérèse des sarcomes axiaux. Actuellement, grâce à de nouveaux implants, les solutions s’imposent progressivement pour la chirurgie des membres chez l’adulte et l’enfant. Au niveau des tumeurs axiales, les progrès de l’imagerie et des techniques d’exérèse améliorent le contrôle local même si celui reste encore perfectible.AbstractThirty years ago, adjuvant chemotherapy dramatically changed the local treatment and prognosis of osteosarcoma. However, even with encouraging results, conservative treatment brought three major problems to light: early deterioration of limb prostheses, childhood limb disorders and unsatisfying local control of trunk sarcomas. New implants specially designed for bone tumours have improved the long-term outcome after joint reconstruction; and progress in medical imaging and updated surgical techniques have improved local control of trunk tumours, although limb surgery remains more reliable.

Prise en charge des sarcomes. Qu’attend le chirurgien du pathologiste?

Lors de la prise en charge des tumeurs de l’appareil locomoteur le chirurgien n’est pas le seul interlocuteur du pathologiste, son intervention s’intègre dans celle de l’équipe pluridisciplinaire susceptible de traiter ce type de patient afin de définir au mieux une stratégie thérapeutique adaptée à la pathologie en cause. Trois phases successives peuvent être schématiquement envisagées : le diagnostic, le traitement avec en particulier l’examen des pièces de résection, la surveillance et le dépistage des rechutes locales.